Fe₃O₄/ZnS Hollow Nanospheres: A Highly Efficient Magnetic Heterogeneous Catalyst for Synthesis of 5‐Substituted 1H‐Tetrazoles from Nitriles and Sodium Azide

An efficient route for the synthesis of 5‐substituted 1 H ‐tetrazole via [2+3] cycloaddition of nitriles and sodium azide is reported using Fe 3 O 4 /ZnS hollow nanospheres as a magnetic separable heterogeneous catalyst. The catalyst is very efficient, affording excellent yields and can be reused for several circles. In addition, the Fe 3 O 4 inner shell exhibits magnetism, making the catalyst easily separated by a magnet.