Multicomponent Tandem Triple Functionalization of Indoles via a Directing-group-free Strategy

The position-selective functionalization of the poorly reactive benzenoid nucleus of indoles has remained a great challenge in organic chemistry. Here we describe a directing-group-free, three-component tandem C3-acylation/C5,6-H disulfenylation of indoles via an iodine-, Lewis acid- and Bronsted acid-cooperated mediated strategy. This protocol is remarkable for its exceptional regio- and chemo-selectivity, broad substrate scope, good functional group tolerance and mild reaction conditions. Advantageously, the present protocol offers great potential for the development of general site-selective functionalization at the benzenoid nucleus of indoles, removing the requirement for neighbouring activating groups.

Automated summary

This study presents a directing-group-free, three-component tandem C3-acylation/C5,6-H disulfenylation method for the position-selective functionalization of the poorly reactive benzenoid nucleus of indoles. The protocol demonstrates exceptional regio- and chemo-selectivity, broad substrate scope, good functional group tolerance, and mild reaction conditions. Importantly, this method offers great potential for the development of general site-selective functionalization at the benzenoid nucleus of indoles without the requirement for neighboring activating groups.