Visible-Light-Mediated Three-Component Synthesis of C2 Alkenylsulfonyl-Substituted Benzothiazoles from Thiomethyl Isocyanides, Alkynes, and Sulfonyl Chlorides.

A visible-light-mediated three-component radical cascade cyclization of 2-(methylthio)phenyl isocyanides, terminal alkynes, and arylsulfonyl chlorides is reported, enabling modular and regioselective synthesis of C2 alkenylsulfonyl-substituted benzothiazoles. This photoredox strategy allows one-pot construction of conjugated sulfonyl-functionalized benzothiazoles under mild, redox-neutral conditions, avoiding substrate prefunctionalization and the stepwise manipulation required in conventional two-component cyclizations and transition-metal-catalyzed cross-couplings. This simple protocol enables diverse scaffold modification with broad functional-group tolerance, affording structurally challenging alkenyl sulfones.