Catalytic Syntheses of Degradable Polymers via Ring-Opening Metathesis Copolymerization Using Vinyl Ethers as Chain Transfer Agents

Commercially available Vince lactam and its deriva-tives are copolymerized with 2,3-dihydrofuran (DHF) in a living fashion based on the unique reactivity of Ru Fischer carbene. The resulting copolymers can be fully degraded into small molecules under mildly acidic conditions, suggesting a uniform incorporation of the DHF units throughout the polymer backbone. The regioselective and ultrafast chain transfer of G3-benzylidene to vinyl ethers enabled us to synthesize a narrowly dispersed triblock copolymer via macroinitiation from poly(ethylene glycol) divinyl ether. This high metathesis activity and regioselectivity of vinyl ethers was further exploited in a kinetically controlled catalytic synthesis of degradable copolymers using vinyl ethers as effective chain transfer agents. This strategy paves the way for a one-pot synthesis of degradable ROMP polymers from easily accessible monomers and chain transfer agents. We report a catalytic copolymerization in which up to 500-fold savings in the expensive and toxic ruthenium carbene complex can be achieved compared to a conventional ROMP. We believe that this cost-effective and environmentally friendly synthesis of degradable polymers will be highly useful for many biomedical applications as well as for environmental sustainability.

Automated summary

In this study, commercially available Vince lactam and its derivatives were copolymerized with 2,3-dihydrofuran (DHF) in a living fashion based on the unique reactivity of Ru Fischer carbene. The resulting copolymers showed complete degradation into small molecules under mildly acidic conditions, indicating uniform incorporation of the DHF units throughout the polymer backbone. The high metathesis activity and regioselectivity of vinyl ethers were further exploited for the synthesis of degradable copolymers using vinyl ethers as effective chain transfer agents. This cost-effective and environmentally friendly synthesis of degradable polymers has potential applications in biomedical and environmental fields.