Regioselectively switchable alkyne cyclotrimerization catalyzed by a Ni(ii)/bidentate P-ligand/Zn system with ZnI2 as an additive

A nickel-catalyzed regioselective cyclotrimerization of alkynes provides straightforward access to 1,2,4- or 1,3,5-trisubstituted benzenes. This protocol features the advantages of broad substrate scope and easily controllable regioselectivity.