Synthesis of gem-Difluorinated Spiro-γ-lactam Oxindoles by Visible-Light-Induced Consecutive Difluoromethylative Dearomatization, Hydroxylation, and Oxidation.

Described herein is a protocol for visible-light-induced consecutive synthesis of gem-difluorinated spiro-γ-lactam oxindoles under mild conditions by means of a process involving sequential radical difluoromethylative dearomatization, hydroxylation, and oxidation. The protocol features high chemo- and regioselectivity, good functional group tolerance, and easy scalability. Several of the functionalized spirooxindole products showed good fungicidal activity, suggesting that they have potential agrochemical applications.