Chemistry Reference
In-Depth Information
PMP
PA
1k
(10 mol %)
AgOAc (5 mol %)
Toluene, rt
HN
PMP
N
+
CO
2
Me
MeO
2
C
H
Ar
Ar
8 examples
73-93% yield
86-88% ee
O
O
P
*
O
O
Ar
H
PMP
N
RO
2
C
H
[M]
Ar
PMP
N
O
O
RO
2
C
H
[M-X]
P
*
O
OH
PMP
HN
CO
2
R
Ar
Scheme 3.57.
binol phosphate complex, which results in a new metal-catalyzed reaction in which the
chiral counterion induces the enantioselectivity (Scheme 3.57 ).
3.6. CONCLUSION
Signifi cant progress has been made recently in the design and development of chiral
Lewis acid and Brønsted acid catalysts for asymmetric reactions, as described herein. In
particular, chiral phosphoric acid catalysts have emerged as novel catalysts in a number
of synthetic reactions. Despite such great achievements, the combined acid and phos-
phoric acid catalysis is still in a state of infancy and there is still much more to learn with
regard to the reactivity. The ultimate goal is to develop versatile catalysts with higher
reactivities and better selectivities. We believe the realization of such an objective will
have a tremendous effect on the development of organic synthesis.
REFERENCES
1. For a review of combined acid catalysis, see: Yamamoto , H. ; Futatsugi , K.
Angew. Chem. Int. Ed.
Engl.
2005
,
44
, 1924 - 1942 .
2. Corey , E. J. ; Shibata , T. ; Lee , T. W.
J. Am. Chem. Soc.
2002
,
124
, 3808 - 3809 .
3. Ryu , D. H. ; Lee , T. W. ; Corey , E. J.
J. Am. Chem. Soc.
2002
,
124
, 9992 - 9993 .
