First Application of Heterogeneous Cobalt Catalysis in Csp2–N Cross‐Coupling of Activated Chloroarenes under Ligand‐Free Conditions

Abstract A heterogeneous Co II /Al 2 O 3 catalyst efficiently catalyses the N ‐arylation of N‐heterocycles and open‐chain secondary amines by activated chloroarenes and chloroheteroarenes under ligand‐free conditions in water to give a series of functionalized tertiary amines. The catalyst was prepared by immobilizing CoBr 2 onto the surface of Al 2 O 3 , and was characterized by X‐ray diffraction, X‐ray photoelectron spectroscopy, scanning electron microscopy, and energy‐dispersive X‐ray analysis. This catalyst could be recycled up to six times without any appreciable loss of catalytic activity.