Ring-opening Metathesis Polymerization

In collaboration with Prof. Kathlyn Parker, we introduced the use of 1-substituted cyclobutenes for ruthenium-catalyzed ring opening metathesis polymerization (ROMP). The ROMP of 1-cyclobutenecarbonyl glycine methyl ester provides stereo and regioregular, head-to-tail, polymers with E-trisubstituted olefins with no stereocenters that could serve as a source of structural ambiguities. Characterization of the polymer products indicates that they have polydispersities ranging from 1.2 – 1.6 and that they are the products of a “living” polymerization. 1-Cyclobutene carboxamide-derived ROMP polymers are excellent prospects for applications that require stereoregular chains to present ligands.

We recently described the highly alternating polymerization of cyclobutene 1-carboxylic esters with cyclohexene derivatives with Grubbs III catalyst. The success of this reaction derives from the combination of two monomers neither of which forms a homopolymer under ROMP reaction conditions. We have demonstrated the utility of this method to prepare antimicrobial polymers.

Catalysis of AROMP with Hoveyda-Grubbs II catalyst, provided entirely cyclic alternating polymer. Conditions for the CAROMP were used to prepare polymer in which one of the repeat units bore a primary alkyl chloride that was used for further elaboration.

We are working to further develop new monomers for ring-opening metathesis polymerization (ROMP) chemistry to provide polymers with precisely alternating functional groups. These polymers are being used in applications ranging from antibacterials to OLEDs.