Efficient amidation of aldehydes and amine hydrochloride salts by magnetic Cu-MOF nanocatalyst

In this study, an efficient magnetic Cu-MOF heterogeneous catalyst is developed for the oxidative amidation of benzaldehyde and amine hydrochloride salts. The catalyst preparation involves modifying Fe3O4 with tetraethyl orthosilicate (TEOS), (3-chloropropyl) trimethoxysilane (CPTMS), and 2-aminoterephthalic acid (NH2-BDC), followed by the in situ formation of Cu-MOF on the surface of magnetic nanostructures. Various characterization techniques, including XRD, SEM, VSM, FT-IR, EDS, and TGA analyses, confirm the catalyst's successful synthesis and structural integrity. Optimal reaction conditions are determined by investigating time, temperature, oxidant, solvent, base, type, and amount of catalyst. Various derivatives of amine hydrochloride salts and aldehydes with both withdrawing and donating groups are also examined in this reaction. The optimum reaction takes place in the presence of benzaldehyde, amine hydrochloride salts, tert-butyl hydroperoxide (TBHP), calcium carbonate (CaCO3), and Cu-MOF at 80 degrees C in acetonitrile solvent. The reaction yield ranges from 80 % to 96 %, and the catalyst remains stable and recyclable over seven cycles without significant efficiency loss. Future work focuses on expanding the substrate scope to include a broader range of aldehydes and amines, investigating the mechanism of the catalytic reaction, and exploring the potential of this catalyst for other oxidative transformations.