We report here a new example of cyclic cotrimerization. The reaction of R, β-enones 1 (1 equiv) and alkynes 2 (2 equiv) proceeded smoothly in the presence of a nickel- organoaluminum catalyst system to give the corresponding cyclic adducts (reaction A in eq 1). Moreover, regioselective cotrimerization was observed in the reaction with 1-alkyne.
