Novel Olefin Metathesis Ruthenium Catalysts Bearing Backbone-Substituted Unsymmetrical NHC Ligands

Stable Ru-based catalysts containing unsymmetrical N-heterocyclic carbene (NHC) ligands with phenyl substituents on the backbone in syn and anti stereochemical relationships have been easily prepared and fully characterized. Preliminary investigation revealed that, depending on the backbone configuration, the new Ru complexes displayed different catalytic behaviors in representative olefin metathesis reactions.