Chiral Mn(III), Co(II) and Ni(II)-Salen complexes which prepared from the schiffbase of (+) or (-) 1, 2-diamino-1, 2-diphenylethane and substituted salialdehyde catalyzed the asymmetric epoxidation of styrene with sodium hypochlorite. The relevance about epoxidation and central metal ion is maybe the structure of ligand, the choice of metal atom and the configuration of the complexes. Good asymmetric epoxidation catalyst has suitable half-wave potential. The configuration of catalyst must be adjust to make the need of enantioselectivity according to the bulkiness of olefins substituent. The data of cyclic voltammograms study about catalysts and experimental facts give rational explain. At the sae time, the mechanism catalyzed by chiral Ni(II)-Salen complex and that catalyzed by chiral Mn(III)-Salen complexes may be different. Both involve free radical mechanism but different active oxidant. The sign of enentioselectivity is changed with the main asymmetric induced factor, the steric hindrance or II-II interaction. For the same catalyst, the kind of active species may be different under different pH.

Key words: EPOXIDATION REACTION, MANGANESE COMPLEX, ETHANEDIAMINE P, NICKEL COMPLEX, STYRENE, BENZALDEHYDE P, COBALT COMPLEX, SCHIFF BASE, BENZENE P