Hydrogen Bond Donor Catalyzed Cationic Polymerization of Vinyl Ethers

The synthesis of high‐molecular‐weight poly(vinyl ethers) under mild conditions is a significant challenge, since cationic polymerization reactions are highly sensitive to chain‐transfer and termination events. We identified a novel and highly effective hydrogen bond donor (HBD)–organic acid pair that can facilitate controlled cationic polymerization of vinyl ethers under ambient conditions with excellent monomer compatibility. Poly(vinyl ethers) of molar masses exceeding 50 kg mol−1 can be produced within 1 h without elaborate reagent purification. Modification of the HBD structure allowed tuning of the polymerization rate, while DFT calculations helped elucidate crucial intermolecular interactions between the HBD, organic acid, and polymer chain end. A unique combination of hydrogen bond donor (HBD) and acid catalysis enabled rapid vinyl ether polymerization under an ambient atmosphere. This controlled polymerization furnished polymers with molecular weights above 60 kg mol−1. Importantly, several key intermolecular interactions between the organic acid and HBD were crucial for successful polymerization.