Defluorinative Carboimination of Trifluoromethyl Ketones

The monofunctionalized carbodefluorination of readily accessible CF₃ groups is acknowledged as an attractive approach for the preparation of partially fluorinated molecules. However, their defluorinative difunctionalization remains a challenging and unmet goal. Herein, we report a defluorinative carboimination of trifluoromethyl ketones via a strategy of silver carbene-initiated rearrangement, in which both the C–F bond and carbonyl group of trifluoromethyl ketones are functionalized simultaneously, thus providing a straightforward synthetic method for medicinally relevant α,α-difluoroimines. The current approach involves a silver carbene-initiated intramolecular cascade process by integrating successive cleavage of the C–F bond and formation of C–C and CN bonds on a single molecule entity, which differs relevantly from the stepwise mechanism of reported carbodefluorination of CF₃ groups. Mechanistic studies disclose that silver catalysis plays a critical role, particularly in the stages of C–F bond cleavage and aza-Claisen rearrangement.