Fe 3 O 4 @SiO 2 @propyltriethoxysilane@o-phenylendiamine as an environmentallybenign functionalized silica-coated magnetic organometallic nanomaterial has been synthesized and characterized by Fourier transforms infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) images and energy dispersive X-ray (EDX) and vibrating sample magnetometer (VSM) analyses. Then, its catalytic activity was investigated for the one-pot three-component condensation reaction between dimedone, malononitrile and various substituted aromatic aldehydes to afford the corresponding 2-amino-4H-chromene derivatives under mild reaction conditions. This nanocatalyst can be easily recovered from the reaction mixture by using a magnet and reused for at least five times without significant decrease in catalytic activity.

This article is the first report of the catalytic application of copper ferrite-coated chitosan in organic reactions as a bio-nanocomposite. CuFe 2 O 4 /chitosan was used as a hybrid nanocatalyst for the multicomponent Strecker synthesis of α-aminonitriles by using aryl aldehydes, trimethylsilyl cyanide (TMSCN) and aromatic amines at room temperature in ethanol as a green solvent. The catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), field-emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDX) analyses. The nanocatalyst was recovered and reused several times without significant loss of catalytic activity. The organic products were obtained easily without need for column chromatography in good-to-excellent yields.

In this work, an efficient method for the immobilization of L-proline on magnetic nanoparticles was offered and evaluated as a recoverable magnetic organocatalyst for synthesis of 3-aminoimmidazo[1,2-a]pyridine from 2-aminopyridine, aromatic aldehyde and trimethylsilyl cyanide (TMSCN). This magnetic organocatalyst proved to be effective and provided the products in high to excellent yield at room temperature. Moreover, the catalyst could be easily recovered by facile separation by magnetic forces and recycled for five times without significant loss of its catalytic activity. The benefits of this study are simplicity, nontoxicity, low cost, simple workup, and an environmentally benign nature.

In this study, we introduce an efficient method for the synthesis of quinazolinone derivatives in the presence of H5PV2Mo10O40/SiO2 polyoxometalate composite. Quinazolinone derivatives were successfully synthesized via one-pot multicomponent reactions strategy from aromatic aldehydes and anthranilamide. High products yield, short reaction times, simplicity of operation, simple work-up and easy purification are advantages of this approach.

In this work, copper ferrite coated chitosan was used as hybrid catalyst for the synthesis of α-amino nitriles by strecker reaction using arylaldehyde, triemethylsilyl cyanide and aromatic amines at room temperature in ethanol as a green solvent. The catalyst was recovered at least five cycles with no significant loss of catalytic activity. Products were isolated easily without need to column chromatography. Good to excellent yields obtained by this method.