Electrochemical Three-Component C–H Functionalization of Indoles with Sodium Bisulfite and Alcohols to Access Indole-Containing Sulfonate Esters

Abstract

Herein, an efficient electrochemical three-component C–H functionalization of indoles with sodium bisulfite and alcohols is described, providing a sustainable and convenient synthetic route for the construction of structurally valuable indole-containing sulfonate esters in moderate to good yields. This protocol proceeds in an undivided cell without any metal catalysts or oxidants, features a broad substrate scope, and has an excellent functional group tolerance. Preliminary mechanistic studies suggest that a radical–radical pathway may be involved in this three-component reaction system.