Helical Substituted Polyacetylene With Pendent Prolineamide Groups:Synthesis And Its Application For Aymmetrcic Aldol Reaction

Helical polymers with many functional groups were designed and synthesized by many scientists. Owing to their unique properties and wide applications in chiral resolution, photoluminescence, chiral memory and asymmetric reactions, they had aroused scientists’ ever-increasing attention. Furthermore, inspired by the reaction catalyzed by enzymes in human body, some scientists begin to develop helical polymers-based catalysts to emulate the way that enzyme works. In this dissertation, various types of transition metal catalysts for preparing helical polymers were reviewed. We also introduced structures and advances of optically active polyacetylene and poly(phenylacetylene) derivatives. Moreover, we prepared novel optically active magnetic microspheres with pendent prolineamide groups and investigated their catalytic ability. The major contents are as follows:A monomer constituted by substituted acetylene and pendent prolineamide group, MIL, was synthesized. The monomer was characterized by FT-IR,1H NMR,13C NMR, and so on. Then achiral N-propargylamide M2 was polymerized with MIL to produce a series of copolymers with helical structure and prolineamide groups. In order to identify the optimized copolymer, the molecular weight and structure of these copolymers were characterized by GPC, specific rotation and circular dichroism techniques. Among these polymers, poly(MlL0.1-co-M20.9) was chosen as the model asymmetric catalytic catalyst for performing Aldol reaction under various reaction conditions.The copolymer of MIL and chiral M3 was synthesized and its structure was studied by FT-IR,1H NMR and circular dichroism methods. Subsequently, Fe3O4 nanoparticles, crosslinking agent and the two monomers mentioned above were combined together by suspension polymerization, resulting in novel optically active magnetic microspheres. Scanning electron microscopy indicates the microspheres had spherical morphology. Conditions for preparing microspheres were optimized. Structure, properties and asymmetric catalytic ability of the microspheres were also studied. We further conducted recycling experiments to verify the potential use of the as-prepared polymeric catalyst for industrial application.