Electrochemical oxidative cyclization of activated alkynes with diselenides or disulfides: access to functionalized coumarins or quinolinones

A direct electrochemical oxidative cyclization of alkynoates and alkynamides with diselenide or disulfide for the synthesis of the coumarins and quinolinones bearing a chalcogen functional group has been developed. This green and efficiency approach was realized through the constant current electrolysis in an undivided cell under metal-free and oxidant-free conditions. Moreover, a series of selenium/sulfur-substituted coumarins and quinolinones products were obtained in moderate to good yields with broad scope and functional group tolerance.