Photoredox‐Catalyzed Transition‐Metal‐Free C(sp2)−H Phosphorylation Using 9‐Mesityl‐10‐Methylacridinium Perchlorate Photocatalyst

Abstract Visible light mediated transition‐metal‐free C( sp 2 )−H phosphorylation of thiazole and quinoxaline derivatives using Mes‐Acr‐MeClO 4 as a photocatalyst has been described. This photoredox‐catalyzed direct C( sp 2 )−H phosphorylation transformation could smoothly proceed under mild conditions, utilizing oxygen in the air as a green oxidant without the addition of metals, bases, additives, and external oxidants. The mechanistic studies helped to rationalize the formation of C( sp 2 )−P bond followed a radical pathway through a SET process.