CO₂-Enabled Electrochemical Selective Deuterodefluorination of β,γ-Unsaturated α,α-Difluoroesters with Tunable Alkene Deuteration

Abstract

Recent advances in deuteration, including C-F bond deuterodefluorination and alkene reductive deuteration, have enabled site-selective isotope labeling of bioactive molecules and functional materials. Nevertheless, most methods rely on precious metals, expensive deuterium sources, strong oxidants, or sacrificial reagents, limiting sustainability and scalability.Moreover, selective control over deuterodefluorination versus alkene deuteration in β,γ-unsaturated α,α-difluoroesters remains largely unexplored. Herein, we report a controllably selective electrochemical deuterodefluorination of β,γunsaturated α,α-difluoroesters, in which concurrent alkene deuteration can be switched on or off by fine tuning electrochemical conditions. Using low-cost D₂O under metal-free conditions, this scalable protocol achieves high chemoselectivity and deuterium incorporation, offering a sustainable one-pot solution to key challenges in deuteration chemistry. Preliminary mechanistic studies support a stepwise radical pathway.