Photocarboxylation of remote C–H bonds through nitrogen-centred radical 1,5-hydrogen atom transfer

Abstract

The carboxylation of the C–H bond utilizing CO₂ represents a challenging but attractive tactic for capitalizing on the abundant availability of CO₂ in organic synthesis. In this investigation, we report visible-light-driven carboxylation of a remote C–H bond via a nitrogen-centered 1,5-hydrogen atom transfer (1,5-HAT) mechanism. The achievement of direct photocarboxylation of the remote benzylic C–H bond has been realized. The functionalization of electron-deficient alkenes, in conjunction with remote aliphatic C–H bonds and CO₂, has been developed employing the 1,5-HAT strategy as well. These methods enable the photocarboxylation of different types of C–H bonds and feature mild reaction conditions, a comprehensive range of substrates, and exceptional functional group tolerance, providing a sustainable and eco-friendly approach to valuable carboxylic acids and derivatives.