A Strategy for Accessing Aldehydes via Palladium‐Catalyzed C−O/C−N Bond Cleavage in the Presence of Hydrosilanes

Abstract We report the catalytic reduction of both active esters and amides by selective C(acyl)−X (X=O, N) cleavage to access aldehyde functionality via a palladium‐catalyzed strategy. Reactions are promoted by hydrosilanes as reducing reagents with good to excellent yields and with excellent chemoselectivity for C(acyl)−N and C(acyl)−O bond cleavage. Carboxylic acid C(acyl)−O bonds are activated by 2‐chloro‐4,6‐dimethoxy‐1,3,5‐triazine (CDMT) to form triazine ester intermediates, which further react with hydrosilanes to yield aldehydes in one‐pot two‐step procedures. We demonstrate that C(acyl)−O cleavage/formylation offers higher yields and broader substrate scopes compared with C(acyl)−N cleavage under the same reaction conditions. magnified image