Photoinduced Pyridine N-Oxide Catalysis for C-H Alkylation of Azauracils and Quinoxalinones with Alkyl Boronic Acids.

A photoinduced pyridine N-oxide-catalyzed C-H alkylation of azauracils and quinoxalinones with alkyl boronic acids has been developed. The transformation proceeds under transition-metal-free aerobic conditions without requiring a separate photoredox catalyst or photosensitizer and exhibits broad substrate scope, including late-stage functionalization of biorelevant molecules and gram-scale synthesis. Mechanistic studies support alkyl radical generation from alkyl boronic acids by photoexcited pyridine N-oxide. This study highlights the potential of pyridine N-oxide organophotocatalysis for radical-mediated synthetic transformations.