Treatment of the cationic incomplete cubane-type sulfido complex [(CP*Mo)(3)(mu(2)-S)(3)(mu(3)-S)][PF(6)](2;Cp* = eta(5)-C(5)Me(5)) with [Ni(cod)(2)] (cod = 1,5-cyclooctadiene) afforded the heterobimetallic mu,eta(2):eta(2)-cod double-cubane-type cluster [{(Cp*Mo)(3)(mu(3)-S)(4)Ni}(2)(mu, eta(2):eta(2)-cod)][PF(6)](2) (3), which further reacted with dimethyl acetylenedicarboxylate (dmad) to produce [(Cp*Mo)(3)(mu(3)-S)(4)Ni(eta(2)-dmad)]-[PF(6)] (4). Cluster 3 or 4 showed high catalytic activity for the intramolecular cyclization of various alkynoic acids to give enol lactones in the presence of Et(3)N.