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 diselenides or disulfides for the synthesis of coumarins and quinolinones bearing a chalcogen functional group has been developed. This green and efficient approach was realized through a constant current electrolysis in an undivided cell under metal-free and oxidant-free conditions. Moreover, a series of selenium/sulfur-substituted coumarin and quinolinone products were obtained in moderate to good yields with a broad scope and functional group tolerance.