Forming a ruthenium isomerisation catalyst from Grubbs II: a DFT study

A DFT investigation into the mechanism for the decomposition of Grubbs 2nd generation pre-catalyst  in the presence of methanol, is presented. Gibbs free energy profiles for decomposition of the pre-catalyst via two possible mechanisms were computed. We predict that decomposition following tricyclohexylphosphane dissociation is most favoured compared to direct decomposition of the pre-catalyst. However, depending on the reaction conditions, an on-pathway mechanism may be competitive with ruthenium hydride formation.