Dication Disulfuranes as Photoactivatable Sources of Radical Organocatalysts

Abstract The recent development of photoredox and energy transfer catalysis has led to a significant expansion of visible‐light‐driven chemical transformations. These methods have demonstrated exceptional efficiency in converting a wide range of substrates into radical intermediates and generating open‐shell catalytic species. However, the simplification of catalytic systems and the direct generation of highly reactive radical organocatalysts through direct visible‐light irradiation from stable precatalysts remains largely an unrealized goal. This challenge is mainly due to the limited availability of precatalysts that are responsive to visible light. Herein, we introduce a new class of bench‐stable dicationic disulfuranes, which release highly reactive thiyl radicals upon blue‐light excitation. Spectroscopic and computational studies reveal that this reactivity arises from a combination of structural features and intermolecular interactions. This family of molecules has been employed to catalyze radical cascades previously incompatible with photoredox conditions, enabling the efficient formation of 1,2‐dioxolanes and 1,3‐hydroxyketones in excellent yields and short reaction times.