New Method for Asymmetric Polymerization: Asymmetric Allylic Substitution Catalyzed by a Planar-Chiral Ruthenium Complex
New Method for Asymmetric Polymerization: Asymmetric Allylic Substitution Catalyzed by a Planar-Chiral Ruthenium Complex
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DOI：
10.1021/ma5008623
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发表时间：
2014-06
期刊：
影响因子：
5.5
通讯作者：
N. Kanbayashi;T. Okamura;K. Onitsuka
中科院分区：
文献类型：
--
作者：
N. Kanbayashi;T. Okamura;K. Onitsuka
报道了一种新型的平面手性环戊二烯基钌（Cp′Ru）配合物催化的不对称烯丙基取代不对称聚合反应。在手性钌配合物催化下，单分子中同时含有烯丙基氯和N-烷氧基酰胺的非手性AB型单体可顺利聚合，单体转化率可达定量，得到光学活性聚酰胺。所得聚合物的特征在于通过旋光，圆二色性，和1H NMR分析，这清楚地表明，聚合系统的作品在一个高度立体选择性的方式，以提供具有高的区域和对映选择性的光学活性聚酰胺。结果表明，平面手性Cp′Ru配合物在聚合反应中也能作为高效的催化剂控制聚合反应的立体化学.
A new type of asymmetric polymerization reaction by asymmetric allylic substitution catalyzed by planar-chiral cyclopentadienyl-ruthenium (Cp′Ru) complexes is described. Achiral AB-type monomers, which feature both the allylic chloride and N-alkoxyamide moieties in a single molecule, are smoothly polymerized by the catalysis of chiral ruthenium complexes with quantitative monomer conversion to afford optically active polyamides in good yields. The resulting polymers are characterized by optical rotation, circular dichroism, and 1H NMR analyses, which clearly show that the polymerization system works in a highly stereoselective manner to afford optically active polyamides with high regio- and enantioselectivities. The results revealed that the planar-chiral Cp′Ru complexes work as a highly efficient catalyst to control the stereochemistry even in the polymerization reaction.