2 Frustrated Lewis Pair Catalyzed Asymmetric Reactions
37
Table 2.4 Catalytic asymmetric hydrogenation of imines
Ar
Me
N
Ph
Ar
Me
HN
Ph
(pS,R)-15 (20 mol %)
H 2 (60 bar), rt
3
5
Entry product
yield (%) ee (%)
1
5a
Ph
Me
HN
Ph
46
52
2
5q
Me
HN
Ph
MeO
61
69
3
5r
Me
HN
Ph
Cl
40
58
4
5d
Me
HN
Ph
MeO
41
42
5
5s
Me
HN
Ph
55
52
Fe
Ph
PMes 2
1. HB(C 6 F 5 ) 2 10
2. H 2 (1.5 bar)
Fe
Ph
PHMes 2
BH(C 6 F 5 ) 2
Fe
Ph
PHMes 2
BH(C 6 F 5 ) 2
(pS)-14
(pS, R)-15
(pS, S)-15
91% yield
ca. 4:1
+
Scheme 2.6 Synthesis of C4-bridged FLP 15