Unlocking Ring-Opening Polymerization of Glycidyl Propargyl Ether via Lewis Pair Organocatalysts

Alkyne groups provide exceptional versatility for functionalization in macromolecular systems. However, the controlled anionic ring-opening polymerization (AROP) of epoxide monomers bearing terminal alkynes remains challenging due to the lability of alkynes under strongly basic conditions. Herein, we present a controlled AROP of glycidyl propargyl ether enabled by Lewis pair organocatalysis, employing a phosphazene base and triethylborane. This catalytic system suppresses undesired interactions with the acidic alkyne proton, allowing precise control over the polymerization degree (25-100) with narrow dispersity (Đ < 1.1) and high initiation efficiency in the synthesis of poly(glycidyl propargyl ether). Moreover, this method yields diverse polymer architectures, including diblock copolymers via atom transfer radical polymerization and triblock copolymers using a macroinitiator strategy. Post-polymerization modification is demonstrated through Cu-catalyzed azide-alkyne cycloaddition and thiol-yne reactions. We envision that this approach significantly broadens access to alkyne-functionalized AROP systems and paves the way for their use in diverse applications.