The Use of Poly(ethylene glycol) Substituted Pyridine Ligands for the Synthesis of Water-soluble Ruthenium Benzylidene Catalysts for Metathesis Reactions in Water

This invention pertains to the use of poly(ethylene glycol) (PEG)-substituted pyridine molecules as ligands for ruthenium benzylidene catalysts, where the nitrogen of the pyridine group coordinates to the ruthenium metal center of the catalyst. Such PEG-functionalization, PEGylation, of these ruthenium catalysts gives new water-soluble catalysts that actively polymerize water-soluble cyclic olefins in water. The usefulness of this invention lies in the ability to perform a range of aqueous based metathesis chemistries, such as ring opening metathesis polymerization, ring-closing metathesis, and cross-metathesis.

The use of these catalysts for the polymerization of polar monomers in water has been demonstrated. The ability to carry out polymerizations in entirely aqueous media is advantageous, as organic solvents can be eliminated and post-polymerization purification is minimized.