Synthesis of Sm (III) complex immobilized in MCM-41: A new heterogeneous catalyst for the facile synthesis of 5-substituted 1H-tetrazoles via [3+2] cycloaddition of nitriles and sodium azide

Samarium (III) complex immobilized in MCM-41 were synthesized via post-functionalization modification of MCM-41. The catalysts were characterized by Fourier transforms infrared (FT-IR) spectra, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analyses (TGA). The results show that the 3,4,5-tri hydroxyphenyl acetic acid ligand and Sm ions are attached to the MCM-41 host. The catalysts were tested in the synthesis of 5-substituted 1H-tetrazoles. This catalyst is an efficient catalyst for [3 + 2] cycloaddition with NaN3 to prepare 5-substituted 1H-tetrazoles. The catalyst was recycled for up to six cycles without significant loss of activity.