Chemistry Reference
In-Depth Information
NHTs
NHTs
NHTs
NHTs
NHTs
218
219
220
221
222
44% yield
67% ee
42% yield
41% ee
67% yield
77% ee
44% yield
82% ee
71% yield
89% ee
Figure 4.18.
Mn - porphyrin
191
- catalyzed intermolecular C - H amination.
NHNs
Rh
2
(
S
-TCPTTL)
4
NsN=IPh
CH
2
Cl
2
, -23°C
82% yield
70% ee
1
8
5
2
2
3
Scheme 4.58.
Rh(II) - catalyzed enantioselective C - H amination.
N
HR
O
S
Boc
p
-Tol
= RNH
2
TsN
226
NH
2
Boc
225
62% yield
99% de
224
225
(1.2 eq)
N
HR
Rh
2
(
S
-NTTL)
4
PhI(O
2
C(
t-
Bu))
2
228
227
88% yield
>99% de
N
HR
OMe
OMe
229
230
62% yield
99% de
Scheme 4.59.
Rh(II) - catalyzed diastereoselective C - H amination.
tion system of
S
-
225
and the chiral dirhodium carboxylate Rh
2
(
S
- NTTL)
4
yielded a
remarkably effective synergistic effect in the amination of various benzylic positions
(Scheme 4.59) [69,263]. With only 1.2 equivalents of the amination agent
S
-
225
,
substrates
224
,
227
, and
229
underwent benzylic C-H amination in 62-88% yield and
with
>
98% de. In comparison, poor yields were obtained with the mismatched catalyst
