Eugenol-based optically active helical polymers: from controlled synthesis to post-polymerization modification and chiral recognition
摘要
The depletion of fossil resources necessitates the development of sustainable polymers from renewable feedstocks. Eugenol, a biomass-derived compound, serves as an ideal platform molecule due to its reactive allyl group and rigid aromatic scaffold. This study introduces a chiral Pd/Wei-Phos catalytic system for the helix-selective living polymerization of achiral eugenol-based diazo acetate monomer, delivering helical polycarbenes in high yield with controlled molecular weight (Mn), narrow dispersity (Đ), and optical activity. Post-polymerization functionalization was achieved via thiol-ene click chemistry, enabling efficient incorporation of diverse functional groups (carboxyl, ester, ketone, and diol) with high conversion (>99%). Additionally, an innovative pentaerythritol tetra(3-mercaptopropionic acid) (PETMP) cross-linked eugenol-based polycarbene system has been constructed. By controlling the polymerization degree and cross-linking density of the polymer, the mechanical properties (tensile strength can reach 15 MPa) of the cross-linked materials can be easily adjusted. Moreover, the cross-linked films exhibit excellent chiral separation ability and can be used for the enantioseparation of enantiomers of various chiral alcohols, with enantiomeric excess (ee) up to 96%. This not only contributes an innovative strategy for designing high-performance functional materials, but also provides inspiring ideas for the development of biomass-derived high-performance materials.