Cu-Catalyzed Desaturation-Relay Imidation of 2-Piperidones

We demonstrate a copper-catalyzed regioselective cascade oxidative desaturation and imidation of saturated heterocycles using <i>N</i>-fluorobenzenesulfonimide (NFSI) as both an oxidant and an imidating reagent. A broad range of substituted piperidones, lactams, and cyclic ketones with high functional group tolerance could be successfully utilized in this transformation. TEMPO-trap experiments, control experiments, and DFT calculations provided supporting evidence for the possible desaturation process.