Ambient-Light-Promoted Stereospecific Synthesis of (Z)-Vinyl Thioesters under Solvent- and Catalyst-Free Conditions

An ambient-light-promoted stereospecific olefinic C(sp2)–S bond construction of thioacids and 1,1-diarylethenes has been demonstrated, affording various (Z)-vinyl thioesters in 51–85% yields under solvent- and catalyst-free conditions. Mechanistic studies indicated that the formation of thioacid–olefin complexes is responsible for generating a carbonyl thiyl radical and dioxygen in the air participates in the reaction and functions as a traceless reagent. Moreover, synthetic applications have been demonstrated by the gram scale synthesis and aggregation-induced emission property of representative compound 3i.