We report a visible-light-driven multicomponent strategy for the synthesis of S-functionalized imidazoles from readily available organic halides, isothiocyanates, and isocyanides. The method operates under mild, photocatalyst-free conditions and exhibits broad substrate scope with excellent functional-group tolerance. Detailed mechanistic investigations support a reaction pathway involving direct photoexcitation of in situ generated thiophenolate intermediates and subsequent radical-based C–S bond formation. This process is likely governed by exciplex-type interactions rather than preassembled electron donor–acceptor complexes. Overall, this work introduces a distinct photochemical activation mode for C–S bond construction and expands the synthetic toolbox for accessing sulfur-containing heterocycles.
Tagarro et al. (Fri,) studied this question.