Photocatalytic Hydrogen Atom Transfer‐Mediated Minisci C(sp ² )H Formylation of Quinolines With 1,3‐Dioxolane

Herein, we report a photocatalytic hydrogen atom transfer strategy for the C(sp ² )−H formylation of electron‐deficient quinolines. The commercially available and inexpensive 1,3‐dioxole serves as the formyl source, with O ₂ acting as a green oxidant, enabling the efficient synthesis of a variety of aromatic aldehydes. This reaction features transition‐metal‐free and mild reaction conditions, broad substrate scope, good functional group tolerance, and operational simplicity. Mechanistic studies suggest a possible radical pathway.