3D-QSAR approach for design of catalysts in asymmetric synthesis

Abstract

A lot of researches of Mn salen catalysts which are capable of epoxidizing various olefins have been reported because they are able to be synthesized from one ethylenediamine and two salicylaldehyde through dehydration reaction, and many derivatives with characteristically steric structures are obtained easily. For the synthesis of catalysts with high enantioselectivity, it is necessary to understand how the catalyst reacts with olefins especially in their geometrical relation and which substituent is effective for successful reaction. Though theoretical calculation such as quantum chemistry would be a useful tool to investigate these mechanisms and search their molecular structure or several physicochemical properties, it is difficult to use this theoretical approach for quantitative prediction of enantioselective reactions because the energy difference between intermediates that lead to enantiomeric products is small. In this study, QSAR approach, mainly CoMFA method, was applied to estimate enantiomer excess in asymmetric epoxidation of olefins using Mn salen complexes as catalysts.