Utilizing Micellar Catalysis for Organic Synthesis: A Desk ...
Chiral Proton Catalysis in Organic Synthesis Proton Catalysis in Organic Synthesis Samantha M....
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Chiral Proton Catalysis in Organic Synthesis
Samantha M. FrawleyOrganic Seminar
September 14th, 2005
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Seminar Outline
IntroductionLewis Acid-assisted Chiral Brønsted Acids
Enantioselective protonation for silyl enol ethers
Chiral Brønsted Acid Catalysis: Polar Covalent Enantioselective synthesis using chiral phosphoric acidsEnantioselective synthesis using di-ol Brønsted acids
Chiral Brønsted Acid Catalysis: Polar IonicDifficulties in formationFirst successful useEnantioselective synthesis using a “chiral proton”
Conclusion
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Lewis Acid Catalysis
AdvantagesStructural diversity and reactivity enabling the design for a variety of ligandsEasily adapted for asymmetric reactions
DisadvantagesMany are metals
ToxicExpensive reagentsCostly waste disposal
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Brønsted Acid Catalysis
AdvantagesMild reaction conditions Non-toxic waste Inexpensive and stable catalysts
DisadvantagesDifficult to accomplish asymmetricallyHard to tune for various reactions
Dalko, R.; Moisan, L. Angew. Chem. Int. Ed. 2001, 40, 3726.List, B.; Lerner, R.; Barbas III, C. J. Am. Chem. Soc. 2000, 122, 2395.
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Tips From Nature
H R2
O
R1 R2
O OH+
H R2
O
R1
OHR1
OH
H
H
R1
OH
H R2
O
R1 R2
O OH+
H R2
OH
R1
OHL*
L H*
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Methods in Chiral Proton Catalysis
Lewis Acid-assisted Chiral Brønsted Acids
Chiral Brønsted Acids: Polar Covalent
Chiral Brønsted Acids: Polar Ionic
M H + substrate H substrate**
L H + substrate H substrate**
L H H substratesubstrate+ **
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Seminar Outline
IntroductionLewis Acid-assisted Chiral Brønsted Acids
Enantioselective protonation for silyl enol ethers
Chiral Brønsted Acid Catalysis: Polar Covalent Enantioselective synthesis using chiral phosphoric acidsEnantioselective synthesis using di-ol Brønsted acids
Chiral Brønsted Acid Catalysis: Polar Ionic Difficulties in formationFirst successful useEnantioselective synthesis using a “chiral proton”
Conclusion
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Lewis Acid-assisted Chiral BrønstedAcids (LBA)
Brønsted acids coordinate to Lewis acidsRestricting orientation of protonsRaising the acidity of the protons
O
O
Ar
ArSnCl4
H
R
O
O
H
R
SnCl4
Nakamura, S.; Kaneeda, M.; Ishihara, K.; Yamamoto, H. J. Am. Chem. Soc. 2000, 122, 8120.Ishihara, K.; Nakashima, D.; Hiraiwa, Y.; Yamamoto, H. J. Am. Chem. Soc. 2003, 125, 24.
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Enantioselective Protonation of SilylEnol Ethers using an LBA
OSiMe3Ph
O
+toluene
-78 oC, 1 h>99% yield
PhO
O
H
R
SnCl4
O OH
RSn
Cl
Cl
Cl
Cl
OSiR3
OSiR3Ar (R) LBA
OAr
Ar
Nakamura, S.; Kaneeda, M.; Ishihara, K.; Yamamoto, H. J. Am. Chem. Soc. 2000, 122, 8120.Ishihara, K.; Nakashima, D.; Hiraiwa, Y.; Yamamoto, H. J. Am. Chem. Soc. 2003, 125, 24.
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Enantioselective Protonation of SilylEnol Ethers-Results
OSiR3Ar
3
BINOL 1-SnCl4
toluene, -78 oC, 1 h100 % conv.
OAr
4
entry 3 (Ar, R3Si) ee (%), (config)
1
2
3
4
5
6
3a (Ph, Me3Si)
3b (Ph, t-BuMe2Si)
3c (p-MeOC6H4, t-BuMe2Si)
3d (p-MeOC6H4, Me3Si)
3e (2-naphthyl, Me3Si)
91, (S)
86, (S)
86, (R)
82, (S)
96, (S)
91, (S)
3b (Ph, t-BuMe2Si)
7 3f (2-naphthyl, t-BuMe2Si) 91, (S)
Nakamura, S.; Kaneeda, M.; Ishihara, K.; Yamamoto, H. J. Am. Chem. Soc. 2000, 122, 8120.
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Enantioselective Protonation of SilylEnol Ethers Acetals Using Various (R,R)-LBAs
OSiMe3Ph
OO
O
Ar
ArSnCl4+
solvent
-78 oC, 1 h>99% yield
Ph
H
R
entry LBA solvent ee (%)
1
2
3
4
5
toluene-CH2Cl2 (1:1)
toluene
toluene
toluene
toluene
66 [S]
51 [S]
35 [S]
96 [S]
96 [S]
1-SnCl4
2-SnCl4
3-SnCl4
4-SnCl4
6-SnCl4
O
O
Ar
ArSnCl4
H
R
1: Ar = Phenyl; R = H2: Ar = 3,4,5-F3C6H2; R = H3: Ar = C6F5; R = H4: Ar = 3,5-(CF3)2C6H3; R = H6: Ar = 3,5-(CF3)2C6H3; R = Bn
Ishihara, K.; Nakashima, D.; Hiraiwa, Y.; Yamamoto, H. J. Am. Chem. Soc. 2003, 125, 24.
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Enantioselective Protonation of Ketene Disilyl Acetals
OSiMe3
CH3
OSiMe3
CO2H toluene, -78 oC
>95% yield
O
O
Ar
ArSnCl4
H
RCH3
Ar
H
OH MeCl
Sn
Cl
Cl
ClO
HF3C
Me3SiOCF3
Favored
OSiMe3
Ar
H
OH MeCl
Sn
Cl
Cl
ClO
HF3C
CF3 OSiMe3
OSiMe3
Unfavored
Ishihara, K.; Nakashima, D.; Hiraiwa, Y.; Yamamoto, H. J. Am. Chem. Soc. 2003, 125, 24.
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Enantioselective Protonation of Ketene Disilyl Acetals with (R,R)-LBAs
R2OSiMe3
R1
OSiMe3
R2 CO2H
R1
toluene, -78 oC>95% yield
Chiral LBA
entry LBA solvent product ee (%)
1
2
3
4
5
6
(R,R)-6-SnCl4
(R,R)-7-SnCl4
(R,R)-7-SnCl4
(R,R)-8-SnCl4
(R,R)-7-SnCl4
(R,R)-7-SnCl4
toluene
toluene
toluene
toluene
toluene
toluene
76 [S]
86 [S]
90 [S]
90 [S]
85 [S]
85 [S]
CO2H
MeO
CO2H
i-Bu
Ph CO2H
Ph CO2H
OMe
CO2H
Ph CO2H
i-Pr
O
OSnCl4
H
R
6: R = Bn7: R = o-FC6H4CH28: R = Me
CF3
F3CF3C
CF3
Ishihara, K.; Nakashima, D.; Hiraiwa, Y.; Yamamoto, H. J. Am. Chem. Soc. 2003, 125, 24.
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Final Thoughts on Lewis Acid-assisted Chiral Brønsted Acid
AdvantagesIncreases the acidity of the proton in the BrønstedacidPreorganizes the orientation of the proton, which improves enantioselectivity
DisadvantagesStill using metals…
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Seminar Outline
IntroductionLewis Acid-assisted Chiral Brønsted Acids
Enantioselective protonation for silyl enol ethers
Chiral Brønsted Acid Catalysis: Polar Covalent Enantioselective synthesis using chiral phosphoric acidsEnantioselective synthesis using di-ol Brønsted acids
Chiral Brønsted Acid Catalysis: Polar IonicDifficulties in formationFirst successful useEnantioselective synthesis using a “chiral proton”
Conclusion
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Polar Covalent Hydrogen Bond-An Introduction
L H + substrate H substrate**
Orientational flexibility on proton is limitedThe proton is acidic enough so there is no need for a Lewis acidFacial preference of proton donation can be promoted by chiral acid to yield a enantiomeric/diastereomeric product
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Using Chiral Phosphoric Acids to Promote Enantioselectivity
BINOL-derived phosphoric acid: forcing selective nucleophilic attack
OO
PO
O
H
R
R
Akiyama, T.; Itoh, J.; Yokota, K.; Fuchibe, K. Angew. Chem. Int. Ed. 2004, 43, 1566.
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Mannich-Type Reaction Catalyzed by a Chiral Phosphoric Acid
R1 H
N
HO
+OTMS
OMeR1
CO2MeHN
HO
OO
POH
O
R
R10 mol%
toluene-78 oC, 24 h
OO
PO
O
H
R
R
R
N
H Nuc
HO
Akiyama, T.; Itoh, J.; Yokota, K.; Fuchibe, K. Angew. Chem. Int. Ed. 2004, 43, 1566.
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Effects of the Aromatic Substituentson Chiral Phosphoric Acids
H
N
HO
+OTMS
OMeR1
CO2MeHN
HO
O
Ar
Ar
OP
OH
O
30 mol%
toluene-78 oC
Entry Ar t [hr] Yield [%] ee [%]
1
2
3
4
5
H
Ph
2,4,6-Me3C6H2
4-MeOC6H4
4-NO2C6H4
22
20
27
46
4
57
100
100
99
96
0
27
60
52
87
Akiyama, T.; Itoh, J.; Yokota, K.; Fuchibe, K. Angew. Chem. Int. Ed. 2004, 43, 1566.
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Enantioselective Mannich-type Reaction Results
R1 H
N
HO
+OTMS
OMeR1
CO2MeHN
HO
OO
POH
O
NO2
NO2
10 mol%
toluene-78 oC, 24 h
Entry R1 Yield [%] ee [%]
1
2
3
4
Ph
p-MeC6H4
p-FC6H4
p-ClC6H4
98
100
100
100
89
89
85
80
Akiyama, T.; Itoh, J.; Yokota, K.; Fuchibe, K. Angew. Chem. Int. Ed. 2004, 43, 1566.
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Diastereoselective Mannich-Type Reaction: Mechanistic Insight
N
HO
+
OTMS
OR3H
R2CO2R3
HN
HO
R2
+CO2R3
HN
HO
R2
OO
POH
O
NO2
NO2
10 mol%
OOP O
OH
N
HO
HR2
R3O OTMS
NO2
Akiyama, T.; Itoh, J.; Yokota, K.; Fuchibe, K. Angew. Chem. Int. Ed. 2004, 43, 1566.
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Diastereoselective Mannich-type Reaction Results
R1
N
HO
+
OTMS
OR3H
R2 R1CO2R3
HN
HO
R2
+
R1CO2R3
HN
HO
R2
OO
POH
O
NO2
NO2
10 mol%
Entry
123456789
10
R1R2 R3 Yield [%] syn / anti ee [%]
96888481889091879091
87:1392:891:994:694:695:593:793:795:5
100:0
1001001001008191
100926579
EtEtEtEtEtEtEtEtEtMe
MeMeMeMeMeMePhCH2
PhCH2
PhCH2
Ph3SiO
Php-MeOC6H4
p-FC6H4
p-MeC6H4
2-ThienylPhCH=CHPhp-MeOC6H4
PhCH=CHPh
Akiyama, T.; Itoh, J.; Yokota, K.; Fuchibe, K. Angew. Chem. Int. Ed. 2004, 43, 1566.
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EnantioselectiveHydrophosphonylation of Imines
R P(Oi-Pr)2R H
N
OMe
PO
HOi--Pr
Oi-Pr+
10 mol%
m-Xylenert
HN
O
OMe
OO
CF3
CF3
CF3
CF3
PO
O
H
Akiyama, T.; Morita, H.; Itoh, J.; Fuchibe, K. Org. Lett. 2005, 7, 2583.
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EnantioselectiveHydrophosphonylation-Results
R1 H
N +10 mol% chiral Phosphoric Acid
OMe
PO
H Oi-PrOi-Pr m-Xylene, rt R1 P(Oi-Pr)2
HN
O
OMe
Entry R1 Yield [%] ee [%]
1
2
3
4
Ph
o-MeC6H4
o-NO2C6H4
p-CH3C6H4CH=CH
84
76
72
52
69
77
time (h)
24
46
24
170
145
171
70
49
46
88
97
80
82
92
86
86
83
82
87
88
90
5
6
7
8
9
p-ClC6H4CH=CH
o-CH3C6H4CH=CH
o-ClC6H4CH=CH
o-NO2C6H4CH=CH
o-CF3C6H4CH=CH
OO
F3C
CF3
F3C
CF3
PO
O H
Akiyama, T.; Morita, H.; Itoh, J.; Fuchibe, K. Org. Lett. 2005, 7, 2583.
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Mechanistic Insight and Experimental Support
OO
F3C
CF3
F3C
CF3
PO
O H
OP
H OR
Ar HORN
OMe10 mol%
m-Xylenert
Ph
NPMP
Ph P(OR)2
HN
O
+ Nu
PMP
OO
F3C
CF3
F3C
CF3
PO
O H
OP
HOR
POH
OROROR
Entry Nu Yield [%] ee [%]
1
2
HPO(O-i-Pr)2
P(O-i-Pr)3
92
23
84
3
Akiyama, T.; Morita, H.; Itoh, J.; Fuchibe, K. Org. Lett. 2005, 7, 2583.
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Enantioselective Reduction of Imines Using Hantzsch Dihydropyridine
R R1
NR2 N
H
OEt
O
EtO
O
R R1
HNR2
Ar
Ar
OO
POOH
5 mol%
*
Rueping, M.; Sugiono, E.; Azap, C.; Theissmann, T.; Bolte, M. Org. Lett. 2005, 7, 3781.
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Catalytic cycle for the Transfer Hydrogenation
R R1
N
ArOArO
POOH
R2
ArOArO
POO
R R1
NR2H
NH
OEt
O
EtO
O
R R1
HNR2
*
NH
OEt
O
EtO
O
ArOArO
POO
N
OEt
O
EtO
O
*
*
*
HH
Rueping, M.; Sugiono, E.; Azap, C.; Theissmann, T.; Bolte, M. Org. Lett. 2005, 7, 3781.
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Catalytic Enatioselective Reduction Results
R CH3
NNH
OEt
O
EtO
O
R CH3
HN
*benzene, 60 oC5 mol% Bronsted acid
OMe OMe
Entry R Yield [%] ee [%]
1
2
3
4
71
76
82
72
74
84
74
91
71
76
62
46
78
78
74
72
72
82
5
6
7
8
9
p-CF3C6H4
Ph
o-FC6H4
o-CH3C6H4
2,4-Me2C6H3
biphenyl
p-MeOC6H4
m-BrC6H4
o-CF3C6H4
OO
F3C
CF3
F3C
CF3
PO
O H
Rueping, M.; Sugiono, E.; Azap, C.; Theissmann, T.; Bolte, M. Org. Lett. 2005, 7, 3781.
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Seminar Outline
IntroductionLewis Acid-assisted Chiral Brønsted Acids
Enantioselective protonation for silyl enol ethers
Chiral Brønsted Acid Catalysis: Polar CovalentEnantioselective synthesis using chiral phosphoric acidsEnantioselective synthesis using di-ol Brønsted acids
Chiral Brønsted Acid Catalysis: Polar Ionic Difficulties in formationFirst successful useEnantioselective synthesis using a “Chiral proton”
Conclusion
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Chiral Brønsted Acid Catalyzed Asymmetric Morita-Baylis-Hillman
2 mol% Bronsted acid
0 oCEt3P
THF,Ph H
OO O
Ph
OH
+
O
O
OCH3
O
O
OCH3
H
7
H
X
OHOH
5a X = H
X
5b X = Br5c X = CHPh2
X
OCH3
OH
6a X = H
X
6b X = Br
entry catalyst % yield %ee
1
2
3
4
5
6
7
8
9
10
5a5b
8a
8e
8b8c
6a
1
6b
5
74
73
73
69
9
70
84
43
15
32
48
79
86
31
88
86
3
3
11
12
13
8d 68 86
7 13 5
5c 36 74
Ar
OHOH
Ar
8a Ar = Ph8b Ar = 3,5 Me2Ph
8d Ar = biphenyl8c Ar = 3,5 (CF3)2Ph
8e Ar = 2,4,6 Me3Ph
McDougal, N.; Trevellini, W.; Rodgen, S.; Kliman, L.; Schaus, S. Adv. Synth. Catal. 2004, 346, 1231.
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Asymmetric Morita-Baylis-Hillman Reaction Results
Ar
OHOH
Ar
8b Ar = 3,5 Me2Ph8c Ar = 3,5 (CF3)2Ph
R H
OO O
R
OH10 mol % catalystEt3PTHF
-10 oC
+
Entry Aldehyde Catalyst Yield [%] % ee
1
2
3
4
5
6
Ph H
O
H
O
n-Pent
H
O
H
OEt
BnO H
O
BnOH
O
8c
8b
8b
8b
8c
8b
88
86
80
72
74
56
90
91
90
96
82
55
7 H
O
8b 71 96
8
9
10
11
12
H
O
O
O
H
O
H
H
O
Ph H
OO2N
O
8b
8c
8b
8b
8b
82
70
40
30
39
95
92
67
34
81
Entry Aldehyde Catalyst Yield [%] % ee
McDougal, N.; Trevellini, W.; Rodgen, S.; Kliman, L.; Schaus, S. Adv. Synth. Catal. 2004, 346, 1231.
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Brønsted Acid vs. Lewis Acid Catalyzed Morita-Baylis-Hillman
OO
Bs-Bus-Bu
Li
Bronsted Acid Catalyzed Results
Entry Aldehyde Time (h) Yield [%] % ee
1
2
3
4
Ph H
O
H
O
H
O
Ph H
O
48
48
48
88
71
82
40
90
96
95
67
48
Heterobimetallic Catalyst Results
Time (h) Yield [%] % ee
48
288
120
49
71
94
32
58
63
99
15
240
Ar
OHOH
Ar
8b Ar = 3,5 Me2Ph8c Ar = 3,5 (CF3)2Ph
Matsui, K.; Takizawa, S.; Sasai, H. Tetrahedron Lett. 2005, 46, 1943.McDougal, N.; Trevellini, W.; Rodgen, S.; Kliman, L.; Schaus, S. Adv. Synth. Catal. 2004, 346, 1231.
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Brønsted Acid Catalyzed Enantioselective Nitroso AldolReaction
O
O
OHOH
(30mol%)
toluene-78 oC, 2h
NR' R'
RR
NO O
NOH
+nn
OO
OHONO
H
NRR
Momiyama, N.; Yamamoto, H. J. Am. Chem. Soc. 2005, 127, 1080.
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N-Nitroso Aldol Synthesis Results
O
O
OHOH
(30mol%)
toluene-78 oC, 2h
NR' R'
RR
NO O
R R
NOH
+nnN
X
X = C: 1bX = O: 1cX = S: 1d
entry enamine n % Yield % ee
1
2
3
4
5
6
7
8
1b 0
1
1
1
1
1
1
2
H, H
Me, Me
<1
81
78
63
67
91
88
81
83
82
91
65
79
77
80
R, R
1b1b
1b
1b
1c
1d
1e
H, H
H, H
H, H
H, H
H, H
(OCH2CH2O) __
1e
N
OO
Momiyama, N.; Yamamoto, H. J. Am. Chem. Soc. 2005, 127, 1080.
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Final Thoughts on Chiral BrønstedAcids: Polar Covalent
AdvantagesNo more metals in the reactionThe acid works to activate the substrate and control the stereochemistryMild reaction conditions
LimitationsVery dependant on aciditySubstrate dependent
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Seminar Outline
IntroductionLewis Acid-assisted Chiral Brønsted Acids
Enantioselective protonation for silyl enol ethers
Chiral Brønsted Acid Catalysis: Polar Covalent Enantioselective synthesis using chiral phosphoric acidsEnantioselective synthesis using di-ol Brønsted acids
Chiral Brønsted Acid Catalysis: Polar IonicDifficulties in formationFirst successful useEnantioselective synthesis using a “chiral proton”
Conclusion
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Developing Enantioselective Polar Ionic Hydrogen Bonds
L H H substratesubstrate+ **
BenefitsNo acidity/basicity catalyst limitationsLigands serve only as a “binding pocket” to deliver a proton asymmetrically to the substrate
ChallengesSpherical nature of empty 1s orbitalProton’s nucleus is more “promiscuous” than other Lewis acidsChiral complex leads to achiral catalysis by solvent-coordinated Brønsted acid
Nugent, B.; Yoder, R.; Johnston, J. J. Am. Chem. Soc. 2004, 126, 3418.
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The First Use of Polar Ionic Bonds as Stereocontrol Elements
4-5 oC*-27 oC
MeON
R'
NH
R H
H
O O+
MeO
OH
O
HHCH2Cl2
MeO
OH
H
H
O
5a 6a
+
H3C(H2C)14
NH2
NH27
9
NH
HON
HO
OH
catalyst (equiv) % yield %ee of 5a
8a (1)
9a (1)
9b (1)
7a (1)<346
70
83
35
011
22
19a (1) 73 26
no catalyst
(5a + ent-5a):(6a + ent-6a) %ee of 6a
<0.1:1
2.4:1
2.5:1
2.8:1
2.8:11.0:1
0 0
0
15
28
33
2
*NH
HONH
8
a: Counterion = tetrakis(3,5-bis(trifouoromethyl)phenyl)borateb: Counterion = picrate
Schuster, T.; Bauch, M.; Dürner, G.; Göbel, M. Org. Lett. 2000, 2, 179.
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Mechanistic Insight on Major Product Formation
The diene is shielded from the backside due to the phenylnaphthalene moiety Cycloaddition occurs at the front
O
OH
H
ON NH
HH
O O
NNH
R H
H
O OH
O
NNH
R H
H
O OH
O
unfavored favored
Schuster, T.; Bauch, M.; Dürner, G.; Göbel, M. Org. Lett. 2000, 2, 179.
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Enantioselective Diels-Alder with Amidinium Ions-Results
H3C(H2C)14
NH2
NH27
HO
OH
NH
HONH
9a
entry catalyst (equiv) % yield %ee of 5b
123
4
5
6
9a (0.25)
9a (0.5)
9a (1)
9a (0.1)3320
70
89
94
3940
40
43
9a (1) 83 40
7(1)
(5b + ent-5b):(6b + ent-6b) %ee of 6b
2.8:1
3.1:13.1:1
3.0:1
2.9:13.2:1
0 0
4244
45
46
50*
4-5 oC*-27 oC
MeON
R'
NH
R H
H
O O+
MeO
OH
O
HHCH2Cl2
MeO
OH
H
H
O
5b 6b
+
Schuster, T.; Bauch, M.; Dürner, G.; Göbel, M. Org. Lett. 2000, 2, 179.
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Did Polar Ionic Hydrogen Bonds Really Play a Role in the Enantioselectivity?
The amidinium ion induced facial selectivity based on one face was sterically blockedWhen a stronger counterion was used, the stereoselectivity disappearedThis work lead to the thought “can we design a chiral proton?”
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Enantioselective Aza-Henry Reaction using a Polar Ionic Hydrogen Bond
R1-C6H4 H
NBocR2 NO2
N
NH
HN
H
NH
H
+ R1-C6H4
NHBocNO2
R2
OTf
10 mol%
-20 oC
NN
N
H H
N H
N
H
Boc
R2 NO2
Nugent, B.; Yoder, R.; Johnston, J. J. Am. Chem. Soc. 2004, 126, 3418.
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Aza-Henry Results
10 mol%
-20 oCR1-C6H4 H
NBocR2 NO2+ R1-C6H4
NHBocNO2
R2
HQuin-BAM-HOTf
entry R1 R2 % Yield dr % ee
1
2
3
4
5
6
7
8
9
10
H
p-NO2
m-NO2
H
p-CF3O
p-Cl
m-NO2
o-NO2
p-CF3
p-NO2
H
H
H
CH3
CH3
CH3
CH3
CH3
CH3
CH3
57
61
65
69
53
59
51
62
50
60
-
-
-
14:1
19:1
17:1
11:1
7:1
19:1
7:1
60
82
95
59
81
82
89
82
84
90
N
NH
HN
H
NH
H
OTf
Nugent, B.; Yoder, R.; Johnston, J. J. Am. Chem. Soc. 2004, 126, 3418.
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Final Thoughts on Chiral BrønstedAcids: Polar Ionic
Advantages:source of a chiral protonAbility to circumnavigate previous problems associated with forming a chiral protonChiral proton is used both to activate and control stereochemistry
LimitationsSubstrate dependent-has to fit in the “binding pocket” of the acid in order to be efficient
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Conclusion
Chiral Brønsted acids are successful at enantioselective proton donation
AdvantagesNo metalsReusable catalystMild reaction conditions
DisadvantagesReactions are very substrate dependentRequires different catalyst for different reactions
Development of other reactionsDevelopment of new catalysts
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AcknowledgementsDr. WagnerDr. TepeGroup Members
VasudhaTeriJasonChrisAdamManasiJamesGwenSam 2Brandon