The development of efficient and novel methods for the synthesis of heterocyclic compounds is a broad and important area of organic chemistry because of their importance as pharmaceuticals. Indoles exhibit a wide range of biological activities and they constitute an important class of compounds for medicinal applications. Although there are many ways to prepare substituted indoles, fused indoles have not been explored systematically. In addition to conjugate addition reactions for the preparation of substituted pyrroles and indoles, these compounds have also been synthesized using other methods. For example, transition metal intermediates, reductive couplings, aza-Wittig reactions, the Paal-Knorr and multi-step reactions have all been used for the preparation of indoles. Very important considerations in devising novel routes are the ease of separation and the purity of the products. We report herein a novel green method for the synthesis of substituted tetrahydropyrrolo[3,2-b]indoles (Scheme 1).

中文翻译：

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在无溶剂条件下一锅法合成 3a,8b-Dihydroxy-1,3a,4,8b-四氢吡咯并[3,2-b]indole-3-carboxylates

由于杂环化合物作为药物的重要性，开发用于合成杂环化合物的有效且新颖的方法是有机化学的一个广泛而重要的领域。吲哚表现出广泛的生物活性，它们构成了一类重要的药用化合物。虽然制备取代吲哚的方法有很多，但稠合吲哚还没有得到系统的探索。除了用于制备取代吡咯和吲哚的共轭加成反应外，这些化合物还可以使用其他方法合成。例如，过渡金属中间体、还原偶联、aza-Wittig 反应、Paal-Knorr 和多步反应都已用于制备吲哚。设计新路线时非常重要的考虑因素是易于分离和产品的纯度。我们在此报告了一种用于合成取代四氢吡咯并 [3,2-b] 吲哚的新型绿色方法（方案 1）。