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 -oxiranes has been accomplished via decarboxylative stereospecific epoxidation of -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.