We report here a method to make a branched and partially ethoxylated polyethyleneimine derivative directly from ethanolamine. The polymerization reaction is catalysed by a pincer complex of Earth-abundant metal, manganese, and produces water as the only byproduct. Industrial processes to produce polyethyleneimines involve the transformation of ethanolamine to a highly toxic chemical, aziridine, by an energy-intensive/waste-generating process followed by the ring-opening polymerization of aziridine. The reported method bypasses the need to produce a highly toxic intermediate and presents advantages over the current state-of-the-art. We propose that the polymerization process follows a hydrogen borrowing pathway that involves (a) dehydrogenation of ethanolamine to form 2-aminoacetaldehyde, (b) dehydrative coupling of 2-aminoacetaldehyde with ethanolamine to form an imine derivative, and (c) subsequent hydrogenation of imine derivative to form alkylated amines.

我们在此报告了一种直接从乙醇胺制备支链且部分乙氧基化的聚乙烯亚胺衍生物的方法。聚合反应由地球上储量丰富的金属锰的钳状络合物催化，并产生水作为唯一的副产物。生产聚乙烯亚胺的工业过程涉及通过能源密集型/产生废物的过程将乙醇胺转化为剧毒化学品氮丙啶，然后进行氮丙啶的开环聚合。所报道的方法不需要生产剧毒中间体，并且比当前最先进的技术具有优势。我们提出聚合过程遵循借氢途径，包括（a）乙醇胺脱氢形成2-氨基乙醛，（b）2-氨基乙醛与乙醇胺脱水偶联形成亚胺衍生物，以及（c）随后亚胺氢化衍生物形成烷基化胺。