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.