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Facile Synthesis of 2,3‐Disubstituted Indoles by NBS/CuCl Mediated Oxidative Cyclization of N ‐Aryl Enamines
Author(s) -
Hu FangZhi,
Zhao SiHan,
Chen Hui,
Yu ShuoWen,
Xu XiaoYing,
Yuan WeiCheng,
Zhang XiaoMei
Publication year - 2017
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201700096
Subject(s) - chemistry , aryl , indole test , alkylation , medicinal chemistry , nitro , oxidative phosphorylation , halide , chloride , ethanol , organic chemistry , catalysis , biochemistry , alkyl
Abstract A one‐pot synthesis of 2,3‐disubstituted indoles has been accomplished through a facile, mild and efficient oxidative cyclization of N ‐aryl enamines mediated by N ‐bromosuccinimide (NBS)/copper chloride (CuCl). This method is applicable to a series of N ‐aryl β ‐enaminoesters and N ‐aryl β ‐amino nitroolefins containing different substituents such as halides, alkyls, heterocycles, etc. A variety of 2‐aryl‐3‐carboxylate indoles and 2‐aryl‐3‐nitro indoles have been prepared with moderate to quantitative yields in only 20 minutes to 2 hours in refluxing ethanol. Moreover, in order to demonstrate the synthetic utility of this transformation, 2‐phenyl‐3‐nitro indole was subjected in reduction and reduction‐alkylation to generate 2‐phenyl‐3‐amino indole and N,N ‐diethyl‐2‐phenyl‐3‐amino indole respectively.