Asymmetric epoxidation catalyzed by Cr(III)-binaphthyl Schiff base complexes

A series of chromic complexes with binaphthyl Schiff base as ligands are synthesized. Their catalytic abilities in asymmetric epoxidation and the effects of reaction conditions such as temperature, solvent and additive have also been studied, leading to the highest ee of 65% for 4-chlorostyrene; the reaction seems to involve a Cr(V)-oxo active species.