Key Laboratory of Medicinal Chemistry for Natural Resource (Yunnan University), Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, P. R. China.
J Org Chem. 2021 Apr 16;86(8):5744-5756. doi: 10.1021/acs.joc.1c00211. Epub 2021 Mar 27.
A novel protocol for the synthesis of pyrido[2,3-]indoles (α-carbolines, ) from ()-3-(2-oxo-2-phenylethylidene) indolin-2-one derivatives and 1,1-enediamine (EDAM) via an unexpected cascade reaction in ethanol was developed. Pyrido[2,3-]indole derivatives were obtained by the same reaction, albeit by stirring the mixture for a longer period of time (about 48 h). As a result, two kinds of functionalized α-carbolines and were synthesized by the facile reaction of the ()-3-(2-oxo-2-phenylethylidene)indolin-2-one derivatives and 2-(nitromethylene)imidazolidine under basic conditions (CsCO) in ethanol. In addition, a diverse array of EDAM substrates (-) were tested in this reaction to afford the expected target compounds . This protocol is suitable for the combinatorial and parallel syntheses of natural-like products, including highly functionalized α-carbolines and pyrroles, especially 2-oxoindolin-3-yl pyrroles. This approach features several advantages, such as being a simple and practical operation (requiring only filtration and washing without column chromatography), furnishing excellent yields (72-98%), and producing diverse libraries of target compounds with potential biological activities.
从（）-3-（2-氧代-2-苯亚乙基）吲哚啉-2-酮衍生物和 1,1-二胺（EDAM）通过在乙醇中的意外级联反应开发了一种合成吡啶并[2,3-]吲哚（α-咔啉，）的新方案。尽管通过搅拌混合物更长的时间（约 48 小时）也可以获得吡啶并[2,3-]吲哚衍生物，但通过相同的反应获得了吡啶并[2,3-]吲哚衍生物。结果，通过（）-3-（2-氧代-2-苯亚乙基）吲哚啉-2-酮衍生物与 2-（亚硝基亚甲基）咪唑烷在碱性条件（CsCO）下在乙醇中的简单反应合成了两种官能化的α-咔啉和。此外，在该反应中测试了多种 EDAM 底物（-）以提供预期的目标化合物。该方案适用于包括高度官能化的α-咔啉和吡咯在内的天然产物的组合和并行合成，特别是 2-氧代吲哚啉-3-基吡咯。该方法具有几个优点，例如操作简单实用（仅需要过滤和洗涤而无需柱层析），产率优异（72-98％），并且可以生成具有潜在生物活性的目标化合物的各种文库。
