Visible‐Light‐Induced Pyridylation of Remote C(sp³)−H Bonds by Radical Translocation of N‐Alkoxypyridinium Salts

Metal‐free, visible‐light‐induced site‐selective heteroarylation of remote C(sp 3 )−H bonds has been accomplished through the design of N‐alkoxyheteroarenium salts serving as both alkoxy radical precursors and heteroaryl sources. The transient alkoxy radical can be generated by the single‐electron reduction of an N‐alkoxypyridinium substrate by a photoexcited quinolinone catalyst. Subsequent radical translocation of the alkoxy radical forms a nucleophilic alkyl radical intermediate, which undergoes addition to the substrate to achieve remote C(sp 3 )−H heteroarylation. This cascade strategy provides a powerful platform for remote C(sp 3 )−H heteroarylation in a controllable and selective manner and is well suited for late‐stage functionalization of complex bioactive molecules.