Electrochemical oxidative regio- and stereo-selective thio(seleno)cyanation of enamides and mechanistic insights

Abstract

An electrochemical oxidative regio- and stereo-selective thio(seleno)cyanation of enamides has been developed to access (E)-β-thio(seleno)cyanated enamide compounds under environmentally-benign conditions without metal and exogenous oxidant in an undivided cell. The protocol features good reaction efficiency and functional group tolerance, providing a sustainable pathway for the thio(seleno)cyanation of enamides. The practicabilities of this protocol were further demonstrated by intramolecular cross-coupling reactions to prepare six- and seven-membered heterocycles by varying the position of halide substituents. Mechanistic investigation reveals that the reaction may proceed via [1,5]-H sigmatropic rearrangement to achieve exclusive E stereoselectivity.