Synthesis of 5-Substituted 1H-Tetrazoles with CuFe₂O₄ Nanoparticles

Significance

Magnetic CuFe₂O₄ nanoparticles catalyzed the [2+3] cycloaddition of aryl nitriles 1 with sodium azide (2) to give the corresponding 5-substituted 1H-tetrazoles 3 in 68-93% yield (18 examples). For the formation of 3a, the catalyst was recovered by an external magnet and reused four times (1^st reuse: 80% yield; 4^th reuse: 75% yield).