Cu-Catalyzed Diarylthiolation of Ynones with Aryl Iodides and Elemental Sulfur: An Access to Tetrasubstituted ( Z )-1,2-Bis(arylthio)alkenes and Benzo[ b ][1,4]dithiines.

A copper-catalyzed three-component reaction of ynones, aryl iodides, and elemental sulfur via a syn -addition process is established. The reaction features operational practicality, broad substrate scope, and readily accessible scale-up synthesis by affording a series of ( Z )-1,2-bis(arylthio)alkenes in good to excellent yield. Moreover, benzo[ b ][1,4]dithiines can be also constructed efficiently by using 1,2-diiodobenzene as the coupling partner.