Copper-catalyzed trifluoromethylation of vinyl azides with BrCF2CO2K: synthesis of α-trifluoromethyl ketones without external fluoride sources

Abstract

Herein, we disclose a copper(I)-catalysed trifluoromethylation of vinyl azides with BrCF₂CO₂K and water, affording α-trifluoromethyl ketones without an external fluoride source. BrCF2CO₂K serves as both a difluorocarbene precursor and an internal fluoride reservoir, enabling net CF₃ incorporation through a copper–difluorocarbene pathway. This mild protocol shows broad substrate scope and good functional-group tolerance, establishing a practical fluoride-source-free approach to α-trifluoromethyl ketones. Product derivatizations and mechanistic observations further demonstrate its synthetic utility and support the involvement of a copper–difluorocarbene intermediate, thereby expanding the synthetic potential of metal difluorocarbene chemistry.