2 Frustrated Lewis Pair Catalyzed Asymmetric Reactions
71
Table 2.31 Synthesis of tetrahydroquinoxalines 74 and 3,4-dihydroquinoxalin-2(1H)-ones 75
entry product
yield (%)
1
74a
H
N
N
H
Me
90
2
74b
H
N
N
H
t Bu
84
3
74c
H
N
N
H
n C 6 H 13
87
4
74d
H
N
N
H
Ph
88
5
74e
H
N
N
H
Ph
84
6
74f
N
N
H
Me
Me
78
7
74g
N
N
H
Me
78
8
75a
H
N
N
H
Me
O
93
9
75b
H
N
N
H
Ph
O
86
10
75c
N
H
H
N
O
Me
85
11
75d
H
N
N
H
Me
NC
NC
O
82
12
75e
O
N
H
Me
O
88