Electrochemical Regioselective C-3 Amination of Imidazo[1,2a]pyridines with Electron-Deficient Sulfonimides

Abstract

The development of sustainable methods for the C-H amination of imidazo [1,2-a]pyridines is of significant interest in medicinal chemistry. While electrochemical C-H amination has proven effective for electron-rich amines, the activation of electron-deficient amines remains a formidable challenge due to their high oxidation potentials and poor nucleophilicity.Herein, we report a general electrochemical strategy for the regioselective C-3 amination of imidazo[1,2-a]pyridines using electron-deficient sulfonimides as nitrogen sources. Distinguished by its metal-and oxidant-free conditions, this protocol operates in an undivided cell and exhibits broad substrate compatibility with various functional groups and fused heterocyclic systems. Mechanistic investigations, supported by cyclic voltammetry and radical trapping experiments, reveal that the transformation proceeds via an anodic oxidation-induced radical pathway, distinct from the conventional quinoneimine mechanism.