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O
O
O
O
O
O
O
O
O
D- xylo
O
P
HN
P
O
P
HN
D- ribo
D- ribo
D- xylo
P
HN
P
O
O
O
O
O
O
O
O
O
O
NH O
O
O
O
O
O
P
O
P
O
P
21e
20f
21a
O
O
23f
O
Me 3 Si
Me 3 Si
t Bu
t Bu
Me 3 Si
O
O
O
O
O
( S ) ax
( R ) ax
( S ) ax
=
O
O
O
O
O
Me 3 Si
t Bu
t Bu
Me 3 Si
Me 3 Si
Nu
R
R
R
% Conv (time)
% ee
Nu-H
L
20f
20f
23f
23f
Ph
Ph
Me
Me
CH 2 (COOMe) 2
BnNH 2
CH 2 (COOMe) 2
BnNH 2
99 (15 min)
98 (6 h)
51 (30 min)
68 (4 h)
98 ( S )
97 ( R )
84 ( S )
84 ( R )
CH(COOMe) 2
CH(COOMe) 2
n
% Conv (time)
% regio
% ee
L
% Conv (time)
% ee
n
1
2
L
21e
90 ( S )
21a
21a
100 (2 h)
52 (6 h)
85 ( S )
91 ( S )
100 (3 h)
70
Figure 10.10 Summary of the best results obtained in the Pd-catalyzed allylic substitution of
several substrates using ligands 20-23.
D- xylo
R 1
R 2
O
O
P
O
O
O
Ph 2 P
=
O
O
O
O
O
O
O
R 1
R 2
a R 1 = R 2 = t Bu
b R 1 = t Bu; R 2 = OMe
c ( R ) ax
d ( S ) ax
24a - d
Figure 10.11 Phosphine-phosphite ligands 24.
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