Suplementary materials for Hydrogen activation by 2-boryl-N … · 2012-06-11 · Suplementary...
Transcript of Suplementary materials for Hydrogen activation by 2-boryl-N … · 2012-06-11 · Suplementary...
Suplementary materials for
Hydrogen activation by 2-boryl-N,N-dialkylanilines: a revision of Piers' ansa-aminoborane
Konstantin Chernichenko, Martin Nieger, Markku Leskelä and Timo Repo* 5
Crystal structure determinations
Crystal structure studies of 2, 2H2 and 3: The single-crystal X-ray diffraction studies of 2 and 2H2 were carried out on a
Bruker-Nonius Kappa-CCD diffractometer and 3 on a Bruker-Nonius APEXIIat 123(2) K using MoKα radiation (λ = 0.71073
Å). Direct Methods (SHELXS-97) were used for structure solution, and full-matrix least-squares refinement on F2 (SHELXL-10
97). [G. M. Sheldrick, Acta Crystallogr. 2008, A64, 112-122] H atoms were localized by difference Fourier synthesis and
refined using a riding model (H(N) and H(B) free).
2: colorless crystals, C27H22BF10N, M = 561.27, crystal size 0.32 x 0.16 x 0.08 mm, monoclinic, space group P21/c (No.14): a
= 7.8910(5) Å, b = 17.3435(15) Å, c = 17.8672(15) Å, β = 101.330(7)°, V = 2397.6(3) Å3, Z = 4, ρ (calc) = 1.555 Mg m
-3,
F(000) = 1144, μ = 0.144 mm-1
, 25679 reflections (2θmax = 55°), 5411 unique [Rint = 0.062], 352 parameters, R1 (I > 2σ(I)) = 15
0.058, wR2 (all data) = 0.121, GooF = 1.03, largest diff. peak and hole 0.292 and –0.271e Å-3
.
2H2: colorless crystals, C27H24BF10N – 0.5 C6D6, M = 605.35, crystal size 0.30 x 0.15 x 0.10 mm, triclinic, space group P-1
(No.2): a = 10.944(1) Å, b = 11.974(1) Å, c = 12.513(1) Å, α = 117.39(1)°, β = 98.29(1)°, γ = 106.57(1)°, V = 1320.4(2) Å3,
Z = 2, ρ (calc) = 1.523 Mg m-3
, F(000) = 618, μ = 0.137 mm-1
, 20736 reflections (2θmax = 55°), 6029 unique [Rint = 0.032], 385
parameters, R1 (I > 2 σ (I)) = 0.044, wR2 (all data) = 0.112, GooF = 1.03, largest diff. peak and hole 0.320 and –0.230 e Å-3
. 20
3: colorless crystals, C20H10BF10N, M = 465.10, crystal size 0.32 x 0.16 x 0.08 mm, monoclinic, space group P21/c (No.14): a
= 9.8216(4) Å, b = 35.0210(15) Å, c = 11.1291(4) Å, β = 107.047(2)°V = 3659.8(3) Å3, Z = 8, ρ (calc) = 1.688 Mg m
-3,
F(000) = 1856, μ = 0.170 mm-1
, 18746 reflections (2θmax = 55°), 8151 unique [Rint = 0.031], 581 parameters, R1 (I > 2 σ (I)) =
0.051, wR2 (all data) = 0.111, GooF = 1.11, largest diff. peak and hole 0.300 and –0.319 e Å-3
.
Crystallographic data (excluding structure factors) for the structures reported in this work have been deposited with the 25
Cambridge Crystallographic Data Centre as supplementary publication no. CCDC 875800 (2), CCDC 875801 (2H2) and
CCDC 975802 (3), respectively. Copies of the data can be obtained free of charge on application to The Director, CCDC, 12
Union Road, Cambridge DB2 1EZ, UK (Fax: int.code+(1223)336-033; e-mail: [email protected]).
Experimental details 30
All the solvents were dried by conventional methods and stored over molecular sieves. Deutereited solvent were dried by
standing over molecular sieves (3 Å) and used without additional purification. All operations were performed under argon
atmosphere by conventional Schlenk technique or in a glove box (Mbraun Unilab). Reagents were purchased from Sigma-
Aldrich, Acros Organics (n-butyllithium, boron trichloride solution), Strem (dimethyltin dichloride) and dried by conventional
methods if needed. 35
NMR spectra were recorded at Varian Mercury 300 MHz NMR (1H,
13C,
19F) or Varian Inova 500 MHz (
1H,
13C,
10B)
spectrometers and were referenced to solvent (1H,
13C) or external standard (
10B,
19F).
13C spectra were
1H decoupled and
10B spectra were not
1H decoupled, if not otherwise stated.
Hydrogen (5.0) was purchased from AGA and dried additionally by passing through the cylinder with molecular sieves.
Hydrogenations (at 2 bar) were performed in thick-wall 25 ml Schlenk vessels or in J. Young valve NMR tubes purchased 40
from Wilmad. Schlenk vessels were equiped with gas-tight teflon valves and Glindemann PTFE sealing rings.
Chloro[bis(pentafluorophenyl)]borane was prepared as described.1
Starting imines and enamines have been prepared by conventional methods: 12, 13, 16, 17 by the TsOH-catalyzed
condensation of the respective amines and the carbonyl compounds with removal of water by either azeotropic distillation or
molecular sieves or sodium sulfate. 15 by a condensation of N-vinylpyrrolidin-2-one with ethyl benzoate.2 14 by a 45
decarboxylation of 2-phenyl-4-quinolinecarboxylic acid.
1-(2-iodophenyl)-2,2,6,6-tetramethylpiperidine (7)
1 D. J. Parks, W. E. Piers and G. P. A. Yap, Organometallics, 1998, 17, 5492.
2 Kirk L. Sorgi, Cynthia A. Maryanoff, David F. McComsey, and Bruce E. Maryanoff, Org. Synth. 1998, 75, 215
Electronic Supplementary Material (ESI) for Dalton TransactionsThis journal is © The Royal Society of Chemistry 2012
I
N
was prepared by a modified procedure.
3 14.1 g of 2,2,6,6-tetramethylpiperidine (0.1 mol), followed by 150 ml of THF, were
placed into a three-neck flask equipped with an internal thermometer. The reaction mixture was cooled to -40 °C with stirring
and 40 ml of 2.5M buthyllithium solution in hexane were added via syringe. Temperature grew up to -20 °C and the reaction
mixture was stirred at this temperature for additional 20 min. The reaction was cooled to -50 °C and 40.8 g of iodobenzene 5
(0.2 mol) in 50 ml of THF were added via syringe, maintaining temperature below -40 °C. The reaction mixture was then
stirred at -40 °C for 1 h and left stirred immersed in a thermally isolated cooling bath over night. 10 ml of aq. NH4Cl followed
by 100 ml of hexane were added and, after several minutes of stirring, the organic layer was separated in a separatory
funnel. The aqueous layer was additionally washed with 50 ml of hexane; the organic extracts were combined, dried over
Na2SO4 and rotavapored. A remaining oil was vacuum-distilled (1 torr) to give some recovered iodobenzene (40 °C), then N-10
phenyl-2,2,6,6-tetramethylpiperidine together with biphenyl (70-100 °C) and the title compound (120 °C) of 95% purity as a
yellowish oil (32%). 1H NMR (300 MHz, CDCl3) ppm: 0.92 (s, 6 H), 1.30 (s, 6 H), 1.50-1.70 (m, 4H), 1.80-1.95 (m, 2H), 6.89 (tm, J=7.5 Hz, 1
H), 7.30 (tm, J=7.5 Hz, 1 H), 7.42 (dm, J=7.8 Hz, 1 H) 7.94 (dm, J=7.8 Hz, 1 H). 13
C NMR (75 MHz, CDCl3) ppm (partial): 18.61, 25.61, 31.59, 41.29, 56.13, 127.21, 127.99, 131.62, 139.76. 15
I
N
CH3CH3
CH3
CH3
9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0ppm
0.00
0.05
0.10
0.15
0.20
0.25
6.00 5.934.162.521.05 0.970.80
Chloroform-d
I
N
CH3CH3
CH3
CH3
230 220 210 200 190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 -10 -20 -30ppm
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Chloroform-d
18.6
1
25.6
1
31.5
9
41.2
9
56.1
3
127.2
1127.9
9
131.6
2
139.7
6
3 S. Tripathy, R. LeBlanc, and T. Durst, Org. Lett., 1999, 1, 1973–1975.
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[2-(dimethylamino)phenyl]lithium (10)
Li
N
Into a 100 ml Schlenk flask 7.23 g of 2-bromo-N,N-dimethylaniline (36.1 mmol) and 30 ml of hexane were placed. It was
cooled in a ice bath and 22.6 ml of 1.6M buthyllithium (36.1 mmol) solution were added in small portions using syringe
during 15 min and stirred with ice bath cooling for another 3 h. Hexane was evaporated in vacuo almost to dryness leaving a 5
white slurry which was transferred to a glass filter and thoroughly washed with 4-6 ml portions of hexane (totally around 30
ml). The white solid was dried in vacuo, 4.13 g (90%). 1H NMR (500 MHz, C6D6) ppm: 2.02 (br. s., 6 H), 7.02 (m, 1 H), 7.34 (m, 2 H), 8.27 (s, 1 H).
13C NMR (75.43 MHz, C6D6) ppm: 46.84 (CH3), 118.93, 126.11, 128.00, 140.21, 166.18 (CN), 168.62 (CLi).
N
CH3
CH3
Li
13 12 11 10 9 8 7 6 5 4 3 2 1 0 -1 -2 -3ppm
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
6.471.791.00
Benzene-d6
10
N
CH3
CH3
Li
230 220 210 200 190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 -10 -20 -30ppm
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
Benzene-d6
46.8
4
118.9
3126.1
1128.0
0
140.2
1
166.1
8168.6
2
[2-(2,2,6,6-tetramethylpiperidin-1-yl)phenyl]lithium (9)
Li
N
Was prepared similar to [2-(dimethylamino)phenyl]lithium. 8.3 g of 1-(2-iodophenyl)-2,2,6,6-tetramethylpiperidine (24.2 15
Electronic Supplementary Material (ESI) for Dalton TransactionsThis journal is © The Royal Society of Chemistry 2012
mmol) in 75 ml of hexane were treated with 15.1 ml of 1.6M buthyllithium solution in hexane with ice bath cooling. The
mixture was stirred at +5 °C for additional 4 h, then cooled to -30 °C and filtered. The white precipitate was washed with
4x10 ml of cold (-30 °C) hexane and dried in vacuum to give 5.22 g (97%) of a white powder.
1H NMR (300 MHz, C6D6) ppm: 0.93 (s, 6 H), 1.28 (s, 6 H), 1.40-1.75 (m, 6 H), 7.20-7.37 (m, 2 H), 7.42 (tm, J=6.6 Hz, 1 5
H), 8.32 (dm, J=6.6 Hz, 1 H). 13
C NMR (75.43 MHz, C6D6) ppm (partial): 18.36, 24.70, 34.71, 44.01, 55.78, 124.75, 124.90, 127.45, 138.89, 154.22. Li
N
CH3CH3
CH3
CH3
12 11 10 9 8 7 6 5 4 3 2 1 0 -1 -2ppm
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
6.34 5.941.830.86
Benzene-d6
9.0 8.5 8.0 7.5 7.0 6.5
1.830.86 0.85
Benzene-d6
Li
N
CH3CH3
CH3
CH3
170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10ppm
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Benzene-d6
18.3
6
24.7
0
34.7
1
44.0
1
55.7
8
124.7
5124.9
0127.4
5
138.8
9
154.2
2
10
Electronic Supplementary Material (ESI) for Dalton TransactionsThis journal is © The Royal Society of Chemistry 2012
1-{2-[bis(pentafluorophenyl)boryl]phenyl}-2,2,6,6-tetramethylpiperidine (2)
B
C6F5
C6F5
N
In two separate Schlenk tubes 1.17 g of [2-(2,2,6,6-tetramethylpiperidin-1-yl)phenyl]lithium (5.26 mmol) was suspended in
15 ml of toluene, and 2 g of chloro[bis(pentafluorophenyl)]borane dissolved in 25 ml of toluene. Both tubes were cooled to -
80 °C and the suspension of the lithium compound was added to the chloroborane via cannula in one portion. The resultant 5
reaction mixture was allowed to warm to room temperature naturally and stirred over night, then evaporated to a half of the
volume and 20 ml of hexane were aded. Lithium chloride was filtered off and the residue evaporated to give the title
compound as spectroscopically pure orange crystalls (2.95 g, 100%). The solid may contain some residual toluene and
minor amounts of a polymeric tar, in this case additional purification can be performed; the crude material was redissolved in
hot hexane and filtered hot, then evaporated and dried in vacuum at 50 °C. An analytical sample was prepared by 10
recrystallization from 5 ml of hexane (1.53 g, 52%). The recrystallizing material should be free of toluene as it is occluded
into the crystals. The crystals suitable for X-ray diffraction analysis were collected from the recrystallization crop.
1H NMR (300 MHz, C6D6), ppm: 0.73 (s, 6 H), 1.0-1.35 (m, 5H), 1.14 (s, 6 H), 1.50-1.70 (m, 1 H), 7.04 (t, J=7.14 Hz, 1 H),
7.23 (m, 2 H), 7.38 (d, J=8.24 Hz, 1 H) 15
13C NMR (75 MHz, C6D6), ppm: 18.32 (s), 26.14 (s), 34.99 (s), 41.27 (s), 55.85 (s), 116.19 (pseudo-t), 124.99 (s), 131.36
(s), 132.80 (s), 135.83 (s), 137.88 (dm, J=255 Hz), 143.33 (dm, J=257 Hz), 147.47 (dm, J=247 Hz), 153.24 (s). 19
F NMR (282 MHz, C6D6), ppm: -127.2 (dm, J=23 Hz, 4F), -149.3 (d, J=20.5 Hz, 2F), -162.1 (m, 4F). 10
B NMR (282 MHz, C6D6), ppm: 62.3 (br. s. 1/2~630 Hz).
HRMS-ESI+: found 562.1781, calc. 562.1758 for [C27H23BF10N]
+, [M+H]
+. 20
N
B
CH3
CH3
CH3CH3
F
F
F
F
F F
FF
F
F
8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0ppm
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
6.005.911.83 0.94 0.86
Benzene-d6
7.9 7.8 7.7 7.6 7.5 7.4 7.3 7.2 7.1 7.0 6.9 6.8 6.7 6.6 6.5 6.4ppm
1.83 0.940.92
Benzene-d6
Electronic Supplementary Material (ESI) for Dalton TransactionsThis journal is © The Royal Society of Chemistry 2012
N
B
CH3
CH3
CH3CH3
F
F
F
F
F F
FF
F
F
230 220 210 200 190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 -10 -20 -30ppm
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Benzene-d6
18.3
2
26.1
4
34.9
9
41.2
7
55.8
5
116.1
9
124.9
9
131.3
6132.8
0135.8
3136.1
9139.5
7
145.8
3149.1
0153.2
4
160 155 150 145 140 135 130 125 120 115ppm
Benzene-d6
116.1
9
124.9
9
131.3
6
132.8
0
135.8
3136.1
9
139.5
7
141.6
2
145.0
4145.8
3
149.1
0
153.2
4
N
B
CH3
CH3
CH3CH3
F
F
F
F
F F
FF
F
F
-115 -120 -125 -130 -135 -140 -145 -150 -155 -160 -165 -170ppm
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
4.23 3.922.00
-162.1
2
-149.2
7
-127.2
9-1
27.2
2
Electronic Supplementary Material (ESI) for Dalton TransactionsThis journal is © The Royal Society of Chemistry 2012
150 100 50 0 -50 -100 -150ppm
-0.1
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
62.2
5
N
B
CH3
CH3
CH3CH3
F
F
F
F
F F
FF
F
F
Electronic Supplementary Material (ESI) for Dalton TransactionsThis journal is © The Royal Society of Chemistry 2012
Hydrido[bis(pentafluorophenyl)][2-(2,2,6,6-tetramethylpiperidinium-1-yl)phenyl]borate(1-)
(2H2)
B-
C6F5
C6F5
N+
H
H
500 mg of 1-{2-[bis(pentafluorophenyl)boryl]phenyl}-2,2,6,6-tetramethylpiperidine and 5 ml of toluene were placed into a 50 5
ml Schlenk tube, the tube was filled with 2 bar of hydrogen by two freeze-pump-thaw cycles and stirred at room temperature
for 30 min. Disappearance of the color occurred at room temperature almost instantly. The solvent was evaporated in
vacuum to give the product quantatively.
Atlernatively 50 mg of pure 1-{2-[bis(pentafluorophenyl)boryl]phenyl}-2,2,6,6-tetramethylpiperidine were dissolved in 0.5 ml 10
of C6D6 and placed into a J. Young valve NMR tube, filled with 2 bar of hydrogen and monitored by NMR at 70 °C. Upon
cooling white crystals precipitated, which were collected and analyzed by X-ray diffraction method.
1H NMR (CDCl3, 300 MHz): ppm 1.30 (s, 6H), 1.39 (s, 6H), 1.8-2.15 (m, 6H), 3.81 (br. q. J=76 Hz, 1H, BH), 7.10-7.35 (m,
3H), 7.91 (d, J=6.8 Hz, 1H), 9.40 (br. s, 1H, NH). 15
13C NMR (CDCl3, 75 MHz): ppm (ppm) 16.22 (s), 27.16 (CH3), 29.16 (s), 37.15 (s), 68.07 (s), 120.01 (s), 125.76 (s),
128.09 (s), 136.84 (d, J=248.5 Hz), 138.5 (d, J=246.8 Hz), 139.15 (m), 139.43 (s), 148.1 (d, J=237.6 Hz), 149.2 (q, J=55
Hz). 19
F NMR (CDCl3, 282 MHz): ppm -131.35 (d, J=24.4 Hz, 4F, o-F), -161.48 (tr, J=24.4 Hz, 2F, p-F), -165.50 (tr. d. J=24 Hz,
J,=21 Hz, 4F, m-F). 20
10B NMR (C6D6, 53.7 MHz): ppm -22.7 (d, JBH=23.5 Hz).
HRMS-ESI-: found 562.1730, calc. 562.1774 for [C27H23BF10N]
-, [M-H]
-.
10.0 9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5
0.00
0.05
0.10
0.15
6.396.003.501.02 1.000.96
Chloroform-d
Electronic Supplementary Material (ESI) for Dalton TransactionsThis journal is © The Royal Society of Chemistry 2012
170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Chloroform-d
149.6
9146.5
4
140.1
7139.4
4139.1
5138.4
5136.9
1135.2
5128.0
9125.7
6
120.0
1 68.0
7
37.1
5
29.1
627.1
6
16.2
2
-110 -115 -120 -125 -130 -135 -140 -145 -150 -155 -160 -165 -170 -175 -180 -185
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
-131.3
4-1
31.4
3
-161.4
8
-165.5
0
Electronic Supplementary Material (ESI) for Dalton TransactionsThis journal is © The Royal Society of Chemistry 2012
N+
B-
H
H
F
F
F
FF
F
F
F
F
F
CH3
CH3
CH3
CH3
110 100 90 80 70 60 50 40 30 20 10 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120ppm
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
-22.8
8-2
2.4
4
Electronic Supplementary Material (ESI) for Dalton TransactionsThis journal is © The Royal Society of Chemistry 2012
2-[bis(pentafluorophenyl)boryl]-N,N-dimethylaniline (3)
BC6F5 C6F5
N
To a solution of 1520 mg of chloro[bis(pentafluorophenyl)]borane (4 mmol) in 10 ml of toluene at -90 °C a precooled to -90 °C suspension of 508 mg [2-(dimethylamino)phenyl]lithium (4 mmol) in 5 ml of toluene was added in one portion via canula. Organolithium was additionally rinsed with 5 ml of toluene and transferred to reaction Schlenk tube. Reaction was allowed to 5
warm to room temperature naturally and stirred over night, then evaporated to a half of the volume and 5 ml of hexane were added. A precipitate was filtered off and the solvent was evaporated in vacuum to give 1820 mg of a crude compound. It was recrystalized from 5 ml of hexane and filtered. Grey crystals were redissolved in a hot 4:1 hexane-toluene mixture (10 + 5 ml) and filtered hot. A filtrate was evaporated to give 1280 mg (69 %) of white crystals. 10
1H NMR (500 MHz, C6D6): ppm 2.10 (s, 6 H), 6.30 (d, J=7.8 Hz, 1 H), 6.96 (t, J=7.8 Hz, 1 H), 7.13 (t, J=7.3 Hz, 1 H), 7.81
(d, J=6.8 Hz, 1 H). 13
C NMR (125.7 MHz, C6D6): ppm 47.90 (s),113.21 (s),115.99 (br. m),128.85 (s),129.81 (s),134.06 (t, J=3.8 Hz),137.68 (dm, J=250 Hz), 140.64 (dm, J=250 Hz),142.60 (br. m),147.70 (dm, J=245 Hz),153.72 (s). 19
F NMR (282 MHz, C6D6): ppm -129.7 (d, J=15.2 Hz, 4F, o-F), -156.57 (t, J=21.3 Hz, 2F, p-F), -163.43 (m, 4F, m-F). 15
10B NMR (53.7 MHz, C6D6): ppm 9.0 (s)
HRMS-ESI+: found 466.0821, calc. 466.0823 for [C20H11BF10N]
+, [M+H]
+.
N
CH3CH3
B
F
F
F
F
F
F
F
F
FF
9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0ppm
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
6.000.73 0.560.55
Electronic Supplementary Material (ESI) for Dalton TransactionsThis journal is © The Royal Society of Chemistry 2012
N
CH3CH3
B
F
F
F
F
F
F
F
F
FF
190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0ppm
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
Benzene-d6
47.9
0
113.2
1
115.9
9
128.8
5129.8
1
134.0
6136.6
4138.7
1
141.6
5142.6
0146.7
2148.6
7
153.7
2155 150 145 140 135 130 125 120 115 110
ppm
Benzene-d6
113.2
1
115.9
9
128.8
5129.8
1
134.0
6
136.6
4
138.7
1139.6
4
141.6
5142.6
0
146.7
2
148.6
7
153.7
2
N
CH3CH3
B
F
F
F
F
F
F
F
F
FF
-125 -130 -135 -140 -145 -150 -155 -160 -165 -170ppm
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
4.10 4.002.01
-163.4
3
-156.5
7
-129.7
8-1
29.7
2
Electronic Supplementary Material (ESI) for Dalton TransactionsThis journal is © The Royal Society of Chemistry 2012
N
B
CH3 CH3
F
F
F
FF
F
F
F
F
F
150 100 50 0 -50 -100 -150ppm
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
8.9
8
[2-(dimethylammonio)phenyl](hydrido)bis(pentafluorophenyl)borate(1-) (3H2)
B-
C6F5 C6F5
N+
H
H
20 mg of 2-[bis(pentafluorophenyl)boryl]-N,N-dimethylaniline were dissolved in 0.5 ml of C6D6 and placed into a J. Young 5
valve NMR tube. The tube was filled with 2 bar of hydrogen by three frease-pump-thaw cycles. The conversion to the title
compound was monitored by NMR.
Alternatively 300 mg of 2-[bis(pentafluorophenyl)boryl]-N,N-dimethylaniline were placed into a 25 ml Schlenk tube followed
by 5 ml of toluene and filled with 2 bar of hydrogen by two frease-pump-thaw cycles and stirred at room temperature for 12-
24 h. The solvent was removed in vacuo to give quantatively a white solid or a colorless sticky oil crystallizing on standing. 10
1H NMR (300 MHz, C6D6): ppm 1.64 (d, J=5.2 Hz, 6H), 3.84 (q, J=76.6 Hz, 1H), 6.10 (d, J=8.2 Hz, 1H), 6.83 (t, J=7.7 Hz,
1H), 7.03 (t, J=7.4 Hz, 1H), 7.78 (br. s., 1H), 9.42 (br. s., 1H) 13
C NMR (75 MHz, C6D6): ppm 44.84 (s), 114.95 (s), 126.79 (s), 129.56 (s), 137.51 (d, J=247 Hz), 137.46 (s), 139.12 (d, J=247 Hz), 143.23 (s), 148.66 (d, J=232 Hz). 15
19F NMR (282 MHz, C6D6): ppm -132.5 (d, J=23 Hz, 4F, o-F), -161.3 (t, J=20.6 Hz, 2F, p-F), -165.3 (m, 4F, m-F).
10B NMR (53.7 MHz, C6D6): ppm -23.7 (d, J=33,3 Hz).
HRMS-ESI-: found 466.0850, calc. 466.0834 for [C20H11BF10N]
-, [M-H]
-.
Electronic Supplementary Material (ESI) for Dalton TransactionsThis journal is © The Royal Society of Chemistry 2012
10.0 9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5
0.00
0.05
0.10
0.15
6.396.003.501.02 1.000.96
Chloroform-d
N+
CH3CH3
B-
F
F
F
F
F
F
F
F
FF
H
H
13 12 11 10 9 8 7 6 5 4 3 2 1 0 -1 -2 -3ppm
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
6.001.071.03 0.77 0.730.62
Benzene-d6
Electronic Supplementary Material (ESI) for Dalton TransactionsThis journal is © The Royal Society of Chemistry 2012
N+
B-
CH3 CH3
H
H
F
F
F
FF
F
F
F
F
F
230 220 210 200 190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 -10 -20 -30ppm
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Benzene-d6
44.8
4
114.9
5
126.7
9129.5
6
135.8
6137.4
6
140.7
6143.2
3147.1
2150.2
0
N+
B-
CH3 CH3
H
H
F
FF
FF
F
F
F
F
F
-90 -95 -100 -105 -110 -115 -120 -125 -130 -135 -140 -145 -150 -155 -160 -165 -170 -175 -180 -185 -190 -195ppm
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
-165.2
9
-161.3
0
-133.0
0-1
32.9
1
N+
B-
CH3 CH3
H
H
F
F
F
FF
F
F
F
F
F
150 100 50 0 -50 -100 -150ppm
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
-23.9
5-2
3.3
7
Catalytic hydrogenation of imines and enamines 5
Into a 25-ml Schlenk tube was placed an imine or enamine (0.25 mmol), catalytic amount of the catalyst (the aminoboranes
2 or 3, or the ammonium borohydrides 2H2 or 3H2) and 1 ml of solvent (benzene-d6 or toluene). The vessel was charged
with 2 bar of hydrogen by two freeze-pump-thaw cycles and stirred at respective conditions (time and temperature). The
content was then analyzed by NMR to define conversions. In case of toluene as a solvent, it was stripped off in vacuo and
the sample redissolved in a deuterated solvent. 10
Electronic Supplementary Material (ESI) for Dalton TransactionsThis journal is © The Royal Society of Chemistry 2012