Metal-Free One-Pot Synthesis of<i>N</i>,<i>N′</i>-Diarylamidines and<i>N</i>-Arylbenzimidazoles from Arenediazonium Salts, Nitriles, and Free Anilines
作者:So Won Youn、Eun Mi Lee
DOI:10.1021/acs.orglett.6b02994
日期:2016.11.4
efficient and facile metal-free, one-pot reaction has been developed to afford diversely substituted N-arylbenzimidazoles through chemoselective in situ generation of N,N′-diarylamidines fromarenediazoniumsalts, nitriles, and free anilines. The advantages of this protocol consist of the operationally easy and simple one-pot procedure under metal-free and mild conditions, the direct use of inexpensive
Cobalt(II)-complex catalyzes efficiently the intramolecular C–N and C–O cross-couplings of Z-N′-(2-halophenyl)-N-phenylamidines and N-(2-bromophenyl)benzamides to afford the corresponding substituted benzimidazoles and benzoxazoles in the presence of K2CO3 at moderate temperature. The protocol is general, air stable and affords the products selectively in moderate to high yield.
钴(II)配合物有效催化Z - N '-(2-卤代苯基)-N-苯基am和N-(2-溴苯基)苯甲酰胺的分子内C – N和C – O交叉偶联,提供相应的取代苯并咪唑在中等温度下在K 2 CO 3存在下使用苯并恶唑和苯并恶唑。该方案是一般的,空气稳定的,并且以中等至高收率选择性地提供产物。