Magnetic covalent organic framework with ionic tags as an efficient catalyst in the preparation of 2,3-disubstituted thiazolidine-4-ones and N‑amino-2-pyridones

The functionalization of magnetic nanoparticles with covalent organic frameworks (COFs) will endow them inspiring characteristics. Herein, a new magnetic covalent organic framework (MCOF) decorated with trifluoroacetate as ionic sections (Fe3O4@COF-TFA) was designed and constructed. To confirm the successful synthesis of this hybrid material, several techniques including Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), derivative thermogravimetry (DTG), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), elemental mapping, transmission electron microscopy (TEM), vibrating-sample magnetometer (VSM) and X-ray diffraction analysis (XRD) were applied. TG/DTG analyses show that Fe3O4@COF-TFA has an excellent thermal stability up to 450 ℃. The FE-SEM analysis revealed that catalyst has the island-like morphology and according to TEM analysis, it has spherical geometry with nanometer scale particle size. Also, surface area of Fe3O4@COF and Fe3O4@COF-TFA are 74 and 12 m2.g−1, respectively. Fe3O4@COF-TFA was applied as a recoverable heterogeneous catalyst for construction of 2,3-disubstituted thiazolidine-4-ones and N‑amino-2-pyridones via a multi-component synthetic strategy. It is worth mentioning that synthesized derivatives have a good yield and short reaction times.