Catalytic Living Ring‐Opening Metathesis Polymerization Using Vinyl Ethers as Effective Chain‐Transfer Agents

Abstract A catalytic living ring‐opening metathesis copolymerization (ROMP) method is described that relies on a degenerative, reversible and regioselective exchange of propagating Fischer‐carbenes. All characteristics of a living polymerization such as narrow dispersity, excellent molar mass control and the ability to form block copolymers are achieved by this method. The method allows the use of up to 200 times less ruthenium complex than traditional living ROMP. We demonstrate the synthesis of ROMP‐ROMP diblock copolymers, ATRP from a ROMP macro‐initiator and living ROMP from a PEG‐based macro chain transfer agent. The cost‐effective, sustainable and environmentally friendly synthesis of degradable polymers and block copolymers enabled by this strategy will find various applications in biomedicine, materials science, and technology.