Synthesis and characterization of Fe3O4@SiO2@(CH2)3NH(CH2)2O2P(OH)2 and its catalytic application in the synthesis of benzo-[h]quinoline-4-carboxylic acids via a cooperative anomeric based oxidation mechanism

In this study, Fe3O4@SiO2@(CH2)(3)NH(CH2)(2)O2P(OH)(2) as a new and recoverable nanocatalyst with magnetic properties was synthesized. The characterization of the novel nanocatalyst confirmed by thermo gravimetric analysis/ differential thermal analysis (TGA/DTA), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM) equipped by energy dispersive spectroscopy (EDS), elemental mapping analysis, Fourier transform infrared (FT-IR) spectroscopy and vibrating sample magnetometer (VSM). The impact of Fe3O4@SiO2@(CH2)(3)NH(CH2)(2)O2P(OH)(2) was carefully considered in the synthesis of benzo-[h]quinoline-4-carboxylic acids via a three component reaction of aryl aldehydes, naphtylamine, and pyrovic acid in the absence of solvent. The suggested mechanism proposed an anomeric based oxidation route for final step of the described synthesis. The described catalyst was recycled and reused without any remarkable decrease in the yield and the reaction time after six runs.