Patent ID: 8703985

Claim:
Method for preparation of a ruthenium-indenylidene carbene catalyst of the formula in which Ru is penta-coordinated in the formal oxidation state +II, X are anionic ligands, L or L′ are, independent from each other, neutral electron donor ligands, R is an aryl, phenyl or substituted phenyl group, said method comprising the steps of a) reacting the precursor compound Ru(PPh 3 ) n X 2 (n=3-4) with a propargyl alcohol derivative of the formula phenyl-C(R)(OH)—C≡C—H in a reaction mixture with a cyclic diether solvent at a temperature in the range of 80 to 130° C., b) optionally adding said neutral electron donor ligand L or L′ (with the exemption of PPh 3 ) to the reaction mixture, and c) precipitating the resulting ruthenium-indenylidene carbene catalyst from said reaction mixture.