Photoredox-Catalyzed Selective Dioxygenation of gem-Difluorocyclopropanes to Generate α,α-Difluorinated-1,3-diethers

Abstract

gem-Difluorocyclopropanes are valuable synthetic intermediates in organofluorine chemistry; however, their reactivity often involves intermediates prone to fluorine elimination, leading to monofluorinated products. Here, we present a photoredox-catalyzed dioxygenation of gem-difluorocyclopropanes with alcohols, which retains both fluorine atoms and yields α,α-difluorinated-1,3-diethers. This method is operationally simple, employs inexpensive and standard reagents, and demonstrates broad functional group tolerance. The reaction is scalable, enabling the use of the gem-difluorocyclopropane motif as a masked precursor for α,α-difluorinated-1,3-diethers in synthetic sequences. Preliminary mechanistic studies suggest a radical-mediated process involving concerted S_N2-like ring-opening functionalization.