Enhanced Stereocontrol in Disyndiotactic-specific Group Transfer Polymerization of Methyl Crotonate—Stereochemical Evidence of Group Transfer
Enhanced Stereocontrol in Disyndiotactic-specific Group Transfer Polymerization of Methyl Crotonate—Stereochemical Evidence of Group Transfer
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DOI：
10.1295/polymj.37.578
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发表时间：
2005-08
期刊：
影响因子：
2.8
通讯作者：
K. Ute;Toshiyuki Tarao;T. Kitayama
中科院分区：
文献类型：
--
作者：
K. Ute;Toshiyuki Tarao;T. Kitayama
研究了以碘化汞和叔丁基二甲基碘化硅为催化剂和助催化剂，含叔丁基二甲基硅基的乙烯酮硅缩醛催化巴豆酸甲酯的基团转移聚合（GTP）。在优化的条件下，GTP产生的双间规聚合物具有窄的分子量分布定量产量。发现引发剂组分中的三烷基甲硅烷基控制GTP的立体化学过程;庞大的叔丁基二甲基甲硅烷基导致最高的间同立构规整度。这一结果为转移硅基参与GTP中的传播步骤提供了直接证据。
Group transfer polymerization (GTP) of methyl crotonate was examined by using a ketene silyl acetal with tert-butyldimethylsilyl group in the presence of HgI2 and tert-butyldimethylsilyl iodide as a catalyst and a co-catalyst, respectively. Under optimized conditions, the GTP produced disyndiotactic polymers with narrow molecular weight distribution in quantitative yields. The trialkylsilyl group in the initiator components was found to exert control over the stereochemical process of the GTP; the bulky tert-butyldimethylsilyl group leads to the highest disyndiotacticity. The results provide a direct evidence for the transferring silyl group to be involved in the propagation steps in the GTP.