Synthesis of polyester–polyether copolymers via postpolymerization modification: Reduction of polyesters

Abstract Postpolymerization modification (PPM) offers a powerful strategy for diversifying polymer structures beyond the limitations of conventional polymerization. In this study, we present a selective decarbonylation‐based PPM approach that partially converts ester bonds in polycaprolactone to ether bonds using a mild InBr 3 /triethylsilane system at room temperature. This transition enables the development of previously inaccessible polyester–polyether copolymers, with controllable composition and properties. These results demonstrate the utility of reductive framework modification as a versatile method for designing structurally and thermally tunable flexible materials.