Visible Light-Driven Interrupted Barton Reaction: Intermolecular Radical-Relay Sulfonyloximation of Alkenes with DABSO and Alkyl Nitrites

A visible light-driven, intermolecular interrupted Barton reaction has been developed for radical-relay sulfonyloximation of alkenes with alkyl nitrites, using DABSO as a trapping reagent. This method overcomes the challenges of competing normal Barton reactions and polarity mismatches by rapidly and irreversibly capturing alkyl radicals, preventing unwanted side reactions. The resulting polarity-reversed sulfonyl radicals undergo highly selective addition to alkenes, yielding α-alkylsulfonyl ketoximes tethered to hydroxyl or ketone groups. Conducted under mild visible light conditions, this approach eliminates the need for harsh mercury lamps, offering a scalable, chemoselective method for synthesizing valuable sulfonylated oxime derivatives.