Fluxional Additives: A Second Generation Control in Enantioselective Catalysis
作者:Mukund P. Sibi、Shankar Manyem、Hector Palencia
DOI:10.1021/ja064472a
日期:2006.10.1
The concept of "fluxional additives", additives that can adopt enantiomeric conformations depending on the chiral information in the ligand, is demonstrated in enantioselective Diels-Alder and nitrone cycloaddition reactions. The additive design is modular, and diverse structures are accessible in three steps. Chiral Lewis acids from main group and transition metals show enhancements in enantioselectivity
Copper(II)-Catalyzed Exo and Enantioselective Cycloadditions of Azomethine Imines
作者:Mukund P. Sibi、Digamber Rane、Levi M. Stanley、Takahiro Soeta
DOI:10.1021/ol800904t
日期:2008.7.17
A strategy for exo and enantioselective 1,3-dipolar cycloaddition of azomethine imines to 2-acryloyl-3-pyrazolidinone is described. The corresponding cycloadducts are isolated with high diastereoselectivities (up to >96:4 exo/endo) and enantioselectivities (up to 98% ee).