Palladium-Catalyzed Conjugate Addition of Arylboronic Acids to β,β-Disubstituted Enones in Aqueous Media: Formation of Bis-benzylic and ortho-Substituted Benzylic Quaternary Centers

Palladium-catalyzed conjugate addition of arylboronic acids to beta,beta-disubstituted enones in aqueous media is reported. Additions of a wide range of arylboronic acids to beta,beta-disubstituted enones occur to form ketone products bearing benzylic all-carbon quaternary centers. These reactions are promoted by a simple catalyst prepared from palladium trifluoracetate and 2,2'-bipyridine. The use of aqueous sodium trifluoracetate as the reaction medium significantly enhances reactivity and enables the formation of challenging bis-benzylic and ortho-substituted benzylic all-carbon quaternary centers.