Copper-Catalyzed Tandem Cyclization/Chalcogenation with Elemental S 8 /Se: Concise Synthesis of 3-(β-Hydroxychalcogen)benzofurans.

A novel copper-catalyzed cyclization/chalcogenation of o -alkynylphenols with epoxides and elemental S 8 /Se was developed for the synthesis of a 3-chalcogen-benzofuran architecture in a domino process with no intermediate isolation or purification. Various sensitive functional groups were compatible at room temperature and furnished chalcogenation derivatives in moderate to good yields.