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The 7th Asian Silicon Symposium


Contents

Welcome 1

Committee 2

Program at a Glance 3

General Information 4

Abstract 8

Plenary Lecture 9

Keynote Lecture 13

Invited Lecture 21

Short Oral Presentation 46

Poster Presentation 57


WELCOME ǀ Page 1

Welcome On behalf of the organizing committee, it is our pleasure to welcome you to the 7th ASIAN

SILICON SYMPOSIUM (ASiS-7), which is held in Nanyang Technological University,

Singapore from 28th July to 31st July 2019.

The Asian Silicon Symposium (ASiS) takes place in Asia biennially and has been hosted in

turn by the silicon research communities of Japan, Korea, and China. Previous ASiS meetings

were successfully held at Miyagi (Japan) in 2007, Jeju (Korea) in 2008, Hangzhou (China) in

2010, Tsukuba (Japan) in 2012, Jeju (Korea) in 2015, Jinan (China) in 2017. This is the first

ASiS meeting to be hosted in Singapore.

Following the success of previous ASiS meetings, ASiS-7 aims at providing an engaging

platform to bring together leading researchers, scientists and students in the field of silicon

chemistry to present their perspective in research, exchange their scientific findings, cultivate

mutual understanding, and foster possible collaborations. ASiS-7 is not only open to the Asian

silicon community, but also the world’s silicon community.

The major themes of ASiS-7 cover synthesis, structure, catalysis and materials. There will be

four plenary lectures, eight keynote lectures, twenty five invited lectures, ten oral presentation

and thirty one poster presentation from various research units participating in the event.

We are looking forward to giving you a warm welcome to you at the ASiS-7. We hope that

you will find the symposium both enjoyable and valuable, whereby you can discuss, interact

and collaborate with silicon chemists from different areas to make a great development in

silicon chemistry.

Cheuk-Wai So

Chairman, ASiS-7

Associate Professor

Division of Chemistry and Biological Chemistry

School of Physical and Mathematical Sciences

Nanyang Technological University


WELCOME ǀ Page 2

Committee ASiS International Advisory Board

Stephen Clarke University of South Australia, Australia

Geun-Mook Choi KCC Corporation, Korea

Shengyu Feng Shangdong University, China

Jianxiong Jiang Hangzhou Normal University, China

Mitsuhiro Takarada Shin-Etsu Chemical Co., Ltd, Tokyo, Japan

Soichiro Kyushin Gunma University, Japan

Ching-Wen Chiu National Taiwan University, Taiwan

Akira Sekiguchi University of Tsukuba, Japan

Hiromi Tobita Tohoku University, Japan

Norihiro Tokitoh Kyoto University, Japan

Caihong Xu Chinese Academy of Science, China

Bok Ryul Yoo Korea Institute of Science and Technology, Korea

Honorary ASiS International Advisory Board

Mitsuo Kira Tohoku University, Japan

Myong Euy Lee Yonsei University, Korea

Local Organizing Committee

Chairman

Cheuk-Wai So

Member

Rei Kinjo, Felipe Garcia

Secretaries

Chia Cher Chiek, Leong Bi-Xiang, Fan Jun, Meldon Wee Yi Shuo, Ong Xin Yi Melissa, Lee

Jiawen


WELCOME ǀ Page 3

Program at a Glance


GENERAL INFORMATION ǀ Page 4

General Information Location

The 7th Asian Silicon Symposium is held at the School of Physical and Mathematical Sciences

(SPMS), Nanyang Technological University (NTU), Singapore.

(https://spms.ntu.edu.sg/ContactUs/Pages/Plan-Your-Visit.aspx). Plenary, keynote and invited

lectures, as well as short oral presentations are held at SPMS-LT1, SPMS-LT2 and SPMS-LT3.

Poster presentation is held at the MAS Atrium.

Access to the School of Physical and Mathematical Sciences, NTU

By Symposium Shuttle Bus

There is a complementary shuttle bus from the Hotel Jen, Tanglin at 8:00 am to the symposium

venue



By Taxi (Travel time: city centre → NTU: 30 mins; Fare: around $30)

All taxis in Singapore use a fare meter and fares are fixed so bargaining is not required.

Payment is usually by cash although a few taxis do accept credit cards. You may enquire about

surcharges when in doubt and request a receipt. https://www.cdgtaxi.com.sg/

By MRT (subway) and Bus (Travel time: city centre → NTU: > 1.5h)

To access public transport in Singapore, it is highly recommended to purchase the Singapore

Tourist Pass (S$ 10) for unlimited rides. The Pass can be purchased at the Airport (Changi

Airport) https://www.ezlink.com.sg/home-tourist.

Take the MRT East-West (Green) line and alight at Pioneer (EW 28) MRT Station (Exit A).

Thereafter, take Singapore Bus Service (SBS) bus service no. 179 at the bus stop located just

next to the MRT station. Alight from the bus at the bus stop B11 WEE KIM WEE Sch of

Comm & Info (27231). Then, walk 10 minutes to the School of Physical and Mathematical

Sciences.



Secretariat

The secretarial office is located at the MAS Atrium on the 3rd floor of the School of Physical

and Mathematical Sciences.

Registration

The registration is conducted in the Welcome Reception on 28th July at 6:00 pm in the Hotel

Jen, Tanglin. It can also be achieved at the Registration Booth in the MAS Atrium on the 3rd

floor of the School of Physical and Mathematical Sciences.

Lecture and Oral Presentation

The official language of ASiS-7 is English. The time allocation for presentation is as follows:

Plenary Lecture : 40 mins + 10-min Q&A

Keynote Lecture : 30 mins + 10-min Q&A

Invited Lecture : 25 mins + 5-min Q&A

Oral Presentation : 15 mins + 5 min Q&A

Presentation should be executed using an appropriate software tool such as Keynote or

PowerPoint. Speakers can use either their own laptops or a desktop provided in each lecture

theatre for presentation. It is necessary to bring a suitable port adapter for Macintosh laptops

and Microsoft Surface. Presentation slides should be set-up at the latest during the break

preceding the presentation and they should be ready before the start of the session.

Poster Presentation

The size of a poster is 594 x 841 mm (Width x Height). Poster presentation is held on 30th July

at 6:00 pm in the MAS Atrium. Posters should be mounted on the poster boards in the MAS

Atrium on 29th July 2019 in accordance with the poster abstract number.

Outstanding poster presentation will be awarded by the Best Poster Award.

Meal

Lunch and coffee break are available in the MAS Atrium on the 3rd floor of the School of

Physical and Mathematical Sciences. Dinner is provided during the poster presentation session.



Social Events

➢ Welcome Reception

Date: 28th July 2019, 6:00 – 8:00 pm

Location: Hotel Jen, Tanglin

➢ Excursion

Date: 31st July 2019, 3:00 – 6:00 pm

Location: Flower Dome and Cloud Forest at The Gardens by the Bay

(https://www.gardensbythebay.com.sg/en.html).

Tour bus is provided in front of the School of Physical and Mathematical Sciences

➢ Banquet

Date: 31st July 2019, 7:00 pm – 9:00 pm

Location: Hotel Jen, Tanglin

➢ Accompanying Person Program

Date: 30th July 2019

Location: NTU registration booth (9:00 am)

Tour: China Town → Merlion → Masjid Sultan → Kampong Glam → Lunch at NTU →

Cooking Class at Tanjong Hall in NTU → Dinner at NTU

Date: 31st July 2019

Location: NTU registration booth (9:00 am)

Tour: Singapore Discovery Centre → Lunch at NTU → Gardens by the Bay


PLENARY LECTURE ǀ Page 8

Abstract

Plenary Lecture

Keynote Lecture

Invited Lecture

Short Oral Presentation



Recent progress in silicon chemistry and its valence isoelectronic

neighbors

Herbert W. Roesky

Institute of Inorganic Chemistry, University of Göttingen, Germany

[email protected]

This year the chemical community celebrates the 150th year of the periodic system and therefore it a

chance for the chemists to report new results on silicon and aluminum, the ubiquitous elements in the

earth`s crust. BF an isoelectronic molecule to SiO was prepared from BF3 and boron at 2000 °C and 1

mm pressure by P. L. Timms in 1967.

BF is only stable at high temperatures and condenses at liquid nitrogen temperature (-196 °C) to a

green polymer, which has not been characterized.

BF3 + 2 B → 3 BF

BF is an interesting molecule because it is isoelectronic to CO and N2. The latter compounds are

forming well known metal complexes.

We stabilized BF during the reduction with cAAC (cyclic alkylamino carbene) according to the

following reaction

This adduct was characterized by single crystal X-ray structural analysis and is stable at room

temperature for several months. The CV of the BF adduct exhibits one electron reversible oxidation.

The formation, isolation and characterization of the cation will be discussed. It is well known that B-Si

compounds have found a brought application in organic chemistry. The corresponding preparation of

Al-Si compounds is so far hardly reported. We used successfully interconnected bissilylen RSi(:)Si(:)R

( R= adamantyl) and AlH3·NR3 for the preparation of Al-Si molecules.

In recent years we were able to stabilize small silicon compounds with cAAC (cyclic alkylamino

carbene) such as SiH2 and various R2SiCl and RSiCl2 radicals.

Moreover, we successfully isolated silanylidene and germanylidene anions, valence isoelectronic

species to phosphinidene. The cAACPLi·(thf)2 dimer reacts with fluorinated carbon compounds as well

as with SiCl4 and GeCl4 under elimination of LiF and LiCl, respectively, to the corresponding

phosphinidene derivatives.

PL – 01



Nanostructuring of Bridged Silsesquioxanes and applications

Michel Wong Chi Man,a*

aInstitut Charles Gerhardt Montpellier, ENSCM, 8 rue de l’école normale, 34296 Montpellier (France)

[email protected]

Bridged Silsesquioxanes (BS)1 represent a family of hybrid silica which has emerged as an important

class of materials in the early 1990s. Since then a large number of such hybrid materials have been used

in several fields of applications. A decade later PMO (Periodic Mesoporous Organosilicas) have been

produced from simple precursors via the surfactant-mediated structuring and, nearly at the same time,

nano-structured BS were obtained by a self-structuring process (Figure 1).

Figure 1. Structuring of Bridged Silsesquioxanes

BS are obtained by hydrolysis-condensation of poly(trialkoxy)organosilanes, (RO)3Si-X-Si(OR)3

(X=organic bridging unit). The organic units are regularly retained throughout the hybrid network

thanks to the strong covalent Si-C bonds. The combination of the organic fragments and of the silica

network allows the structuring as well as the fine-tuning of targeted properties of these materials. My

talk will be focused on the following:

- Synthesis and self-structuring of BS,2,3

- Synthesis of Nano-PMO,4

- Applications in catalysis,5

- Application of mechanized nano-PMO in nanomedicine field.6-8

References

1. Corriu R. J. P., Moreau J. J. E., Thépot P. Wong Chi Man M. Chem. Mater. 1992, 114, 1217-1224.

2. Moreau J. J. E., Vellutini L., Bied C., Wong Chi Man M., J. Am. Chem. Soc. 2001, 123, 6700-6710.

3. Arrachart G., Creff G., Wadepohl H., Blanc C., Bonhomme C., Babonneau F., Alonso B., Bantignies J-L., Carcel C.,

Moreau J. J. E., Dieudonné P, Sauvajol J-L, Massiot D., Wong Chi Man M. Chem. Eur. J. 2009, 15, 5002-5005.

4. Croissant J., Cattoën X., Wong Chi Man M., Dieudonné P., Charnay C., Raehm L., Durand J-O. Adv.Mater., 2015, 27,

145 -149.

5. Monge-Marcet A., Pleixats R., Cattoën X., Wong Chi Man M. J. Mol. Catal. A, Chemical 2012, 357, 59-66.

6. Théron C., Gallud A., Carcel C., Gary-Bobo M., Maynadier M., Garcia M., Lu J., Tamanoi F., Zink J. I., Wong Chi Man

M. Chem. Eur. J., 2014, 20 (30), 9372-9380.

7. Croissant J., Maynadier M., Mongin O., Hugues V., Blanchard-Desce M., Chaix A., Cattoën X., Wong Chi Man M.,

Gallud A., Gary-Bobo M., Garcia M., Raehm L., Durand J-O. Small, 2015, 11, 295-299.

8. Noureddine A., Gary-Bobo M., Lichon L., Garcia M., Zink J. I., Wong Chi Man M., Cattoën X., Chem. Eur. J., 2016, 22,

9624-9630.

PL – 02



A Systematic Study on Metallabenzenyl Anions

Substituted by a Heavier Group 14 Element

Norihiro Tokitoh,a,b,* Shiori Fujimori,a Shingo Tsuji,a Yoshiyuki Mizuhataa,b

aInstitute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan b Integrated Research Consortium on Chemical Sciences, Uji, Kyoto 611-0011, Japan

[email protected]

We have recently reported the synthesis and isolation of 2-tert-butylgermabenzenylpotassium (K+.2-),

the first example of heavy phenyl anion, i.e., a Ge analogue of phenylpotassium, by the reaction of 1-

Tbt-2-tert-butylgermabenzene 1 with KC8.1 Spectroscopic and X-ray crystallographic analysis together

with theoretical calculations revealed that K+.2- exhibits not only aromatic character due to the C5Ge

-system but also germylene character due to the delocalization of negative charge on the five ring

carbon atoms.1-3 Stannabenzenylpotassium (K+.4-), the Sn analogue of K+.2-, was also synthesized and

isolated by the treatment of an equilibrated mixture of the corresponding stannabenzene 34 and its dimer

with KC8.5

Next, we attempted the synthesis of the corresponding silabenzenyl anion. However, the treatment of

1-Tbt-2-t-Bu-silabenzene 4 with KC8 or LiNpah resulted in the formation of dianion 52- as yellow

crystals as shown in Scheme 1.6 The formation of dianions (2K+.52- and 2Li+.52-) was evidenced by

their X-ray crystallographic analysis and the trapping with D2O giving the deuterated product 6.

The structures, properties, and formation mechanisms of metallabenzenyl anions (K+.2- and K+.4)

and dianions (2K+.52- and 2Li+.52-) will be discussed in detail.

References

1. Mizuhata, Y.; Fujimori, S.; Sasamori, T.; Tokitoh, N. Angew. Chem. Int. Ed. 2017, 56, 4588-4592.

2. Fujimori, S.; Mizuhata, Y.; Tokitoh, N. Chem. Commun. 2018, 54, 8044-8047.

3. Fujimori, S.; Mizuhata, Y.; Tokitoh, N. Chem. Lett. 2018, 37, 708–710.

4. Mizuhata, Y.; Fujimori, S.; Noda, N.; Kanesato, S.; Tokitoh, N. Dalton Trans. 2018, 47, 14436-14444.

5. Fujimori, S.; Mizuhata, Y.; Tokitoh, N. Chem. Eur. J. 2018, 24, 17039-170

6. Tsuji, S.: Mizuhata, Y.; Tokitoh, N. 99th CSJ Annual Meeting, 3PC-20, Kobe, 2019, March 18.

PL – 03



Challenge: Mimicking transition metals using Si

Tsuyoshi KATO

a Université de Toulouse, UPS, LHFA, 118 route de Narbonne, F-31062 Toulouse, France, and CNRS, LHFA

UMR 5069, F-31062 Toulouse, France.

[email protected]

Silylenes are neutral silicon species featuring a divalent silicon atom with only six valence electrons

and they are in general highly reactive transient species with a short life time. Since the discovery of

first stable silylenes, several methods to stabilize such species have been developed. Among them, the

use of a donating ligand, which thermodynamically stabilizes silylenes by elecron donation but also

increases the steric protections, have been recognized to be an efficient methodology to synthesize

various types of silylenes.

Since several years, we are developing the chemistry of silylenes complexed with a phosphine ligand

I. Of particular interest, they retains the silylene reactivity in spite of their high stability and presents

somewhat transition metal like behavior.1 Here we will show their chemistry and some interesting

perspectives.

References

1. a) R. Rodriguez, D. Gau, T. Kato, N. Saffon-Merceron, A. De Cózar, F. P. Cossío, A. Baceiredo, Angew. Chem. Int. Ed.

2011, 50, 10414; b) R. Rodriguez, Y. Contie, D. Gau, N. Saffon-Merceron, K. Miqueu, J.-M. Sotiropoulos, A. Baceiredo,

T. Kato, Angew. Chem. Int. Ed. 2013, 52, 8437; c) R. Rodriguez, Y. Contie, Y. Mao, N. Saffon-Merceron, A. Baceiredo,

V. Branchadell, T. Kato, Angew. Chem. Int. Ed. 2015, 54, 15276; d) R. Rodriguez, Y. Contie, R. Nougué, A. Baceiredo,

N. Saffon-Merceron, J.-M. Sotiropoulos, T. Kato, Angew. Chem. Int. Ed. 2016, 55, 14355.

PL – 04


KEYNOTE LECTURE ǀ Page 13

Heavier Unsaturated Group 14 Species: Beyond the Carbon Copy

David Scheschkewitz*

Chair in General and Inorganic Chemistry, Saarland University, 66123 Saarbrücken, GERMANY

[email protected]

Heavier double bonds attracted enormous interest since more than a century. Early attempts to

synthesize stable species with such double bonds exclusively resulted in oligo-or polymeric materials

despite occasional claims to the contrary. As a consequence, the classical "double bond rule" surmised

that double bonds between two elements beyond the 2nd row of the periodic table would be unstable.

The search for exceptions to this rule and thus for parallels to carbon chemistry was on and finally

successful with the isolation of stable compounds with formal Ge=Ge, Sn=Sn, Si=Si, and P=P units in

the late 1970s and early 1980s. The first 20 years of research in this area focussed on the structural

peculiarities and the reactivity of the heavier alkene analogues and to this day enormous efforts are

devoted to mimic the hallmarks of C=C bonds in organic chemistry such as conjugation and functional

group tolerance.1

As a deeper understanding of the theoretical foundations of the peculiar bonding in heavier main

group elements develops, an additional focus has been directed to the differences rather than the

similarities between the first two rows and the rest of the periodic table. In unsaturated systems in

particular, a strong preference for cluster-like arrangements has become obvious, increasingly so as the

number of cluster vertices and the degree of unsaturation rises.2 The unique structure and electronic

properties of unsaturated clusters of the heavier main group elements reflect those of the corresponding

nanomaterials and bulk surfaces, which potentially opens a wide field of application, e.g. in

photovoltaics, microprocessors or data storage.

References

1. For examples of reviews see: (a) Fischer, R. C.; Power, P. P Chem. Rev. 2010, 110, 3877. (b) Präsang, C.; Scheschkewitz,

D. Chem. Soc. Rev. 2016, 45, 900.

2. Recent review: Heider, Y., Scheschkewitz, D. Dalton Trans. 2018, 47, 7104.

KL – 01



Siloles as Precursors for Unusual Silicon Compounds

Zhaowen Dong, Crispin Reinhold, Thomas Müller*

Institute of Chemistry, Carl von Ossietzky University Oldenburg

Carl von Ossietzky-Str. 9-11, D-26129 Oldenburg, Federal Republic of Germany, European Union

[email protected]

Siloles are of great interest, in particular in materials chemistry, due to their favorable photophysical

properties.1 We started our experimental work on siloles with an attempt to stabilize silyl radicals 1 and

we found during this endeavour an easy synthetic access to silole dianions 2.2 These silole dianions 2

have been the starting point for the synthesis of an intriguing set of unusual silicon compounds including

silacalicenes 3, isomers of disilabenzene 4 and unusual silylenes 5 that are stabilizes by

homoconjugation with a remote C=C double bond.3,4 In this presentation, we will summarize parts of

our exciting journey through silole chemistry and point out future directions.

Figure 1. Unusual silicon compounds derived from siloles.

References

1. Yamaguchi, S.; Tamao, K. J. Chem. Soc., Dalton Trans. 1998, 3693 - 3704.

2. Dong, Z.; Reinhold, C. R. W.; Schmidtmann, M.; Müller, T. Organometallics 2018, 37, 4736 - 4734.

3. Reinhold, C. R. W.; Dong, Z.; Winkler, J. M.; Steinert, H.; Schmidtmann, M.; Müller, T. Chem. Eur. J. 2018, 24, 848-

854.

4. Dong, Z.; Reinhold, C. R. W.; Schmidtmann, M.; Müller, T. J. Am. Chem. Soc. 2017, 139, 7117-7123.

KL – 02



A New Form of Silicon: Metal-Atom Encapsulating Silicon Cage

Compounds

Atsushi Nakajima

Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi,

Kohoku-ku, Yokohama 223-8522, Japan

[email protected]

Since well-established function miniaturization of silicon (Si) devices with photolithography has

almost reached its technological limit, it is urgent to explore new Si based low-dimensional functional

nanomaterials (e.g. Si nanodots, nanowires, nanosheets) with bottom-up technologies utilizing

physicochemical synthetic methods in the gas and liquid phases. Furthermore, silicene, a counter part

of graphene, is a two-dimensional (2D) Si nanomaterial, exhibiting high in-plane electric conductivity.

Since the Si atom, unlike the C atom, generally prefers to sp3 hybridization, sp2-like Si-Si bonds should

be formed to make the 2D flat silicene. However, the 2D silicene on a metal surface is non-flat due to

the structural deviation from the sp2 conformation. Alternatively, one can assume that a rounded silicene

will have a caged surface consisting of sp2-Si by analogy with C60 fullerene. Although a lot of

experimental and theoretical researches have been conducted, a “zero dimensional (0D)” caged Si

compound, including Si60, has not been identified.

A suggestive clue for the 0D Si cage was shown to be metal-encapsulation inside a Si cage, M@Sin,

by mass spectrometry for mixed vapors of metal and Si in 1987.1 Although some other experimental

and theoretical researches have been reported, the caged Si compounds have never been realized as a

new Si form. On the other hand, a physical concept of “superatoms” has been introduced, where new

atomic-like orbitals (super atomic orbital; SAO) are constructed by valence electrons delocalized over

nanoclusters comprised of several to hundreds of atoms.

We have found a periodic family of M@Si16 superatoms based on mass spectrometry, where halogen-

like (Sc@Si16–), rare gas-like (Ti@Si16

(0)), and alkali-like (V@Si16+, Ta@Si16

+) SAs have been

demonstrated by the group-3, -4, and -5 atom encapsulations, respectively. They complete their SAO

closure for the same number of valence electrons (68e), where 64 and 4 electrons come from the 16 Si

atoms and the central M atom including charged states. Beyond the surface

immobilization of the M@Si16 superatoms,2,3,4 we have developed a large-

scale synthesis method for M@Si16 (M = Ti and Ta) by scaling up the clean

dry-process with a highpower impulse magnetron sputtering (nanojima®)

and by a direct liquid embedded trapping (DiLET) method5. The

spectroscopic results reveal that the structures of isolated M@Si16

superatoms are the metalencapsulating tetrahedral Si-cage (METS)

consisting of sp2-Si atoms.6

References:

1. S.M. Beck, J. Chem. Phys. 1989, 90, 6306.

2. M. Nakaya, T. Iwasa, H. Tsunoyama, T. Eguchi, A. Nakajima, Nanoscale 2014, 6, 14702.

3. M. Shibuta, T. Ohta, M. Nakaya, H. Tsunoyama, T. Eguchi, A. Nakajima, J. Am. Chem. Soc. 2015, 137, 14015.

4. M. Shibuta, T. Kamoshida, T. Ohta, H. Tsunoyama, A. Nakajima, Comm. Chem. 2018, 1, 50.

5. H. Tsunoyama, H. Akatsuka, M. Shibuta, T. Iwasa, Y. Mizuhata, N. Tokitoh, A. Nakajima, J. Phys. Chem. C 2017, 121,

20507.

6. H. Tsunoyama, M. Shibuta, M. Nakaya, T. Eguchi, A. Nakajima, Acc. Chem. Res. 2018, 51, 1735.

KL – 03



Preparation of Functional Silicone Materials via Thiol-ene Click

Reaction

Shengyu Feng

Key Laboratory of Special Functional Aggregated Materials & Key Laboratory of Colloid and Interface

Chemistry (Shandong University), Ministry of Education; School of Chemistry and Chemical Engineering,

Shandong University, Jinan 250100, P. R. China

[email protected]

Silicone materials possess many unique properties such as non-toxicity, physiological inertness,

flame retardancy, high- and low- temperature resistance, weather resistance, and electrical insulation,

and functional silicone materials have more special applications. 1, 2 Among them, silicone materials

have great potential in wastewater treatment. The thiol-ene reaction is one of the click reactions.3 The

application of thiol-ene click reaction to the synthesis of sewage treatment functional silicone materials

is of great significance for increasing the productivity.

The lecture intends to introduce a few functionalized silicone materials including functional

polysiloxanes, silicone gels, and silicone sponges prepared by the thiol-ene click reaction (Scheme 1).

The polyether modified polysiloxanes were used to detect Hg2+ and Fe3+ in water, and detection limits

were wide. The silicone gels and silicone sponges were used for fast oil water separation, and they both

had high separation efficiency. The super-amphiphilic silicone sponge was used for the efficient

adsorption and filtration of dye and metal ion, and the filtrate can reach drinkable levels. 4, 5 This lecture

will also enlarge the applications of silicone materials.

Scheme 1. Preparation of functional silicone materials via thiol-ene click reaction

References

1. Feng S, Zhang J, Li M, and Zhu Q. Organosilicon Polymers and Application. Beijing: Chemical Industry Press, 2010; pp

1-20.

2. Yilgör E and Yilgör I. Prog. Polym. Sci. 2014, 39, 1165-1195.

3. Lowe AB. Polym. Chem. 2014, 5, 4820-4870.

4. Cao J, Wang D, An P, Zhang J, and Feng S. J. Mater. Chem. A 2018, 6, 18025-18030.

5. Zuo Y, Cao J and Feng S. Adv. Funct. Mater. 2015, 25, 2754-2762.

KL – 04



Low-Valent Silicon Chemistry from an Industrial Perspective

Elke Fritz-Langhalsa, Richard Weidnera,*

aWacker Chemie AG, Consortium für Elektrochemische Industrie,

Zielstattstraße 20, D-81379 Munich, Germany

[email protected]

Silyliumylidene cations RSi:+ are of increasing interest in chemistry. Two vacant orbitals and a lone

pair of electrons combine the characters of both strongly electrophilic silylium cations R3Si+ and

nucleophilic silylenes R2Si:. 1 Whereas the reactivity of silylenes R2Si: and silylium cations has been

investigated in detail within the past 20 years, the reactivity of silyliumylidene cations RSi:+, however,

is still in its infancy. Jutzi’s Cp*Si:+ B(C6F5)4- (1, Cp* = pentamethylcyclopentadienyl),2 however, repre-

sents a unique cationic silyliumylidene structure, because the cationic silicon center is only stabilized

on one side by a Cp* residue and therefore has free coordination sites. The catalytic potential of this

extraordinary structure, however, was unknown.

We found that Cp*Si:+ efficiently catalyzes reactions which are of technical relevance in industrial

organosilicon chemistry. For example, it is a very efficient nonmetallic catalyst for the hydro-silylation

of alkenes3 (eq. 1) at low catalyst amounts of < 0.01 mole %, and for the Piers-Rubinsztajn reaction (eq.

2) which is a versatile tool to make controlled silicone architectures.

References

1. (a) Ahmad, S.U.; Szilvasi, T.; Inoue, S. Chem. Commun. 2014, 50, 12619. (b) Lee, V.Y; Sekiguchi, A. Organometallic

Compounds of Low-Coordinate Si, Ge, Sn and Pb; Wiley: Chichester, 2010. 2Jutzi, P.; Mix, A.; Rummel, B.; Schoeller,

W.W.; Neumann, B., Stammler, H.-G. Science 2004, 305, 849. 3Fritz-Langhals, E.; Jutzi, P.; Weidner, R. WACKER

Chemie AG, Precious metal-free hydrosilylation of unsaturated compounds catalyzed by cationic Si(II) complexes,

WO2017/174290 (12.10.2017).

KL – 05



Synthesis and Reactivity of Acyclic Silylenes

Shigeyoshi Inoue

Department of Chemistry, WACKER-Institute of Silicon Chemistry and Catalysis Research Center, Technische

Universität München, Lichtenbergstraße 4, 85748 Garching bei München, Germany

[email protected]

Silylenes have recently shown fascinating reactivity patterns, which are normally observed almost

exclusively for transition metal complexes. In particular, very reactive representatives are considered

as promising candidates, which may become powerful and economical alternatives for catalytic

applications in the future. Acyclic silylenes are considered as very reactive species, due to their

proposed small HOMO-LUMO gaps. Recently, we found that imidazoline-2-iminato ligand supported

acyclic silylenes show unique reactivity and are capable to activate - and π- bonds of small molecules

under very mild reaction conditions.1-5 In this presentation, synthesis of selected acyclic silylenes and

their unique reactivity towards various small molecules will be described.

References

1. Ochiai, T.; Franz, D.; Inoue, S. Chem. Soc. Rev. 2016, 45, 6327.

2. Inoue, S.; Leszszyńska, K. Angew. Chem., Int. Ed. 2012, 51, 6167.

3. Wendel, D.; Reiter, D.; Porzelt, A.; Altmann, P.J.; Inoue, S.; Rieger, B. J. Am. Chem. Soc. 2017, 139, 17193.

4. Wendel, D.; Porzelt, A.; Herz. F. A.; Sarkar, D.; Jandl, C.; Inoue, S.; Rieger, B. J. Am. Chem. Soc. 2017, 139, 8134.

5. Reiter, D.; Holzner, R.; Porzelt, A.; Altmann, P.J.; Frisch, P.; Inoue, S. submitted.

KL – 06



Synthesis and Reactions of a Cyclic Dialkylsilylene Containing a

Robust Carbon-Based Substituent

Ryo Kobayashi,a Shintaro Ishida,a Takeaki Iwamotoa

a Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan

[email protected]

Silylenes have received much attention as important and reactive low-coordinate species in silicon

chemistry. Since the pioneering works on stable silylenes,1 various cyclic and acyclic silylenes that are

stabilized kinetically and electronically have been synthesized as isolable species and their structures

and reactivity have been extensively investigated. Previously, we have synthesized stable cyclic

dialkylsilylenes 1 that have a five-membered ring with four trialkylsilyl groups at 2,5-positions.2 These

silylene exhibit spectroscopic properties and reactivity that resemble those of transient dialkylsilylenes

with an intrinsic nature of silylene. Nevertheless, these cyclic dialkylsilylenes are not thermally very

stable; 1a and 1b undergo facile 1,2-silyl migration providing the corresponding cyclic silenes, while

1c provides unidentified insoluble materials upon heating. Very recently, we designed a more robust

substituent that contains bulky carbon-based protecting groups with a diminished migratory propensity

relative to that of the trialkylsilyl group. In this presentation, we would like to talk about synthesis and

reactions of new two-coordinate cyclic dialkylsilylene 2.3

Figure 1. Stable Two-coordinate Cyclic Dialkylsilylenes.

References

1. Jutzi, P.; Kanne, D.; Krüger, C. Angew. Chem. Int. Ed. Engl. 1986, 25, 164; Karsch, H. H.; Keller, U.; Gamper, S.; Müller,

G. Angew. Chem. Int. Ed. 1990, 29, 295; Denk, M.; Lennon, R.; Hayashi, R.; West, R.; Belyakov, A. V.; Verne, H. P.;

Haaland, A.; Wagner, M.; Metzler, N. J. Am. Chem. Soc. 1994, 116, 2691.

2. Kira, M.; Ishida, S.; Iwamoto, T.; Kabuto, C. J. Am. Chem. Soc. 1999, 121, 9722; Abe, T.; Tanaka, R.; Ishida, S.; Kira,

M.; Iwamoto, T. J. Am. Chem. Soc. 2012, 134, 20029; Ishida, S.; Abe, T.; Hirakawa, F.; Kosai, T.; Sato, K.; Kira, M.;

Iwamoto, T. Chem. Eur. J. 2015, 21, 15100.

3. Kobayashi, R.; Ishida, S.; Iwamoto, T. Angew. Chem. Int. Ed., (DOI: 10.1002/anie.201905198).

KL – 07



IRON, COBALT AND NICKEL COMPLEXES WITH SILYLENE

LIGANDS

Chunming Cui,* Yunping Bai

State Key Laboratory of Elemento-Organic Chemistry and College of Chemistry, Nankai University, Tianjin

300071, China

[email protected]

Silylenes, the carbene analogues of silicon, have emerged as a class of powerful ligands in

coordination chemistry and catalysis since the first N-heterocyclic silylene was reported in 1994 by

West. Recent advances in this field have shown that silylenes with different coordination numbers could

be available, and thus provided more chemical space for the tuning their electronic properties. However,

the employments of silylenes in organic catalysis remained largely unexplored. In this presentation, we

report the synthesis of iron and cobalt complexes with multiple dentate silylene ligands and their unique

chemical transformations.

We found these silylene-supported transition metal compounds enabled catalytic transformations of

C-H functionalization, alkyne trimerization and dinitrogen fixation. The mechanism and structural

analysis disclosed the silylenes both act as excellent σ-donors and π-acceptors in different coordination

spheres. These preliminary results demonstrated that the potentials of silylene ligands in coordination

chemistry and homogeneous catalysis can be widely explored.

Figure 1. Representative Silylene Complexes.

Acknowledgment.

We thank the National Natural Science Foundation of China for the support of this work.

References

1. Raoufmoghaddam, S.; Zhou, Y.; Wang, Y.; Driess. M. J. Organomet. Chem. 2017, 829, 2.

2. Ren, H.; Zhou, Y.; Bai, Y.; Cui, C.; Driess, M. Chem. Eur. J. 2017, 23, 5663.

3. Bai, Y.; Zhang, J.; Cui, C. Chem. Commun. 2018, 54, 8124.

KL – 08


INVITED LECTURE ǀ Page 21

Molecular Silicon Clusters with Six and Seven Unsubstituted

Vertices via a Two‐step Reaction from Elemental Silicon

Thomas Fässler

Prof. Dr. Thomas Fässler, Technische Universität München, Department of Chemistry & WACKER Institute of

Silicon Chemistry, 85748 Garching, Germany,

[email protected]

Unsaturated silicon clusters with partial substitution and thus “naked” Si atoms are well studied

species as they are proposed intermediates in gas‐phase deposition processes. Although a remarkable

number of stable molecular clusters have been reported, they are typically obtained by multistep

syntheses. Herein we report on the application of a newly developed synthetic approach and the

formations of protonated [H2Si9]2−, and functionalized siliconoids [{Si(TMS)3}3Si9]−,

[{Si(TMS)3}2Si9]2− , [{Si(tBu)2H}3Si9]−, [{Si(iPr)3}2Si9]2−, [{Sn(Cy)3}2Si9]2−, and [{Sn(Cy)3}3Si9]−

through a one‐step synthesis from the binary alloy K12Si17 which is obtained by simply fusing the

elements K and Si.

The protonated [H2Si9]2− reveal a rather unexpected 1H‐NMR shift at ‐0.7 ppm and coupling with all

nine Si atoms indicating dynamic processes.1,2 The molecular functionalized anions display a

remarkable 29Si‐NMR shift range for example of +18 to ‐359 ppm for [{Si(tBu)2H}3Si9]−. The anions

are further characterized by ESI mass spectrometry and 13C as well as 119Sn NMR spectroscopy. Various

clusters are isolated as their (K‐222crypt)+ salts and structurally characterized by single crystal X‐ray

structure determination.3 For the first time also Raman spectra are reported and vibrations originating

from Si–Si inter‐cluster bonds as well as Si‐C exo‐bonds are assigned by comparison to calculated

(DFTPBE0) spectra.

References 1. Charged Si9 Clusters in Neat Solids and Solution – A Combined NMR, Raman, Mass Spectrometric, and Quantum

Chemical Investigation.

L. J. Schiegerl, A. J. Karttunen, J. Tillmann, S. Geier, G. Raudaschl-Sieber, M. Waibel, T. F. Fässler,

Angew. Chem. Int. Ed. 57 (2018) 12950 –12955.

2. Silicon Containing Nine Atom Clusters from Liquid Ammonia Solution: Crystal Structures of the First Protonated Clusters

[HSi9]3– and [H2{Si/Ge}9]2–

T. Henneberger, W. Klein, T. F. Fässler

Z. Anorg. Allg. Chem. 644 (2018) 1018-1027

3. Anionic Siliconoids from Zintl Phases: R3Si9- with Six and R2Si9

2− with Seven Unsubstituted Exposed Silicon Cluster Atoms

(R = Si(tBu)2H)

L. J. Schiegerl, A. J. Karttunen, W. Klein, T. F. Fässler

Chem. Eur. J. 24 (2018) 19171–19174

IL – 01



Comparison of Reactivity towards Acyl Chlorides among an Isolable Dialkylsilylene and Its Germanium and Tin Congeners

Huaiyuan Zhu, Xupeng Liu, Chenting Yan, Qiong Lu, Ningka, Wei, Xu-Qiong Xiao, Zhifang Li, and Mitsuo Kira

Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou

Normal University, Hangzhou 311121, P. R. China

mitsuo.kira.e2@ tohoku.ac.jp

Though insertion reactions of tetrylenes into various C-Cl bonds offer a useful technique for

derivatization of the tetrylenes, generally, the reaction mechanisms are not simple or straightforward.

We have recently reported that when isolable dialkyltetrylenes 1a -1c are treated with an equimolar

amount of (4-substituted)benzoyl chlorides 2 in hexane or THF at room temperature, the corresponding

benzoyl(chloro)tetrylenes 3 are obtained in high yields, indicating that the C–Cl bond is much more

reactive than the carbonyl group (Eq. (1)).1-3

In contrast, the reactivity towards simple alkanoyl chlorides is very dependent on the tetrylenes.3 As

shown in Scheme 1, typically, the reaction of germylene 1b with acetyl chloride gives a mixture of the

corresponding acetyl(chloro)germane, diacetylgermane, and dichlorogermane, while related reactions

with silylene 1a and stannylene 1c give a complex mixture and dichlorostannane, respectively. While

remarkable difference of the reactivity among tetrylenes 1a-1c is suggestive of the radical nature of the

reactions, the reaction mechanisms remain open.

Scheme 1. Diverse Reactions of Tetrylenes 1a-1c with Simple Alkanoyl Chlorides.

Interestingly, diakanoylgermanes 5 show two separated n(O)→ π*(C=O) bands at 350 and 400 nm

in the UV/Vis spectra. The origin will also be discussed.

References

1. Xiao, X.-Q.; Liu, X.; Lu, Q.; Li, Z.; Lai, G.; Kira, M. Molecules 2016, 21, 1376.

2. Lu, Q.; Yan, C.; Xiao, X.-Q.; Li, Z.; Wei, N.; Lai, G.; Kira, M. Organometallics 2017, 36, 3633.

3. Zhu, H.; Wei, N.; Li, Z.; Yang, Q.; Xiao, X.-Q.; Lai, G.; Kira, M. Organometallics 2019, 38, 1955.

IL – 02



Silicon Bond: Interaction to Form Micelles in a LC Phase

Soichiro Kyushin,a,* Kenji Nanba,a Kimio Yoshimura,b Yue Zhao,b Yasunari Maekawab

aGraduate School of Science and Technology, Gunma University, Kiryu, Gunma 376-8515, Japan bTakasaki Advanced Radiation Research Institute, National Institutes for Quantum and Radiological Science

and Technology, Takasaki, Gunma 370-1207, Japan

[email protected]

Liquid crystal molecules consist of rigid central cores and flexible side chains. Recenty, we have

reported that a silyl group bearing two hydrogen atoms and a long alkyl group works as a flexible side

chain.1 For example, 4-hexyloxy-4’’-pentylsilyl-p-terphenyl (1: R1 = R2 = H) shows a SmA phase, in

which rod-like molecules are arranged in a parallel mannar.

When the two hydrogen atoms of the silyl group are replaced by methyl groups, the liquid crystalline

phase is dramatically changed to an unusual phase. The liquid crystalline phase observed with a

polarizing microscope does not show a usual liquid crystalline texture but a dark field. Reflections were

observed only by small-angle X-ray scattering. These results and other data show that the liquid

crystalline phase is isotropic cubic phase, in which molecules are arranged in a head-to-head manner to

form micelles. Theoretical calculations indicate that driving force to form this phase is intermolecular

electrostatic interaction between the negatively charged methyl groups and the positively charged

silicon atoms. This interaction resembles the hydrogen bond and can be regarded as the silicon bond.

This bond is cleaved by further replacement of the methyl groups by ethyl, propyl, and pentyl groups

to lead a SmB phase, in which molecules are arranged in a head-to-tail manner.

Figure 1. Molecular arrangement in the liquid crystalline phases of 4-hexyloxy-4’’-silyl-p-terphenyls.

Reference

1. Otsuka, K.; Ishida, S.; Kyushin, S. Chem. Lett. 2012, 41, 307–309.

R1 = R2 = H R1 = H, R2 = Me

R1 = R2 = Me

R1 = R2 = Et (25 C) R1 = R2 = PeR1 = R2 = Et (55 C)

R1 = R2 = Pr (25 C)

liquid

1

IL – 03



Improved synthesis and reactivity of the

tris(pentafluoroethyl)silanide ion

Natalia Tiessen, Nico Schwarze, Berthold Hoge*

Bielefeld University, Center for Molecular Materials, 33615 Bielefeld, Germany,

[email protected]

The literature-known synthesis of tris(pentafluoroethyl)silanide salts1 proceeds via the deprotonation

of Si(C2F5)3H, which is synthesized via four steps:2

The reaction of commercially available SiCl3H with in situ generated LiC2F5 3 allows an access of

Si(C2F5)3H within one step. The subsequent treatment of the resulting Et2O solution with neutral

phosphazene bases R3P=NtBu (R = -N=P(NEt2)3 and -NC(NMe2)2) leads to a two-step synthesis of the

corresponding [R3PN(H)tBu]+[Si(C2F5)3]- salts.

The [Si(C2F5)3]- ion exhibits Lewis amphoteric character and adds carbonyl derivatives side-on. An

intermediary addition of CO2 leads to a liberation of CO and a dimerization of the resulting silanolate

ions.

References

1. N. Schwarze, S. Steinhauer, B. Neumann, H.-G. Stammler, B. Hoge, Angew. Chem. 2016, 128, 16390-16394. N. Schwarze,

S. Steinhauer, B. Neumann, H.-G. Stammler, B. Hoge, Angew. Chem., 2016, 128, 16395-16398.

2. S. Steinhauer, J. Bader, H.-G. Stammler, N. Ignat'ev, B. Hoge, Angew. Chem., 2014, 126, 5307- 5310

3. M. Heinrich, A. Marhold, A. Kolomeitsev, A. Kadyrov, G.-V. Röschenthaler, J. Barten (Bayer AG), DE 10128703A 1,

2001; M. H. Königsmann, Dissertation, Universität Bremen, 2005; A. A. Kolomeitsev, A. A. Kadyrov, J. Szczepkowska-

Sztolcman, H. Milewska, G. Bissky, J. A. Barten, G.-V. Röschenthaler, Tetrahedron Lett. 2003, 44, 8273–8277

IL – 04



Power of Silyl-substituents: From Cyclobutadiene Dianion to

Cyclobutadienes, Tetrahedranes, and Pyramidanes

Akira Sekiguchia,b,*

aDepartment of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba,

Ibaraki 305-8571, Japan

bInterdisciplinary Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science

and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan

[email protected]; [email protected]

The chemistry of the cyclobutadiene (CBD) and tetrahedrane (THD) was long a fascinating target for

both synthetic and computational chemists. In this symposium, the chemistry of the silyl-substituted

cyclobutadienes, tetrahedranes, and the related compounds such as pyramidanes, derived from the

cyclobutadiene dianion will be reported.

The dilithium salt of tetrakis(trimethylsilyl)cyclobutadiene dianion [(Me3Si)4C4]2–•2Li+ (1)

underwent two electron oxidation, giving the tetrakis(trimethylsilyl)cyclobutadiene [(Me3Si)4CBD] (2),

which was then converted to the tetrakis(trimethylsilyl)tetrahedrane (Me3Si)4THD (3), in which the four

trimethylsilyl groups sterically and electronically stabilize the skeleton of 3. Furthermore,

functionalization of 3 through the desilylation–metalation allowed for the preparation of the

tris(trimethylsilyl)tetrahedranyllithium (Me3Si)3THD-Li (4), which opened the way to new members of

tetrahedrane family. We have also extended the palladium-catalyzed cross-coupling reaction of 4 with

aryl halides, forming various aryl-substituted tetrahedrane derivatives (5), which were photochemically

isomerized to the corresponding cyclobutadiene derivatives Ar(Me3Si)3CBD (6). Moreover, a new class

of polyhedral compounds, pyramidanes (7), with C4-bases and Ge or Sn atoms at the apex of the square-

pyramid, was recently prepared by the reaction of 1 with ECl2 (E = Ge, Sn). The peculiar structural and

bonding features of these compounds were verified by combined experimental and computational

studies.

IL – 05



Formation of 1,2- and 1,4-Disilabenzenes

Takahiro Sasamori,a,* Tomohiro Sugahara,b Norihiro Tokitoh,b Jing-Dong Guo,a,b Shigeru Nagase,c and Daisule Hashizumed

a Graduate School of Natural Sciences, Nagoya City University, Yamanohata 1, Mizuho-cho, Mizuho-ku,

Nagoya, Aichi 467-8501, JAPAN. b Institute for Chemical Research, Kyoto Univ., Gokasho, Uji, Kyoto 611-0011, JAPAN.

c Fukui Institute for Fundamental Chemistry, Kyoto Univ., Sakyo-ku, Kyoto 606-8103, JAPAN. d RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, JAPAN.

[email protected]

In contrast to the wealth of physical functionality of benzene, chemically it is generally inert due to

considerable aromatic stabilization energy. However, replacing a C-H moiety of benzene with a heavier

main-group moiety significantly affects the physical and chemical properties of the cyclic-π- conjugated

systems.1 Therefore, we are interested in the replacement of C–H moieties with moieties that contain

heavier group 14 elements (E–R; E = Si, Ge, Sn, or Pb; R = organic substituent) in order to control the

physical and chemical properties. Since Sekiguchi et al. have reported the synthesis of the first stable

1,2-disilabenzenes by the reaction of the stable disilyne, the chemistry of 1,2-dimetallabenzenes have

been developed.2 Recently, we have reported the synthesis of the stable 1,2- and 1,4-digermabenzenes

by the analogous reactions, i.e., the reaction of the diaryldigermyne with alkynes. However, a 1,4-

disilabenzene is still hitherto unknown even though several efforts of attempted syntheses. Herein, we

report the synthesis of stable 1,2- and 1,4-disilabenzenes by the reactions of the stable diaryldisilyne,

TbbSi ≡ SiTbb (Tbb = 2,6-[CH(SiMe3)2]2-4-t-Bu-C6H2), with terminal- and internal-alkynes.3 The

reaction formation mechanism of the 1,2- and 1,4-disilabenzenes will also be discussed.

Scheme 1. Reactions of the diaryldisilyne with alkynes to give 1,2- or 1,4-disilabenzenes.

References

1. Tokitoh, N. Acc. Chem. Res. 2004, 37, 86–94; Nagase, S. Bull. Chem. Soc. Jpn. 2014, 87, 167–195.

2. Sugahara, T.; Guo, J.-D.; Sasamori, T.; Karatsu, Y.; Furukawa, Y.; Espinosa Ferao, A.; Nagase, S.; Tokitoh, N., Bull.

Chem. Soc. Jpn. 2016, 89, 1375-1384; Sasamori, T.; Sugahara, T.; Agou, T.; Guo, J.-D.; Nagase, S.; Streubel, R.; Tokitoh,

N., Organometallics 2015, 34, 2106-2109; Sugahara, T.; Guo, J.-D.; Hashizume, D.; Sasamori, T.; Tokitoh, N., J. Am.

Chem. Soc. 2019, 141, 2263-2267.

3. Sugahara, T.; Guo, J.-D.; Hashizume, D.; Sasamori, T.; Nagase, S.; Tokitoh, N. Dalton Trans. 2018, 47, 13318-13322;

Sugahara, T.; Sasamori, Tokitoh, N. Dalton Trans., in press [doi: 10.1039/C9DT01322A].

IL – 06



Recent Development of Janus Siloxanes

Masafumi Unno,*,a.b Yujia Liu,b Naoki Oguri,a Chika Kobuna,a Mana Kigure,a,b Taishi Uchida,a Ryoji Tanaka,a Kazunori Asami,a Thanawat Chaiprasert,a Yasunobu

Egawa,a Nobuhiro Takedaa

a Department of Chemistry and Chemical Biology, Faculty of Science and Technology, Gunma University, Kiryu

376-8515, Gunma, Japan b Gunma University Initiative for Advanced Research (GIAR) - International Open Laboratory with Montpellier

France – Institute Charles Gerhardt (CNRS/ENSCM/UM)

[email protected]

In the field of materials science, well-defined silsesquiixanes have recently attracted significant

attention. Among them, cage octasilsesquioxane or T8 is nano-scale organic/inorganic hybrid molecules,

with an inorganic core and eight organic substitutions in a single molecule. In 2016, we reported the

synthesis and structure determination of Janus cube that is a cage octasilsesquioxane possessing two

different substituents on the opposite face.1 Following this Janus Cube (1st gen.), we then extended the

investigation on Janus cube with reactive substituents (2nd gen.), and those with larger framework (3rd

gen.).2 In all cases we successfully determined the structures by X-ray crystallography, and revealed

their properties.

In addition, we also succeeded in the synthesis of small Janus cage silsesquioxesanes with T6

framework. We named it Janus prism. Introduction of disilane moiety to this Janus prism drastically

alters their electronic properties.

In this presentation, we also report Janus ring, that was first introduced by Bassindale and Taylor

group,3 and show their reaction to afford laddersiloxanes.4

Scheme 1. Janus cubes, prisms, rings, and Lantern cage

References

1. Oguri, N.; Egawa, Y.; Takeda, N.; Unno, M. Angew. Chem., Int. Ed. 2016, 55, 9336−9339.

2. Uchida, T.; Egawa, Y.; Adachi, T.; Oguri, N.; Kobayashi, M.; Kudo, T.; Takeda, N.; Unno, M.; Tanaka, R. Chem. Eur. J.

2019, 25, 1683-1686.

3. Panisch, R.; Bassindale, A. R.; Korlyukov, A. A.; Pitak, M. B.; Coles, S. J.; Taylor, P.G. Organometallics, 2013, 32, 1732–

1742

4. Presented in the poster session in this symposium by Thanawat Chaiprasert et al.

IL – 07



Transision Metal-Catalyzed Precise Synthesis of Organosilicon

Compounds Starting from Halosilanes

Yumiko Nakajima, Yuki Naganawa, Kazuhiko Matsumoto, Teruo Beppu, Kazuhiko Sato, Shigeru Shimada

Interdisciplinary Research Center for Catalytic Chemistry

National Institute of Advanced Industrial Science and Technology (AIST)

Tsukuba, Ibaraki 305-8565, Japan

[email protected]

Chlorosilanes are cheap and readily available silicon feedstocks produced by Müller–Rochow

“Direct Process”. Various useful organosilicon compounds are commonly prepared from chlorosilanes

via introduction of organic substituents on the silicon atom using stoichiometric organometallic species

such as organolithium or Grignard reagents. Meanwhile, transition metal-catalyzed cross coupling

approaches via Si–X bond activation of halosilanes have drawn increasing attention for the purpose of

new Si–C bond formations.1 Especially, catalytic transformation of a Si–Cl bond is still challenging due

to higher bond strength (Si–Cl: 98 kcal/mol) compared to those of other halosilanes (Si−Br: 76 kcal/mol,

Si−I: 57 kcal/mol).

In this study, we have demonstrated the first example of direct silyl-Heck reaction of chlorosilanes

using the Ni catalyst with an electron donating PCy3 ligand (Scheme 1).2 Interestingly, highly selective

mono-alkenylation of di- or trichlorosilanes were achieved.

Scheme 1. Ni-catalyzed Alkenylation of Me2SiCl2

Hydrogenolysis of various halosilanes was also examined. By using iridium amido complexes as

catalysts, hydrogenolysis of various halosilanes were achieved to produce the corresponding

hydrosilanes.3 Interestingly, selective monohydrogenolysis of di- and trichlorosilanes similarly

proceeded, resulting in the formation of chlorohydrosilanes (R2SiHCl or RSiHCl2) as synthetically

important building blocks for various functionalized silicones.

Scheme 2. Ir-catalyzed Hydrogenolysis of Halosilanes

References

1. B. Vulovic, D. A. Watson Eur. J. Org. Chem. 2017, 4996.; A. P. Cinderella, B. Vulovic, D. A. Watson, J. Am. Chem. Soc.

2017, 139, 7741.; B. Vulovic, A. P. Cinderella, D. A. Watson, ACS Catal. 2017, 7, 8113.

2. K. Matsumoto, J. Huang, Y. Naganawa, H. Guo, T. Beppu, K. Sato, S. Shimada, Y. Nakajima, Org. Lett., 2018, 20, 2481.;

Y. Naganawa, H. Guo, K. Sakamoto, Y. Nakajima, ChemCatChem. In press.

3. T. Beppu, K. Sakamoto, Y. Nakajima, K. Matsumoto, K. Sato, S. Shimada, J. Organomet. Chem. 2018, 869, 75.

IL – 08



Silsesquioxanes-Based Multifunctional Porous Polymers

Hongzhi Liu

School of Chemistry and Chemical Engineering, Shandong University, China

[email protected]

Research on porous materials has developed explosively, as indicated by extensive increases in the

number of publications. Recently, more attention has been devoted to hybrid porous polymer

considering their exhibiting some unique properties by combination with the advantages of inorganic

and organic components. Cage silsesquioxanes have proven to be an ideal building block to prepare

hybrid nanoporous polymers with enhanced thermal and mechanical properties in view of their rigidity

and multifunctionality.1,2

Very recently, octavinylsilsesquioxane (OVS) has been successfully used to prepare silsesquioxanes-

based porous materials via Friedel-crafts reaction and Heck reaction, cationic polymerization by us.3-5

These silssesquioxanes-based porous polymers exhibited high surface area and thermal stability, even

excellent luminescence, which make them multifunctional and potentially apply in gas storage, water

treatment, energy storage and sensors etc.

References:

1. Furgal, J. C.; Jae Hwan, J.; Theodore, G.; Laine, R. M. Analyzing Structure-Photophysical Property Relationships for

Isolated T8, T10, and T12 Stilbenevinylsilsesquioxanes. J. Am. Chem. Soc. 2013, 135, 12259-12269.

2. Watcharop, C.; Masaru, K.; Takahiko, M.; Ayae, S. N.; Atsushi, S.; Tatsuya, O. Porous Siloxane-Organic Hybrid with

Ultrahigh Surface Area Through Simultaneous Polymerization-Destruction of Functionalized Cubic Siloxane Cages. J.

Am. Chem. Soc. 2011, 133, 13832-13835.

3. Yang, X.; Liu, H. Ferrocene-Functionalized Silsesquioxane-Based Porous Polymer for Efficient Removal of Dyes and

Heavy Metal Ions. Chem. Eur. J. 2018, 24, 13504-13511.

4. Ge, M.; Liu, H. A Silsesquioxane-Based Thiophene-Bridged Hybrid Nanoporous Network as A Highly Efficient

Adsorbent for Wastewater Treatment. J. Mater. Chem. A. 2016, 4, 16714-16722.

5. Y. Du, M. Ge, H. Liu, Porous Polymers Derived from Octavinylsilsesquioxane by Cationic Polymerization. Macromol.

Chem. Phys. 2019, 220, 1800536-1800543.

IL – 09



Cobalt-Catalyzed Selective Hydrosilylation of Unsaturated

Hydrocarbons

Shaozhong Ge*

Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore

[email protected]

Organosilanes are valuable reagents in organic synthesis due to their high stability and low toxicity.

The research in my group at National University of Singapore (NUS) focuses on the development of

base metals (Fe, Co, Ni, and Cu) catalyzed hydrofunctionalization of unsaturated hydrocarbons to

access these synthetically versatile oragnoboron compounds1-7 and organosilanes.8-12 In this

presentation, I will discuss a series of regio-, stereo-, or enantioselective cobalt-catalyzed

hydrosilylation of alkenes, alkynes, allenes, enynes, and conjugated dienes (Figure 1). The cobalt

catalysts are generated in situ from bench stable cobalt precursors and bisphosphine ligands. The scope

and mechanism of these reactions will be discussed.

Figure 1. Cobalt-Catalyzed Hydrosilylation of Unsaturated Hydrocarbons to Prepare Organosilanes

References

1. Wang, C.; Wu, C.; Ge, S. ACS Catal. 2016, 6, 7585–7589.

2. Yu, S.; Wu, C.; Ge, S. J. Am. Chem. Soc. 2017, 139, 6526–6529.

3. Teo, W. J.; Ge, S. Angew. Chem., Int. Ed. 2018, 57, 1654–1658.

4. Sang, H. L.; Yu, S.; Ge, S. Org. Chem. Front. 2018, 5, 1284–1287.

5. Teo, W. J.; Ge, S. Angew. Chem., Int. Ed. 2018 57, 12939–12939.

6. Wang, C.; Ge, S. J. Am. Chem. Soc. 2018, 140, 10687–10690.

7. Wu, C.; Liao, J.; Ge, S. Angew. Chem., Int. Ed. 2019 58, doi:10.1002/anie.201903377.

8. Wu, C.; Teo, W. J.; Ge, S. ACS Catal. 2018, 8, 5896–5900.

9. Sang, H. L.; Yu, S.; Ge, S. Chem. Sci. 2018, 9, 973–978.

10. Wang, C.; Teo, W. J.; Ge, S. Nat. Commun. 2017, 8, 2258.

11. Teo, W. J.; Wang, C.; Tan, Y. W.; Ge, S. Angew. Chem., Int. Ed. 2017, 56, 4328–4332.

12. Wang, C.; Teo, W. J.; Ge, S. ACS Catal. 2017, 7, 855–863.

IL – 10



Bridged Polysilsesquioxane Membranes for Water Desalination

Joji Ohshita

Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University

Higashi-Hiroshima 739-8527, JAPAN

Bridged polysilsesquioxane (PSQ) membranes prepared by the sol-gel process of organically bridged

trialkoxysilanes, [(R’O)3SiRSi(OR’)3], have been reported as promising precursors of robust separation

membranes. They usually show high permeability compared to silica or non-bridged PSQ membranes,

because the organic bridges expand the siloxane network as a “spacer” to enhance porosity. Previously,

we reported that PSQs prepared from bis(triethoxysilyl)ethane (BTESE1 in Chart 1) could be used for

robust RO membranes because of their high chlorine tolerance and thermal stability of up to 90 °C.1

However, the liquid permeability is much lower than that of commercially available polyamide

membranes. In our efforts to improve the water permeability, we found that the introduction of

ethenylene and ethynylene units in place of the ethylene bridge increased the water permeability by

increasing the rigidity and polarity of the bridges (BTESE2 and BTESE3).2

Preparation of bridged PSQ RO membranes from other bridged silica precursors in Chart 1 will be

also described.

Chart 1. Chemical structures of bridged alkoxysilanes precursors for water desalination membranes

References

1. Ibrahim, S. M.; Xu, R.; Nagasawa, H.; Naka, A.; Ohshita, J.; Yoshioka, T.; Kanezashi, M.; Tsuru, T. RSC Adv. 2014, 4,

23759–23769.

9. Xu, R.; Kanezashi, M.; Yoshioka, T; Okuda, T; Ohshita, J; Tsuru, T ACS Appl. Mater. Interfaces 2013, 5, 6147–6154; Xu,

R.; Ibrahim, S. M.; Kanezashi, M.; Yoshioka, T.; Ito, K.; Ohshita, J.; Tsuru, T. ACS Appl. Mater. Interfaces 2014, 6, 9357–

9364.

10. Yamamoto, K.; Ohshita, J.; Mizumo, T.; Kanezashi, M.; Tsuru, T. Sep. Purif. Technol. 2015, 156, 396-402

11. Zheng, F.-T.; Yamamoto, K.; Kanezashi, M.; Tsuru, T.; Ohshita, J. J. Membr. Sci. 2018, 546, 173-178.

IL – 11



Boron Cation Catalyzed Hydrosilylation and Cyanosilylation

Hsi-Ching Tseng, Yen-Tzu Huang, Ching-Wen Chiu*

Department of Chemistry, National Taiwan University, Taipei, Taiwan 10617

[email protected]

Hydrosilylation and cyanosilylation are important synthetic strategies for organosilicon derivatives.

In addition to transition metal-based catalysts, recent studies have showed that such catalytic

transformation could be performed with Lewis acid p-block compounds as well. Given the fact that

tricoordinate boron derivatives are prototypical Lewis acidic catalyst for versatile organic synthesis,

halogenated boranes have been examined for catalytic silylation reactions. As the library of neutral

boron catalyst continues to expand, boron cation catalysis has also emerged in the past few years.

Besides the well-established oxazaborolidine-type catalysts, carbene and pyridine stabilized

tricoordinate borenium cations are effective catalysts for hydrogenation of imine, hydrosilylation of

carbonyl compounds, and hydroboration of alkene.1 However, catalytic activity of other types of boron

cations is less explored. During our study of Cp*-subsituted boron cations, we came to discovered that

the central hypercoordinate boron atom remains highly acidic.2 [Cp*B-R]+ cation can be viewed as a

masked potent Lewis acid that serves as an efficient catalyst for hydrosilylation and cyanosilylation of

carbonyl compounds. The steric and electronic stabilization effects of Cp* were found to be critical in

realizing robust boron cation catalyst. In this presentation, experimental details and mechanistic studies

of the [Cp*B-R]+ catalyzed hydrosilylation and cyanosilylation will be discussed.

Figure 1. Proposed reaction mechanism for [Cp*B-Mes]+ catalyaed hydrosilylation/hydrodeoxygenation of ketone.

References

1. Einsenberger, P.; Crudden, C. M. Dalton Trans. 2017, 46, 4874.

12. Tseng, H.-C.; Shen, C.-T.; Matsumoto, K.; Liu, Y.-H.; Peng, S.-M.; Yamaguchi, S.; Chiu, C.-W. to be submitted.

IL – 12



Soluble Silicon Materials for 193 nm Lithography and Capacitor

Fabrication

Hyeon Mo Cho

University College, Yonsei University, Incheon 21983, South Korea

(past: Samsung SDI, Suwon, Gyeonggi, 16698, South Korea)

[email protected]

The progress of semiconductor fabrication technology to create more integrated circuits and

nanosized patterns provides us innovative electrical and electronic devices. Since the fabrication is a

multiple-step sequence of photolithographic and chemical processing steps, a variety of chemicals and

new materials are demanded. In semiconductor manufacturing, there are essential silicon materials,

such as silicon substrates, silicon oxide and silicon nitride. Lithography, which specifically includes

light exposure, etching, and developing processes, requires silicon materials that are photosensitive to

light sources and have etch selectivity for plasmas. For example, the spin-on hardmask (SOH) process

requires a silicon material with specific optical and etch properties. Silicon material of SOH process

plays a dual role: as an anti-reflective layer for proper photoresist patterning in the exposure step, which

requires specific optical properties and as a hardmask layer for pattern transfer to a layer below during

the etch step, which is ensured by the high etch resistance to oxygen plasma. The advantage of spin

coating is its ability to quickly and easily produce very uniform films with good planarity and fill

trenches with a high aspect ratio. In order to apply to the spin coating process, the material must be in

a liquid state or well dissolved in a solvent.

In this presentation, the synthesis and application of soluble silicon materials absorbing 193 nm light

for nanosized patterning (Figure 1) and a developable silicon material for capacitor manufacturing will

be discussed.

Figure 1. Preparation of silicon thin films from a new class of soluble polycyclosilane-polysiloxane hybrid materials.

IL – 13



Synthesis of trialkylsilylboranes through Rh-catalyzed borylation

of trialkylsilanes and generation of a broad range of trialkysilyl

nucleophiles

Hajime Ito,a,b* Ryosuke Shishido,b Minami Uesugi, b Koji Kubota a,b

aGraduate School of Engineering, Hokkaido University, Sapporo, 060-8628, Japan bWPI-ICReDD, Hokkaido University, Sapporo, 001-0021, Japan

[email protected]

Silyl anion is a fundamental species in silicon chemistry and was focused by many researchers for a

long time. The generation of silyl anion highly depends on the reduction of chlorosilanes and disilanes.

However, this method requires at least one aromatic substituent on the silicon atom to enable the

formation of the silyl anion. Other methods through transmetallation from silyl mercury and silyl tin

compounds are also known but were not widely used due to the high toxicity of the precursors. In

general, generation of trialkyl silyl anion with the practically applicable method is still an unsolved

issue in silicon chemistry. In 2001, Kawauchi and Tamao first reported the generation of silyl

nucleophiles from non-toxic silylborane compounds in the reaction with nucleophiles such as MeLi,

KOtBu.1 We also reported the first silylboration of styrene compounds with silylborane/KOtBu in

2012.2,3 This is a promising method for generation of silyl anions, but the synthesis of silylboranes is

still limited: many silylboranes are synthesized from silyl anions. In 2008, Hartwig reported an Ir-

catalyzed synthesis of trialkylsilylboranes.4 Et3SiB(pin) was synthesized from Et3SiH and B2(pin)2

without generation of elaborating trialkylsilyl anion. The combination of borylation of trialkylsilanes

and nucleophile-catalyzed activation of silylboranes can be an excellent complemental method of

conventional production of silyl anions, but the narrow scope of the Hartwig method limits this

procedure.

In this work, we developed a rhodium-catalyzed Si–H borylation of hydrosilanes for the

synthesis of silylborane compounds. This new method can synthesize silylboranes that could not be

obtained by previous means. Various hydrosilanes, including bulky hydrosilanes, underwent the

borylations effectively to give the corresponding silylboranes in good yield. Furthermore, the synthesis

of oligosilanes using the Si-Si coupling reactions of various silylboranes with silyl electrophiles was

achieved.

Figure 1. Rh-catalyzed Borylation of Hydrosilane and MeLi-mediated Si-Si bond Formation.

References

1. Kawachi, T. Minamimoto, K. Tamao, Chem. Lett. 2001, 30, 1216-1217.

2. H. Ito, Y. Horita, E. Yamamoto, Chem. Commun. 2012, 48, 8006-8008

3. (a) E. Yamamoto, K. Izumi, Y. Horita, H. Ito, J. Am. Chem. Soc. 2012, 134, 19997-20000; (b) E. Yamamoto, S. Ukigai,

H. Ito, Chem. Sci. 2015, 6, 2943-2951; (c) R. Uematsu, E. Yamamoto, S. Maeda, H. Ito, T. Taketsugu, J. Am. Chem. Soc.

2015, 137, 4090-4099; (d) E. Yamamoto, K. Izumi, R. Shishido, T. Seki, N. Tokodai, H. Ito, Chem. Eur. J. 2016, 22,

17547-17551. (e) C. Kleeberg, C. Borner, Eur. J. Inorg. Chem. 2013, 2799-2806; (f) B. Cui, S. Jia, E. Tokunaga, N.

Shibata, Nat. Commun. 2018, 9, 4393-4400; (g) X.-W. Liu, C. Zarate, R. Martin, Angew. Chem. Int. Ed. 2019, 58, 2064-

2068; (h) K. Kojima, Y. Nagashima, C. Wang, M. Uchiyama, ChemPlusChem 2019, 84, 277-280.

4. T. A. Boebel, J. F. Hartwig, Organometallics 2008, 27, 6013-6019.

IL – 14



Fabrication and Application of Hollow Multi-Au@SiO2

Nanosystems, and Nanohybrids with Coordination Polymer

Framework Derivatives

Hyojong Yoo

Department of Chemistry, Hallym University, Chuncheon, Gangwon-do, 24252, Republic of Korea

[email protected]

Advanced hybrid nanomaterials tailored with unique morphologies and multiple functions can be

fabricated by the rational combination of two or more well-designed components. We report facile

synthetic strategies for metallic nanostructures/silica/polymeric framework nanohybrids. The material

properties (i.e., surface area, size, and shape) of the resultant nanohybrids can be readily controlled by

simply varying reaction kinetics and the relative amount of precursors used. The as-synthesized

nanohybrids can act as sacrificial templates for the preparation of unique inorganic nanomaterials via

chemically- and thermally-induced approaches, which can be applied for a variety of area.1

Spherical nanoparticles (multi-Au@SiO2 NPs) and nanowires (multi-Au@SiO2 NWs) with a core

comprising multiple Au nanodots and silica shell are fabricated in high yields through reverse (water-

in-oil) microemulsion-based methods. By simple treatments, york-shell multi-Au@SiO2 NPs and

peapod-like one-dimensional Au nanoparticles array within hollow silica nanotubes (pp multi-

Au@SiO2 NTs) can be successfully synthesized.2 These hollow multi-Au@SiO2 nanosystems can be

used as efficient nanoreactors for fabrication of hybrid nanoparticles assembly and catalysis.

Gold multipod nanoparticle (GMN) core–zeolitic imidazolate framework (ZIF-67) shell

(GMN@ZIF-67) nanohybrids can be successfully synthesized.3 The as-prepared GMN@ZIF-67

nanohybrids can be the precursors for the preparation of GMN core–cobalt sulfide shell (GMN@CoxSy)

nanostructures, with unique cage-like morphology.4 The examination of electrocatalytic oxygen

evolution reaction (OER) of the prepared nanohybrids reveals that a type of GMN@CoxSy nanohybrids

shows a substantially lower overpotential value compared with those of GMNs and CoxSy nanomaterials.

We also report a shape-controllable synthetic protocol for zinc-based coordination polymer nanocubes

(Zn-CPNs).5 2,6-bis[(4-carboxyanilino)carbonyl] pyridine ([N3]) ligand is employed as an efficient

shape-directing modulator to control the size and shape of Zn-CPNs. More importantly, the [N3] ligand

provides metal binding sites suitable for the decoration of other functional metals such as copper ions.

The copper-modified Zn-CPNs (Cu_Zn-CPNs) show good activities in a heterogeneous catalytic

reaction.

Mesoporous silica nanoparticles, which have high surface areas and an abundance of pores, can be

used to synthesize mesoporous silica core–metal shell nanostructures with catalytically active sites.

Highly fluorescent multiple Fe3O4 nanoparticles core-silica shell nanoparticles (FL multi-Fe3O4@SiO2

NPs) are successfully synthesized and fully characterized.6 In addition, dendritic fibrous nanosilica

(DFNS) with a high surface area is successfully employed as a template to synthesize DFNS/MOF,

DFNS/Au, and DFNS/Au/MOF hybrid nanomaterials.7

References

1. Mai, H. D.; Rapiq, K.; Yoo, H. Chem. Eur. J. 2017, 23, 5631.

2. Byoun, W.; Yoo, H. ChemistrySelect. Eur. J. 2017, 2, 2414.

3. Mai, H. D.; Le, V. C. T.; Thi, M. T. P.; Yoo, H. ChemNanoMat 2017, 3, 857.

4. Mai, H. D.; Le, V. C. T.; Yoo, H. ACS Appl. Nano Mater 2019, 2, 678.

5. Ngoc, T. M.; Mai, H. D.; Yoo, H. Nano Research 2018, 11, 5890.

6. Byoun, W.; M. G. Jang.; Yoo, H. J. Nanopart. Res. 2019, 21, 1.

7. Byoun, W.; Jung, S.; Ngoc, T. M.; Yoo, H. ChemistryOpen 2018, 7, 349.

IL – 15



Silicon-Mediated Organic Synthesis (SiMOS): Silicon-Substitution

Effect (SiSE) in Asymmetric Catalysis

Li-Wen Xu

Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, and Key

Laboratory of Organosilicon Material Technology of Zhejiang Province, Hangzhou Normal University, P. R.

China

[email protected]

In the past decades, organosilicon compounds are finding important and new applications in organic

synthesis, such as the effective application of organosilicon compounds in the transition metal-catalyzed

cross-coupling reactions, the syntheses and application of silicon-stereogenic organosilicon compounds,

the silicon-containing organocatalysts or chiral ligands, silicon-based Lewis acids in catalytic organic

transformation, and the use of silanes and its functional materials as stoichiometric reductants in a range

of chemo-, stereo-, and enatioselective catalytic reductions. Undoubtedly, the unabated growth of

applications of organosilicon compounds and related materials in the resolution of synthetic problems

has continued.

Figure 1. SiMOS: From Organosilicon-Enhanced Asymmetric Catalysis to the Synthesis of Silicon-Stereogenic Molecules

Herein, we would like to present our effort in the exploring of organosilicon compounds and related

silicon-based functional organic materials as reagents, catalysts, and supporter for various organic

transformations in asymmetric catalysis.1-11 Our exploration could be expected to lead to continuing

research on wide exploration of organosilicon compounds and related materials for the establishment

of highly efficient and stereoselective transformations, aiming to develop new approach and strategy

for the facile preparation of synthetically useful molecules with environmentally benign and practical

procedure.

References

1. Xu, L.-W.; Li, L.; Lai, G.-Q.; Jiang, J.-X. Chem. Soc. Rev. 2011, 40, 1777-1790.

2. Xu, L.-W. Angew. Chem. Int. Ed. 2012, 51, 12932-12934.

3. Ye, F.; Zheng, Z. J.; Li, L.; Yang,K. F.; Xia, C. G.; Xu, L.-W. Chem. Eur. J. 2013, 19, 15452-15457.

4. Bai, X.-F.; Deng, W.-H.; Xu, Z.; Li, F.-W.; Deng, Y.; Xia, C.-G.; Xu, L.-W. Chem. Asian. J. 2014, 9, 1108-1115.

5. Song, T.; Li, L.; Zhou, W.; Zheng, Z.-J.; Deng, Y.; Xu, Z.; Xu, L.-W. Chem. Eur. J. 2015, 21, 554-558.

6. Xu, L.-W.; Chen, Y.; Lu, Y. Angew. Chem. Int. Ed., 2015, 54, 9456–9466.

7. Lin, Y.; Jiang, K.-Z.; Cao, J.; Zheng, Z.-J.; Xu, Z.; Cui, Y.-M.; Xu, L.-W. Adv. Synth. Catal. 2017, 359, 2247-2252.

8. Cramm, N. T. U.S. Patent 7,005,423, Sep 13, 2005.

9. Mu, Q.-C.; Wang, X.-B.; Ye, F.; Sun, Y.-L.; Bai, X.-F.; Chen, J.; Xia, C.-G.; Xu, L.-W. Chem. Commun., 2018, 54, 12994-

12997.

10. Long, P.-W.; Bai, X.-F.; Ye, F.; Li, L.; Xu, Z.; Yang, K.-F.; Cui, Y.-M.; Zheng, Z.-J.; Xu, L.-W. Adv. Synth. Catal. 2018,

360, 2825-2830.

11. Cao, J.; Chen, L.; Sun, F.-N.; Sun, Y.-L.; Jiang, K.-Z.; Yang, K.-F.; Xu, Z.; Xu, L.-W. Angew. Chem. Int. Ed. 2019, 58,

897 –901.

SiMOSSi-Reagent

Si-Additive Si-Catalyst

Sakurai Reaction

Silicon-stereogenic Silanes

Allylation/etherification

Huisgen and Oxidative HuisgenOxidative Esterification

Allylic Etherification of SilanolsReductive etherification

Silicon-involved Reactions

Reductive DecarbonylationHydrogenation/isomerization

Lithiation/Silylation/Condensation

Organocatalytic multicomponent reaction

Si-H/Si-C/Si-O Functional Group

Organosilicon Chemistry

Asymmetric Catalysis

Si-Ligand

IL – 16



Si-N Unit-containing Polymers: Synthesis and Application

Liqing Aia,b, Yongming Luoa, Zongbo Zhanga, Yongming Lia, Caihong Xua,b*

aInstitute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China bUniversity of Chinese Academy of Sciences, Beijing, 100049, P. R. China

[email protected]

A series of new polymers containing Si-N bonds, including polysiloxazane, polysilazanes,

phenylene-silazane-acetylene polymers, and polyborosilazanes were synthesized. The cross-coupling

reactions between acetylene terminated silicon-containing monomers and diiodoarylenes produced

silarylene-siloxane-acetylene polymers and phenylene-silazane-acetylene polymers. Various

polysilazanes were prepared by coammonolysis reaction of chlorosilane derivatives or their mixtures.

The application of the new silicon-containing polymers in the fields of adhesive, coating, and porous

materials were investigated.

References

1. Liu Wei; Luo Yongming; Xu Caihong, High Perform. Polym., 2013, 25, 543-550.

2. Lin Xiankai; Zhang Zongbo; Chen Limin; Zeng Fan; Luo Yongming; Xu Caihong, J. Organometa. Chem. 2014, 749, 251-

254

3. Zhang Zongbo; Wang Dan; Xiao Fengyan; Liang Qianying; Luo Yongming; Xu Caihong, RSC Adv., 2018, 8, 16746-

16752

4. Guo Xiang; Wang Dan; Guo Zhen; Zhang Zongbo; Cui Mengzhong; Xu Caihong, Surface& Coatings Tech., 2018,

350,101-109

IL – 17



Catalytic Construction of Silacarbocycles Using Borylsilanes as

Synthetic Equivalents of Silylene

Toshimichi Ohmura*

Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto

University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan

[email protected]

Recently silicon-containing organic groups have received increasing attention as new bioisosteres in

the drug discovery field.1 A particular interest in the screening of silicon-based bioisosteres is silicon-

containing cyclic skeletons. However, the skeletons that can be constructed by conventional synthetic

methods have been limited to date. Development of efficient methods to construct new silicon-

containing cyclic skeletons is highly attractive and could accelerate the developmet of silicon-

containing drugs.

We have reported that borylsilanes bearing a dialkylamino group on the silicon atoms react as

synthetic equivalents of silylene (:SiR2) in the presence of a palladium catalyst. Based on this process,

we established alkyne-alkyne-silylene [2+2+1] cycloaddition to afford 1-silacyclopenta-2,4-dienes2 and

1,3-diene-silylene [4+1] cycloaddition to give 1-silacyclopent-3-enes.3 Here, we describe new catalyst

system using borylsilanes bearing an alkoxy group on the silicon atoms. We found that 1,6-enynes 1

underwent alkene-alkyne-silylene [2+2+1] cycloaddition in the presence of rhodium catalyst, affording

1-silacyclopent-2-enes 2.4 It was suggested that formation of rhodium silylenoid is a key for proceeding

of the catalytic cycle. We applied the rhodium silylenoid-based catalytic system to construction of

seven-membered silacarbocycles. Thus, the rhodium-catalyzed reaction of deca-1,3-dien-8-ynes 3 with

borylsilane afforded 1-silacyclohepta-2,5-dienes 4 through [4+2+1] cycloaddition.

Scheme 1. Catalytic Construction of Silacarbocycles Using Borylsilanes as Synthetic Equivalents of Silylene

References

1. (a) Franz, A. K.; Wilson, S. O. J. Med. Chem. 2013, 56, 388–405. (b) Ramesh, R.; Reddy, D. S. J. Med. Chem. 2018, 61,

3779–3798.

2. Ohmura, T.; Masuda, K.; Suginome, M. J. Am. Chem. Soc. 2008, 130, 1526–1527.

3. Ohmura, T.; Masuda, K.; Takase, I.; Suginome, M. J. Am. Chem. Soc. 2009, 131, 16624–16625.

4. Ohmura, T.; Sasaki, I.; Suginome, M. Org. Lett. 2019, 21, 1649–1653.

IL – 18



Fluorescent Silica Nanocages

Vuthichai Ervithayasuporn

Department of Chemistry, Center for Inorganic and Materials Chemistry, and Center of Excellence for

Innovation in Chemistry, Faculty of Science, Mahidol University, Rama VI Rd, Bangkok 10400, Thailand

[email protected]

Silica is one of the most naturally abundant compounds on the Earth. It is used in building materials,

electronic devices, in environmental remediation, and in chemical industry. Silica gel is a commonly

used laboratory sorbent for chromatographic separations, the binding properties of which can be tailored

through surface functionalization. For example, amine groups appended to the silica surface allow for

chemical adsorption of CO2, which generates a chelating group allowing sequestration of metal ions.

Interestingly, the mode of adsorption for organic molecules by silica is still controversial. While a

mechanism has been postulated and the outstanding capacity and absorptivity properties of silica are

well-known, very few studies have been devoted to determine the actual role of silica in the adsorption

of organic species. This may relate to the poor solubility of these sorbents in water or organic solvents,

hindering investigations using solution phase techniques (fluorescent emission, UV-vis absorption or

nuclear magnetic resonance). Meanwhile, polyhedral oligomeric silsesquioxane or silsesquioxane cages

can be considered as representative molecules for silica due to their closely related empirical formulae

(RSiO1.5). These systems consist of a rigid cage-like silica framework with organic groups attached to

the periphery, where it is possible to choose the desired size (from 0.5 nm). Herein, octasilsesquioxane

nanocubes or the smallest silica cages functionalized with organic fluorescent dye were presented, while

their anion recognition ability was probed through monitoring of fluorescence emission and UV-vis

absorption changes.1,2

References

1. Chanmungkalakul, S.; Ervithayasuporn, V. et al., Chem. Commun. 2017, 53, 12108.

2. Chanmungkalakul, S.; Ervithayasuporn, V. et al., Chem. Sci. 2018, 9, 7753.

IL – 19



Direct Amidation of Carboxylic Acids Using Alkoxysilanes

Paul D. Lickiss,a* D. Christopher Braddock,a Ben C. Rowley,a David Pugh,a Teresa Purnomo,a Gajan Santhakumara and Steven J. Fussell,b

a Chemistry Department, Imperial College London, Molecular Sciences Research Hub, White City Campus,

Wood Lane, W12 0BZ, UK b Pfizer Limited, Ramsgate Road, Sandwich, Kent, CT13 9NJ, UK

[email protected]

The amide group is present in about 25% of all pharmaceuticals on the market and the need for a

convenient and inexpensive synthesis of amides was highlighted as the top priority by the ACS GCI

Pharmaceutical Roundtable in 2007.1 Since that time, the need for green, non-toxic, cost effective

organic functional group transformations, including direct amide bond formation, has become of

increasing interest to the chemical industry. The desire for inexpensive and convenient amidation

reagents together with some literature precedent for the use of silicas2 for amide formation prompted us

initially to investigate molecular silanols such as Ph3SiOH as direct amidation catalysts. We found that

several molecular silanols do indeed act as amidation catalysts, but the yields are low and catalyst

condensation reactions to give siloxanes can be a problem. More recently we turned our attention to

tetraalkoxysilanes (see Scheme 1, R = Me or Et) and find that (MeO)4Si is a particularly effective direct

amidation reagent.

Scheme 1. Use of alkoxysilanes to effect direct amidation

We have found3 that both (MeO)4Si and (EtO)4Si may be used as reagents to effect direct amidation

with (MeO)4Si being the more effective reagent.4 Thus, (MeO)4Si is a convenient and high yielding

reagent for direct amidation of a range of aliphatic and aromatic carboxylic acids with primary, cyclic

and acyclic secondary aromatic amines, and anilines. The method can even be applied successfully to

the direct amidation of an aromatic carboxylic acid with an aniline, a particularly difficult

transformation. The amide products can be isolated easily and in high yield without the need for

chromatographic purification as excess alkoxysilane can be removed by hydrolysis, and any remaining

amine or carboxylic acid is removed by an acid or base wash. The simple work-up procedure leads to

very low Process Mass Intensities compared to more conventional synthetic routes. In addition, we have

scaled up the method to one mole scale to give amides in near quantitative yield.

References

1. Constable, D. J. C.; Dunn, P. J.; Hayler, J. D.; Humphrey, G. R; Leazer Jr., J. L.; Linderman, R. J.; Lorentz, K.; Manley,

B. A.; Wells A.; Zaks, A.; Zhang, T. Y.; Green Chemistry 2007 9, 411-420.

2. For a recent example see, Zakharova, M. V.; Kleitz, F.; Fontaine, F.-G.; Dalton Trans., 2017 46, 3864-3876.

3. Braddock, D. C.; Lickiss, P. D.; Rowley, B. C.; Pugh, D.; Purnomo, T.; Santhakumar, G.; Fussell, S. J.; Organic Letters,

2018, 20, 950-953.

4. Previous work by Mukaiyama on less accessible reagents such as tetrakis(pyridine-2-yloxy)silane and tetrakis(1,1,1,3,3,3-

hexafluoro-2-propoxy)silane has also shown that (RO)4Si work well for direct amidation, see for example, Tozawa, T.;

Yamane, Y.; Mukaiyama, T.; Chem. Lett, 2005, 34, 1586-1587.

IL – 20



Heavy Cyclobutadienes

Tsukasa Matsuo

Department of Applied Chemistry, Faculty of Science and Engineering,

Kindai University, 3-4-1, Kowakae, Higashi-Osaka, Osaka 577-8502, JAPAN

[email protected]

We have studied a variety of low-coordinate compounds of heavier group 14 elements by using the

bulky Rind (1,1,3,3,5,5,7,7-octa-R-substituted s-hydrindacen-4-yl) groups.1,2 Previously, we reported

the synthesis of the cyclobutadiene (CBD) silicon analogue, tetrasilacyclobutadiene, Si4(EMind)4 (1a),

bearing the bulky EMind groups (EMind = 1,1,7,7-tetraethyl-3,3,5,5-tetramethyl-s-hydrindacen-4-yl).3

The Si4 ring shows a planar rhombic charge-separated structure originating from the polar Jahn-Teller

(J-T) distortion to counteract the antiaromaticity with a cyclic 4π-electron system. This result is in sharp

contrast to the fact that the carbon CBDs are mostly stabilized by the covalent J-T distortion, thus

leading to the formation of a rectangular-shaped C4 ring with two isolated C=C bonds.

We now present the synthesis of some new heavy CBDs, Si4(Eind)4 (1b), Ge4(EMind)4 (2a),4 and

Ge4(Eind)4 (2b) (Eind = 1,1,3,3,5,5,7,7-octaethyl-s-hydrindacen-4-yl), which can be obtained as room-

temperature stable crystalline compounds. We are now investigating the reactivity of the heavy CBDs.

Figure 1. Rind Groups and Heavy CBDs

References

1. T. Matsuo, N. Hayakawa, Science and Technology of Advanced Materials (STAM) 2018, 19, 108–129.

2. T. Matsuo, K. Tamao, Bull. Chem. Soc. Jpn. 2015, 88, 1201–1220 (Inside Cover).

3. K. Suzuki, T. Matsuo, D. Hashizume, H. Fueno, K. Tanaka, K. Tamao, Science 2011, 331, 1306–1309.

4. K. Suzuki, Y. Numata, N. Fujita, N. Hayakawa, T. Tanikawa, D. Hashizume, K. Tamao, H. Fueno, K. Tanaka, T. Matsuo,

Chem. Commum. 2018, 54, 2200–2203 (Front Cover).

IL – 21



Controlled Synthesis of Oligosiloxanes

Kazuhiro Matsumoto, Yasushi Satoh, Masayasu Igarashi, Kazuhiko Sato, Shigeru Shimada

National Institute of Advanced Industrial Science and Technology (AIST)

1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan

[email protected]

Oligo- and polysiloxanes (silicones) are used as irreplaceable materials in a wide range of fields

owing to their excellent properties including high thermal stability, light stability and transparency, high

gas permeability, electrical insulation property, and constancy of properties over a wide temperature

range. For the further development of high performance siloxane materials, precise structural control of

oligo- and polysiloxanes is indispensable. However, synthetic methods for siloxane compounds are

surprisingly unexplored, and it is difficult to synthesize siloxane materials with well-defined structures

by the conventional methods, hydrolytic condensation reaction of chlorosilanes or alkoxysilanes and

base- or acid-catalyzed ring-opening polymerization of cyclic oligosiloxanes. Although some new

synthetic methods for siloxane compounds have recently been developed, accessible structures are still

very limited.

We have recently succeeded in developing several methods that achieve controlled syntheses of

oligosiloxanes.1 One is a highly efficient one-pot synthesis of sequence-controlled oligosiloxanes. By

repeating two reactions, 1) B(C6F5)3-catalyzed selective dehydrocarbonative coupling of a

dihydrosilane and an alkoxysilane and 2) B(C6F5)3-catalyzed hydrosilylation of a monohydrosiloxane

and a ketone (Scheme 1), various sequence-controlled oligosiloxanes (up to undecasiloxane) were

synthesized in high yields in one-pot manner. Other new procedures for controlled/selective synthesis

of oligosiloxanes are also presented.

Scheme 1. Example of one-pot iterative synthesis of sequence-controlled oligosiloxanes

This work was supported by the "Development of Innovative Catalytic Processes for Organosilicon

Functional Materials" project (PL: K. Sato) from the New Energy and Industrial Technology

Development Organization (NEDO).

References

1. Igarashi, M.; Kubo, K.; Matsumoto, T.; Sato, K.; Ando W.; Shimada, S. RSC Adv., 2014, 4, 19099-19102; Satoh, Y.;

Igarashi, M.; Sato, K.; Shimada, S. ACS Catal. 2017, 7, 1836-1840; Matsumoto, K.; Sajna, K. V.; Satoh, Y.; Sato, K.;

Shimada, S. Angew. Chem. Int. Ed. 2017, 56, 3168-3171. Igarashi, M.; Matsumoto, T.; Yagihashi, F.; Yamashita, H.;

Ohhara, T.; Hanashima, T.; Nakao, A.; Moyoshi, T.; Sato, K.; Shimada, S. Nat. Commun. 2017, 8, 140. Matsumoto, K.;

Ohba, Y.; Nakajima. Y.; Shimada, S.; Sato, K. Angew. Chem. Int. Ed. 2018, 57, 4637-4641; Matsumoto, K.; Shimada, S.;

Sato, K. Chem. Eur. J. 2019, 25, 920-928.

IL – 22



The curious case of silylene in transition metal chemistry

Shabana Khan

Department of Chemistry, Indian Institute of Science Education and Research (IISER) Pune,

Dr. Homi Bhaba Road, Pune-411008, India

[email protected]

The interaction of transition metals, especially the coinage metals (Cu, Ag, Au) with arenes is of high

importance as they serve as the key intermediates in various catalytic reactions e.g. cycloaddition, cross

coupling, cycloisomerization, C-H functionalization and also display multifarious coordination

chemistry. However, the isolation of these complexes is a challenging task due to weaker interactions

between them. We have explored the utility of silylene, [PhC(NtBu)2SiN(SiMe3)2], as a ligand to

prepare the Cu(I) and Au(I)-arene cationic complexes.1 An appealing facet of [PhC(NtBu)2SiN(SiMe3)2]

is that it accepts electron density from the metal as evidenced in its coinage metal complexes.2 This

potential has been duly realized through the isolation and characterization of an unprecedented [Cu(η6-

C6H6)]+ and [Au(η1-C6H6)]+ complexes.3,4 For a direct systematic comparison, we have carried out the

same reactions with N-heterocyclic carbene which reveals, unlike silylene, there is no M→CNHC back-

bonding. These complexes are further used for their reactivity study and catalytic application.

Chart 1. Selected Si(II) supported Cu(I) and Au(I)-arene complexes.

References

1. (a) S. Khan, S. K. Ahirwar, S. Pal, N. Parvin, N. Kathewad, Organometallics, 2015 , 34, 5401–5406. (b) S. Khan, S. Pal,

N. Kathewad, P. Parameswaran, S. De, I. Purushothaman, Chem. Commun., 2016, 52, 3880–3882. (c) N. Parvin,

R.Dasgupta, S. Pal, S. S. Sen, S. Khan, Dalton Trans., 2017, 46, 6528-6532.

2. N. Parvin, S. Pal, S. Khan, S. Das, S. K. Pati, H. W. Roesky, Inorg. Chem., 2017, 56, 1706–1712.

3. N. Parvin, S. Pal, J. Echeverría, S. Alvarez, S. Khan, Chem. Sci., 2018, 9, 4333-4337.

4. N. Parvin, S. Khan (unpublished result).

IL – 23



Exhaustively Trichlorosilylated Tetrelides: Synthesis and

Reactivity

Matthias Wagner,a,* Chantal Kunkel,a Isabelle Georg,a Julian Teichmanna

aGoethe-Universität Frankfurt, Campus Riedberg, 60438 Frankfurt/Main, Germany

[email protected]

Treatment of Si2Cl6 with [R4N]Cl in CH2Cl2 generates the transient silanide intermediate [SiCl3]‒,

which can react further with Si2Cl6 to furnish linear, cyclic, or cage-type oligosilanes (“silafulleranes”).1

If [SiCl3]‒ is liberated in the presence of CCl4 or GeCl4, the methanide 1C2 or germanide 1Ge3 is

formed in essentially quantitative yields. The corresponding silanide 1Si1,4 is best prepared from

Si(SiCl3)4 through chloride-induced heterolytic cleavage of one of its Si‒Si bonds.1,3 1Si has been

advertised as weakly coordinating anion.4 Herein we disclose series of adducts 2C-2Ge of various

Lewis acids (LA) with 1C-1Ge.3 A special case is the Lewis acid AlCl3, which abstracts a chloride ion

from 1C (likely) to generate an intermediate silene, which can subsequently add various

organochlorides to afford corresponding organosilanes 3.5 AlCl3 also induces the skeletal rearrangement

of 1Ge to give the mixed oligo(germane-silane) 4.3

While 1C (and its higher carbon homologues, which we have also prepared) is a versatile building

block for functionalized silicone precursors,2 compounds of type 2 and 4 are relevant for the

semiconductor industry.3

Figure 1. Tris(trichlorosilyl)tetrelides 1 and some of their reaction products 2-4; LA = Lewis acid.

References

1. Review: Teichmann, J.; Wagner, M. Chem. Commun. 2018, 54, 1397-1412.

2. Georg, I.; Teichmann, J.; Bursch, M.; Tillmann, J.; Endeward, B.; Bolte, M.; Lerner, H.-W.; Grimme, S.; Wagner, M. J.

Am. Chem. Soc. 2018, 140, 9696-9708.

3. Teichmann, J.; Kunkel, C.; Georg, I.; Moxter, M.; Santowski, T.; Bolte, M.; Lerner, H.-W.; Bade, S.; Wagner, M. Chem.

Eur. J. 2019, 25, 2740-2744.

4. Olaru, M.; Hesse, M. F.; Rychagova, E.; Ketkov, S.; Mebs, S.; Beckmann, J. Angew. Chem. Int. Ed. 2017, 56, 16490-

16494.

5. Kunkel, C.; Teichmann, J.; Lerner, H.-W.; Wagner, M. DE 102019104543.6 (priority date: 22. 02. 2019).

IL – 24



Low-coordinate Silicon Chemistry Enabled by Anionic N-

Heterocyclic Olefins

Eric Rivard,a,* Matthew M. D. Roy,a Samuel R. Baird,a Alvaro Omana,a Linkun Miao,a Yuqiao Zhou,a Michael J. Fergusona

aDepartment of Chemistry, University of Alberta, 11227 Saskatchewan Dr., Edmonton, Alberta, CANADA

[email protected]

In this presentation, a series of sterically hindered N-heterocyclic olefin (NHO) ligands and their

anionic counterparts will be discussed.1 Focus will be given to the preparation of a stable acyclic, two-

coordinate vinyl- and divinylsilylenes featuring anionic NHO ligands,2 and their ability to activate small

molecules. Time permitting, the bulkiest NHC to date will be described,3 as well as the use of

intramolecular Frustrated Lewis Pair ligands to coordinate reactive main group hydrides (EH2; E =

group 14 element).

References

1. For review articles, see: a) Rivard, E. Chem. Soc. Rev. 2016, 45, 989-1003. b) Roy, M. M. D.; Rivard, E. Acc. Chem. Res.

2017, 50, 2017-2025.

2. Hering-Junghans, C.; Andreiuk, P.; Ferguson, M. J.; McDonald, R.; Rivard, E. Angew. Chem. Int. Ed. 2017, 56, 6272-

6275.

3. Roy, M. M. D.; Ferguson, M. J.; McDonald, R.; Rivard, E. Chem. Commun. 2018, 54, 483-486.

IL – 25


SHORT ORAL PRESENTATION ǀ Page 46

Reactions of a W-Si Triple Bonded Complex with Aldehydes:

Metathesis-Like Fragmentation of the Four-Membered Products

Hisako Hashimoto,a,* Takashi Yoshimoto,a Nozomi Takagi,b Shigeyoshi Sakaki,b,c

Naoki Hayakawa,d Tsukasa Matsuo,d Hiromi Tobitaa,*

aDepartment of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan bElements Strategy Initiative for Catalysts and Batteries, Kyoto University, Nishikyo-ku, Kyoto 615-8245, Japan

cFukui Institute for Fundamental Chemistry, Kyoto University, Sakyo-ku, Kyoto 606-8103, Japan dFaculty of Science and Engineering, Kindai University, Kowakae, Higashi-Osaka, 577-8502, Japan

[email protected]

Metathesis of unsaturated organic compounds catalyzed by transition metal complexes having a

metal-carbon multiple bond, i.e. carbene and carbyne complexes, is one of the most important chemical

transformation reactions and widely applied to organic syntheses.1 On the contrary, metathesis reactions

mediated by the heavier Group 14 analogues have never been reported.2 In the metathesis reactions, it

is proposed that four-membered metallacycles are key intermediates and their formation via [2+2]

cycloaddition and subsequent fragmentation of them into two unsaturated organic species via retro-

[2+2] cycloaddition are both essential processes.

Our group recently succeeded in synthesizing silylyne complexes of tungsten by developing a

new synthetic strategy.3,4 The one bearing a bulky aryl group (Eind) on silicon, 1, which takes a dimeric

from in the solid state but is in rapid dissociation equilibrium with its monomer in solution, reacted with

several unsaturated organic compounds via [2+2] cycloaddition.4 When aldehydes were employed as

substrates, four-membered metallacycles 2 were formed through formation of [2+2] cycloaddition

intermediates A followed by addition of the second aldehyde to A. Upon heating, the metallacycles 2

underwent metathesis-like fragmentation into W≡C and Si=O species, the latter of which was isolated

as a dimeric form, 1,3-cyclodisiloxane B (Scheme 1).5 This is the first metathesis-like fragmentation of

silametallacycles. Here we will present these reactions with aldehydes as well as detailed theoretical

calculations on the reaction mechanism.

Scheme 1. Reactions of silylyne complex 1 with aldehydes.

References

1. a) Chauvin, Y. Angew. Chem. Int. Ed. 2006, 45, 3741-3747; b) Schrock, R. R. Angew. Chem. Int. Ed. 2006, 45, 3748-

3759; c) Grubbs, R. H. Angew. Chem. Int. Ed. 2006, 45, 3760-3765; d) Fürstner, A. Angew. Chem. Int. Ed. 2013, 52, 2794-

2819; e) Engel, P. F.; Pfeffer, M. Chem. Rev. 1995, 95, 2281-2309.

2. Hashimoto, H.; Tobita, H. Coord. Chem. Rev. 2018, 355, 362-379.

3. Fukuda, T.; Yoshimoto, T.; Hashimoto, H.; Tobita, H. Organometallics 2016, 35, 921-924.

4. Yoshimoto, T.; Hashimoto, H.; Hayakawa, N.; Matsuo, T.; Tobita, H. Organometallics 2016, 35, 3444-3447.

5. Yoshimoto, T.; Hashimoto, H.; Takagi, N.; Sakaki, S.; Hayakawa, N.; Matsuo, T.; Tobita, H. Chem. Eur. J. 2019, 25,

3795-3798.

OP – 01



Synthesis of Hexahydrosilaphenalene by Two Different methods:

Trianion Route and Triple Metathesis Route

Kenkichi Sakamoto,* Takumi Sugino, Shohei Oka, Junghun Lee, Ayaka Furusawa, Shunya Nagata, Satoshi Ozaki, Haruka Takagi

Department of Chemistry, Faculty of Science, Shizuoka University

836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan

[email protected]

Phenalenyl is an odd alternant

hydrocarbon having a non-bonding

orbital and its derivatives are investigated

from various points of view. However,

only a few compounds of heteroatom

substituted phenalenyls and phenalenes

are known so far. We wish to report

herein two different synthetic methods of

hexahydrosilaphenalene 1 as a candidate of silaphenalene’s precursor. The compound consists of a

bowl shaped tricyclic moiety and a stem made of Si-R bond; thus we call it “cocktail glass compound”.

Because the bowl inversion does not occur unless the Si-R bond cleavage takes place, the compounds

are obtained as a racemic mixture of C3-symmmetic enantiomers.

(1) Trianion route. Recently, we have found that trilithiocyclododecatriene 3 is obtained by the

reaction of tribromide 2 with tert-BuLi quantitatively. Compound 3 is stable for several hours at rt in

THF and allowed to react with trichlorosilanes to give 1 in low to moderate yields (R = H, Me, Ph, 4-

Ph-C6H4, and Mes) as shown in eq. 1.

(2) Triple Metathesis Route. A short-cut synthesis of 1 is achieved by intramolecular triple

metathesis of tri(1-cyclobutenyl)silane 4 using Grubbs' catalysts as shown in eq. 2. Although the

Grubbs metathesis of alkenylsilanes sometimes give poor results due to the steric hindrance, the

isomerization of 4 in the presence of second-generation Grubbs' catalyst proceeds to give 1 in moderate

yield (R = Me, Ph, and 2-Me-C6H4). Releasing of the high ring strain energy of cyclobutenyl moieties

should be a driving force of the isomerization; the estimated stabilization energy from 4 to 1 is 72.9

kcal/mol (R = Me) by DFT calculations at the M06, 6-31G* level.

(1)

(2)

OP – 02



Highly Compression-Tolerant and Durably Hydrophobic

Macroporous Silicone Sponges Synthesized by One-Pot Click

Reaction for Rapid Oil/Water Separation

Jinfeng Cao, Shengyu Feng*

Key Laboratory of Special Functional Aggregated Materials & Key Laboratory of Colloid and Interface

Chemistry (Shandong University), Ministry of Education; School of Chemistry and Chemical Engineering,

Shandong University, Jinan 250100, P. R. China

[email protected]

We first report a novel and simple method for the synthesis of macroporous silicone sponges via one-

pot thiol-ene click reaction at -10oC.1,2 The successful synthesis was confirmed by scanning electron

microscopy, fourier transform infrared spectroscopy and elemental analysis. The sponge has high

porosity, low density, durably and high hydrophobicity, super-oleophilicity, good thermal insulation,

and excellent compressibility (11.01 MPa at 93% strain, superior to all the previously reported silicone

sponges) in addition to conventional advantages of silicone such as non-flammability, excellent stability,

and non-toxicity. The morphology, pore size, density, and compression properties of the sponge are also

controllable by adjusting the synthesis conditions. Furthermore, the sponge could be used for rapid

oil/water separation with good absorption ability, excellent reusability and separation efficiency

(>99%).3, 4

Scheme 1. Schematic illustration of the preparation of the silicone sponge.

References

1. Cao J, Wang D, An P, Zhang J, and Feng S. Journal of Materials Chemistry A 2018;6(37):18025-18030.

2. Cao J, Zuo Y, Lu H, Yang Y, Feng S, Journal of Photochemistry and Photobiology A: Chemistry, 2018; 350: 152-163.

3. Lowe AB. Polym. Chem 2014(5):4820-4870.

4. Feng S, Zhang J, Li M, and Zhu Q. Organosilicon polymers and application. Beijing: Chemical Industry Press, 2010, 1-

20.

OP – 03



Hydroboration of Nitriles Catalyzed by a Ruthenium-Bis(silyl)

Chelate Complex and Subsequent Deborylative N-Arylation

Takeo Kitano, Takashi Komuro, Hiromi Tobita*

Department of Chemistry, Graduate School of Science, Tohoku University,

6-3, Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, JAPAN

[email protected]

Selective conversion of nitriles to organic imines and amines under mild conditions is a useful

chemical transformation in organic synthesis. One possible route for this conversion is hydroboration

of nitriles and subsequent deborylative N-arylation of the resulting N-borylated products. In the last

several years, catalytic hydroboration of nitriles has been investigated by several groups, which mostly

resulted in double hydroboration of C–N triple bonds to give N,N-bis(boryl)amines. However, catalysts

that are active for both double and single hydroboration reactions have not been reported.

We have previously demonstrated that 16-electron ruthenium complexes Ru[3(Si,O,Si)-

xantsil](PR3)(CO) (1, R = alkyl, amino) with a bis(silyl) chelate ligand xantsil [(9,9-dimethylxanthene-

4,5-diyl)bis(dimethylsilyl)] catalyze the reactions of arylalkynes with hydrosilanes to give unusual

products via silylation of the aryl group1 or double silylation of the aryl group and the C–C triple bond.2

These findings prompted us to investigate hydroboration of nitriles catalyzed by complexes 1, and we

found that complex 1a [R = cyclopentyl (Cyp)] became an active catalyst for both double and single

hydroboration reactions of nitriles using pinacolborane (HBpin) for the former reaction and 9-

borabicyclo[3.3.1]nonane (9-BBN) for the latter reaction under mild conditions.3 Furthermore, we

applied Buchwald’s method for conversion of arylbromides to arylamines4 to deborylative N-arylation

of the hydroboration products, i.e. bis(boryl)amines 2 and N-borylimines 3, and succeeded in opening

novel one-pot synthetic routes from nitriles to N,N-diarylamines 4 and N-arylaldimines 5.3

Possible mechanisms for the double and single hydroboration reactions will also be discussed.

References

1. Komuro, T.; Kitano, T.; Yamahira, N.; Ohta, K.; Okawara, S.; Mager, N.; Okazaki, M.; Tobita, H. Organometallics 2016,

35, 1209-1217.

2. Kitano, T.; Komuro, T.; Ono, R.; Tobita, H. Organometallics 2017, 36, 2710-2713.

3. Kitano, T.; Komuro, T.; Tobita, H. Organometallics 2019, 38, 1417-1420.

4. Guram, A. S.; Rennels, R. A.; Buchwald, S. L. Angew. Chem. Int. Ed. Engl. 1995, 34, 1348-1350.

OP – 04



Flame-retardant Polymer Foam Composites Via Coating Silicone Resin

Lianbin Wu*, Qian Wu, Jin Cheng, Yongbing Pei

Key Laboratory of Organosilicon and Materials Technology Ministry of Education, Hangzhou Normal

University, Hangzhou, 311121, P. R. China

[email protected]

In this study, highly flame retardant polymer foam composites were fabricated via coating silicone

resin (SiR) polymer through the dip-coating method. After coating SiR on polymer foam surface, the

mechanical property and thermal stability of SiR-coated polymer foam (PSiR) composites were greatly

enhanced.The minimum oxygen concentration to support the combustion of foam materials is greatly

increased, i.e. from LOI 14.6% for pure foam to LOI 26-29% for the PSiR composites studied.

Especially, adjusting pendant group to Si-O-Si group ratio (R/Si ratio) of SiRs produces highly flame

retardant PSiR composites with low smoke toxicity. Cone calorimetry results demonstrate that 44-68%

reduction in the peak heat release rate for the PSiR composites containing different R/Si ratios over

pure foam is achieved by the presence of appropriate SiR coating. Digital and SEM images of post-burn

chars indicate that the SiR polymer coating can be transformed into silica self-extinguishing porous

layer as effective inorganic barrier effect. This research provided a universal method to produce flame

retardant polymer foam composites with enhanced mechanical and thermal properties.

Figure 1. (a) Formation of silica self-extinguishing layer

transferred from Silicone resin coating during the combustion

process; (b) FTIR spectra and (c) EDS results of PSiR

composites after combustion

Figure 2. Combustion process of (upper) pure PU

foam and (lower) PSiR composite recorded at different

time.

References

1. Q. Wu, Q. Zhang, L. Zhao, S.N. Li, L.B. Wu, J.X. Jiang, L.C. Tang, Journal of Hazardous Materials 2017,336, 222-231.

2. Q. Wu, L.-X. Gong, Y. Li, C.-F. Cao, L.-C. Tang, L. Wu, L. Zhao, G.-D. Zhang, S.-N. Li, J. Gao, Y. Li, Y.-W. Mai, ACS

nano 2018, 12, 416-424.

OP – 05



Aerobic [M]-/Organo-Catalyzed Oxidation of Siloxanes – Perspective Way to the Functionalized Siloxanes

Irina K. Goncharova, Ashot V. Arzumanyan, Aziz M. Muzafarov

Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova Street,

Moscow 119991, Russian Federation

[email protected]

Synthesis of organosilicon products with a “polar” functional group within organic substituents is

one of the most fundamentally and practically important challenges in today’s chemistry of silicones.

Incorporation of a “polar” function into organosilicon compounds opens quite unique opportunities for

their subsequent modification and preparation of new copolymers, MOFs, HOFs and other hybrid

materials. In addition, modification by incorporation of functional groups would also allow other

problems to be solved, namely, the low mechanical strength and “incompatibility” of silicones with

organic polymers.

To solve these problems obtaining of functionalized (–OH, –C6H4C(O)OH) siloxanes via the aerobic

oxidation of hydride or p-tolyl-siloxanes was suggested (Scheme 1). This approach is based on “green”,

commercially available, simple, and inexpensive reagents and employs mild reaction conditions:

Cu(OAc)2 or Co(OAc)2 / NHPI or NHSI – catalytic system, O2 as the oxidant, process temperature from

30 to 60 °C, atmospheric pressure.

Scheme 1

It was shown that it is principally possible to perform the gram-scale aerobic [M]-/organo-catalyzed

oxidation of a Si−H group to a Si−OH group with retention of the organosiloxane core. This method

allows various monomeric, oligomeric and polymeric siloxanols of linear, branched and cyclic structure

to be synthesized.1

This approach was later extended to p-carboxyphenyl-siloxanes synthesis.2 The reaction is general

and allows to synthesize both mono- and di-, tri-, and poly(p-carboxyphenyl)siloxanes. Furthermore, it

was shown that the suggested method is applicable for the oxidation of organic alkylarene derivatives

(Ar−CH3, Ar−CH2−R) to the corresponding acids and ketones0 (Ar−C(O)OH and Ar−C(O)−R).

All the organosilicon products were obtained and isolated in gram amounts (up to 5 g) and

characterized using complex of physico-chemical methods (1D- and 2D-NMR, IR, ESI-HRMS, GPC,

X-ray). Molecular structure of bis(trimethylsiloxy)methylsilanol that is liquid at room temperature was

confirmed using in situ crystallization. X-ray data also confirmed that para-carboxyphenylsiloxanes in

crystalline state tend to form hydrogen-bonded polymers (HOF-like structures).

References

1. Arzumanyan, A. V.*; Goncharova, I. K.; Novikov, R. A.; Milenin, S. A.; Boldyrev, K. L.; Solyev, P. N.; Volodin, A.D.,

Smol’yakov, A. F.; Korlyukov, A. A.; Muzafarov, A. M.* Green Chem. 2018, 20 (7), 1467−1471.

2. Goncharova, I. K.; Silaeva, K.P.; Arzumanyan, A.V.*; Anisimov, A.A.; Milenin, S.A.; Novikov, R.A.; Solyev, P.N.;

Tkachev, Ya.V.; Volodin, A.D.; Korlyukov, A.A.; Muzafarov A.M. J. Am. Chem. Soc. 2019, 141, 5, 2143-2151

This work was supported by the Grant of the Government of the Russian Federation No. 14.W03.31.0018.

OP – 06



Fluorescent Polysiloxane-based Materials for Bioimaging

Yujing Zuo,a and Shengyu Fengb,*

a Institute of Fluorescent Probes for Biological Imaging, School of Chemistry and Chemical Engineering,

School of Materials Science and Engineering, University of Jinan, Jinan 250100, P. R. China b Key Laboratory of Special Functional Aggregated Materials (Shandong University), Ministry of Education;

School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China

[email protected]

Fluorescent materials have been applied in luminescent imaging techniques due to its unique

advantages, including low photodamage to the samples, weak background fluorescence, and high

spatial resolution. To the best of our knowledge, polysiloxane-based fluorescent materials applied in

bioimaging have not been well discussed to date. This lecture intends to introduce a series of

polysiloxane-based materials with superior fluorescent property. The lecture involves three parts: 1).

Two photon luminescence of elastomers was detected. More interestingly, the fluorescence intensity of

elastomers exhibited thermally responsive properties, which could be observed by the naked eye.1 2).

Polysiloxane has been found as a powerful tool for detecting the ClO-/GSH cycle in situ both in lived

cells and in zebrafishs. 3). We presented a facile, and cost-less Stöber method to fabricate robust silica

nanoparticles (SiO2 UCNPs), which could discriminate live and apoptosis cells by taking advantage of

the unique surface property of SiO2 UCNPs for the first time. These works demonstrated that the

potential of polysiloxane based fluorescent probes for versatile in vivo or in vitro applications in future.

Scheme 1. Illustration of the thermal responsive process and the application of the elastomers

References

1. Yujing Zuo, et al., Chemical Science, 2018, 9, 2774–2781.

2. Yujing Zuo, et. al., Anal. Chem., 2019, 91, 1719−1723.

3. Yujing Zuo, et. al., Anal. Chem., 2018, 90, 14602−14609.

4. Yujing Zuo, et. al., Sensor and Actuator B, 2019, 291, 235-242.

OP – 07



Trinuclear Pt Complexes with Si-ligands and their Catalysis

Kohtaro Osakada

Laboratory for Chemistry and Life Science, Tokyo Institute of Technology.

4259 Nagatsuta, Yokohama 226-8503, Japan.

[email protected]

Hydrosilylation of carbonyl compounds using Pt catalysis is much less common than the reaction

using other transition metals such as Fe, Ni, Cu, and Rh. Triplatinum(0) complexes with bridging

diarylsilylene ligands, formulated as [{Pt(PMe3)}3(μ-SiPh2)3] catalyzes hydrosilyation of benzaldehyde

with H2SiPh2 to produce diphenyl(benzyloxy)silane along with concurrent hydrosilyation and

dehydrosilyation of phenyl(methyl)ketone (eq 1).1 Dehydrogenative coupling of H2SiPh2 and phenol

is also catalyzed to yield

diphenyl(4-methylphenoxy)silane.

Kinetic studies of the reactions

using various aromatic aldehydes

and using deuterated labelled

diphenylsilane suggested that the

catalyst keeps the triangular

trinuclear structure throughout the

reaction and that the reaction

mechanism is totally different from

those catalyzed by Pt(PPh3)3.2

The reaction involves addition of H2SiPh2 to the Pt3Si3

complex to produce a Pt3Si4 complex, [{Pt(PMe3)}3(H)2(-

SiPh2)4] and further insertion of carbonyl group into the Pt-

Si bond. The intermediate formed by addition of H2SiPh2

was isolated and characterized by X-ray crystallography

(Figure 1) and NMR spectroscopy. Thermodynamic

parameters of the process are determined to be G° = –8.0

kJ mol-1, H° = –51.7 kJ mol-1, and S° = –146 J mol-1K-1.

The stoichiometric and catalytic reactions using

[{Pt(PMe3)}3(-SiPh2)3]3 will be also mentioned.

Figure 1 Structure of [{Pt(PMe3)}3(H)2(-SiPh2)4]

References

1. Tanabe, M.; Kamono, M.; Tanaka, K. Osakada, K. Organometallics 2017, 36, 1929-1935.

2. Tsuchido, Y.; Kamono, M.; Tanaka, K.; Osakada, K. Bull. Chem. Soc. Jpn. 2018, 91, 858-864.

3. Tanabe, M.; Tanaka, K.; Omine, S.; Osakada, K. Chem. Commun. 2014, 50, 6839-6842.

OP – 08



Hybrid of POSS-Based Porous Polymers with Polysiloxanes

Ruixue Sun,a,b Shengyu Feng,a,b Dengxu Wang,a,b* Hongzhi Liua,b

a National Engineering Research Center for Colloidal Materials, b Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and

Chemical Engineering, Shandong University, Jinan 250100, P. R. China

[email protected]

Porous organic polymers have been widely applied in gas storage, separation, catalysis, sensing, etc.

However, most of these materials cannot be processed due to their highly crosslinked and stiff networks,

thus limiting their application extension.1 Herein, we report a facile approach to realize their

processibility by the hybrid of them with polysiloxane, affording novel composite materials. One typical

example is physically blending them into a thiol-containing polysiloxane matrix (PMMS) followed by

an efficient thiol-ene crosslinking reaction, resulting in novel silicone elastomers (Figure 1).2 The

applied porous materials are polyhedral oligomeric silsesquioxane-based hybrid porous polymers

(HPPs), which were prepared by the Heck reactions of octavinylsilsesquioxane with 4,4’-

dibrombiphenyl and/or 1,3,6,8-tetrabromopyrene. They exhibit tunable fluorescence with a continuous

color change from blue to red by altering the molar ratio of biphenyl and pyrene units. This remarkable

fluorescence modulation endows the elastomers incorporated with HPP materials similar multicolor

emissions from blue to red depending on the added HPP. It was observed that HPP materials were well

dispersed in the polymeric matrix when the amount of HPPs was below 20 mg per gram of PMMS.

Furthermore, multicolored UV-LEDs based on these silicone elastomers were constructed by an in-situ

crosslinking method; the devices show color-transformable property by controlling the light switches

(Figure 1). These results reveal that blending insoluble porous materials with polymer matrix is an

effective strategy to realize their processibility and result in novel functional composites. This simple

strategy could be certainly expanded to other insoluble porous materials.

Figure 1. Hybrid of POSS-based fluorescent porous polymers with polysiloxane matrix for silicone elastomers and

multicolored UV-LEDs

References

1. Das, S.; Heasman, P.; Ben, T.; Qiu, S. L. Chem. Rev. 2017, 117, 1515-1563.

2. Sun, R.; Feng, S.; Wang, D.; Liu, H. Chem. Mater. 2018, 30, 6370-6376.

OP – 09



A Dimeric Cobaltosilylene Complex for Catalytic C-C Bond

Formation

Cheuk-Wai So*

a Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang

Technological University

[email protected]

Treatment of the amidinato silicon(I) dimer [PhC(NtBu)2Si:]2 (1) with CoBr2 in toluene for 10 days

afforded the dimeric amidinato cobaltosilylene [(LSi)μ-{CoBr(LSiBr)}]2 (2). It is capable of catalysing

C–H bond functionalization, whereby a combination of 2, phosphine and MeMgI can regio- and

stereoselectively promote the addition of the ortho-C-H bond in arylpyridines with the CC triple bonds

in alkynes. Other transition-metal and main-group element complexes supported by the amidinato

silicon(I) dimer will also presented

Scheme 1. The addition of the ortho-C-H bond in arylpyridines with the C-C triple bonds in alkynes

References

1. Khoo, S.; Cao, J.; Yang, M.-C.; Shan, Y.-L.; Su, M.-D.; So, C.-W. Chem. - Eur. J. 2018, 24, 14329-143.

OP – 10


POSTER PRESENTATION ǀ Page 56

Plenary Lecture

Keynote Lecture

Invited Lecture

Short Oral Presentation

Abstract

Poster Presentation



Platinum-Catalyzed Reactions of 3,4-Bis(dimethylsilyl)- and

2,3,4,5-Tetrakis(dimethylsilyl)thiophene with Alkynes and Alkenes

Akinobu Naka*, Takashi Mihara

Department of Life Science, Kurashiki University of Science and the Arts, Nishinoura, Tsurajima-cho,

Kurashiki, Okayama 712-8505, Japan

[email protected]

We have reported that the platinum-catalyzed reactions of 2,3-bis(diethylsilyl)thiophene with alkynes

such as diphenylacetylene, 3-hexyne, phenylacetylene, trimethylsilylacetylene, afforded the respective

[1,4]disilino[2,3-b]thiophenes.1 We also demonstrated that the reactions of 2,3-

bis(diisopropylsilyl)thiophene with alkynes having the bulky substituents, such as

trimethylsilylacetylene and mesitylacetylene gave the products arising from sp-hybridized C-H bond

activation of the alkynes.2 In this paper we report the platinum–catalyzed reactions of 3,4-

bis(dimethylsilyl)thiophene (1) and 2,3,4,5-tetrakis(dimethlsilyl)thiophene with mono- and di-

substituted alkynes, and with mono-substituted alkenes.

Treatment of compound 1 with diphenylacetylene in the presence of a catalytic amount of Pt(PPh3)4

in refluxing benzene for 2 h gave 1,1,4,4-tetramethyl-2,3-diphenyl-1,4-dihydro-[1,4]disilino[2,3-

c]thiophene (2) in quantitative yield (Scheme 1). Similar reactions of 1 with 3-hexyne and

phenyltrimethylsilylacetylene afforded 2,3-diethyl-1,1,4,4-tetramethyl-1,4-dihydro-[1,4]disilino[2,3-

c]thiophene (3) and 1,1,4,4-tetramethyl-2-phenyl-3-(trimethylsilyl)-1,4-dihydro[1,4]disilino[2,3-

c]thiophene (4) in 62% and 98% yields, respectively.

Scheme 1. Reactions of 1 with diphenylacetylene, 3-hexyne and phenyltrimethylsilylacetylene.

We also report the reaction of 1 with alkenes in the presence of a platinum catalyst in refluxing

benzene, and the reaction of 2,3,4,5-tetrakis(dimethylsilyl)thiophene (5) with diphenylacetylene and

styrene.

Scheme 2. Reactions of 5 with diphenylacetylene.

References 1. Naka, A.; Mihara, T.; Kobayashi, H.; Ishikawa, M. J. Organomet. Chem. 2016, 822, 221-227.

2. Naka, A.; Mihara, T.; Kobayashi, H.; Ishikawa, M. ACS omega 2017, 2, 8517-8525.

P – 01



Synthesis and Reactions of Hexahydrosilaphenalenes Using

Trilithiocyclododecatriene

Ayaka Furusawa, Haruka Takagi, Shohei Oka, Takumi Sugino, Kenkichi Sakamoto*



[email protected]

Recently, we have synthesized hexahydrosilaphenalenes 3a-e (R = H, Me, Ph, Mes, 4-PhC6H4) in

low to moderate yields by the reactions of the corresponding trichlorosilanes with 1,5,9-

trilithiocyclododeca-1,5,9-triene (2), prepared by triple-lithiation of tribromide 1 with 6 equiv of tert-

butyllithium in THF (Scheme 1).

Scheme 1. Preparation of hexahydrosilaphenalenes by the reaction of trilithiocyclododecatriene with trichlorosilane.

We wish to report herein halogen- and alkoxy-substituted hexahydrosilaphenalenes 4 as shown in

Scheme 2. Compound 4 should be a useful building brock of the tricyclic compounds, e.g. reactions of

4 with LiAlH4 and n-butyllithium give 3a and 3f in high yields, respectively.

Scheme 2. Preparation and reactions of halogen and alkoxy substituted hexahydrosilaphenalenes

As shown in Figure 1,

compound 3 is obtained as a

racemic mixture of optical

isomers P and M1 having a chiral

C3 symmetric bowl shape

structure. Optical resolution of 3

is now in progress.

References

1. Petruhina, M. A.; Andreini, K. W.; Scott, L. T. Angew. Chem, Int. Ed. 2004, 43, 5477-5481.

3a (R = H, 20 %), 3b (R = Me, 40 %), 3c (R = Ph, 30 %), 3d (R = Mes, 12 %), 3e (R = 4-PhC6H4, 13 %)

Figure 1. Enantiomers of 3 and their schematic drawings.

P – 02



A Novel Bis-NHI-Stabilized Silyliumylidene and its Reactivity

towards Transition Metals

Franziska Hanusch and Shigeyoshi Inoue*



[email protected]

In the family of low-coordinate silicon compounds, two of the youngest family members are

silyliumylidenes and silylones. Sterically shielding and electron donating ligands are a game changer,

when it comes to stabilizing those highly reactive species. Bis-N-heterocyclic imines (bis-NHIs) are

particularly strong σ- and π-donors that create highly electron rich and therefore nucleophilic metal

centers without showing π-acceptor abilities - like NHCs do. While the number of silyliumylidenes and

silylones has grown over the last years, their reactivity towards transition metals and in terms of

catalysis is still in its infancy.1, 2

Figure 1. Reactivity of bis-NHI-stabilized silyliumylidene 1 towards transition metal reagents.

Herein, we present our latest results regarding the reactivity of bis-NHI-stabilized silyliumylidene 1

towards transitions metals for coordination chemistry and beyond.

References

1. P. Jutzi, A. Mix, B. Rummel, W. W. Schoeller, B. Neumann and H.-G. Stammler, Science, 2004, 305, 849. (b) K.

Leszczyńska, A. Mix, R. J. F. Berger, B. Rummel, B. Neumann, H.-G. Stammler and P. Jutzi, Angew. Chem. Int. Ed. 2011,

50, 6843. (c) K. C. Mondal, H. W. Roesky, M. C. Schwarzer, G. Frenking, B. Niepötter, H. Wolf, R. Herbst-Irmer and D.

Stalke, Angew. Chem. Int. Ed., 2013, 52, 2963.

2. Reviews: (a) S. Yao, Y. Xiong and M. Driess, Acc. Chem. Res., 2017, 50, 2026. (b) P. K. Majhi, T. Sasamori, Chem. Eur.

J. 2018, 24, 9441. (c) S. L. Powley, S. Inoue, Chem. Rec. 2019, doi:10.1002/tcr.201800188. (d) T. Ochiai, D. Franz, S.

Inoue, Chem. Soc. Rev. 2016, 45, 6327

P – 03



Synthesis of new laddersiloxanes with reactive functional groups

for applications in supported catalysis

Yujia Liu, Kazuki Onodera, Peiyao Zhang, Nobuhiro Takeda, Armelle Ouali, Masafumi Unno

Gunma University Initiative for Advanced Research (GIAR) - International Open Laboratory with Montpellier

France – Institute Charles Gerhardt (CNRS/ENSCM/UM),

Department of Chemistry and Chemical Biology, Faculty of Science and Technology,

Gunma University, Kiryu 376-8515, Gunma, Japan

In recent years, increasing demands have been observed on the development of materials with high

function like thermal stability, low-k value, or high refractive index. Among the possible candidates of

these materials, silsesquioxanes (RSiO3/2 where R can be hydrogen, alkyl or aryl groups) with well-

defined structures is one of the most promising compounds. Especially, the cubic polyhedral

oligosilsesquioxanes (T8) have been the most studied for various applications.1 In the past decade, the

synthesis, structure determination, and thermal properties of ladder oligosilsesquioxanes with defined

ladder structures (named “laddersiloxane”) have been reported as well.2 By introducing reactive

substituents, the resulting laddersiloxanes can potentially be used as nanometer-scale precursors and

building blocks in electronic materials, medicinal chemistry and catalysis. Our work is focusing on the

synthesis of high-ordered nano-sized laddersiloxanes as building blocks for new supported catalysts

and exploitation of their catalytic activities. We succeeded in preparing new laddersiloxanes bearing

divinyl, tetravinyl and allyl functional groups and carrying out hydrosilylation reactions of these

synthesized laddersiloxanes as well.

References

1. D. B. Cordes, P. D. Lickiss, F. Rataboul, Chem. Rev. 2010, 110, 2081-2173.

2. (a) M. Unno, A. Suto, T. Matsumoto, Russ. Chem. Rev. 2013, 82, 289-302; (b) H. Endo, N. Takeda, M. Unno,

Organometallics 2014, 33, 4148-4151.

P – 04



Bisboryloxysilylene: Synthesis and Reactivity

Lu Ying, Simon Aldridge*

Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Park Road,

Oxford OX1 3QR

*[email protected]

Silicon is the second most abundant element in the Earth’s crust after oxygen, consisting of ca. 28%

by mass, making it a sustainable and easily obtainable element on which to base new main group bond

activation processes. One type of low valent silicon species, silylenes (R2Si:), have attracted much

attention in recent decades, starting with a landmark report of an N-heterocyclic silylene in 1994.1 The

acyclic subspecies, however, had not been reported until 2012.2 Although challenging to synthesize,

two-coordinate acyclic silylenes have shown interesting reactivity towards small molecules due to the

relatively narrow HOMO-LUMO gap typically encountered.2a

Herein, an acyclic silylene bearing bulky ancillary boryloxyl ligands has been synthesized (1, Fig

1),3 and its reactivity studied. This system represents the first example of a two-coordinate acyclic

silylene with two oxygen-based ligands, and readily activates carbon dioxide and water to give the

Si(IV) products (2 and 3, Fig 1) respectively. Upon reacting with triphenylphosphine oxide, the silylene

abstracts the oxygen atom from the phosphine oxide, forming the corresponding silanone as its

phosphine oxide adduct (4, Fig 1).

Scheme 1. Reactivity of bisboryloxysilylene 1

References:

1. M. Denk, R. Lennon, R. Hayashi, R. West, A. V. Belyakov, H. P. Verne, A. Haaland, M. Wagner, N. Metzler, J. Am.

Chem. Soc. 1994, 116, 2691-2692.

2. (a) A. V. Protchenko, K. H. Birjkumar, D. Dange, A. D. Schwarz, D. Vidovic, C. Jones, N. Kaltsoyannis, P. Mountford,

S. Aldridge, J. Am. Chem. Soc. 2012, 134, 6500-6503; b) B. D. Rekken, T. M. Brown, J. C. Fettinger, H. M. Tuononen, P.

P. Power, J. Am. Chem. Soc. 2012, 134, 6504-6507.

3. Y. K. Loh†, L. Ying†, M. Á. Fuentes, D. C. H. Do, S. Aldridge, Angew. Chem. Int. Ed. 2019, 58, 4847-4851. (†Equal

contribution)

N

B

N

O

Dipp

Dipp

SiO B

N

N

Dipp

Dipp

bisboryloxysilylene, 1

2 CO2, -CO

hexane, rt

N

B

N

O

Dipp

Dipp

SiO B

N

N

Dipp

Dipp

H OH

N

B

N

O

Dipp

Dipp

SiO B

N

N

Dipp

Dipp

OO

O

2 PPh3=O, -PPh3

benzene, rt

carbonate, 2

O–H activation, 3

H2Ohexane, rt

silanone, 4

N

B

N

O

Dipp

Dipp

SiO B

N

N

Dipp

Dipp

O

OPPh3

P – 05



Approach to ViPh-Janus cube and

synthesis of tetrafunctional Double-Decker siloxanes

Mana Kigure, Yujia Liu, Armelle Ouali, Nobuhiro Takeda, Masafumi Unno

Department of Chemistry and Chemical Biology, Faculty of Science and Technology,

Gunma University, and Gunma University Initiative for Advanced Research (GIAR),

Kiryu 376-8515, Japan

Cage octasilsesquioxanes (T8) are the most studied among all of silsesquioxanes due to their

high degree of symmetry with functional groups in each octant, their nanometer size, and numbers of

preparation methods. In particular, “Janus cube” octasilsesquioxane,1 which is a nanometer-scale Janus

particle with two kinds of substituents, was synthesized by the cross-coupling reaction of a “half-cube”

cyclic silanolate salt with another half-cube cyclic fluorosiloxane in our laboratory1. However, Janus

cubes with reactive substituents have been scarcely synthesized yet.

Therefore, we tried to synthesize Janus cube with vinyl groups. Vinyl group can be used for

hydrosilylation and addition reaction, thus they are useful industrial application. We tried to synthesize

the target compound by cross-coupling reaction (Figure. 2).

On the other hand, we were also trying to use silsesquioxanes for building blocks for complex

inorganic-organic hybrid materials. We succeeded in the synthesis of tetravinyl- and tetraallyl-

substituted closed Double-Decker siloxanes (Figure 3, Figure 4) and they could successfully undergo

hydrosilylation quantitatively.2

Figure 1. Janus cube Figure 2. Approach to ViPh-Janus cube

Figure 3. DDSQ-Vinyl4 Figure 4. DDSQ-Allyl4

References

1. N. Oguri, Y. Egawa, N. Takeda, and M. Unno, Angew. Chem. Int. Ed., 55, 9336 (2016).

2. Y. Liu, N. Takeda, A. Ouali, and M. Unno, Inorg. Chem., 58, 4093-4098 (2019).

P – 06



Construction of Novel Group-14 Species

Aming Tautomerizable Heavy Carbonyl Compounds

Mariko Yukimoto, Min Woo Jo, Norihiro Tokitoh

Institute for Chemical Research, Kyoto University,

Gokasho, Uji, Kyoto 611-0011, Japan

[email protected]

Kinetic stabilization afforded by bulky substituents has been successfully applied to the synthesis and

isolation of highly reactive species such as doubly and triply bonded heavier main group element

compounds.1 Although keto-enol tautomerization reaction is one of the most important concepts in

organic chemistry,2 tautomerization has never been explored for the so-called heavy ketones and heavy

amides (double-bond compounds between heavier group 14 and 16 elements) due to the difficulty in

the synthesis and steric protection of the reactive heavy carbonyl bonds having an alpha-hydrogen.

In this research, we first examined the synthesis of overcrowded aminosilanes as a precursor for

tautomerizable heavy amides, and aminosilane 1 was obtained by the reaction of BbtSiH3 with t-

BuNHLi. We are now investigating the transformation of aminosilane 1 into the expected heavy amides

and related low-coordinated silicon compounds. In relation to the chemistry of heavy amides, we

examined the synthesis of heavy ketones having an alpha-hydrogen. Thus, the reaction of methylene-

substituted germylene 2 with elemental selenium gave the corresponding germaneselone 3. The

syntheses, structures and reactions of 2 and 3 as well as those of aminosilane 1 will be discussed.

References

1. Tokitoh, N., Okazaki, R. In The Chemistry of Organic Silicon Compounds, Vol. 2; Rappoport, Z., Apeloig, Y., Eds.; John

Wiley & Sons: Chichester, 1998; pp 1063–1103; Weidenbruch, M. In The Chemistry of Organic Silicon Compounds, Vol.

3; Rappoport, Z., Apeloig, Y., Eds.; John Wiley & Sons: Chichester, 2001; pp 391–428.

2. In Tautomerism: Methods and Theories; Antonov, L. Ed.; Wiley-VCH Verlag GmbH & Co.: Weinheim, 2014; pp 1–20.

P – 07



Reactivity of an Iminodisilene

Richard Holzner and Shigeyoshi Inoue*



E-Mail: [email protected]

The synthesis of Mes2Si=SiMes2, the first compound containing a Si=Si double bond by West and

coworkers in 1981 was a milestone in modern main group chemistry.1 This disilene readily reacts with

white phosphorus in a selective fashion, resulting in the two central Si-atoms bridged by two P-atoms.2

In recent years, our group presented an iminodisilene,3 bearing strongly π-donating N-heterocyclic

imino (NHI) substituents4 and sterically demanding Si(TMS)3 groups. Although interesting reactivities

towards oxidation reagents were observed,5 the investigation of this disilene is limited by its thermal

instability, especially in solution. Therefore, we modified the silyl substituents to SitBu2Me and obtained

the stable iminodisilene 1.

Scheme 1: Synthesis and characterization of compounds 2 and 3.

Here, we present the one-electron oxidation of iminodisilene 1 furnishing the cationic radical 2

(Scheme 1). Furthermore, the reaction product of 1 with white phosphorus 3 will be shown. Compound

3 exhibits an unprecedented structure. The two former sp2 Si-atoms are bridged by a P4 tetrahedron. In

addition, further reactivity of iminodisilene 1 will be presented and discussed.

References

1. R. West, M. J. Fink, J. Michl, Science 1981, 214, 1343.

2. M. Driess, A. D. Fanta, D. R. Powell, R. West, Angew. Chem. Int. Ed. Engl. 1989, 28, 1038-1040; Angew. Chem. 1989,

101, 1087-1088.

3. D. Wendel, T. Szilvási, C. Jandl, S. Inoue, B. Rieger, J. Am. Chem. Soc. 2017, 139, 9156-9159.

4. T. Ochiai, D. Franz, S. Inoue, Chem. Soc. Rev. 2016, 45, 6327-6344.

5. D. Wendel, T. Szilvási, D. Henschel, P. J. Altmann, C. Jandl, S. Inoue, B. Rieger, Angew. Chem. Int. Ed. 2018, 57, 14575-

14579; Angew. Chem. 2018, 130, 14783-14787.

P – 08



Reduction of 1,2-Dibromodisilene Bearing the Bulky Eind Groups

Ryoma Ohno,a Alfredo Rosas-Sanchez,b Daisuke Hashizume,b Tsukasa Matsuoa,*

aDepartment of Applied Chemistry, Faculty of Science and Engineering, Kindai University,

3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, JAPAN bRIKEN Center for Emergent Matter Science (CEMS),

2-1 Hirosawa, Wako, Saitama 351-0198, JAPAN

[email protected], [email protected]

We have focused on exploring the chemistry of unsaturated compounds of the heavier group 14

elements employing the bulky aryl groups based on a rigid fused-ring 1,1,3,3,5,5,7,7-octa-R-substituted

s-hydrindacen skeleton, called “Rind” groups.1,2

Here we present the reduction reaction of 1,2-dibromodisilene supported bythe bulky Eind groups,

(Eind)BrSi=SiBr(Eind) (Eind = 1,1,3,3,5,5,7,7-octaethyl-s-hydrindacen-4-yl).3A halogen-substituted

three-membered-ring unsaturated silicon compound, cyclotrisilene, Si3Br(Eind)3, has been obtained as

pale yellow crystals by the reaction of the 1,2-dibromodisilene with 1 equiv of lithium metal. The

molecular structure of the cyclotrisilene has been determined by X-ray crystallography. A new

tetrasilacyclobutadiene, Si4(Eind)4, has also been synthesized by a similar reaction using 2 equiv of

lithium metal.The Eind-substituted tetrasilacyclobutadiene is found to be more thermally stable than

the less bulky EMind-substituted tetrasilacyclobutadiene, Si4(EMind)4.4We are now investigating the

reactivities of the unsaturated cyclic siliconcompounds.

References

1. T. Matsuo, N. Hayakawa, Science and Technology of Advanced Materials (STAM) 2018, 19, 108–129.


3. K. Suzuki, T. Matsuo, D. Hashizume, K. Tamao, J. Am. Chem. Soc. 2011, 133, 19710–19713.

4. K. Suzuki, T. Matsuo, D. Hashizume, H. Fueno, K. Tanaka, K. Tamao, Science 2011, 331, 1306–1309.

P – 09



Synthesis of Hexahydroboraphenalene by Silicon-Boron

Exchange

Satoshi Ozaki, Shohei Oka, Takumi Sugino, Kenkichi Sakamoto*



[email protected]

Boraphenalene 1 is receiving theoretical attention because the

compound is an isoelectronic molecule of phenalenyl cation

having aromatic character.1 However, synthetic studies aimed at

formation of boraphenalene structures have not been reported so

far, except for synthesis of a saturated tricyclic compound 3 by H.

C. Brown.2

In this work, we have synthesized hexahydroboraphenalene 2 as a starting material of 1 by triple

silicon-boron exchange. The Si-B metathesis is known to be a powerful method for the synthesis of

organoboron compounds and some interesting molecules are obtained by this reaction.4 Thus, as a

direct precursor of 2, we have employed tris(trimethylsilyl)cyclododecatriene (6), that is obtained by

the reaction of tribromide 4 with tBuLi followed by the addition of Me3SiCl in a quantitative yield.

The reaction of 6 with

tribromoborane to give 2 was carried

out in CDCl3 at rt and monitored by 1H

NMR as shown Figure 1. The 1H

NMR peaks of 6 are disappeared

within 4 hours and new peaks are

found at 6.63, 2.39, 2.32, and 0.59.

The new peaks are successfully

identified as protons of 2 and

trimethyl-bromosilane by comparing

the observed values with calculated

ones. The yield of 2 is 70%

determined by 1H NMR.

References

1. For example: Aihara, J. Bull. Chem. Soc.

Jpn., 2008, 81, 241-247.

2. Brown, H. C., Negishi, E. J. Am. Chem. Soc., 1967, 89, 5478.

3. Untch, K. G., Martin, D. L., J. Am. Chem. Soc., 1965, 87, 3518.

4. For example: Gross, U. Chem. Ber., 1987, 120, 991.

Figure 1. Spectral change during the reaction of 6 with BBr3 to give 2 and

Me3SiBr. Values in parentheses are calculated chemical shifts (DFT, B3LYP,

6-31G*).

P – 10



Synthetic Studies on Silabenzenyl Anion

Shingo Tsuji,a,* Yoshiyuki Mizuhata,a Norihiro Tokitoha

aInstitute for Chemical Research, Kyoto University, Gokasho Uji-city, Kyoto, Japan 611-0011

[email protected]

Recently, heavier group 14 element analogues of phenyl anions, ‘metallabenzenyl anions,’ 1− and 2−

were synthesized inreactions of Tbt-substituted stable metallabenzenes 3 and 4 with KC8, respectively

(Scheme 1, left).1,2 Experimental and calculational results revealed they have characters as both

aromatic compounds and divalent species (metallylenes).

In general, group 14 elements have a tendency to get stable as divalent species as the period goes

down. Comparing 1− and 2−, the former is more aromatic while the latter is more divalent, reflecting the

tendency (Scheme 1, right).

Scheme1. Left: Synthesis of Germa-and Stannabenzenyl Anions. Right: Resonance Contributions.

Asilicon analogue, ‘silabenzenyl anion,’ 5− is predicted to possess more increased aromatic character

than that of 1−, but the synthesis and elucidation of the character and reactivity have not yet been

achieved. Therefore, we attempted the systhesis of 5− to gain fundamental insights about

metallabenzenyl anions.

The reaction of silabenzene 6 with KC8 resulted in the generation of dianion 72−, instead of the

expected 5−, without the elimination of the bulky substituent on the silicon atom (Scheme 2). This result

reflects the influences of central heavier group 14 atoms on the elimination step of the aryl group.

Scheme 2. Attempted Synthesis of Silabenzenyl Anion 5−.

References

1. Mizuhata, Y.; Fujimori, S.; Sasamori, T.; Tokitoh, N. Angew. Chem. Int. Ed. 2017, 56, 4588.

2. Fujimori, S.; Mizuhata, Y.; Tokitoh, N. Chem. Eur. J. 2018, 24, 17039.

P – 11



Synthesis of Hexahydrosilaphenalene by Intramolecular Triple

Metathesis of Tri(1-cyclobutenyl)silane

Shunya Nagata, Junghun Lee, Shohei Oka, Takumi Sugino, and Kenkichi Sakamoto*



[email protected]

Phenalenyl is an odd alternant hydrocarbon having a non-bonding orbital and its derivatives are

investigated as the basis for materials science in the field of molecular electronics and photonics.1

However, only a few compounds of heteroatom substituted phenalenyls and phenalenes are known so

far. Recently, we have developed a new method to synthesize of hexahydrosilaphenalene 1 as a precusor

of silaphenalene. As shown in eq. 1, a reaction of trichlorosilanes with trilithiocyclododecatriene 3

derived from the corresponding tribromide 2 gives 1 in moderate yields (R = H, Me, Ph, 4-Ph-C6H4,

and 2-Me-C6H4, Mes). Compound 1 has a unique molecular shape like a cocktail-glass with a local

chiral C3 symmetry. We wish to report herein other synthetic methods of 1 by intramolecular triple

metathesis of tri(hexa-1,5-dien-2-yl)silane 4 and tri(1-cyclobutenyl)silane 5 using Grubbs' catalysts as

shown in eq 2, respectively.

Compound 4 was obtained by the reaction of hexa-1,5-dien-2-yllithium2 with trichlorosilanes (R =

H, Me, OMe). The compound expected to be a straightforward precursor of 1 and allowed to react with

various Grubbs' catalysts (eq. 2); however, formation of the desired product 1 does not occur completely.

DFT calculations (B3LYP, 6-31G*) reveal that the metathesis is not thermodynamically favorable due

to the strain of silicon containing fused ring systems.

Preparation of compound 5 was accomplished by the reaction of 1-cyclobutenyllithium3 with

trichlorosilanes (R = H, Me, Ph, 2-Me-C6H4). We have investigated the isomerization of the derivatives

of 5 in the presence of various Grubbs' catalysts systematically and found that the methyl, phenyl, and

2-methylphenyl substituted compounds give the desirable product 1. For example, reaction of 5 (R =

Ph) with the second-generation Grubbs' catalyst (30 mol%) is resulted in 56% conversion of 5 and gives

1 in 81% yield based on the conversion.

References

1. Goto, K.; Kubo, T.; Yamamoto, K.; Nakasuji, K.; Sato, K.; Shiomi, D.; Takui, T.; Kubota, M.; Kobayashi, T.; Yakushi,

K.; Ouyang, J. J. Am. Chem. Soc. 1999, 121, 1619.

2. Peterson, P. E.; Nelson, D. J.; Risener, R. J. Org. Chem. 1986, 51, 2381.

3. Jayathilaka, L. P.; Deb, M.; Standaert, R. F. Org. Lett. 2004, 6, 3659.

P – 12



Controllable Synthesis and Application of Dendritic Fibrous

Nanosilica-Based Hybrid Nanomaterials

Soeun Jung, Ngoc Minh Tran, and Hyojong Yoo*

Department of Chemistry, Hallym University

Chuncheon, Gangwon-do, Republic of Korea, 24252

* [email protected]

Morphologically unique silica nanoparticles can be used as effective templates to prepare hybrid

materials, which are highly applicable in a variety of areas. In this work, dendritic fibrous nanosilica

(DFNS) with low density, high stability and permanent porosity is successfully employed as a template

to grow gold nanoparticles and/or zinc-based coordination polymer particles (Zn-CPPs) to fabricate

DFNS-based hybrid nanomaterials. Au nanodots are initially anchored on the surface of the DFNS

through the selective reduction of Au ions to form DFNS/Au dots. A seed-mediated growth method is

used to controllably grow Au nanoparticles on the DFNS/Au dots to generate DFNS-Au nanoparticles

nanohybrids (DFNS/Au). The DFNS and DFNS/Au hybrids subsequently employed as efficient

templates to grow Zn-CPPs via solvothermal process, and this leads to the formation of DFNS@Zn-

CPPs and DFNS/Au@Zn-CPPs core-shell nanohybrids, respectively. The obtained hybrid

nanomaterials exhibit an enhancement of catalytic performance.

P – 13



Synthesis and characterization of a well-defined sized Ladder-

structure silsesquioxanes using intramolecular cyclization

reaction mediated by B(C6F5)3

Thanawat Chaipraserta, Nobuhiro Takedaa and Masafumi Unnoa

a Department of Materials and Bioscience, Graduate School of Science and Technology, Gunma University, 1-

5-1 Tenjin-cho, Kiryu, 376-8515, Japan

Symmetrical Ladder-type silsesquioxanes, including T4D4, and T4D2, and unsymmetrical one T4D3

were, for the first time, synthesized by B(C6F5)3 using [Ph-Si(O)-SiMe2H]4 as the starting materials. In

this work, the products were investigated and characterized using multinuclear NMR spectroscopy,

mass spectrometry, and CHN analysis. The structures and thermal properties of products were

investigated using x-ray crystallography, DSC, and TGA. According to our finding, we found that T4D4

and T4D2 are white crystalline products, whereas T4D3 is colorless oil.

Reference

1. M. Unno, H. Endo, N. Takeda, Heteroatom Chem., 2014, pp 525–532

13. Robin P., Alan R. B., Alexander A. K., Mateusz B. P., Simon J. C., and Peter G. T., Organometallics, 2013, 32 (6), pp

1732–1742

14. Julian C., Sławomir R., James A. C., Witold F., Marek C., Jan K., and Krzysztof K., Organometallics, 2005, 24 (25), pp

6077–6084

P – 14



Cleavage of a P=Si Double Bond Mediated by NHC

Tomohiro Obayashi,a Kazuya Sadamori,a Takayoshi Yoshimura,b Miho Hatanaka,b Tsukasa Matsuoa,*


3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, JAPAN bNara Institute of Science atd Technology (NAIST), 8961-5 Takayama, Ikoma, Nara, 630-0192 JAPAN


We have studied a variety of low-coordinate compounds of main group elements as well as transition

metals by taking advantage of the steric protection with fused-ring bulky Rind groups (Rind =

1,1,3,3,5,5,7,7-octa-R-substituted s-hydrindacen-4-yl).1 Recently, we reported the metathesis-like

reaction of the Rind-substituted diphosphenes, (Rind)P=P(Rind) (Rind = Eind and EMind),2 with two

moleculesof N-heterocyclic carbene (NHC), thus leading to the formation of the NHC-coordinated

phosphinidene adducts, NHC→P(Rind).3 We examined the reaction mechanism of the NHC-mediated

P=P double bond-breakingof the diphosphenes using DFT calculations.

Here we report a unique P=Si double bond cleavage reaction of the phosphasilene with NHC. The

EMind-substituted phosphasilene, (EMind)P=SiPh(EMind)(EMind = 1,1,7,7-tetraethyl-3,3,5,5-

tetramethyl-s-hydrindacen-4-yl),4 reacted with two equivalents of NHC to afford a mixture of the NHC-

phosphinidene adduct, NHC→P(EMind), and the silicon(IV) compound, which were characterized

spectroscopically and crystallographically. We present the DFT computations on the mechanism of the

NHC-mediated P=Si double bond cleavage.

References


16. B. Li, S. Tsujimoto, Y. Li, H. Tsuji, K. Tamao, D. Hashizume, T. Matsuo, Heteroat. Chem. 2014, 25, 612–618.

17. N. Hayakawa, K. Sadamori, S. Tsujimoto, M. Hatanaka, T. Wakabayahsi, T. Matsuo, Angew. Chem. Int. Ed. 2017, 56,

5765–5769.

18. B. Li, T. Matsuo, T. Fukunaga, D. Hashizume, H. Fueno, K. Tanaka, K. Tamao, Organometallics 2011, 30, 3453–3456.

P – 15



Transition Metal-Capped Silicon Cage Si8Ar6L2 Stabilized by

Multiple Si–Si σ Bonding

Yang Li,a Jianying Zhang,a and Chunming Cuia,b

a State Key Laboratory of Elemento-Organic Chemistry and College of Chemistry, Nankai University,

Tianjin 300071, People’s Republic of China b Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072,

People’s Republic of China

[email protected]

Main group element compounds of the formula (ER)n (n 4) have long been of great interest because

of their unique bonding, structures and chemical and physical properties in comparison with their

carbon congeners. For example, group 14 (ER)6 tends to adopt polyhedral structures with E−E -bonds

rather than to form the aromatic benzene analogues,1 which are probably the most challenging synthetic

targets in group 14 element chemistry. Despite the great interest in organosilicon clusters, incorporation

of transition metals into silicon clusters have been particularly attractive for the development of

catalysis and materials2.

Herein, we reported that, by the introduction of silylene moieties on the skeleton of an organosilicon

cluster, it is possible to construct well-defined metal-capped silicon clusters by the reaction of the silicon

cluster with simple low-valent organometallic precursors under normal conditions (Scheme 1).

Remarkably, the isomerization of the silicon skeleton in the presence of transition metals was observed.

X-ray structural analysis and DFT calculations disclosed the novel geometry of the metal in the cages

with significant Si–Si σ-bonding.

Scheme 1. Synthesis of transition metal-capped Si8L2Ar2 silicon cage 3 and 43.4

References

1. (a) Sekiguchi, A.; Yatabe, T.; Kabuto, C.; Sakurai, H. J. Am. Chem. Soc. 1993, 115, 5853−5854. (b) Abersfelder, K.;

White, A. J. P.; Rzepa, H. S.; Scheschkewitz, D. Science 2010, 327, 564−566. (c) Abersfelder, K.; White, A. J. P.; Berger,

R. J. F.; Rzepa, H. S.; Scheschkewitz, D. Angew. Chem., Int. Ed. 2011, 50, 7936−7939. (d) Abersfelder, K.; Russell, A.;

Rzepa, H. S.; White, A. J. P.; Haycock, P. R.; Scheschkewitz, D. J. Am. Chem. Soc. 2012, 134, 16008−16016. (e) Tsurusaki,

A.; Iizuka, C.; Otsuka, K.; Kyushin, S. J. Am. Chem. Soc. 2013, 135, 16340−16343.

2. (a) Kumar, V.; Briere, T. M.; Kawazoe, Y. Phys. Rev. B 2003, 68, 155412–155421. (b) Khanna, S. N.; Rao, B. K.; Jena,

P.; Nayak, S. K. Chem. Phys. Lett. 2003, 373, 433–438.

3. Li, Y.; Li, J.; Zhang, J.; Song, H.; Cui, C. J. Am. Chem. Soc. 2018, 140, 1219–1222.

4. Sen, S. S.; Roesky, H. W.; Henn, D.; Stern, J.; Stalke, D. J. Am. Chem. Soc. 2010, 132, 1123–1126

P – 16



Co-oligomerizations of 2,5-Dibromo-1,1-disubstituted-3,4-

diphenyl-siloles with 4,4'-(Hexafluoroisopropylidene)diphenol or

4,4'-Biphenol and their Characteristics

Jong Wook Lim, Young Tae Park*

Department of Chemistry, Keimyung University, Daegu 42601, Korea

[email protected]

2,5-Dibromo-1,1-disubstitued-3,4-diphenyl-siloles (e.g, diisopropyl, dihexyl) as monomers were

prepared by intramolecular reductive cyclization reactions of disubstituted-bis(phenylethynyl)silanes

using lithium naphthalenide, anhydrous ZnCl2, and N-bromosuccinimide (NBS), respectively.

Co-oligomerization reactions of 2,5-dibromo-1,1-disubstitued-3,4-diphenyl-siloles with 4,4'-

(hexafluoroisopropylidene)diphenol or 4,4'-biphenol were carried out by the nucleophilic substitution

reaction of two bromine groups in the presence of potassium carbonate under the co-solvent of N-

methyl-2-pyrrolidinone (NMP) and toluene by azeotrope using Dean-Stark trap.

The crude oligomeric products were purified by extraction using the solvents of tetrahydrofuran and

dichloromethane, and washed with deionized water. The oligomeric product materials were

characterized by 1H, 13C, and 29Si NMR as well as GPC. We also studied the photoelectronic properties

by UV-vis absorption, excitation, and fluorescence emission spectroscopic methods, in particular.

Scheme 1. Co-oligomerizations of 2,5-dibromo-1,1-disubstituted-3,4-diphenyl-siloles

with 4,4'-(hexafluoroisopropylidene)diphenol.

Acknowledgment

This work was supported by the Basic Science Research Program through the National Research Foundation of

Korea (NRF) grant funded by the Ministry of Education of the Republic of Korea (NRF-2017R1D1A3B03028014).

P – 17

mailto:[email protected]



Synthesis of 1,1-Disubstituted-2,5-bis{(trimethylsilyl)ethynyl}-3,4-

diphenyl-siloles and their Characteristics

Jong Wook Lim, Young Tae Park*

Department of Chemistry, Keimyung University, Daegu 42601, Korea

[email protected]

2,5-Dibromo-1,1-disubstituted-3,4-diphenyl-siloles (e.g, diethyl, dihexyl, diisopropyl) were

prepared by reactions of disubstituted-bis(phenylethynyl)silanes with lithium naphthalenide, anhydrous

ZnCl2, and N-bromosuccinimide (NBS), respectively.

Palladium chloride, copper iodide, and triphenylphosphine as co-catalyst were used to replace two

bromine groups of the prepared siloles with trimethylsilylacetylene (TMSA) under the reaction

condition of diisopropylamine as solvent. The crude products were refined by recrystallization or

column chromatography in the solvent of hexane.

The product materials were characterized by 1H, 13C, and 29Si NMR. We also studied the

photoelectronic properties of the materials by UV-vis absorption, excitation and fluorescence emission

spectroscopic methods.

Scheme 1. Synthesis of 2,5-bis{(trimethylsilyl)ethynyl}-3,4-diphenyl-siloles.

Acknowledgment

This work was supported by the Basic Science Research Program through the National Research Foundation of

Korea (NRF) grant funded by the Ministry of Education of the Republic of Korea (NRF-2017R1D1A3B03028014).

P – 18

mailto:[email protected]



Nickel-Catalyzed Selective Cross-Coupling of Chlorosilanes with

Organoaluminum Reagents

Yuki Naganawa,* Guo Haiqing, Kei Sakamoto, Yumiko Nakajima*

Interdisciplinary Research Center for Catalytic Chemistry

National Institute of Advanced Industrial Science and Technology

Tsukuba, Ibaraki 305-8565, Japan


Chlorosilanes are important raw materials for the production of various organosilicon materials, such

as silicones and silane coupling reagents. The performance of the organosilicon materials is highly

dependent on the substituent groups on the silicon atom; thus, the synthesis of chlorosilanes bearing

various organic substituents (organochlorosilanes) occupies a fundamental position in the silicon

industry. One of common preparative methods to access organochlorosilanes is alkylation and arylation

of chlorosilanes with organometallic reagents. However, the use of the highly reactive organometallic

reagents, which often suffer from the low reaction selectivity, is a troublesome issue. Thus, the

development of new methods for the precise introduction of organic substituents into chlorosilanes is

of great importance.

Transition metal-catalyzed cross-coupling reactions of organohalides offer a general synthetic route

to the formation of C–C bonds. In contrast to the significant advances in this field, the corresponding

catalytic reactions of halosilanes for the formation of Si–C bonds remain relatively unexplored.1,2 In

this context, we have thus far reported nickel-catalyzed silyl-Heck reaction of chlorosilanes with

styrenes as the first example of the direct catalytic transformation of chlorosilanes as cheap and versatile

silicon feedstocks.3 To expand a scope of coupling partners in the reactions, we developed nickel-

catalyzed cross-coupling reactions of chlorosilanes with organoaluminum reagents.4

The reaction of dichlorosilanes with 2 equivalents of trialkylaluminum reagents proceeded to provide

the corresponding alkylated products in the presence of Ni(cod)2 (5 mol%) and PCy3 (10 mol%).

Monoalkylated product was predominantly formed accompanied by the dialkylated product as a minor

product. Trichlorosilanes underwent selective double substitution to furnish the corresponding

monochlorosilanes. Overall, the selective synthesis of a series of alkylmonochlorosilanes from di- and

trichlorosilanes was achieved using the present catalytic systems (Figure 1).

Figure 1. Nickel-catalyzed cross-coupling reaction of di- and trichlorosilanes with trialkylaluminum.

References

1. Cinderella, A. P.; Vulovic, B.; Watson, D. A. J. Am. Chem. Soc. 2017, 139, 7741–7744.

19. Vulovic, B.; Cinderella, A. P.; Watson, D. A. ACS Catal. 2017, 7, 8113–8117.

20. Matsumoto, K.; Huang, J.; Naganawa, Y.; Guo, H.; Beppu, T.; Sato, K.; Shimada, S.; Nakajima, Y. Org. Lett. 2018, 20,

2481–2485.

21. Naganawa, Y.; Guo, H.; Sakamoto, K.; Nakajima, Y. ChemCatChem in press. (DOI: 10.1002/cctc.201900047)

P – 19



Hydrosilylation of Alkenes and Alkynes Catalyzed by Platinum Complexes Bearing SiS3-type Tripodal Tetradentate Ligand

Takatoshi Kageyama, Yutaka Komeda, Nobuhiro Takeda, and Masafumi Unno

Graduate School of Science and Techonology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515,

Japan

[email protected]

Transition metal complexes with tripodal tetradentate ligands have attracted much attention from the

viewpoints of activation of small molecules, catalytic activities, stabilization of reactive species, and so

on. There are many reports on tripodal tetradentate ligands containing amine or phosphine moieties as

donors, however, tripodal tetradentate silyl ligands tethered with three thioether moieties are very rare.

Complexes bearing the SiS3-type ligandsare expected to show high stability resulted from the strong

silicon–metal bond and ready ligand exchange with the thioether moieties due to their weak σ-donating

ability. Recently, we have synthesized platinum complexes1a and b bearing tripodal tetradentate SiS3-

type ligands, (2-RSC6H4)3Si-(R = t-Bu, i-Pr)1.

In this paper, we report the application of platinum complexes 1a, b bearing SiS3-type tripodal

tetradentate ligand to catalysts for hydrosilylation of alkenes and alkynes. Platinum complexes 1a, b

catalyzed hydrosilylation of 4-phenyl-1-butenewith HSi(OEt)3 to give the corresponding silane 3

selectively. The hydrosilylation of phenylacetylene catalyzed by platinum complexes 1a, b resulted in

the formation of the corresponding E-alkene 4 (58% for 1a, 70% for 1b) in good selectivity along with

α-alkene 5 (19% for 1a, 29% for 1b) (Scheme 2). The catalytic hydrosilylation using platinum

complexes 1a, b and the application to the hydrosilylation of various alkenes are now in progress.

Scheme 1. Platinum complexes 1a, 1b, 2a, 2b.

Scheme 2. Catalytic hydrosilylation using platinum complexes 1aand 1b.

References

1. N. Takeda, D. Watanbe, T. Nakamura, and M. Unno, Organometallics., 29, 2839-2841 (2010).

P – 20



Selective Hydrosilylation Reactions

of Allylic Compounds

Koya Inomata, Kazuhiko Sato, Yumiko Nakajima

Interdisciplinary Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science

and Technology (AIST)

[email protected]

Hydrosilylation reactions of alkenes are one of the most important methods for the synthesis of

various organosilicon compounds. Although Pt complexes are widely utilized as powerful and efficient

catalysts in these reactions, the systems still suffer from some drawbacks. One major problem is the

occurrence of the unwanted side reactions, which would cause the deleterious effects on the quality or

propreties of the final organosilicon materials. Thus, development of efficient hydrosilylation catalysts

is highly desired. In this study, we have focused on the hydrosilylation of allylic compounds, which are

significantly important for the production of silane coupling agents in the silicon industry. Pt-catalyzed

hydrosilylation of allylic compounds are often accompanied by the side products due to the Tsuji-Trost

reaction.1 In this context, we have developed novel Rh and Ru catalyst systems, which achieved

selective hydrosilylation reactions of allylchloride and allyl polyethylene glycols (allyl PEG).

Highly selective hydrosilylation reaction of allylchloride with HSiCl3 was achieved using a Rh

catalyst composed of [RhCl(cod)]2 (0.05 mol%) and a bidentate-phosphine ligand (0.1 mol%).2

Mechanistic study suggested the in-situ formation of a -allyl Rh complex, which further reacted with

HSiCl3 to form trichloro(propyl)silane as a side-product. We also demonstrated that a reaction catalyzed

by [RhCl(dppbzF)]2 (dppbzF = 1,2-bis(diphenylphosphino)-3,4,5,6-tetrafluorobenzene) selectively

furnished the corresponding hydrosilylated product, trichloro(3-chloropropyl)silane (1), at a catalyst

loading of 0.0005 mol%/Rh. This catalyst showed the high turn over number (TON) of 140,000

(Scheme 1).

Scheme 1. Rh-catalyzed hydrosilylation of allylchloride

Hydrosilylation reactions of PEGs are one of the key reactions to prepare functional PEGs, which

are potentially available as biorelated materials, polymer electrolytes, etc. Although conventional Pt

catalysts such as Speier’s catalyst and Karstedt’s catalyst can be utilized in these reactions,

isomerization reaction of allyl PEGs also proceeds.3 We are currently investigating the new catalyst

systems, which achieve high selective hydrosilylation reaction of allyl PEGs. The results will be also

discussed at the presentation.

References

1. P. Gigler, M. Drees, K. Riener, B. Bechlars, W. A. Herrmann, F. E. Kühn, J. Catal. 2012, 295, 1.

22. K. Inomata, K. Sato, Y. Nakajima, The CSJ Annual Meeting, 2D1-02, Hyogo, March 2019.

23. H. Shin, B. Moon, J. Polym. Sci. A. Polym. Chem. 2108, 56, 527.

P – 21



Preparation and Photochemical Property of a Heterobimetallic

AuPd2 Complex with Bridging Silylene Ligand

Kazuki Okuma,a Atsushi Kanda,a Yoshitaka Tsuchido,a Makoto Tanabea and Kohtaro Osakada a*

a Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology,

4259-R1-3, Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.

[email protected]

The metal alloy which consists of two or more kinds of transition metal atoms shows unique

electronic states and the chemical properties, e.g. gold-palladium heterogeneous nanoparticles were

known as the efficient oxidation catalyst1). To investigate the related multinuclear metal complex is

important to gaining a well understanding of the role of these metals in the catalytic reaction. Only a

few examples of cationic AuPd complex, however, have been reported by Pignolet2) and Tanase3). The

biaryl silylene group (:SiAr2) have been applied as the ligand for the tetranuclear Pd complex4). In this

study, we have prepared a neutral trinuclear AuPd2 complex having diphenylsilylene group,

[AuPd2(PCy3)2(3-SiPh2)(-SC6H4CF3-4)] (3). Reaction of gold(I)-thiolate complex,

[Au(PCy3)(SC6H4CF3-4)] (1), with palladium dinuclear complex with bridging silylene ligand,

[{Pd(PCy3)2}{Pd(PCy3)}{-SiPh2}] (2), afforded complex 3 in 78% isolated yield (Scheme 1). This

reaction was progressed immediately at room temperature. An X-ray crystallographic study of 3

revealed that SiPh2 ligand is bounded to both two Pd and Au atoms. The Pd, Au, and Si atoms formed

a planar parallelogram core. The Au-Si bond length is 2.61 Å which is much longer than that of reported

gold silyl complex (2.36 Å) 5). Complex 3 exhibits green color in the solid state and solution (max =

611 nm, in toluene), which is caused by the intramolecular Charge-Transfer (CT) excitation between

Pd2S unit (HOMO) and AuSi unit (LUMO) based on the DFT calculations. The electron-withdrawing

silylene ligand induced the unique photochemical properties of complex 3. We will also discuss the

reactivity of AuPd2 trinuclear complex 3 with various organic molecules.

Scheme 1. Preparation of trinuclear complex 3.

References

1. Kaizuka, K.; Miyamura H.; Kobayashi S. J. Am. Chem. Soc. 2010, 132, 15096–15098.

24. Ito, N. L.; Johnson, J. B.; Mueting, M. A.; Pignolet, H. L. Inorg. Chem. 1989, 28, 2026-2028.

25. Goto, E.; Begum, A. R.; Ueno, C.; Hosokawa, A.; Yamamoto, C.; Nakamae, K.; Kure, B.; Nakajima, T.; Kajiwara, T.;

Tanase, T. Organometallics 2014, 33, 1893-1904.

26. Yamada, T.; Mawatari, A.; Tanabe, M.; Osakada, K.; Tanase, T. Angew. Chem., Int. Ed. 2009, 48, 568-571.

27. Joost, M.; Estevez, L.; Mallet-Ladeira, S.; Miqueu, K.; Amgoune, A.; Bourissou, D. J. Am. Chem. Soc. 2014, 136, 10373-

10382.

P – 22



Preparation of Photosensitive Organosilicon Prepolymer and Its

Application in Photocuring 3D Printing

Qiu Chen

Key Laboratory of Organosilicon Chemistry and Material Technology, Hangzhou Normal University,

Hangzhou 311121, China

In recent years, People have higher and higher requirements for the quality of photocurable three-

dimensional printing products. At present, the main raw materials used in the three-dimensional

photocuring printing technology are epoxy resin and acrylic resin. Although these two types of resins

can meet the basic requirements for three-dimensional photocuring, they cannot meet the higher

requirements for three-dimensional printing due to problems such as large viscosity of the resin, large

volume shrinkage after curing, and poor toughness of molded products.

Photocured organic/inorganic hybrid polymers have the advantages of both organic and inorganic

materials. In this work, photocurable silica sol of organic-inorganic hybrid prepolymers were

synthesized from tetraethylorthosilicate (TEOS) and γ-methacryloxypropyltrimethoxysilane (KH570).

A synthetic silica sol was used as a photosensitive resin component to prepare a photosensitive resin

composition that can be used for three-dimensional rapid molding. The effect of different amounts of

silica sol prepolymer on the properties of the photosensitive resin composition was studied. The

experimental results show that the addition of synthetic silica sol prepolymer can play a role in

increasing the mechanical and thermodynamic properties, reducing volume shrinkage and also meet the

other requirements of the photocuring three-dimensional printing consumables.

P – 23



Complex on Silica Substrate

Joon Soo Han,a,* Song Yi Kim,a,b Jihee Choi,a,b

aMaterials Architecturing Research Center, Korea Institute of Science and Technology, Hwarangro 14-gil 5,

Seongbuk-gu, Seoul 02792, Republic of Korea bDept. of Chemistry, Graduate School of Science, Korea Univ. Anam-ro 145, Seongbuk-gu, Seoul 02841,

Republic of Korea

[email protected]

Eu3+ possess fascination optical properties such as large Stokes shifts, long lifetime, and unique line-

like emission in the red region.1 However, like other lanthanides, europium ion itself has weak

luminescence properties due to its low absorption coefficient. This problem can be overcome by

coordinating organic chromophore ligands such as β-diketonate, which are referred to as antennas or

sensitizers.

A variety of fluorescence-based devices have been reported using europium complexes as sensing

elements, and in many cases, silane coupling agents (SCAs) have been used to immobilize the europium

complex.2 However, systematic studies on the effects of SCA functional groups on the emission

properties of europium have been rarely conducted

Figure 1. Excitation (λem 613 nm) and emission (λex 345 nm) spectra of EuTTA(SCA)x solutions (5.6 µM in toluene). SCA/Eu3+

mole ratio = 2.0, except AEA/Eu3+ = 1.0. MPT: (3-mercaptopropyl)trimethxoysilane; APT: (3-aminopropyl) trimethoxysilane;

AEA: [3-(2-aminoethylamino)propyl]trimethoxysilane; DPPOSi: diphenyl[3-(trimethoxysilyl)propyl] phosphine oxide.

In this presentation, we will show results of grafting europium complex to silica-based substrates

such as glass, nano-silica, or SiO2 film, and discuss how SCA changes the luminescent properties of

europium complex.

References

1. Ma, Y.; Wang, Y. Coord. Chem. Rev. 2010, 254, 972–990.

2. Sanchez, C.; Belleville, P.; Popalld, M.; Nicol, L. Chem. Soc. Rev. 2011, 40, 696–753.

P – 24



Study on Damping Mechanism Based on the Free Volume for

Polysiloxanes by Molecular Dynamics Simulation and

Experiments

Lin Zhu,a ChuanJian Zhouab,*

aSchool of Materials Science and Engineering, Shandong University, Jinan 250061,China. bKey Laboratory of Special Functional Aggregated Materials, Ministry of Education,Jinan 250061, China

[email protected]

The influences of the free volume and the temperature on the damping property of

polydimethylsiloxane (PDMS), poly(dimethyl-co-methylphenylsiloxane)(PDMS-co-PMPS) and

poly(dimethyl-co-diphenylsiloxane)(PDMS-co-PDPS) were investigated by full-atom molecular

dynamics simulation (MD)[1], dynamic mechanical analysis (DMA), differential scanning calorimetry

(DSC) and linear thermal expansion[2], respectively. From the variations of free volume fraction (FFV)

as a function of temperature, glass transition temperatures can be observed. In order to clarify the

damping mechanics, the Williams-Landel-Ferry (WLF) equation based on free volume theory has been

successfully used to establish a direct quantificational relationship between the free volume and the

damping property[3], which indicates that the free volume plays an important role in determining the

damping property. These results provide a basis for the design and fabrication of high-performance

polysiloxanes.

Figure 1. FFV vs Linear thermal expansion of three polysiloxanes

Figure 2. Log10[tan δ(T)] versus relative fractional free volume (1 -frg/fr) for (a) PDMS, (b)PDMS-co-PMPS and

(c) PDMS-co-PDPS at 1, 10, and 100 Hz.

References

1. M. Huang, L.B. Tunnicliffe, A.G. Thomas, J.J.C. Busfield. Eur. Polym. J. 2015,67, 232–241.

2. Wu G, Nishida K, Takagi K, Sano H, Yui H..Polymer 2004,45,3085-3090.

3. Yuchan Z, Guangsu H.J. Phys. Chem. B 2007, 111, 11388-11392.

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Atmospheric Pressure Chemical Vapor Deposition on a Self-

assembled Silicone Coating

Yuta Goto,a Kohei Masuda,a Koichi Higuchi,a,* Graham Garner,b Susan Farhatb and Mary Gilliamb,*

a Shin-Etsu Chemical Co., Ltd., Silicone Electronics Materials Research Center, Gunma, Japan b Department of Chemical Engineering, Kettering University, Flint, MI USA


A self-assembly is the autonomous organization of components into patterns or structures without

human intervention, whose processes are common throughout nature and technology. Several papers

about the concept of self-assembly in organosilicon compounds have been reported.1 We also have

reported a paper about the self-assembly silicone acrylate coating (Figure 1).2 Although our research

effort has been devoted to develop radiation-curable coating with high weather durability, we proposed

how to easily detect the structure of a self-assembled silicone coating and identified the factor for self-

assembly. It is essential to include both the silicone acrylate 3 and hexanediol diacrylate (HDDA) in the

coating formulation for self-assembly to occur. The acrylate 3 was prepared by transesterification of

silicate oligomer 1 with -functionalized acrylic alcohol 2 (Scheme 1). Outdoor weathering results of

the self-assembled silicone coatings are obtained after 1 year of testing in Florida and Arizona, which

showed better performance than the non-silicone or the uniform single-layer silicone coating systems.

It is possible that the unique structure of the coating protects the coating from UV- or water-induced

degradation. Moreover, atmospheric pressure chemical vapor deposition on the self-assembled silicone

coatings is being undertaken in our group,3 which is expected to improve durability against scratch and

abrasion and enhanced protection from exposure compared to the uniform single-layer silicone coatings.

The results will be presented in this poster session.

Figure 1. Self-assembly silicone acrylate coating

Scheme 1. Synthesis of silicone acrylate 3

References

1. Lu, Y.; Fan, H.; Doke, N.; Loy, D. A.; Assink R. A.; LaVan, D. A.; Brinker, C. J. J. Am. Chem. Soc. 2000, 122, 5258-

5261. b) Zhang, W.; Fang, B.; Walther, A.; Müller, A. H. E. Macromolecules 2009, 42, 2563-2569. c) Zheng, L.; Hong,

S.; Cardoen, G.; Burgaz, E.; Gido S. P.; Coughlin E. B. Macromolecules 2004, 37, 8606-8611.

2. Masuda, K.; Tsuchida, K.; Inoue, T.; Gilliam, M. Journal of Coatings Technology and Research 2019, 16, in print. (DOI:

https://doi.org/10.1007/s11998-018-00171-5)

3. Gilliam, M.; Farhat, S.; Higuchi, K.; Masuda, K.; Yoshii, R. International Application PCT/US2019/024223, 2019.

MeO Si O Me

OMe

OMe

ROH (2)(R = CH2CH2OCOCH=CH2)

transesterification

1

n

RO Si O R

OR

OR n3

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Preparation of robust Reverse Osmosis membranes for water

desalination Effects of co-polymerization with BTESPA on their

performance

Dian Zhang,a Joji Ohshita,a Feng-Tao Zheng,a Kazuki Yamamotob

aDepartment of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima

739-8527, Japan bPure and applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, Chiba 278-

8510, Japan

Water scarcity has been discussed as a global issue and the development of an efficient strategy for

water purification is needed. Reverse osmosis (RO) with a semipermeable membrane is widely used for

water desalination. Organically bridged polysilsesquioxanes can be used for RO membranes with high

thermal stability and chlorine resistance. According to our previous research, a rigid and polar bridged

structure can improve the porosity and hydrophilicity of the membranes, thus, we anticipate that co-

polymerization with polar and bridged structure can also improve water permeability. Another thing

that we anticipate is co-polymerization with a highly thermostable and chlorine resistance precursor

BTESE can improve the chemical stability of membranes.

In this work, to increase the resistance of chlorine and thermostability and improve RO performance

of membranes, we used two kinds of nitrogen-containing precursors BTESPA and BTESMAz for co-

polymerization with BTESE, the results show that the RO performance and robustness are improved

significantly.

Fig 1. Structures of BTESE, BTESPA and BTESMAz

References

1. M. Elimelech, W.A. Phillip, Science 2011, 333, 712.

28. Zheng, F.-T, Kazuki Yamamoto, Masakoto Kanezashi, 2018. 546: p. 173-178.

29. G. A. Tularam and M. Ilahee, J. Environ. Monit. 2007, 9, 805.

30. L. Weinrich, C. N. Haas, M. W. LeChevallier, J. Water Reuse Desal. 2013, 3, 85.

31. R. Xu, J. Wang, M. Kanezashi, T. Yoshioka, T. Tsuru, Langmuir 2011, 27, 13996.

P – 27



Hydride and p-Tolylsiloxanes Oxidation: Development of Catalytic

Approaches

Irina K. Goncharova, Ashot V. Arzumanyan, Aziz M. Muzafarov

Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova Street, Moscow

119991, Russian Federation

[email protected]

Organosilicone chemistry was the much slowlier developing field of chemistry compared to organic

chemistry. So, much methods for obtaining [Si]-derivatives, functionalized ones, in particular, still are

time-consuming, require harsh conditions, stoichiometric amounts of toxic and expensive reagents

producing waste (some of them are commercially unavailable) which provokes Si–O-, Si–C- and other

bonds destruction. Sometimes these methods are of low functional group tolerance.1

On the other side, functionalized siloxanes are believed will widen the fields of applicability of such

compounds. So, developing of “green” and commercially available systems for functionalization of

siloxanes is an actual task. Green chemistry, is thought, will became the only suitable appproach for

selective synthesis of siloxanes with complex structures.

Two target types of compounds were chosen for elaboration of suitable method: siloxanols and p-

carboxyphenylsiloxanes. Both they can be obtained via oxidation of easily accesible hydride siloxanes

and p-tolylsiloxanes.

Well proven peroxide and metal combination was the first system to be tried for these oxidtions

(Scheme 1, route A).2,3 After optimizing the conditions we concluded, that this system allows simple

compounds to be oxidixed with high conversions (such as triethylsilane and p-

tolylpentamethyldisiloxane), but requires more harsh conditions for more complex ones.

Then O2 was chosen as an oxidant in combination with transition metal and organic catalyst. After

optimizing the conditions we found out that this approach is applicable for both hydride and p-

tolylsiloxanes of varios structures oxidation in good conversions and yields (Scheme 1, route B).4,5

References

1. Abakumov, G. A.; Piskunov, A. V.; Cherkasov, V. K. et al. Russ. Chem. Rev. 2018, 87 (5), 393−507.

2. Arzumanyan, A. V.*; Goncharova, I. K.; Novikov, R. A. et. al. Synlett. 2018, 29 (4), 489−492.

3. Goncharova, I. K.; Arzumanyan, A. V.*; Milenin, S.A.; et. al. J.Organomet. Chem. 2018, 862, 28−30.

4. Arzumanyan, A. V.*; Goncharova, I. K.; Novikov, R. A. et.al. Green Chem. 2018, 20 (7), 1467−1471.

5. Goncharova, I. K.; Silaeva, K.P.; Arzumanyan, A.V.* et.al. J. Am. Chem. Soc. 2019, 141 (5), 2143-2151.

This work was supported by the Grant of the Government of the Russian Federation No. 14.W03.31.0018.

P – 28



Chemical Bonding Information on Ylidene-substituted Silanes

from Experimental Electron Density Distribution

Alfredo Rosas-Sánchez,a,* Tsuyoshi Kato,b Daisuke Hashizumea

aRIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan bUniversité de Toulouse, UPS, and CNRS, LHFA UMR 5069, 31062 Toulouse, France

[email protected]

Phosphoranylidenes, R3P=YRn’, have proved to act as good electron donor substituents towards

low-valent species such as carbenes and silylenes.1 Recently, we reported the development of a novel

boron-based phosphoranylidene (borylidene phosphorane, R3P=BR’) which shows an exceptionally

strong π-electron donating character, compared to its carbon analogue phosphonium ylide.2 Indeed, the

N-heterocyclic silylene (NHSi) substituted by the borylidene phosphorane presents considerably

increased stability and nucleophilic character.3 To gain deeper insight into the nature and the electron

donating ability of the newly discovered borylidene phosphorane, we have performed experimental

Electron Density Distribution (EDD) analyses on cyclic amino (dihalo) silanes bearing the borylidene

(1) and carboylidene (2) moieties (Figure 1, top), and examined the chemical bonding by means of

Source Function (SF) contributions at bond critical points (BCPs). Analysis of the SF at BCPB-Si in 1

and BCPC-Si in 2 (Figure 1a and b, bottom) revealed both ylidene moieties acting as electron donors

towards the tetracoordinated silicon atoms. However, SF at BCPs associated to the interactions of NHC

and phosphorane groups with boron in 1, showed that both substituents contribute to increase the

electron density in the borylidene moiety, contrary to the imino and phosphorane substituents in 2,

which act as electron withdrawing groups for the carboylidene moiety.

Figure1.top: Structures of cyclic amino(dihalo)silanes bearingendocyclic borylidene 1andendocyclic carboylidene 2. bottom:

SF contribution of atomic basins at a) BCPB-Siin 1; b) BCPC-Siin 2.

References

1. a) Kobayashi, J.; Nakafuji, S.; Yatabe, A; Kawashima, T. Chem. Commun. 2008, 6233–6235. b) Karni, M.; Apeloig, Y.

Organometallics 2012, 31, 2403−2415 and references cited therein.

2. Rosas-Sánchez, A.; Alvarado-Beltran, I.; Baceiredo, A.; Hashizume, D.; Saffon-Merceron, N.; Branchadell, V.; Kato, T.

Angew. Chem. Int. Ed. 2017, 56, 4814 –4818.

3. Rosas-Sánchez, A.; Alvarado-Beltran, I.; Baceiredo, A.; Saffon-Merceron, N.; Massou, S.; Branchadell, V.; Kato, T.

Angew. Chem. Int. Ed. 2017, 56, 10549 –10554.

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Synthesis and Property of Doubly Bonded Rhodium-Silylene

Complex

Shintaro Takahashi, Norio Nakata*, Akihiko Ishii

Department of Chemistry, Graduate School of Science and Engineering, Saitama University, Shimo-okubo,

Sakura-ku, Saitama-city, Saitama, 338-8570, JAPAN.

[email protected]

Transition metal-silylene complexes have been widely investigated as important intermediates in

catalytic reactions of organosilicon compounds such as hydrosilylation, dehydrocoupling, and so on.

Since two Lewis base-stabilized metal-silylene complexes were independently reported in 1987,1 the

coordination chemistry of silylene toward trantision metal complexes have been developed dramatically

until now.2 In particular, amidinato silylenes have drawn much attention due to their strong coordination

ability toward transition metal complexes. Meanwhile, we recently succeeded in the synthesis and

characterization of iminophosphonamido chlorosilylene 1 that has higher nucleophilicity and stronger

σ-donor ability than the corresponding amidinate analogue.3 Herein we present the synthesis and

property of a novel rhodium-silylene complex having a distinct double bond character.

Mono coordinated Rhodium-silylene complex 2 was obtained by the reaction of [RhCl(cod)]2 with

2 molar equivalents of 1. Interestingly, the reaction of [RhCl(cod)]2 with 6 molar equivalents of 1

resulted in the formation of cationic rhodium-silylene complex 3. X-ray crystallographic analysis of 3

revealed that the middle Si–Rh bond [2.133(1)Å] is shorter than the other two Si–Rh bonds [2.342(1),

2.332(1)]Å and approximately 8% shorter than typical Si–Rh single bonds, indicating a double-bond

character between silicon and rhodium atoms. We also discuss further details for the bond nature in 3

from the viewpoints of experimental results and theoretical calculations.

Figure1. Iminophosphonamido silylene and theirrhodium complexes

References

1. a) Zybill, C.; Muller, G. Angew. Chem. Int. Ed. 1987, 26, 669−670. b) Straus, D. A.; Tilley, T. D.; Rheingold, A. L.; Geib,

S. J. J. Am. Chem. Soc 1987, 109, 5872−5873.

2. Álvarez-Rodríguez, L.; Cabeza, J. A.; Garcia-Alvarez, P.; Polo, D. Coord. Chem. Rev. 2015, 300, 1−28. 3. So, C.-W.; Roesky, H. W.; Magull, J.; Oswald, R. B. Angew.Chem. Int. Ed. 2006, 118, 3948−3949.

P – 30



π-Conjugated Ditetrene Compounds with Thiophene Rings

Shogo Yagura,a Ryoma Ohno,a Shogo Nishimura,a Naoki Hayakawa,a Daisuke Hashizume,b Tsukasa Matsuoa,*


3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, JAPAN bRIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, JAPAN


We have studied a varietyof π-electron systems containing a Si=Si double bond stabilized by the

fused-ring bulky Rind groups (Rind = 1,1,3,3,5,5,7,7-octa-R-substituted s-hydrindacen-4-ly).1

Previously, we reported the synthesis and photophysical properties of a series of 1,2-diaryldisilenes,

(Eind)ArSi=SiAr(Eind) (Eind = 1,1,3,3,5,5,7,7-octaethyl-s-hydrindacen-4-yl).2,3 The 1,2-dinaphthyl-

disilenes are air-stable in the solid state and exhibitan intense emission at room temperature.2

Here we report the synthesis and characterization of the thienyl-and bithienyl-substituted disilenes

supported by the bulky Eind groups.4 The photophysical properties and theoretical calculations provide

clear evidence for the effective π-conjugation between the Si=Si double bond and thiophene units. We

also present the π-conjugated digermene compound, 1,2-dithienyldigermene, bearing the bulky Eind

groups, which can be obtained by the reaction of the 1,2-dibromodigermene, (Eind)BrGe=GeBr(Eind),5

with 2-thienyllithium.

References

1. T. Matsuo, N. Hayakawa, Science and Technology of Advanced Materials (STAM) 2018, 19, 108–129. 2. a) M. Kobayashi, N. Hayakawa, K. Nakabayashi, T. Matsuo, D. Hashizume, H. Fueno, K. Tanaka, K. Tamao, Chem. Lett.

2014, 43, 432–434. b) T. Matsuo, M. Kobayashi, K. Tamao, Dalton Trans. 2010, 39, 9203–9208. c) M. Kobayashi, T.

Matsuo, T. Fukunaga, D. Hashizume, H. Fueno, K. Tanaka, K. Tamao, J. Am. Chem. Soc. 2010, 132, 15162–15163. 3. M. Kobayashi, N. Hayakawa, T. Matsuo, B. Li, T. Fukunaga, D. Hashizume, H. Fueno, K. Tanaka, K. Tamao, J. Am.

Chem. Soc. 2016, 138, 758–761. 4. N. Hayakawa, S. Nishimura, N. Kazusa, N. Shintani, T. Nakahodo, H. Fujihara, M. Hoshino, D. Hashizume, T. Matsuo,

Organometallics 2017, 36, 3226–3233. 5. N. Hayakawa, T. Sugahara, Y. Numata, H. Kawaai, K. Yamatani, S. Nishimura, S. Goda, Y. Suzuki, T. Tanikawa, H.

Nakai, D. Hashizume, T. Sasamori, N. Tokitoh, T. Matsuo, Dalton Trans. 2018, 47, 814–822.

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