Magnetically recoverable Fe3O4@SiO2@SBA-3@2-ATP-Cu: an improved catalyst for the synthesis of 5-substituted 1H-tetrazoles†

Functionalization of Fe₃O₄@SiO₂@SBA-3 with double-charged 3-chloropropyltrimethoxysilane (CPTMS) and 2-aminophenol, followed by mechanical mixing of the solid product with copper(I) chloride produces a new, greener and efficient Fe₃O₄@SiO₂@SBA-3@2-ATP-Cu catalyst for the synthesis of 5-substituted 1H-tetrazoles. XRD, SEM, atomic absorption, TGA, N₂ adsorption–desorption, and VSM analyses were performed for the characterization of the Fe₃O₄@SiO₂@SBA-3@2-ATP-Cu structure. Nitrogen adsorption–desorption analysis revealed that Fe₃O₄@SiO₂@SBA-3@2-ATP-Cu has a surface area of 242 m² g⁻¹ and a total pore volume of 55.72 cm³ g⁻¹. In synthesizing 5-substituted 1H-tetrazoles, Fe₃O₄@SiO₂@SBA-3@2-ATP-Cu shows superior yields in short reaction times at 120 °C. This catalyst also showed high thermal stability and recyclability at least for 4 runs without apparent loss of efficiency.