Reactions of nickel-group 6 complexes with a bulky terminal alkyne to afford alkyne-carbonyl coupled products: X-ray structure of the heterobimetallic nickelacyclobutenone complex [(η5-C5Me5)Mo(CO)2(η5-C5H4Me)] (Ni-Mo)

The bulky terminal alkyne HCCCPh2(OMe) reacts with the unsaturated heterobimetallic complex [(η-C5Me5)NiMo(CO)3(η-C5H4Me)], to give, regioselectively and exclusively, the alkyne-carbonyl coupled metallacyclic product shown. The structure of this species was determined by a single crystal X-ray diffraction study. Similar products are obtained with related heterobimetallic NiMo and NiW complexes.