Intermolecular Anti-Markovnikov Hydroamination of Alkenes with Sulfonamides, Sulfamides, and Sulfamates

A general method for the light-driven intermolecular anti-Markovnikov hydroamination of alkenes with primary sulfonamides, sulfamides, and sulfamates is presented. The reaction is mediated by a ternary catalyst system composed of an iridium(III) chromophore, a fluorinated alkoxide base, and a thiol H-atom donor. We hypothesize that the reactions proceed via a proton-coupled electron transfer (PCET) mechanism wherein implementation of the alkoxide base imparts additional thermochemical driving force for the homolytic activation of strong N-H bonds that were previously inaccessible using this methodology. This furnishes electrophilic N-centered radicals that subsequently interface with a wide range of unactivated alkenes for C-N bond formation. This protocol exhibits a broad substrate scope and great functional group tolerance, further highlighting the advantages of excited-state PCET as a platform for catalytic radical generation from common organic functional groups.