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 [SOCl 2 /AlCl 3 in CHCl 3 and SOCl 2 /DMSO (1 : 1) in CHCl 3 at 25 °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 °C), which shows the synthetic utility of the developed method.