Mahmood Qaiser, Xu Guangqiang, Zhou Li, Guo Xuanhua, Wang Qinggang
Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
Polymers (Basel). 2020 Oct 15;12(10):2365. doi: 10.3390/polym12102365.
Chiral 4,8-diphenyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (DiPh-TBD) was synthesized and applied to a ring-opening polymerization of -lactide (-LA). The chiral DiPh-TBD promoted the synthesis of isotactic enriched polylactides (PLAs) with controlled molecular weight and narrow molecular weight distributions under mild, metal-free conditions. When the [-LA]/[Cat.] ratio was 100/1, full monomer conversion was achieved within only 1 min and a moderate probability of 0.67 dyads () was obtained at room temperature. A chain-end control mechanism (CEC) was found to be responsible for the isoselectivity based on the homodecoupled H NMR spectrum, the chiral HPLC measurement, and kinetic studies.
合成了手性4,8-二苯基-1,5,7-三氮杂双环[4.4.0]癸-5-烯（DiPh-TBD），并将其应用于丙交酯（-LA）的开环聚合反应。手性DiPh-TBD在温和的无金属条件下促进了等规富集聚乳酸（PLA）的合成，所得产物分子量可控且分子量分布窄。当[-LA]/[催化剂]比例为100/1时，仅在1分钟内即可实现单体完全转化，并且在室温下获得了中等概率的0.67的双全同立构二元组（）。基于同核去耦1H NMR光谱、手性HPLC测量和动力学研究，发现链端控制机制（CEC）是导致等规选择性的原因。
