Synthesis of a novel and reusable biological urea based acidic nanomagnetic catalyst: Application for the synthesis of 2-amino-3-cyano pyridines via cooperative vinylogous anomeric based oxidation

In the current study, a novel and reusable biological urea based nano magnetic catalyst namely Fe3O4@SiO2@(CH2)(3)-urea-benzimidazole sulfonic acid was designed and synthesized. The structure of the titled catalyst was fully characterized using several skills including Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo gravimetric analysis/ differential thermal analysis (TG/DTG) and vibrating sample magnetometer (VSM). Then, the catalytic performance of Fe3O4@SiO2@(CH2)(3)-urea-benzimidazole sulfonic acid was successfully inspected towards the multicomponent synthesis of 2-amino-3-cyano pyridine derivatives through a vinylogous anomeric based oxidation pathway. Highlights: Fe3O4@SiO2@(CH2)(3)-urea-benzimidazole sulfonic acid as a novel catalyst was designed, synthesized and fully characterized. The described catalyst was applied as elegant catalyst for the facile preparation of new 2-amino-3-cyano pyridines through a vinylogous anomeric based oxidation pathway. The mentioned catalyst shows high potent of recovering and reusing capability.