Ring-closing metathesis in biphasic BMI.PF6 ionic liquid/toluene medium: a powerful recyclable and environmentally friendly process.

Biphasic BMI[middle dot]PF(6)/toluene solvent is a remarkably suitable and clean medium for performing olefin metathesis with a new 2nd generation ionic liquid supported-ruthenium catalyst: high levels of recyclability and reusability combined with a high reactivity were obtained with a variety of di- or tri-substituted and/or oxygen-containing dienes, and very low residual ruthenium levels were detected (1 to 22 ppm) in the products.