Phosphine/Photoredox Catalyzed anti-Markovnikov Hydroamination of Olefins with Primary Sulfonamides via a-Scission from Phosphoranyl Radicals

New strategies to access radicals from common feedstock chemicals hold the potential to broadly impact synthetic chemistry. We report a dual phosphine and photoredox catalytic system that enables direct formation of sulfonamidyl radicals from primary sulfonamides. The method is proposed to proceed via -scission of the sulfonamidyl radical from a phosphoranyl radical intermediate, generated upon sulfonamide nucleophilic addition to a phosphine radical cation. As compared to the recently well-explored β-scission chemistry of phosphoranyl radicals, this strategy is applicable to activation of N-based nucleophiles and is catalytic in phosphine. We highlight application of this activation strategy to an intermolecular anti-Markovnikov hydroamination of unactivated olefins with primary sulfonamides. A range of structurally diverse secondary sulfonamides can be prepared in good to excellent yields under mild conditions.