Ruthenium Olefin Metathesis Catalysts Containing Six-Membered Sulfone and Sulfonamide Chelating Rings

The preparation and X-ray structure characterization of new olefin metathesis initiators containing sulfone- and sulfonamide-substituted benzylidene ligands are described. We observed that these catalysts exhibit Ru···O(SO)R interactions, forming six-membered chelates. Tuning the electronic and steric factors of the benzylidene part as well as selecting the proper NHC ligands can have a direct impact on catalyst activity and stability, leading to promising new catalysts.