Assembly of Substituted 3-Aminoindazoles from 2-Bromobenzonitrile via a CuBr-Catalyzed Coupling/Condensation Cascade Process
摘要:
CuBr-catalyzed coupling reaction of 2-halobenzonitriles with hydrazine carboxylic esters and CuBr/4-hydroxy-L-proline-catalyzed coupling reaction of 2-bromobenzonitriles with N'-arylbenzohydrazides proceed smoothly at 60-90 degrees C to provide substituted 3-aminoindazoles through a cascade coupling/condensation (or coupling/deacylation/condensation) process. A wide range of 3-aminoindazoles with substituents at both the 1-position and the phenyl ring part can be prepared from the corresponding coupling partners.
AbstractThe N1‐selective arylation of 3‐aminoindazoles using copper catalysis is herein reported. The reaction uses readily accessible aryl bromides as coupling partners, including those from heterocycles, and allows easy access to a broad variety of substituted 3‐aminoindazoles. The methodology was also examined on other aminoazoles of interest for the pharmaceutical industry.
Assembly of Substituted 3-Aminoindazoles from 2-Bromobenzonitrile via a CuBr-Catalyzed Coupling/Condensation Cascade Process
作者:Lanting Xu、Yinsheng Peng、Qiangbiao Pan、Yongwen Jiang、Dawei Ma
DOI:10.1021/jo400071h
日期:2013.4.5
CuBr-catalyzed coupling reaction of 2-halobenzonitriles with hydrazine carboxylic esters and CuBr/4-hydroxy-L-proline-catalyzed coupling reaction of 2-bromobenzonitriles with N'-arylbenzohydrazides proceed smoothly at 60-90 degrees C to provide substituted 3-aminoindazoles through a cascade coupling/condensation (or coupling/deacylation/condensation) process. A wide range of 3-aminoindazoles with substituents at both the 1-position and the phenyl ring part can be prepared from the corresponding coupling partners.