Abstract
Asymmetric catalysis constitutes a key strategy for the enantioselective synthesis
of natural products and bioactive compounds. Chiral ligands are crucial for achieving
the required reactivity and enantioselectivity in asymmetric catalytic reactions.
Consequently, the rational design of chiral ligands is central to the development
of new asymmetric transition-metal-catalyzed reactions. Our group has been actively
engaged for many years in the development of chiral ligands for a wide range of asymmetric
transformations. This Account presents our recent efforts in the design of chiral
ligands specifically for the asymmetric [3+2] azomethine ylide cycloaddition, an important
transformation for the asymmetric synthesis of pyrrolidines. We detail their application
in Zn-catalyzed [3+2] cycloadditions, discuss the underlying transition states responsible
for the observed selectivity, and highlight synthetic applications of this important
reaction.
1 Introduction
2 Metal-Catalyzed Azomethine Ylide Cycloaddition
3 Ligand Design: UCD-Imphanol Ligands
4 Application of UCD-Imphanol Ligands in Zn(II)-Catalyzed Azomethine Ylide [3+2]
Cycloaddition
5 Synthetic Applications
6 Conclusions
Key words
asymmetric catalysis - chiral ligand design - planar chiral ligands - paracyclophanes
- azomethine ylides - [3+2] cycloaddition
