Synthesis of Clickable Isotactic Poly(vinyl ether)s through Organocatalytic Stereoselective Cationic Copolymerization

By virtue of the high reliability of click chemistry, polymers with clickable groups provide a useful platform for the rapid synthesis of polymer materials with diverse functionalities and architectures. However, the polymerization of clickable vinyl monomers with a concurrent regulation on tacticity remains underdeveloped. Herein, we report the successful development of a stereoselective cationic copolymerization of C-C triple bond-containing vinyl ethers with simple alkyl vinyl ethers by employing confined Brønsted acid as catalyst, which allows for the synthesis of alkyne-functionalized vinyl ether copolymers with high isotacticity (up to 90 % m), controlled molecular weight, and variable content of C-C triple bonds. Further transformation of the pendant clickable alkyne groups via thiol-yne click reactions and copper(I)-catalyzed alkyne-azide cycloaddition reaction enables a modular access to isotactic polymers with various functional groups.