Nickel-Catalyzed Cross-Dehydrogenative Coupling of Aldehydes and Alkenes toward Skipped Enones

The direct transformation of C-H bonds into C-C bonds via cross-dehydrogenative coupling (CDC) represents a powerful strategy in synthetic chemistry, enabling streamlined bond construction without the need for prefunctionalized substrates. While traditional CDC approaches rely on polar mechanisms and preactivation of one of the C-H partners, recent advances have introduced radical-based strategies that employ a hydrogen atom transfer (HAT) approach to access carbon-centered radicals from unactivated substrates. Herein, we report a nickel-catalyzed CDC reaction between aldehydes and alkenes for the synthesis of skipped enones, leveraging aryl radicals as intermolecular HAT agents. The transformation proceeds via the <i>in situ</i> generation of aryl radicals from aryl bromides, which mediates HAT from both the aldehydic and allylic C-H bonds to generate acyl and allylic radicals, respectively. These radicals are then engaged in a nickel-catalyzed radical-radical cross-coupling to deliver the skipped enone products. This method demonstrates a broad substrate scope, high chemoselectivity, and excellent tolerance to diverse functional groups, providing a versatile platform for late-stage functionalization and synthesis of valuable skipped enone scaffolds.