Reaction of the <i>in-Situ</i>-Generated Ruthenium−Acetylide Complex C₅Me₅Ru(PPh₃)C⋮CPh with Small Molecules

Abstract

A coordinatively unsaturated acetylide species C 5 Me 5 Ru(PPh 3 )C⋮CPh ( 1 ) was generated in situ from the reaction of ruthenium−vinylidene complex C 5 Me 5 Ru(Cl)(PPh 3 ) C CHPh ( 2 ) with Et 3 N. The vinylidene complex 2 was prepared from the substitution reaction of C 5 Me 5 Ru(PPh 3 ) 2 Cl with PhC⋮CH. The in-situ -generated 1 was found to react readily with a variety of small molecules. For example, the reaction of 1 with CO produced the stable adduct C 5 Me 5 Ru(CO)(PPh 3 )C⋮CPh ( 3 ) in 85% yield, the structure of which was established by X-ray crystallography. The similar reactions of 1 with H 2 and PhC⋮CPh also gave the hydride complex C 5 Me 5 Ru(PPh 3 )(H)(H 2 C CHPh) ( 4 ) (76% yield) and the alkyne complex C 5 Me 5 Ru(PPh 3 )(PhC⋮CPh)C⋮CPh ( 5 ) (85% yield), respectively. The reaction of 1 with CO 2 produced the carboxylate complex C 5 Me 5 Ru(PPh 3 )(η 2 -O 2 CC⋮CPh) ( 6 ) from the insertion of CO 2 to the ruthenium−acetylide carbon bond.