Magnetic Nanoparticles of Ferrite Complex Oxides: A Cheap, Efficient, Recyclable Catalyst for Building the CN Bond under Ligand‐Free Conditions

A series of magnetic nanoparticles of ferrite complex oxides were simply prepared by using a citric acid complex method and characterized by using XRD, FT‐IR spectroscopy, TEM, the BET nitrogen adsorption/desorption technique, and a vibrating sample magnetometer. The magnetic nanoparticles were used for the N‐arylation of nitrogen nucleophiles to form new CN bonds. CuFe2O4 nanoparticles calcined at 850 °C exhibited the best activity with moderate to excellent yields under ligand‐free conditions. Notably, CuFe2O4 is completely recoverable with an external magnet and can be reused eight times without significant loss of catalytic activity.