功能化α,ω-二烯的催化区域和立体选择性循环聚合和与乙烯的共聚
Haobing Wang1, Yanan Zhao2, Masayoshi Nishiura1,3
1Advanced Catalysis Research Group , RIKEN Center for Sustainable Resource Science , 2-1 Hirosawa , Wako , Saitama 351-0198 , Japan.
Journal of the American Chemical Society
|July 26, 2019
概括
这项研究使用催化剂证明了功能化的二烯的受控循环聚合,从而实现了高的区域和立体选择性. 这些发现为制造精确结构的循环聚合物提供了新的途径.
科学领域:
- 聚合物化学
- 有机金属化学
- 催化剂
背景情况:
- 在异原子功能化α,ω-的循环聚合过程中,对区域和立体化学的精确控制是一个重大挑战.
- 现有的方法往往缺乏生产明确的循环聚合物架构所需的选择性.
研究的目的:
- 为了实现以太和乙烯功能化的1,6-二烯的区域选择性和立体规律性循环聚合.
- 研究催化剂-单体相互作用在控制聚合结果中的作用.
- 探索功能化二烯与乙烯的共聚.
主要方法:
- 使用半三明治催化剂进行1,6-heptadiene衍生物的环聚合.
- 使用密度函数理论 (DFT) 计算来理解反应机制.
- 使用4-基-1,6-二烯和4-基-1,6-二烯进行了聚合实验.
主要成果:
- 实现了4-基-1,6-乙烯的异型环聚合,产生1,2,4-基替代乙烯cyclopentane (ECP) 微结构 (95% mmm).
- 在聚合4--1,6-乙烯时获得高同位性 (95% rrr),仅形成1,2-转-1,4-cis-ECP单元.
- DFT计算证实了-异原子相互作用在控制区域和立体化学中的关键作用.
- 证明了功能化的1,6-heptadienes与乙烯的受控共聚.
结论:
- 半三明治催化剂可以精确控制1,6-二烯循环聚合的区域和立体化学.
- 催化剂与二烯单体中的异原子之间的相互作用是实现立体规律性的关键.
- 这项工作提供了一种新方法来合成具有定义微结构的功能循环聚合物和共聚合物.
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