Visible-Light Photoredox-Catalyzed Synthesis of trans-Oxiranes via Decarboxylative Stereospecific Epoxidation of trans-Cinnamic Acids by Aryldiazonium Salts

An efficient visible-light-induced synthesis of trans-oxiranes has been accomplished via decarboxylative stereospecific epoxidation of trans-cinnamic acids by aryldiazonium salts using CuCl, eosin Y, TBHP, and DBU. The reaction is facile, straightforward, and endowed with good functional group tolerability and a good substrate scope.