Search Result

A novel polyionene modified magnetic nanoparticle with a core-shell-shell structure was developed for utilization as a heterogeneous catalyst in the metal free synthesis of dihydropyrimidinone derivatives under solvent-free conditions at 100 ◦C. The structural, surface, and magnetic characteristic of the nano sized catalyst were investigated by various techniques such as infrared spectroscopy (FT-IR), nucleus magnetic resonance (HNMR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), thermo gravimetric analysis (TGA), differential scanning calorimeter (DSC), and vibrating sample magnetometer (VSM). The supported catalyst could simply separated and recovered from the reaction mixture with the assistance of an external magnet and reused at least 7 times without significant degradation in the activity.

Authors: Elham Dezfoolinezhad, Keivan Ghodrati, Rashid Badri

A novel Fe3O4@SiO2@(CH2)3N+Me3I3- magnetite nanoparticle was prepared and utilized in the synthetic conversion of aldehydes to imidazole derivatives in solvent-free conditions. These functionalized magnetic core–shell nanoparticles (MNPs) were characterized by Standard technique such as TEM, SEM, EDX, FT-IR, XRD, and VSM. The work up of reaction was very simple containing only a magnetic decantation. This novel catalyst could be separated easily and recycled several times without any significant decreasing of catalytic activity.

Authors: Esmail Korani, Keivan Ghodrati, Manzarbano Asnaashari

A novel Fe3O4@SiO2@(CH2)3N+Me3I−3 magnetite nanoparticle was prepared and utilized in the synthetic conversion of aldehydes to imidazole derivatives in solventfree conditions. These functionalized magnetic core–shell nanoparticles (MNPs) were characterized by standard techniques such as TEM, SEM, EDX, FTIR, XRD, and VSM. The workup of the reaction was very simple containing only a magnetic decantation. This novel catalyst could be separated easily and recycled several times without any significant decrease of catalytic activity.

Authors: Esmail Korani, Keivan Ghodrati, Manzarbano Asnaashari

The four-component Hantzsch condensation reaction of dimedone, ethyl acetoacetate, ammonium acetate, and various aromatic and aliphatic aldehydes in the presence of catalytic amount of a magnetic nanoparticle-supported tribromide, as a green catalyst, under solvent‐free conditions at 80 °C affords functionalized 5-oxo-hexahydroquinolines in good to excellent yields. The magnetic Fe3O4-SiO2-(CH2)3N+Me3Br3–, was characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD)spectroscopy, transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The method offers several advantages including high yields, short reaction time, simple work-up procedure and catalyst reusability for several runs. The catalyst could be readily separated by using a magnetic force and reused six times without any significant loss of catalytic activity.

Authors: Azita Farrokhi, Issa Yavari, Keivan Ghodrati

A simple and effective synthesis of 3,4-dihydropyrimidin-2(1H)-one and thione derivatives has been developed in the presence of nano cobalt manganese oxide as catalyst under thermal solvent-free conditions. The proposed procedure ensures easy to handle, recyclable, and good yields after purification by recrystallization. In addition, the products were characterized by H NMR and C NMR.

Authors: Changiz Karami, Hadi Mohammadi, Keivan Ghodrati, Hossein Ahmadian, Fariba Jamshidi, Maryam Nouri , Nahid Haghnazarie

Functionalized magnetic core–shell nanoparticles [Fe3O4/SiO2/(CH2)3N+Me3Br3−] are prepared by coprecipitation method, characterized by transmission electron microscopy, FT-IR, X-ray diffraction, and vibrating sample magnetometer. The catalytic activity of these nanoparticles was tested in the syntheses of imidazole, benzothiazole, and perimidine derivatives, under solvent-free conditions. The catalyst was readily recycled by the use of an external magnetic field and could be reused five times without significant loss of activity or mass.

Authors: Azita Farrokhi , Keivan Ghodrati , Issa Yavari

An efficient and green method has been developed for the synthesis of amidoalkyl naphthol derivatives through a one-pot three component condensation of 2-naphthol, aldehydes, and amide in the presence of nano silica sulfuric acid as heterogeneous catalyst
under solvent-free conditions.

Authors: Keivan Ghodrati, Azita Farrokhia, Changiz Karamia & Zohre Hamidi