Trihaloisocyanuric acids in ethanol: an eco-friendly system for the regioselective halogenation of imidazo-heteroarenes†
Abstract
Herein, we describe an efficient, rapid and benign protocol for the direct C(sp2)–H bond halogenation (Cl, Br, I) of 2-arylimidazo[1,2-a]pyridines using trihaloisocyanuric acids in ethanol. Furthermore, this sustainable protocol was successfully extended to imidazopyrimidine, imidazothiazole and indazole heterocycles showing the broadness of this useful approach.