2 Frustrated Lewis Pair Catalyzed Asymmetric Reactions
63
Table 2.24 Catalytic asymmetric hydrosilylation of imines
R
R'
N
PMP
1
R
R
HN
PMP
1
HB(C 6 F 5 ) 2 (2 mol %)
9i (1 mol %)
PhMe 2 SiH
3
5
entry product
yield (%) ee (%)
1
5m
Ph
Me
HN
PMP
1
>99
67
2
5x
Me
HN
PMP
1
MeO
99
65
3
5j’
Me
HN
PMP
1
Br
96
68
4
5k’
Me
HN
PMP
1
MeO
MeO
OMe
96
82
5
5l’
Ph
Et
HN
PMP
1
>99
50
6
5m’
Me
HN
PMP
1
86
44
7
5n’
Me
HN
PMP
1
70
60
was carried under mild conditions and exhibited good substrate tolerance.
The chiral skeletons may influence the reactivity and enantioselectivity to a large
extent. C 2 -Symmetric 1,1’-spirobiindane chiral dienes have been successfully developed by the Du group [58]. With chiral dicarboxylic acid 65 as starting material, ester