2 Frustrated Lewis Pair Catalyzed Asymmetric Reactions
49
NH N
Me
Me
L-tartaric acid
liquid
+
crystal
D-tartaric acid
NaOH
crystal
NH N
Me
Me
NaOH
NH N
Me
Me
33i
(S,S)-33i
73% (>99% ee)
(R,R)-33i
74% (>99% ee)
ΙΙ
Ι
Scheme 2.12 Resolution of racemic piperidine 33i
Table 2.13 Enantioselective metal-free hydrogenation of 1,8-naphthyridines 34
N
N
N
N
H
R
R'
R
R'
chiral diene 9k (5 mol %)
HB(C 6 F 5 ) 2 10 (10 mol %)
H 2 (30 atm)
34
35
Entry product
yield (%) ee (%)
1
35a
N
N
H
Ph
Me
93
47
2
35b
N
N
H
Me
F
96
52
3
35c
N
N
H
Me
MeO
93
74
4
35d
N
N
H
Me
S
92
33
5
35e
N
N
H
Ph
i Bu
96
17
6
35f
N
N
H
Me
Me
94
48