Kundu Samrat, Banerjee Ankush, Maji Modhu Sudan
Department of Chemistry , Indian Institute of Technology Kharagpur , Kharagpur 721302 , West Bengal , India.
J Org Chem. 2019 Dec 20;84(24):16003-16012. doi: 10.1021/acs.joc.9b02474. Epub 2019 Dec 4.
A Brønsted acid-catalyzed pinacol-type rearrangement pathway is reported here to synthesize various substituted α-(3-indolyl) ketones by employing unprotected indoles and α-hydroxy aldehydes as coupling partners. Utilization of economic and readily available Brønsted acid catalyst and use of simple starting precursors exemplify the economic viability of this method. Under this developed protocol, selective migration of aryl over alkyl or a second aryl group is observed depending upon the migratory aptitude of the substituents. Applicability of this method was further demonstrated by synthesizing highly substituted carbazoles through a simple extension of this method to one-pot cascade annulation strategy.
本文报道了一种布朗斯特酸催化的频哪醇型重排途径，该途径通过使用未保护的吲哚和α-羟基醛作为偶联伙伴来合成各种取代的α-(3-吲哚基)酮。使用经济且易于获得的布朗斯特酸催化剂以及简单的起始前体体现了该方法的经济可行性。在这个开发的方案下，根据取代基的迁移能力，可以观察到芳基相对于烷基或第二个芳基的选择性迁移。通过将该方法简单扩展到一锅串联环化策略来合成高度取代的咔唑，进一步证明了该方法的适用性。
