Direct Imidation to Construct 1<i>H</i>-Benzo[<i>d</i>]imidazole through Pd<sup>II</sup>-Catalyzed CH Activation Promoted by Thiourea
作者:Qing Xiao、Wen-Hua Wang、Gang Liu、Fan-Ke Meng、Jia-Hua Chen、Zhen Yang、Zhang-Jie Shi
DOI:10.1002/chem.200900154
日期:2009.7.27
method to construct 1H‐benzo[d]imidazole was developed by means of PdII‐catalyzed intramolecular CHactivation starting from easily available N‐phenylbenzimidamide (see scheme). The detailed mechanism studies indicated that a palladacycle monomer or dimer is the key intermediate for this transformation and thiourea was used for the first time to promote the efficiency of CHactivation.
通过Pd II催化的分子内CH活化作用,从容易获得的N -苯基苯甲酰胺开始(见方案),开发了一种新的直接构建1 H苯并[ d ]咪唑的方法。详细的机理研究表明,palladacycle单体或二聚体是该转化的关键中间体,硫脲首次用于提高CH活化效率。
Palladium-Catalyzed Intramolecular C(sp<sup>2</sup>)–H Amidination by Isonitrile Insertion Provides Direct Access to 4-Aminoquinazolines from <i>N</i>-Arylamidines
An efficient method for the synthesis of 4-amino-2-aryl(alkyl)quinazolines from readily available N-arylamidines and isonitriles via palladium-catalyzed intramolecular aryl C-H amidination by isonitrile insertion has been developed.
Synthesis of Quinazolin-4(3<i>H</i>)-ones via Pd(II)-Catalyzed Intramolecular C(sp<sup>2</sup>)–H Carboxamidation of <i>N</i>-arylamidines
作者:Bin Ma、Yong Wang、Jiangling Peng、Qiang Zhu
DOI:10.1021/jo2007362
日期:2011.8.5
An efficient synthesis of quinazolin-4(3H)-ones from N-arylamidines, through palladium-catalyzed intramolecular C(sp(2))-H carboxamidation, has been developed. The reaction, carried out in the presence of 1.0 equiv of CuO as oxidant under atmospheric pressure of CO, provides diversified 2-aryl(alkyl)-quinazolin-4(3H)-ones in reasonable to good yields from N-arylamidines, which are readily derived from anilines and nitriles. Compared with existing approaches to quinazolin-4(3H)-ones, the current strategy features atom-economy and step-efficiency.