Alcohol- and Water-Tolerant Living Anionic Polymerization of Aziridines
Alcohol- and Water-Tolerant Living Anionic Polymerization of Aziridines
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DOI：
10.1021/acs.macromol.8b01320
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发表时间：
2018-08-14
期刊：
影响因子：
5.5
通讯作者：
Wurm, Frederik R.
中科院分区：
文献类型：
--
作者：
Gleede, Tassilo;Rieger, Elisabeth;Wurm, Frederik R.
活性阴离子聚合提供了获得明确定义的聚合物的途径，但它需要严格的试剂和溶剂纯化。本工作介绍了氮杂环丙烷的氮杂阴离子聚合（AAROP）作为一个强大的活性聚合技术，易于控制的自由基聚合。AAROP不需要惰性气氛，并且在大量水或醇的存在下仍然存在。甲磺酰基，甲苯磺酰基，或brosyl活化的氮杂环丙烷聚合与高达100倍过量的质子杂质相对于引发剂和仍然是活性的扩链。这允许在没有保护基团的情况下通过阴离子聚合制备多元醇，因为醇仅发生少量引发。对质子添加剂的耐受性在于活化基团的吸电子效应，降低了增长物种的碱度，同时保持了强的亲核特性。以这种方式，竞争的醇和水仅轻微地参与聚合，使得活性阴离子聚合成为一种易于进行的技术，以得到定义明确的聚酰胺和胺。
Living anionic polymerization gives access to well-defined polymers, but it demands strict purification of reagents and solvents. This work presents the azaanionic polymerization (AAROP) of aziridines as a robust living polymerization technique, with the ease of controlled radical polymerizations. AAROP does not require inert atmosphere and remains living in the presence of large amounts of water or alcohols. Mesyl-, tosyl-, or brosyl-activated aziridines were polymerized with up to 100-fold excess of a protic impurity with respect to the initiator and still being active for chain extension. This allowed the preparation of polyols by anionic polymerization without protective groups, as only minor initiation occurred from the alcohols. The tolerance toward protic additives lies in the electron-withdrawing effect of the activating groups, decreasing the basicity of the propagating species, while maintaining a strong nucleophilic character. In this way, competing alcohols and water are only slightly involved in the polymerization, making living anionic polymerization an easy-to-conduct technique to well-defined polyamides and -amines.