Visible-Light-Mediated gem-Difunctionalization of Diazo Compounds with Vinyl Sulfoxonium Ylides and Thiols

A visible-light-induced multicomponent reaction of vinyl sulfoxonium ylide, thiol, and diazo ester to generate tertiary sulfide is described. The present diastereoselective gem-difunctionalization of the diazo ester can be achieved under mild conditions, as it does not require any additives, catalysts, or transition metals and is tolerant of air and moisture. Due to more nucleophilicity, vinyl sulfoxonium ylide undergoes S–H insertion with thiols to generate an allyl sulfide intermediate. Simultaneously, diazo ester undergoes photolysis to generate a carbene intermediate. Subsequently, the coupling of carbene and allyl sulfide intermediates generates sulfonium ylide, which undergoes Doyle–Kirmse rearrangement to generate tertiary sulfide scaffolds.