使用鲁催化剂的Cis选择性环开放元解聚合.
Benjamin K Keitz1, Alexey Fedorov, Robert H Grubbs
1Arnold and Mabel Beckman Laboratories of Chemical Synthesis, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
Journal of the American Chemical Society
|January 14, 2012
概括
基于的催化剂使得循环基的 cis-选择性环开放元解聚合成为可能. 聚合物cis含量达到96%,可以通过单体结构和聚合温度控制进行调节.
科学领域:
- 聚合物化学 聚合物化学
- 有机金属化学 有机金属化学
- 催化剂是一种催化剂.
背景情况:
- 环开元化聚合 (ROMP) 是一种用于聚合物合成的多功能方法.
- 在ROMP中实现高的cis选择性对于定制聚合物特性至关重要.
- 基于的催化剂在转化反应中提供可调节的反应性和选择性.
研究的目的:
- 报告各种单环和norbornene类型单体的 cis-选择性环开放元解聚合.
- 研究单体结构和温度对聚合物cis含量的影响.
- 为了证明C-H激活的以为基础的催化剂对受控聚合物的有效性.
主要方法:
- 使用C-H激活的,以为基础的转化催化剂.
- 在各种单环基,诺波和氧波衍生物上进行环开转化聚合.
- 多样化的聚合温度和单体结构,以研究它们对聚合物立体化学的影响.
主要成果:
- 实现了研究单体的 cis-选择性环开放性转化聚合.
- 证明了得到的聚合物的cis含量受到单体结构和反应温度的显著影响.
- 通过优化聚合条件,特别是通过降低温度,获得高CIS含量高达96%的聚合物.
结论:
- 开发的以为基础的催化剂有效地促进了 cis-选择性的 ROMP.
- 在ROMP中的聚合物立体化学可以通过调整单体设计和反应温度来精确控制.
- 降低聚合温度是最大化ROMP中cis选择性的关键策略.
相关概念视频
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01:16Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
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Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.