Pd-Catalyzed Cross-Coupling of Cyclopropanols with 2-Br-p-Quinone Methides/2-Br-Cinnamate Esters Followed by a 1,6- and 1,4-Conjugate Addition Reaction

A novel cascade Pd-catalyzed cross-coupling reaction of cyclopropyl alcohol-derived ketone homoenolate with 2-Br-p-quinone methides and 2-Br-cinnamate esters followed by a 1,6- and 1,4-conjugate addition reaction is disclosed. This protocol converts various cyclopropyl alcohols into ketone homoenolate, which undergoes C-C bond formation by a cross-coupling reaction with 2-Br p-quinone methides and 2-Br-cinnamate esters. The salient features of this methodology include its operational simplicity, mild reaction conditions, an environmentally benign protocol, high efficiency, good to excellent yields, and a wide substrate scope.