Iridium-Catalyzed Condensation of Amines and Vicinal Diols to Substituted Piperazines
作者:Linda L. R. Lorentz-Petersen、Lars Ulrik Nordstrøm、Robert Madsen
DOI:10.1002/ejoc.201201099
日期:2012.12
A straightforward procedure is described for the synthesis of piperazines from amines and 1,2-diols. The heterocyclization is catalyzed by [Cp*IrCl2]2 and sodium hydrogen carbonate and can be achieved with either toluene or water as solvent. The transformation does not require any stoichiometric additives and only produces water as the byproduct. The reaction can be performed between a 1,2-diamine
描述了从胺和 1,2-二醇合成哌嗪的简单程序。杂环化由 [Cp*IrCl2]2 和碳酸氢钠催化,可以用甲苯或水作为溶剂来实现。该转化不需要任何化学计量添加剂,只产生水作为副产品。该反应可以在 1,2-二胺和 1,2-二醇之间或通过伯烷基胺和 1,2-二醇之间的双缩合进行。哌嗪环上至少需要一个取代基才能以良好的收率实现环化。该机制被认为涉及 1,2-二醇脱氢为 α-羟基醛,后者与胺缩合形成 α-羟基亚胺。后者重排为相应的α-氨基羰基化合物,