Mn-Mediated Amide Synthesis via Transamidation of Tertiary Amides and Amidation of Esters with Nitroarenes
作者单位：天津大学 Department of Chemistry Tianjin Key Laboratory of Molecular Optoelectronic Sciences and Tianjin Collaborative Innovation Center of Chemical Science & Engineering Tianjin University Laboratory of Inorganic Synthesis and Catalysis Institute of Chemical Sciences and Engineering Ecole Polytechnique Federale de Lausanne (EPFL)
会议名称：《中国化学会·第十六届全国有机合成化学学术研讨会》
会议日期：2019年
学科分类：07[理学] 070303[理学-有机化学] 0703[理学-化学]
关 键 词：N-aryl amides nitroarenes transamidation amidation reductive coupling
摘 要：Amides are the ubiquitous compounds in pharmaceutical,agrochemical,and materials chemistry.The study of streamlined synthesis of amides is among the important research areas in organic synthesis.Amidation of carboxylic acids with aryl amines in the presence of stoichiometric coupling reagents has long been used to synthesize N-aryl amides.This conventional method requires the prior reduction of nitroarenes to arylamines for subsequent amidation.On the other hand,nitroarenes are more stable,more readily available,and less expensive than arylamines.Thus,the direct use of nitroarenes for amide synthesis would be more step-economical and practical.To this end,we describe two alternative methods for direct amide synthesis using nitroarenes as nitrogen sources.In the presence of Mn powder and TMSI additive,reductive transamidation of tertiary amides with nitroarenes proceeded smoothly（Figure 1,top）.Based on this work,we found that Mn metal could also mediate the reductive amidation of esters with nitroarenes（Figure 1,bottom）.These two protocols allowed the utilization of a wide range of tertiary amides,esters,and nitroarenes as substrates.A myriad of N-aryl amides could also be synthesized,including several druglike molecules.