Nickel-Catalyzed Homo- and Cross-Coupling of Allyl Alcohols via Allyl Boronates

A nickel-catalyzed homo- and cross-coupling of allylic alcohols to 1,5-dienes in the presence of B(2)pin(2) with excellent regioselectivity has been developed. Mechanistic studies indicate that the reaction proceeds via sequential nickel-catalyzed borylation of allyl alcohols followed by cross-coupling of the resulting allyl boronates with allyl alcohols. The method was effectively applied to nickel-catalyzed allylation of aldehydes using allylic alcohols directly.