A green and efficient strategy for the synthesis of benzoxazoles, benzothiazoles and benzimidazoles has been developed by using inexpensive, readily available, dioxygen-stable and recyclable CuFe₂O₄ as the nanocatalyst, and o-substituted aminobenzene and various aldehydes as the starting materials. The CuFe₂O₄ nanoparticles are dioxygen insensitive and easily recoverable with an external magnet from the reaction medium. The catalyst can be reused ten times without significant loss of catalytic activity.