A Novel Example of Chiral Counteranion Induced Enantioselective Metal Catalysis:  The Importance of Ion-Pairing in Copper-Catalyzed Olefin Aziridination and Cyclopropanation

Abstract

A new ion-pairing route to achieve asymmetric catalysis has been observed in the copper-catalyzed aziridination of styrene with a chiral counteranion. Structural studies suggest that enantioinduction occurs via ion-pairing of the cationic copper catalyst in the chiral pocket created by the anion. The degree of asymmetric induction can be tuned with features that affect ion-pairing, such as achiral and chiral ligands, temperature, and solvent polarity.