2 Frustrated Lewis Pair Catalyzed Asymmetric Reactions
55
Table 2.18 Asymmetric hydrogenation reactions of 2-substituted quinolines 48
N
R'
N
H
R'
R
R
H 2 (20 or 50 bar)
spiro-bicyclic bisborane 47
48
49
entry product
yield (%) ee (%)
1
49a
N
H
Me
97
91
2
49b
N
H
n Bu
98
92
3
49c
N
H
90
95
4
49d
N
H
Me
PinB
90
90
5
49e
N
H
Me
O
98
91
6
49f
N
H
Me
O
63
91
7
49g
N
H
Ph
94
98
8
49h
N
H
O
95
98
9
49i
N
H
N
Me
94
96
10
49j
N
H
Ph
86
96
11
49k
N
H
Ph
98
96
12
49l
N
H
Ph
91
98