Chemistry Reference
In-Depth Information
TABLE 7.4. Asymmetric Hydrogenation of Enamides
R
R
Rh catalysts
NHAc
*
NHAc
% ee
(Confi g.)
Ligand
R
a
S
/
C
Reaction Conditions
b
Reference
H
500
MeOH, 22 ° C, 6 psi H
2
143
(
R, R
) - Me - BPE
95.2 (
R
)
Me
500
MeOH, 22 ° C, 6 psi H
2
143
95.4 (
R
)
H
5,000
MeOH, 25 ° C, 10 bar H
2
5 2
(
R, R
) - Ph - BPE
99 (
R
)
Et -
35
H
100
MeOH, rt, 10 atm H
2
68b
96 (
S
)
(
R,S,S,R
) - DIOP *
H
50
MeOH, rt, 10 bar H
2
98.8 (
R
)
144
Me
50
MeOH, rt, 10 bar H
2
97.3 (
R
)
144
(
S,S
) -
108
H
100
CH
2
Cl
2
, rt, 1 atm H
2
98.5 (
R
)
145
Me
100
CH
2
Cl
2
, rt, 1 atm H
2
>
99 (
R
)
145
93
H
100
MeOH/toluene, rt, 1 atm H
2
96 (
S
)
146
(
S,S
) -
t
Bu - BisP *
H
100
MeOH, rt, 3 atm H
2
98 (
R
)
147
(
S,S,R,R
) - TangPhos
H
10,000
MeOH, rt, 20 psi H
2
99.3 (
R
)
8 4
Me
100
MeOH, rt, 20 psi H
2
98 (
R
)
8 4
(
R,R,S,S
) - DuanPhos
H
100
MeOH, rt, 20 psi H
2
> 99 (
R
)
5 8
(
R
) - H
8
- BDPAB
H
200
THF, 5 ° C, 1 atm H
2
96.8 (
R
)
148
(
S
C
,
R
P
,
S
a
)
- 103
H
5,000
CH
2
Cl
2
, rt, 10 bar H
2
99.3 (
R
)
93a
(
S
) - MonoPhos
H
100
CH
2
Cl
2
, − 20 ° C, 300 psi H
2
95 (
S
)
149
(
S
)
- 54
H
100
THF, 5 ° C, 300 psi H
2
99 (
R
)
6 6
(
S
) - H
8
- MonoPhos
H
100
THF, − 10 ° C, 300 psi H
2
96 (
R
)
150
(
S
) - SIPHOS
H
200
Toluene, 5 ° C, 10 atm H
2
98.7 (
S
)
94a
(
R
) -
40
H
100
CH
2
Cl
2
, rt, 1 atm, 24 h
96 (
R
)
131
Me
100
CH
2
Cl
2
, rt, 1 atm, 24 h
99 (
R
)
131
(
R,R
) - Me - UCAP - Ph
H
100
MeOH, rt, 5 atm, 3 h
94 (
R
)
151
63
Me
100
CH
2
Cl
2
, rt, 10 atm H
2
96.7 (
S
)
152
(
S,S
) - BINAPHANE
Me
100
CH
2
Cl
2
, rt, 20 psi H
2
99.1 (
S
)
153
(
R,R
) - BICP
Me
100
Toluene, rt, 40 psi H
2
95.0 (
R
)
46b
(
R,R,R,R
) -
113
Me
100
MeOH, rt, 45 psi H
2
98 (
S
)
154
(
R,R,R,R
) - SK - Phos
Me
100
MeOH, rt, 45 psi H
2
97 (
S
)
154
(
S,S
) - Me - UCAP -
(1 - Nap)
Me
500
MeOH, 30 ° C, 4 atm, 15 h
95 (S)
155
a
E/Z
mixture when R = Me.
b
Complete conversion unless otherwise noted.
