Nanoparticles of cobalt ferrite (CoFe2O4-NPs) and pure cobalt (Co-NPs) were synthesized, and after characterization, their catalytic activities for dehalogenative intramolecular C–O and C–N bond formation reactions were investigated and compared. These inexpensive and efficient catalysts enabled creation of new methods for the synthesis of benzimidazoles and benzoxazoles in green media, with ligand-free and mild reaction conditions. All the reactions resulted in moderate to excellent yields under the optimized reaction conditions; however, the reactions using Co-NPs as the catalyst were completed in relatively shorter reaction times. Furthermore, analysis showed that the reusability of the two catalytic systems is approximately comparable.
