The efficacy of [bmim][X] ionic liquids (ILs) (X = PF(6) (-), BF(4) (-) and NTf(2) (-)) as reaction media for methyl oleate metathesis was compared with that of conventional organic solvents (PhCl, PhMe, DCM and DCE) using the well-defined first and second generation Grubbs precatalysts, RuCl(2)(PCy(3))(L)(=CHPh) (L = PCy(3) or H(2)IMes). Best catalytic performance, with excellent selectivity (>98%) at moderate reaction temperatures, was achieved in [bmim][X] ILs compared to conventional solvents. The effects of anion, reaction temperature, solvent polarity, solvent viscosity, and ligand-anion interaction on the reaction are also addressed.
Keywords: RuCl2(PCy3)(L)(=CHPh); [bmim][X]; metathesis; methyl oleate.