Grubbs-Hoveyda olefin metathesis is important in the industrial production of a wide range of products from pharmaceuticals to polymers. An academic collaboration with AstraZeneca, UK, scientists shows how the ruthenium-containing pre-catalyst is activated: It forms a complex in which the incoming olefin substrate and the outgoing alkoxy ligand are both tied to the ruthenium center. The rate-determining step in the catalytic mechanism turns out to be an interchange rather than a dissociative step.

Such insights might help in the optimization of reactions or the design of new catalysts.

• What is the initiation step of the Grubbs-Hoveyda olefin metathesis catalyst?
  I. W. Ashworth, I. H. Hillier, D. J. Nelson, J. M. Percy, M. A. Vincent,
  Chem. Commun. 2011, 47, 5428-5430.
  DOI: 10.1039/C1CC11230A