KI-assisted Sulfur Activation/Insertion/Denitration Strategy towards Dual C?S Bond Formation for One-pot Synthesis of ?-Carboline-tethered 2-Acylbenzothiophenes

Abstract

A simple and efficient KI promoted sulfur activation-insertion/de-nitration strategy has been developed for the synthesis of ?-carboline C1 tethered 2-acylbenzothiophenes via one-pot assembly of 1-acetyl ?-carbolines (an alkaloid based scaffold), 2-nirobenzaldehydes and elemental sulfur. This expeditious reaction proceeds through the formation of ?-carboline linked nitro-chalcones followed by embodiment of elemental sulfur to generate the multifunctional ?-carboline linked benzothiophene derivatives. The highlighted features of this efficient methodology are transition metal-free conditions, use of inexpensive and non-toxic catalyst, easy procedure, short reaction time, and broad substrate scope with good yields. The scope of this protocol has been extended for the synthesis of a range of novel compounds with significant diversity. � 2021 Wiley-VCH GmbH