Metal–Ligand Cooperative Iron Catalysis Enabling the One‐Pot Synthesis of Imidazo[1,2‐ a ]Quinolines and Imidazo[1,2‐ a ]Pyridines

ABSTRACT Herein, we present an atom‐economical sustainable protocol for the synthesis of imidazo[1,2‐ a ]pyridines and imidazo[1,2‐ a ]quinolines catalyzed by a well‐defined Fe(II)‐catalyst 1a supported by the redox‐noninnocent pincer ligand 2‐((4‐chlorophenyl)diazenyl)‐1,10‐phenanthroline. The method provides a broad range of imidazopyridine and imidazoquinoline derivatives from primary alcohols, terminal alkynes, and amines, affording products in yields of up to 80% with only 3.0 mol% catalyst loading. Under the same conditions, isoquinolin‐1‐amine furnished the corresponding imidazoisoquinoline derivative in moderate yield. Control experiments suggest that the catalytically active species is the one‐electron‐reduced azo‐anion radical [ 1a ] − , generated in situ. The redox transformations occur at the aryl–azo ligand, while the Fe(II)‐center primarily serves as a structural template.