Gold-Catalyzed Synthesis of 2-Substituted, 2,3-Disubstituted and 1,2,3-Trisubstituted Indoles in [bmim]BF<sub>4</sub>
作者:Fabio Marinelli、Ilaria Ambrogio、Antonio Arcadi、Sandro Cacchi、Giancarlo Fabrizi
DOI:10.1055/s-2007-982572
日期:2007.7
Cyclization of 2-alkynylanilines in the presence of NaAuCl4·H2O using [bmim]BF4 as the reaction medium afforded 2-substituted indoles in high yields. The catalyst system was best recycled using n-Bu4NAuCl4. 2,3-Disubstituted indoles could be prepared from 2-alkynylanilines and 3-buten-2-one through a one-flask annulation-alkylation sequence and 1,2,3-trisubstituted indoles were obtained from the same starting materials via an aza-Michael addition-annulation-alkylation process.
使用 [bmim]BF4 作为反应介质,在 NaAuCl4-H2O 存在下对 2-炔基苯胺进行环化反应,可以高产率获得 2-取代的吲哚。使用 n-Bu4NAuCl4 对催化剂体系进行了最佳回收。通过一釜环化-烷基化顺序,可从 2-炔基苯胺和 3-丁烯-2-酮制备出 2,3-二取代吲哚;通过氮杂迈克尔加成-环化-烷基化过程,可从相同的起始原料制备出 1,2,3-三取代吲哚。