Asymmetric Reactions Catalyzed by Chiral Metal Complexes. LXX. Steric and Electronic Effects of Substrates and Rhodium Chiral Catalysts in Asymmetric Cyclopropanation.

Abstract

We have prepared several new, efficient, chiral N-acyl pyrrolidine carboxylic acid ligands for dirhodium-catalyzed asymmetric cyclopropanation and found that the steric and electronic effects of the rhodium(II) complexes and substrates influenced the enantioselectivity and catalytic activity. These electron-rich catalysts were shown to be efficient for asymmetric cyclopropanation using 1-chloro-1-fluoroethylene as a substrate.