Bismuth-Catalyzed Photoinduced Ligand-to-Metal Charge Transfer (LMCT) Hydrodecarbonylation of Aldehydes

Herein, we disclose a visible-light, bismuth-catalyzed strategy for the hydrodecarbonylation of aliphatic aldehydes. Mechanistic studies highlight chlorine radical formation via Ligand-to-Metal Charge Transfer (LMCT) from <i>in situ</i> generated Bi^IIICl₅^2-. After C(sp²)-H abstraction by the chlorine radical, decarbonylation followed by Hydrogen Atom Transfer (HAT) furnishes the desired products. Deuterium-labeling studies confirm that water serves as the hydrogen source. The reaction demonstrates excellent functional-group tolerance, including substrates bearing complex, drug-like motifs.