NHC-Catalyzed Single-Electron Oxidation and Alkylation of Imines: Alkene Difunctionalization and Dehydrogenative Coupling

The development of a catalytic activation model enables the innovation of synthetic methods toward functional molecules. Recently, radical NHC catalysis has attracted considerable attention and has achieved numerous successes. It unlocks the potential to activate inert substrates and access valuable ketones that are beyond the reach of conventional methods. However, this strategy has so far been limited to the activation of carbonyl compounds for ketone synthesis. In contrast, the radical activation of imines under NHC catalysis for facile synthesis remains an unmet challenge. Herein, we report the NHC-catalyzed single-electron oxidation and alkylation of imines. Various agents, including Togni reagent, α-iododifluoroacetate, phenyl(difluoroiodomethyl)sulfone, perfluoroalkyl iodide, and peroxyester, proved to be effective single-electron oxidants. This versatility enabled the development of both alkene difunctionalization and a dehydrogenative coupling reaction. Preliminary mechanistic studies supported the proposed reaction pathway. The utility of this method is demonstrated through the late-stage functionalization of pesticide-related molecules and the divergent transformation of the products.