Synthesis of 2-Amino-6-(1H-Indol-3-yl)-4-Phenylnicotinonitriles and Bis(Indolyl) Pyridines Using a Novel Acidic Nanomagnetic Catalyst via a Cooperative Vinylogous Anomeric-Based Oxidation Mechanism

Abstract

In the presence study, we reported the synthesis of a novel acidic nanomagnetic catalyst by supporting the prepared urea-based ligand onto the surface of Fe3O4@SiO2 nanoparticles. Afterwards, characterization of prepared recoverable catalyst was made by several methods, such as Fourier-transform infrared (FT-IR) spectroscopy, energy-dispersive X-ray (EDX) spectroscopy, elemental mapping, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetry/derivative thermogravimetry (TG/DTG), and vibrating-sample magnetometry (VSM). We investigated its catalytic performance for the synthesis of new series of 2-amino-6-(1H-indol-3-yl)-4-phenylnicotinonitriles and also bis(indolyl) pyridine derivatives through a cooperative vinylogous anomeric-based oxidation mechanism.