A Direct Intermolecular Cross-Benzoin Type Reaction: N-Heterocyclic Carbene-Catalyzed Coupling of Aromatic Aldehydes with Trifluoromethyl Ketones

A direct intermolecular cross-benzoin-type condensation catalyzed by an N-heterocyclic carbene has been developed. The cross-coupling of commercially available aromatic aldehydes and trifluoromethyl ketones results in alpha-hydroxy-alpha-trifluoromethyl ketones bearing a quaternary stereocenter with excellent chemoselectivity and good to excellent yields.