Selective Functionalization of Indole: Synthesis of Bioinspired 2,2′-thiobisindoles, 3-substituted Oxindoles, and 1-(chloromethyl) Indoline-2-dione in One-pot manner

Abstract

Indolyl thioethers and indolin-2-one motifs are extremely common in pharmaceuticals and organic materials, therefore developing a method to create these scaffolds is considered to be a vital endeavour in the chemical sciences. Here we have reported a unified strategy developed by the fine-tuning of catalyst-solvent combination [SOCl2 /AlCl3 in CHCl3 and SOCl2/DMSO (1 : 1) in CHCl3 at 25 degrees C] towards selective functionalization of Indole to synthesize 2,2 '-thiobisindoles and 3-chloro-3-alkyl substituted oxindoles selectively in one-pot manner with good to satisfactory yield (52-86 %; 26 Examples). In application, reactions of 3-subsituted indole and isatin derivatives produced the 1-(chloromethyl) indoline-2,3-diones by just changing the reaction condition (60 degrees C), which shows the synthetic utility of the developed method.