<p>We report a
Ni(0)-catalyzed cross coupling reaction between simple ketones and 1,3-dienes. A
variety of a-allylic
alkylation products were formed in an 1,2-addition manner with excellent regioselectivity.
Water was found to significantly accelerate this transformation. A HO-Ni-H
species generated from oxidative addition of Ni(0) to H<sub>2</sub>O is
proposed to play a “dual role” in activating both the ketone and the diene
substrate.</p>