SO3H-dendrimer functionalized magnetic nanoparticles (Fe3O4@D NH (CH2)4SO3H): Synthesis, characterization and its application as a novel and heterogeneous catalyst for the one-pot synthesis of polyfunctionalized pyrans and polyhydroquinolines

Self Cite

In the present work, the nanocrystalline particles of hydroxyapatite (HAp) using an easy alkoxide‐based sol–gel technique including triethyl phosphate [PO (OC2H5)3] and Ca (NO3)2·4H2O as P and Ca precursors have been synthesized. The sample characterization was performed by X‐ray diffraction, Fourier transform‐infrared analysis, scanning electron microscopy, thermal analysis (thermogravimetric analysis/differential thermal analysis), and elemental analysis of energy‐dispersive X‐ray analysis. It is interesting that single phase of HAp was obtained at a low firing temperature of 500°C. Modified Scherrer equation as the Williamson−Hall method was applied for the measurement of crystallite size distributions and micro‐strain of the sample. The determined crystallite size by complementary technique of transmission electron microscopy has good consistency with those obtained from the Scherrer formula. Moreover, we reported the one‐pot synthesis of 3,4‐disubstituted isoxazole‐5(4H)‐ones through the aqueous solution reaction of three components of ethyl acetoacetate, hydroxylamine hydrochloride and various aromatic aldehydes at room temperature. This protocol offers several advantages, including a simple work‐up procedure, very short reaction times (under 25 min), in accordance with the principles of green chemistry, recyclability, excellent yields (87–98%) and environmentally friendly.

Section: Resultsmentioning

confidence: 97%

Synthesis and characterization of nanocrystalline hydroxyapatite and its catalytic behavior towards synthesis of 3,4‐disubstituted isoxazole‐5(4H)‐ones in water

Maleki

Chahkandi

Tayebee

et al. 2019

Self Cite

“…The as‐fabricated nano‐catalyst was confirmed by a series of spectroscopic techniques. Transmission electron microscopy (TEM) indicated that magnetic nanoparticles were dispersed in a dendrimer matrix . The reaction was failed in the absence of the catalyst.…”

Section: Magnetically Recoverable Nanocatalysts In Synthesis Of Polyhmentioning

confidence: 99%

“…Transmission electron microscopy (TEM) indicated that magnetic nanoparticles were dispersed in a dendrimer matrix. [136] The reaction was failed in the absence of the catalyst. Solvent type and catalyst loading were two key factors to find the standardized conditions (Scheme 27).…”

Section: Magnetic Nanoparticlessupported Acidic-catalystsmentioning

confidence: 99%

Magnetically Recoverable Catalysts: Catalysis in Synthesis of Polyhydroquinolines

Kazemi

Mohammadi

2019

166

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.

“…[1][2][3][4][5][6][7] Its central aim is the control of chemical reactions by changing the size, dimensionality, chemical composition and morphology of the reaction center, and by changing the kinetics using nanopatterning of the reaction centers. [8][9][10][11][12] Nanoparticles can substitute conventional materials, and serve as active and stable heterogeneous catalysts or as support materials for various catalytic groups. [13][14][15][16][17][18] Due to their small sizes, catalytic-active nanoparticles have higher surface areas and increased exposed active sites, and thereby improved contact areas with reactants, akin to those of homogeneous catalytic systems.…”

Section: Introductionmentioning

confidence: 99%

Pd(0)‐guanidine@MCM‐41: a very effective catalyst for rapid production of bis (pyrazolyl)methanes

Filian

Kohzadian

Mohammadi

et al. 2020

In this research, a rapid, green and efficient protocol for synthesis of bis (pyrazolyl)methane derivatives in the presence of Pd(0)‐guanidine@MCM‐41 catalysts under solvent‐free conditions by the following two methods has been reported: (i) via the one‐pot pseudo five‐component reaction among phenylhydrazine (2 equivalents), ethyl acetoacetate (2 equivalents) and aromatic aldehydes (1 equivalent); and (ii) the one‐pot pseudo three‐component reaction between 3‐methyl‐1‐phenyl‐1H‐pyrazol‐5(4H)‐one (2 equivalents) and aromatic aldehydes (1 equivalent). Some advantages of this protocol include: green conditions, extremely short times, high efficiency, proper one‐pot operation, generality of method, easy work‐up and recyclability, and reusability of the catalyst up to five times without significant loss in catalytic activity.