Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati-781039, Assam, India.
Org Biomol Chem. 2021 Aug 28;19(32):7041-7050. doi: 10.1039/d1ob01188j. Epub 2021 Aug 3.
An efficient, useful and one-pot protocol for the synthesis of quinoline-2,4-dicarboxylate scaffolds is accomplished from aryl amines and dimethyl/diethyl acetylenedicarboxylates using 20 mol% molecular iodine as a catalyst in acetonitrile at 80 °C. In addition, the mechanistic explanation for the formation of the desired products is disclosed. The pivotal role of molecular iodine in the formation of the major products, diester quinoline derivatives, and the minor product, triesters, in two cases is described in the mechanism. The notable advantages of this method are non-involvement of a metal catalyst, avoiding of metal contamination in the final product as well as waste generation, use of a low cost and eco-friendly catalyst, ease of handling, high regioselectivity, shorter reaction time, the formation of one C-N and two C-C bonds and a broad substrate scope with good yields.
一种高效、有用且一锅法的合成喹啉-2,4-二甲酸酯支架的方法，由芳基胺和二甲/二乙酯基乙炔二羧酸酯在 80°C 的乙腈中，使用 20mol%的分子碘作为催化剂来完成。此外，还揭示了形成目标产物的机理解释。在机理中描述了分子碘在主要产物（二酯喹啉衍生物）和次要产物（三酯）形成中的关键作用。该方法的显著优点是非金属催化剂的参与，避免了最终产物中的金属污染和废物的产生，使用了一种低成本和环保的催化剂，易于操作，高区域选择性，较短的反应时间，形成一个 C-N 和两个 C-C 键，以及具有良好收率的广泛底物范围。
