Enantio- and diastereoselective polymerization: asymmetric allylic alkylation catalyzed by a planar-chiral Cp'Ru complex
Enantio- and diastereoselective polymerization: asymmetric allylic alkylation catalyzed by a planar-chiral Cp'Ru complex
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对映和非对映选择性聚合：平面手性 CpRu 配合物催化的不对称烯丙基烷基化
DOI：
10.1039/c6py00484a
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
K.
中科院分区：
文献类型：
--
作者：
Kanbayashi;N.; Hosoda;K.; Okamura;T.; Aoshima;S.; Onitsuka;K.
本文研究了平面手性环戊二烯基钌（Cp′Ru）配合物（（S）-1）催化的不对称烯丙基烷基化反应的区域选择性、非对映选择性和对映选择性聚合。用（S）-1聚合了含有1，3-二酮和烯丙基氯的非手性AB型单体，并定量测定了单体转化率。所得聚合物（3）通过NMR分析表征;由（S）-1催化的聚合反应以高区域选择性进行，并且单体单元的邻位立构中心可以控制。该聚合物在其CD光谱中在270 nm附近显示出Cotton效应，这归因于每个苯发色团的π-π* 跃迁矩之间的双信号耦合。结果表明，聚合反应是以立体选择性的方式进行的，得到了光学活性聚合物。
In this study, we examined the regio-, diastereo-, and enantioselective polymerization using asymmetric allylic alkylation catalyzed by a planar-chiral cyclopentadienyl-ruthenium (Cp′Ru) complex ((S)-1). Achiral AB type monomers bearing 1,3-diketone and allylic chloride moieties were polymerized by (S)-1 with quantitative monomer conversion. The resulting polymer (3) was characterized by NMR analyses; the polymerization reaction catalyzed by (S)-1 proceeded with high regioselectivity, and the vicinal stereocenters of the monomer unit can be controlled. The polymer showed a Cotton effect at around 270 nm in its CD spectrum, which was ascribed to the bisignate coupling between the π–π* transition moment of each benzene chromophore. The results suggested that the polymerization proceeded in a stereoselective manner to give optically active polymers.