Tetrahydroxydiboron‐Mediated Palladium‐Catalyzed Deoxygenative Transfer Hydrogenation of Aryl Ketones

Abstract We describe a palladium‐catalyzed deoxygenative transfer hydrogenation of ketones using B 2 (OH) 4 as the sole additive. Deuterium labeling experiments using B 2 (OD) 4 show that the incorporated protons originate exclusively from the diboron reagent. Spectroscopic evidence implicates the intermediacy of a borate ester. A variety of aromatic ketones can be deoxygenated using this approach. magnified image