Synthesis, characterization, and catalytic activity of a ruthenium carbene complex coordinated with bidentate 2-pyridine-carboxylato ligands

The halide and phosphine free complex [(sIMes)(C5H4N-2-CO2)2Rudouble bond; length as m-dashCHPh] (7) (sIMes = 1,3-dimesitylimidazolidin-2-ylidene) bearing two bidentate 2-pyridinecarboxylato ligands was synthesized from the carbene complex [(sIMes)(PCy3)(Cl)2Rudouble bond; length as m-dashCHPh] (4) and the silver 2-pyridine-carboxylate (8). The molecular structure of the octahedral complex 7 reveals that the two carboxylato functions are coordinated in cis geometry to the ruthenium center. Catalyst 7 exhibits activity in ring-closing metathesis (RCM) reactions after addition of a cocatalyst (HCl) in dichloromethane as well as in methanol solution.