γ-Fe 2 O 3 @SiO 2 @4-(sulfoamino)butanoic acid as a novel superparamagnetic nanocatalyst promoted green synthesis of 5-(aryl)-5 H -spiro[diindeno[1,2- b :2′,1′- e ]pyridine-11,3′-indoline]-2′,10,12-trione derivatives

摘要: Grafting of 4-(sulfoamino)butanoic acid on superparamagnetic γ-Fe2O3@SiO2 nanoparticles afforded γ-Fe2O3@SiO2@4-(sulfoamino)butanoic as a novel heterogeneous nanocatalyst, which was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometry, field emission scanning electron microscopy, and thermal gravimetric analysis. In this research, we report convenient one-pot efficient direct protocol for the pseudo four-component preparation 5-(aryl)-5H-spiro[diindeno[1,2-b:2′,1′-e]pyridine-11,3′-indoline]-2′,10,12-trione derivatives via cascade condensation reaction 1,3-indandione isatins with various aromatic amine in presence catalytic amount under green conditions aqueous media. This procedure offers several advantages such as: very easy conditions, simple work-up, or purification, excellent yields, high purity desired product, atom economy, short times. The catalyst is magnetically separable retained chemical stability after recycling at least five consecutive runs without detectable activity loss.