Rh-Mediated C1-Polymerization: Copolymers from Diazoesters and Sulfoxonium Ylides

In this paper, we present new results obtained in our investigations of Rh-catalyzed C1 (co)polymerization reactions using carbene units as monomers. We demonstrate here, for the first time, the use of transition metal catalysts in carbene polymerization using sulfur ylides as the carbene monomer precursors. Furthermore, we show that it is possible to generate unique diblock copolymers from sulfoxonium ylides and diazoesters as the respective carbene monomer precursors. This constitutes an entirely new approach to the synthesis of functional copolymers. The copolymerization reactions were successful, and high-M-w poly(methylene)-poly(ester carbene) copolymers were obtained with a diblock-syndiotactic microstructure in decent yields. These copolymers can be used as blending agents to mix polyethylene or polymethylene with poly(ethyl 2-ylidene-acetate). The copolymer properties are highly dependent on the functional-group content. Model studies and investigations on the influence of the catalyst structure on the obtained polymer yields provide insights into the catalyst activation and deactivation processes operative under the applied reaction conditions.