Highπ-Facial Selectivity Through Chelation of Magnesium Ions in the DMD Epoxidation ofα,β-Unsaturated Imides with Chiral Pyrrolidinone Auxiliaries
作者:Waldemar Adam、Aimin Zhang
DOI:10.1002/ejoc.200300544
日期:2004.1
diastereoselectivity, but of the opposite sense, is observed in the epoxidation (DMD or mCPBA) of α,β-unsaturated imides equipped with pyrrolidinone-type chiral auxiliaries that bear either a hydroxymethyl or trityloxymethyl side chain. This unprecedented reversed π-facial differentiation is promoted by chelation of a magnesium ion, which results in conformational control over the essential steric interactions
在配备带有羟甲基或三苯甲氧基甲基侧链的吡咯烷酮型手性助剂的 α,β-不饱和酰亚胺的环氧化(DMD 或 mCPBA)中观察到高非对映选择性,但具有相反的意义。镁离子的螯合促进了这种前所未有的反向 π 面分化,这导致对基本空间相互作用的构象控制。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)