Synthesis of Enantiopure Epoxide Compounds Using Dimeric Chiral Salen Catalyst

摘要

The stereoselective synthesis of chiral terminal epoxide is of immense academic and industrial interest due to their utility as versatile starting materials as well as chiral intermediates.In this review,we investigate the research and development trend in the asymmetric ring opening reactions using cobalt salen catalysts.Hydro-lytic kinetic resolution(HKR)technology is the very prominent way to prepare optically pure terminal epoxides among available methods.We have synthesized homogeneous and heterogeneous chiral dinuclear salen complexes and demonstrated their catalytic activity and selectivity for the asymmetric ring opening of terminal epoxides with variety of nucleophiles and for asymmetric cyclization to prepare optically pure terminal epoxides in one step.The resolved ring opened product combined with ring closing in the presence of base and catalyst afforded the enantioriched terminal epoxides in quantitaive yield.Potentially,these catalysts are using on an industrial scale to produce chiral intermediates.The experimental results of HKR technology applied to the synthesis of various chiral compounds are presented in this paper.