Polysulfide Anions as Visible Light Photoredox Catalysts for Aryl Cross-Couplings

Herein, we disclose the use of polysulfide anions as visible light photoredox catalysts for aryl cross-coupling reactions. The reaction design enables single-electron-reduction of aryl halides upon photo-excitation of tetrasulfide dianions (S₄^2–). The resulting aryl radicals are engaged in (hetero)biaryl cross-coupling, borylation, and hydrogenation in a redox catalytic regime involving S₄^•–/S₄^2– and S₃^•–/S₃^2– redox couples.