Oxidant-Switchable Selective Synthesis of 2-Aminobenzimidazoles via C–H Amination/Acetoxylation of Guanidines
摘要:
The iodine(III) compound promoted CH amination and tandem CH amination/acetoxylation of guanidines are achieved for the first time to provide efficiently 2-aminobenzimidazoles and acetoxyl-substituted 2-aminobenzimidazoles, respectively. The amount and type of iodine(III) compounds control the selective syntheses of two types of 2-aminobenzimidazoles. This reaction shows good regioselectivity when unsymmetrical substrates are used.
three-component reaction of cyanamides, amines, and diaryliodonium triflates was developed for the synthesis of guanidines. The mild reaction accommodates both aromatic and aliphatic amines and provides the products in good yields with good functional group tolerance. Moreover, it was demonstrated that C–H activation of the arenes could be realized for the direct preparation of guanidines.
Copper-Catalyzed Oxidative Three-Component Synthesis of <i>N</i>, <i>N</i>′,<i>N</i>″-Trisubstituted Guanidines
作者:Jihui Li、Luc Neuville
DOI:10.1021/ol4029622
日期:2013.12.20
copper-catalyzed three-component synthesis of trisubstituted N-aryl guanidines involving cyanamides, arylboronic acids, and amines has been developed. This operationally simple oxidative process, which is performed in the presence of K2CO3, a catalytic amount of CuCl2·2H2O, bipyridine, and oxygen (1 atm), allows the rapid assembly of N,N′,N″-trisubstituted aryl guanidines.
已开发出一种铜催化的三取代三取代N-芳基胍的三组分合成方法,涉及氰胺,芳基硼酸和胺。这种操作简单的氧化过程,这是在K的存在下进行2 CO 3,氯化亚铜催化量2 ·2H 2 O,吡啶和氧气(1个大气压),允许快速组装-N,N ',Ñ “ -三取代的芳基胍。