Photoredox-Catalyzed Allylic Defluorinative Alkoxycarbonylation of Trifluoromethyl Alkenes through Intermolecular Alkoxycarbonyl Radical Addition.

The gem -difluoroalkene moiety is an ideal carbonyl bioisostere in medicinal chemistry, but efficient synthesis of β- gem -difluoroalkene esters remains challenging so far. Herein, we disclose a photoredox-catalyzed allylic defluorinative alkoxycarbonylation of trifluoromethyl alkenes enabled by intermolecular alkoxycarbonyl radical addition. A wide variety of alcohol oxalate derivatives were amenable, affording various β- gem -difluoroalkene esters with excellent functional group tolerance. Notably, the potential synthetic value of this method is highlighted by successful late-stage modification for bioactive molecules.