Synthesis of some derivatives of 1,8-dioxo-octa-hydro xanthene and 9-aryl-hexahydro acridine-1,8-dione using metal ion-exchanged NaY zeolite as heterogeneous catalyst.

A method for synthesizing xanthene and acridine derivatives using transition metal catalysts supported by de-alumination zeolite-NaY is described. Some transition metal ion-exchanged NaY zeolite was prepared and evaluated in a reaction toward the synthesis of xanthene and acridine. The most active catalyst in this field is a heterogeneous copper/zeolite catalyst. The synthesis of xanthene with a wide range of aldehydes/dimedone with a molar ratio of 1/2 and acridine synthesis with a molar ratio of dimedone/aromatic/ammonium nitrate of 2/1/1 was carried out in one pot and solvent-free conditions. Sensing in the presence of supported metal catalysts is operationally simple, does not require expensive or toxic reagents, and gives high yields in a short period.

Efficient One-Pot Synthesis of 1,4-Dihydropyridines Catalyzed by Magnetic MnFe2O4 Nanoparticles.

The efficient one-pot synthesis of some 1,4-dihydropyridines is described by a condensation reaction of some aldehyde derivatives, ethyl acetoacetate and ammonium acetate in the presence of superparamagnetic manganese ferrite nanoparticles at 80 °C. The advantages of this protocol include selectivity, high purity of the products, excellent yields, short reaction times, ease of processing, and environmentally friendly conditions for the synthesis of 1,4-dihydropyridines. In addition, the catalyst can be recovered and reused in multiple runs without significantly reducing the product yield.

Ultrasmall Monodisperse NiO Nanocrystals as a Heterogeneous Catalyst for the A3-Coupling Reaction Toward Propargylamines.

Ultrasmall monodisperse NiO nanoparticles (7-9 nm) were synthesized through thermal decomposition of Ni-oleylamine complexes. Various measurement techniques involving Fourier-transform infrared spectroscopy (FT-IR), diffuse reflectance UV-Vis spectroscopy (DRS), X-ray diffractometer (XRD), energy dispersive X-ray analysis (EDX), scanning electron microscopy (SEM), dynamic light scattering technique (DLS), and vibrating sample magnetometer (VSM) were employed to characterize the synthesized catalyst. Propargylamine derivatives were synthesized with aldehydes, terminal alkynes and primary amines through a one-pot A3-coupling reaction by using a 3 mol% amount of the NiO nanocrystals at 80 °C under solvent-free conditions with good to excellent yields. The structures of the products were confirmed by 1H and 13C NMR spectroscopy. The catalyst presents many advantages including being environmentally friendly, easy to recover, reusable, stable, and applicable to a wide variety of substrates, as well as having cost-effective preparation.

A Brønsted acidic ionic liquid anchored to magnetite nanoparticles as a novel recoverable heterogeneous catalyst for the Biginelli reaction.

In this study, simple and effective methods were used for the preparation of an ionic liquid that immobilized magnetite nanoparticles. Fe3O4 nanoparticles were prepared via a chemical co-precipitation method. Then, a SiO2 shell was coated on the magnetic core via the Stober method. Finally, CPTES (chloropropyltriethoxysilane) and morpholine were coated on the SiO2 shell. Morpholine sulfate, an acidic ionic liquid, was successfully bound to magnetite nanoparticles (Mag@Morph-AIL) and this was used as an efficient catalyst for the preparation of 3,4-dihydropyrimidinones. Compared to previous works, the easy separation of the nanocatalyst using an external magnet and the recyclability, non-toxicity, versatility, and high stability of the catalyst, combined with low reaction times and excellent yields, make the present protocol very useful for the synthesis of the title products. The synthesized products and catalyst were confirmed via 1H-NMR, 13C-NMR, FT-IR, scanning electron microscope, X-ray diffraction, and elemental analysis.