Biomedical Engineering Reference
In-Depth Information
TABLE 7.2 Phase-Transfer-Catalyzed Enantioselective Benzylation of Alanine Schiff Base
O
O
H
3
O
+
catalyst
conditions
Ar
N
H
2
N
+
*
PhCH
2
Br
O
t
-Bu
O
t
-Bu
Me
Me
Ph
25
26
Yield
(%)
ee (%)
(Configuration)
Catalyst (mol%)
Conditions
Reference
Cl
-
Ar = 4-Cl-C
6
H
4
,K
2
CO
3
/
KOH aq, CH
2
Cl
2
,rt
80
44 (
R
)
34
OH
+
N
N
H
1b
(10 mol%)
Ar = 4-Cl-C
6
H
4
,K
2
CO
3
/
KOH aq, Toluene, rt
95
87 (
S
)
35
-
Cl
+
H
N
OH
N
6c
(10 mol%)
Ar = 2-Napht, RbOH,
Toluene, -35
C
91
95 (
S
)
36
Br
-
+
H
N
F
F
O
N
F
6a
(10 mol%)
-
Ar = 4-Cl-C
6
H
4
,
CsOH·H
2
O,
Toluene-CH
2
Cl
2
,
-70
C
83
89 (
R
)
12b
2BF
4
Me
4-MeO-C
6
H
4
+
N
O
Me
t
-Bu
4-MeO-C
6
H
4
4-MeO-C
6
H
4
O
+
N
Me
4-MeO-C
6
H
4
8b
(10 mol%)
Ar
Ar = 4-Cl-C
6
H
4
,
CsOH·H
2
O, Toluene,
0
C
85
98 (
R
)
33
-
Br
+
N
Ar
(
S
,
S
)-
5e
(1 mol%)
(Ar = 3,4,5-F
3
-C
6
H
2
)
Ar
Ar = 4-Cl-C
6
H
4
,
CsOH·H
2
O, Toluene,
0
C
63
98 (
R
)
23
Br
-
+
Bu
Bu
N
Ar
(
S
)-
17a
(0.05 mol%)
(Ar = 3,4,5-F
3
-C
6
H
2
)
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