Thioarylation of Alkynes to Generate Dihydrothiopheniums through Gold(I)/(III)-Catalyzed Cyclization–Cross-Coupling

A thioarylation method is developed for the synthesis of 2,3-dihydrothiopheniums through an electrophilic-cyclization-cross-coupling mechanism, harnessing the gold(I)/(III) cycle of the recently developed MeDalPhosAuCl catalyst. Single-crystal X-ray crystal structural analysis of the dihydrothiophenium products characterized the antiaddition of the sulfur and Csp