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
posted on 2015-09-04, 00:00authored byRyan Van Zeeland, Levi M. Stanley
Palladium-catalyzed conjugate addition
of arylboronic acids to
β,β-disubstituted enones in aqueous media is reported.
Additions of a wide range of arylboronic acids to β,β-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.