Nickel-catalyzed cycloadditive couplings of enynes and isocyanates.

A mild and general route for preparing dienamides is described. Nickel imidazolylidene complexes were used to mediate cycloadditive coupling between enynes and isocyanates. Dienamides were prepared in excellent yields and with good E:Z selectivity. These dienamides can be further manipulated through oxidative cyclization methods. When a terminal enyne is employed, cyclization affords a lactam rather than a dienamide.