Reaction of Tp(PPh3)Ru(η2-O2CCHPh2) with Carbene and Vinylidene Precursors

• Published in: Organometallics 2001-12, Vol.20 (25), p.5455-5463
• Main Authors: Sanford, Melanie S, Valdez, Michelle R, Grubbs, Robert H
• Format: Article
• Language: English
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/om010558v

Tp(PPh3)Ru(η2-O2CCHPh2) (1) [Tp = tris(pyrazolyl)borate] has been prepared by the reaction of TpRu(Cl)(PPh3)2 with 1.2 equiv of NaO2CCHPh2. Complex 1 reacts with diphenylcyclopropene to generate the metallacycle Tp(PPh3)Ru[κ2-(C,Ο)-C(CHCHPh2)OC(CHPh2)O] (2). A trace of the carbene Tp(PPh3)(η1-O2CCHPh2)RuCHCHC(Ph)2 (3) is also observed in the crude reaction mixture. Compound 1 reacts with phenyldiazomethane to form the benzylidene Tp(PPh3)(η1-O2CCHPh2)RuCHPh (4). A similar species is also available by the reaction between AgO2CCHPh2 and Tp(PCy3)(Cl)RuCHCHC(CH3)2 (5), which affords Tp(PCy3)(η1-O2CCHPh2)RuCHCHC(CH3)2 (6). With the addition of an excess of HCl, complexes 4 and 6 release free HO2CCHPh2 and are converted to Tp(PPh3)(Cl)RuCHPh (7) and complex 5, respectively. The reaction of 1 with phenylacetylene yields the five-membered chelate Tp(PPh3)Ru[κ2-(C,Ο)-C(CHPh)OC(CHPh2)O] (8). Complex 8 is also formed in the reaction of Tp(PPh3)(Cl)RuCCHPh with 1.2 equiv of AgO2CCHPh2. Compounds 1, 2, and 8 have been characterized by X-ray crystallography. Complexes 2, 5, 6, 7, and 8 do not catalyze olefin metathesis reactions, while 4 is an active initiator for the ring-opening metathesis polymerization of norbornene.