Simple and efficient nickel-catalyzed cross-coupling reaction of alkenylalanes with alkynyl halides for synthesis of conjugated enynes

A NiCl 2 (PPh 3 ) 2 /XantPhos catalyzed synthesis of conjugated enynes by the cross-coupling of terminal alkynyl halides with alkenylaluminum reagents at room temperature in DME solvent was developed under mild reaction conditions. The aryls bearing electron-donating or electron-withdrawing groups in alkynylhalides give the corresponding cross-coupling products conjugated enynes in good to excellent isolated yields up to 97%. This process was simple and easily performed, which provides an efficient method for the synthesis of conjugated enynes derivatives. On the basis of the experimental results, a possible catalytic cycle has been proposed.