Direct Intramolecular C-H Amination Reaction Cocatalyzed by Copper(II) and Iron(III) as Part of an Efficient Route for the Synthesis of Pyrido[1,2-a]benzimidazoles from N-Aryl-2-aminopyridines
Direct Intramolecular C-H Amination Reaction Cocatalyzed by Copper(II) and Iron(III) as Part of an Efficient Route for the Synthesis of Pyrido[1,2-a]benzimidazoles from N-Aryl-2-aminopyridines
复制标题
铜(II)和铁(III)催化的直接分子内C-H胺化反应作为N-芳基-2-氨基吡啶合成吡啶并[1,2-a]苯并咪唑的有效路线的一部分
DOI：
10.1021/ja1067993
复制
发表时间：
2010-09-29
影响因子：
15
通讯作者：
Zhu, Qiang
中科院分区：
文献类型：
--
作者：
Wang, Honggen;Wang, Yong;Zhu, Qiang
通过N-芳基-2-氨基吡啶的分子内芳环C-H胺化反应，合成了吡啶并[1，2-M]苯并咪唑类化合物。该反应是在DMF中，Cu（OAc）（2）和Fe（NO3）（3）中心点9 H（2）O的共催化下进行的。用此方法可以中等到优异的产率得到含有各种取代模式的多样化吡啶并[1，2-a]苯并咪唑。机理研究的结果表明，Cu（III）催化的亲电芳族取代（SEAr）的途径是在这个过程中操作。铁（III）的独特作用被认为在于其促进更亲电的Cu（III）物质形成的能力。在没有铁（III）的情况下，发生效率低得多且可逆的Cu（II）介导的SEAr过程。
A novel and efficient synthesis of pyrido[1,2-Mbenzimidazoles through direct intramolecular aromatic C-H amination of N-aryl-2-aminopyridines has been developed. The reaction, cocatalyzed by Cu(OAc)(2) and Fe(NO3)(3)center dot 9H(2)O, is carried out in DMF under a dioxygen atmosphere. Diversified pyrido[1,2-a]benzimidazoles containing various substitution patterns are obtained in moderate to excellent yields by using this procedure. The results of mechanistic studies suggest that a Cu(III)-catalyzed electrophilic aromatic substitution (SEAr) pathway is operating in this process. The unique role of iron(III) is believed to lie in its ability to facilitate formation of the more electrophilic Cu(III) species. In the absence of iron(III), a much less efficient and reversible Cu(II)-mediated SEAr process takes place.