Synthesis of bi‐functional immobilized polymer catalysts via a two‐step radiation‐induced graft polymerization process
Synthesis of bi‐functional immobilized polymer catalysts via a two‐step radiation‐induced graft polymerization process
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两步辐射诱导接枝聚合法合成双功能固定化聚合物催化剂
DOI：
10.1002/cctc.202001451
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发表时间：
2021
期刊：
影响因子：
4.5
通讯作者：
Yasuo Sato
中科院分区：
文献类型：
--
作者：
Yoshinori Okuno;Takako Shibata;Akie Oyo;Rie Suzuki;Mayuko Takegami;Satoshi Kato;Shigeki Isomura;Shoji Aoki;Jun-ichi Kan-no;Yasuo Sato
在此，我们设计并合成了两种基于脯氨酸酰胺-酸组合的双功能固定化聚合物催化剂，用于流动体系中的直接不对称Aldol反应。其中两种官能团存在于相同接枝聚合物上的常规双官能催化剂在再循环流动系统中提供高达99%的产率和> 99%的对映体过量（ee）。我们还研究了双功能催化剂，其中两种功能位于不同的接枝聚合物上。我们提出了一种简单的催化剂固定化方法，该方法允许通过进行辐射诱导接枝聚合过程（RIGP）的两个连续步骤将位于不同接枝聚合物上的两种不同催化剂分别引入到同一聚合物上。我们证实了接枝聚合物（接枝聚催化剂和聚丙烯酸链）之间的相互作用促进了Aldol反应，具有高转化率和ee.这种设计策略可能比传统的多功能相互作用合成催化剂的方法优越上级。
Here, we designed and synthesized two types of bi‐functional immobilized polymer catalysts based on the prolineamide‐acid combination for direct enantioselective aldol reaction in flow systems. Conventional bi‐functional catalysts in which the two functions are present on the same graft polymer afforded up to 99 % yield and >99 % enantiomeric excess (ee) in a recirculating flow system. We also investigated bi‐functional catalysts in which the two functions are located on different graft polymers. We present a straightforward catalyst immobilization method that allows two different catalysts located on different graft polymers to be introduced separately onto the same polymer by conducting two successive steps of radiation‐induced graft polymerization process (RIGP). We confirmed that the graft polymers (grafted polycatalyst and polyacrylic acid chain) interact with each other to promote the aldol reaction with high conversion and ee. This design strategy may be superior to the conventional approach for synthesizing catalysts in which multiple functions interact.