Formation of an Aza‐nickelacycle by Reaction of an Imine and an Alkyne with Nickel(0): Oxidative Cyclization, Insertion, and Reductive Elimination

Cyclize, add, reduce: The oxidative cyclization of an imine and an alkyne with nickel(0) followed by the insertion of a second alkyne gives a seven-membered aza-nickelacycle (see scheme). Subsequent reductive elimination yields a 1,2-dihydropyridine. This sequential reaction process is expanded to a one-step nickel-catalyzed [2+2+2] cycloaddition of two alkynes and an imine.