Direct C–H alkylation, acylation, and silylation of N-heteroarenes enabled by the self-quenching of quinolinones

Abstract

A sustainable C–H/C–H cross-dehydrogenative coupling strategy has been developed for the direct C–H functionalization of N-heteroarenes. This C–H activation platform leverages the photogenerated radical cation of a quinolinone-derived photocatalyst to mediate hydrogen-atom transfer (HAT) via a novel mechanism. While showcasing a broad substrate scope (>90 examples), this method dispenses with the need for stoichiometric oxidants, exogenous HAT reagents, and excess acid/base additives, thereby maximizing alignment with the Twelve Principles of Green Chemistry and affording a superior EcoScale score. Moreover, the integration of flow chemistry, together with excellent compatibility with late-stage functionalization of bioactive molecules, underscores the practical utility and synthetic potential of this fully metal-free strategy.