Decarboxylative Cross-Acyl Coupling of Carboxylic Acids with Aldehydes Enabled by Nickel/Photoredox Catalysis.

We present a general method for accessing unsymmetrical alkyl-aryl and alkyl-alkyl ketones via nickel/photoredox-catalyzed decarboxylative cross-acyl coupling reactions between carboxylic acids and aldehydes without the need for an additional preactivation procedure. Specifically, by using the peroxide as both an oxidant and hydrogen atom transfer (HAT) reagent, we achieved the unprecedented combination of oxidative single electron transfer (SET) of carboxylates and HAT of aldehydes, in which the generated alkyl and acyl radicals were chemoselectively coupled by nickel catalysis. This method features a broad substrate scope with good functional group compatibility and offers new access to structurally diverse ketones.