Surface modified SPIONs‐Cr(VI) ions‐immobilized organic‐inorganic hybrid as a magnetically recyclable nanocatalyst for rapid synthesis of polyhydroquinolines under solvent‐free conditions at room temperature

The magnetically recyclable graphene oxide‐Fe3O4/polyallylamine (PAA)/Ag nanocatalyst was prepared via a green route using Eucalyptus comadulensis leaves extract as both reducing and stabilizing agent. The catalytic activity of this nanocatalyst was investigated for the reduction reaction of methylene blue and methyl orange in the presence of NaBH4 in aqueous medium at room temperature. The prepared nanocatalyst was characterized by different methods such as Fourier transformed infrared spectroscopy, X‐ray diffraction, scanning electron microscopy–energy dispersive X–ray spectroscopy, thermogravimetric analysis, vibrating sample magnetometer, transmission electron microscopy, and UV–visible spectroscopy. The results show that graphene oxide/PAA/Ag nanocatalyst has good activity and recyclability, and can be reused several times without major loss of activity in the reduction process. The apparent rate constants of the methyl orange (MO) and methylene blue (MB) were calculated to be 0.077 s−1 (3 mg of catalyst) and 0.15 s−1 (2 mg of catalyst), respectively.

“…To demonstrate benefit of this work, our catalyst was compared with that used in other published methods . Some results for the reduction of MO and MB are summarized in Table .…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Green synthesis of silver nanoparticles using Eucalyptus comadulensis leaves extract and its immobilization on magnetic nanocomposite (GO‐Fe₃O₄/PAA/Ag) as a recoverable catalyst for degradation of organic dyes in water

Esmaili

Mohammadi

Abbaszadeh

et al. 2020

“…In 2018, Maleki and his research team have reported the successful preparation of a magnetic dichromate hybrid with triphenylphosphine surface modified with superparamagnetic iron oxide nanoparticles (Scheme ) . The resulting nano‐composite (Fe 3 O 4 @SiO 2 @PPh 3 @Cr 2 O 7 2− ) was confirmed by a series of spectroscopy techniques such as FT‐IR, XRD, SEM, VSM, TGA, XRF, TEM and dynamic light scattering.…”

Section: Magnetically Recoverable Nanocatalysts In Synthesis Of Polyhmentioning

confidence: 99%

“…The resulting nano‐composite (Fe 3 O 4 @SiO 2 @PPh 3 @Cr 2 O 7 2− ) was confirmed by a series of spectroscopy techniques such as FT‐IR, XRD, SEM, VSM, TGA, XRF, TEM and dynamic light scattering. The SEM analysis demonstrated that the magnetite nanocatalyst particles are spherical with a mean diameter of 25 nm and with uniform size and good dispersity . The efficiency of the Fe 3 O 4 @SiO 2 @PPh 3 @Cr 2 O 7 2− as a magnetically recoverable catalyst was then evaluated in the synthesis of polyhydroquinolines via the four‐component reactions of various aldehydes, dimedone, ethyl acetoacetate and ammonium acetate under solvent‐free conditions at room temperature (Scheme ).…”

Section: Magnetically Recoverable Nanocatalysts In Synthesis Of Polyhmentioning

confidence: 99%

Magnetically Recoverable Catalysts: Catalysis in Synthesis of Polyhydroquinolines

Kazemi

Mohammadi

2019

158

Molecules that contain polyhydroquinoline structural scaffolds are N‐containing heterocycles which are of great interest to organic chemists and biologists. Polyhydroquinoline structural scaffolds which are known as calcium channel blockers have emerged as one of the most important class of drugs used for the treatment of cardiovascular and Alzheimer's diseases. Besides, recovery and reusability of catalysts are important issues to be discussed in modern catalysis research especially in organic synthesis. The concept of magnetically recoverable catalysts has been rapidly developed in recent times. Magnetic separation is an efficient strategy for the rapid separation of catalysts from the reaction medium. Also, an alternative to time‐, solvent‐, and energy‐consuming separation techniques. In this review, we focused on the fabrication, surface‐modification and characterization of nanomagnetic materials and their application, as magnetically recoverable catalysts, in the synthesis of polyhydroquinoline structural scaffolds.

“…Surface functionalization of magnetic nanoparticles (MNPs) is a well‐designed way to bridge the gap between heterogeneous and homogeneous catalysis. The introduction of MNPs in a variety of solid matrices allows the combination of well‐known procedures for catalyst heterogenization with techniques for magnetic separation . So, these types of catalysts play a vital role in approaching the green chemistry goal.…”

Section: Introductionmentioning

confidence: 99%

Gallic acid grafted to amine‐functionalized magnetic nanoparticles as a proficient catalyst for environmentally friendly synthesis of α‐aminonitriles

Maleki

Azadegan

Rahimi

2019

Self Cite

An effective approach of one‐pot catalytic Strecker reaction between aromatic aldehydes, aniline or toluidine and trimethylsilyl cyanide in the presence of amine‐functionalized Fe3O4@SiO2 nanoparticles grafted with gallic acid (GA) as a powerful catalyst was developed. The fabricated reusable catalyst demonstrated high efficiency in the synthesis of α‐aminonitriles along with facile work‐up procedure. Fe3O4@SiO2‐NH2‐GA was characterized by Fourier transform‐infrared spectroscopy, scanning electron microscopy image, vibrating‐sample magnetometer curve, energy‐dispersive X‐ray analysis and thermogravimetric analysis.