Synthesis of substituted pyrimidine using ZnFe2O4 nanocatalyst via one pot multi-component reaction ultrasonic irradiation

A highly efficient, eco-friendly, recyclable heterogeneous ZnFe₂O₄ nanocatalyzed synthesis of 2-amino-4-substituted 1,4-dihydrobenzo[4,5]imidazo[1,2-a]pyrimidine-3-carbonitrile (4a-j) derivatives via one pot multicomponent reaction of benzimidazole ( 1 ), substituted aromatic aldehyde ( 2a-j ) and malononitrile ( 3 ) under ultrasonic irradiations. Significance of this synthetic approach is short reaction time, easy handling, simplicity, efficiency, high yield, and recoverable catalyst.     

Design and characterization of Dendrimer of MNPs as a novel,heterogeneous and reusable nanomagnetic organometallic catalyst for one‐pot synthesis of hydroxyl naphthalene‐1,4‐dione derivatives under solvent‐free conditions

A novel super acidic magnetic nanoparticle as catalyst was successfully synthesized. The preparation of this dendrimer sulfonic acid functionalized γ‐Fe₂O₃ magnetic core‐shell silica nanoparticles as a new recoverable and heterogeneous nanocatalyst was described. The new catalyst was characterized using various techniques such as scanning electron microscopy (SEM), energy dispersive spectrum (EDS), and thermo gravimetric synthesis (TGA). Moreover, we have examined the catalytic activity of the catalyst for one‐pot, efficient and facile synthesis of 2‐hydroxy‐1,4‐naphthoquinone derivatives via a three‐component condensation reaction of 2‐hydroxynaphthalene‐1,4‐dione, aromatic aldehydes and aniline derivatives. High yields of products, short reaction times, waste‐free, mild, ambient and solvent‐free reaction conditions are advantages of this protocol. Also, the catalyst can be easily recovered by an external magnetic and reused several times without significant loss of its catalytic activity.     

CeO2/CuO@N-GQDs@NH2 nanocomposite as a high-performance catalyst for the synthesis of benzo[g]chromenes

A three-component reaction of aromatic aldehydes, malononitrile or ethyl cyanoacetate and 2-hydroxy-1,4-naphthaquinone has been achieved in the presence of an amino-functionalized CeO₂/CuO@ nitrogen graphene quantum dot nanocomposite as a highly effective heterogeneous catalyst to produce benzo[g]chromenes. The catalyst has been characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, energy-dispersive X-ray spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller (BET) and vibrating sample magnetometry. This new catalyst has been demonstrated to be highly effective in the preparation of benzo[g]chromenes.     

Copper‐Polymer Nanocomposite Catalyst for Synthesis of 1,4‐Diphenylbutadiyne‐1,3

A new catalyst for cross‐coupling synthesis of 1,4‐diphenylbutadiyne‐1,3 was prepared by thermolysis of copper(II) poly‐5‐vinyltetrazolate. It presents heterogeneous catalyst, in which copper nanoparticles are supported on polymeric matrix surface. The catalyst is recovered, recycled, and shows high catalytic activity in cross‐coupling synthesis of 1,4‐diphenylbutadiyne‐1,3. The reaction proceeds in aerobic conditions at room temperature in the presence of pyridine.     

Synthesis of Tetrahydrobenzo[g]Quinoline Derivatives Using Recoverable Carbonaceous Material as Heterogeneous Catalyst

A variety of substituted benzo[g ]quinoline‐5,10‐dione derivatives were synthesized via one‐pot three‐component reaction of 2‐hydroxynaphthalene‐1,4‐dione, aromatic aldehydes, and (E )‐3‐aminobut‐2‐enoates using carbonaceous material as the heterocyclic catalyst. This procedure is simple and efficient owing to short reaction times, easy work‐up, and recovery of heterogeneous catalyst. This procedure develops an efficient and promising synthetic method to construction of the benzo[g ]quinoline‐5,10‐dione skeleton.     

二氧化硅键合丙基哌-N-氨基磺酸作为可回收固体酸催化剂制备2-氨基-3-氰基-4-芳基-5,10-二氧代-5,10-二氢-4H-苯并[g]苯并吡喃和羟基取代的萘-1,4-二酮衍生物(英文)

An efficient method for the synthesis of 2-amino-3-cyano-4-aryl-5,10-dioxo-5,10-dihydro-4H- ben-zo[g]chromenes and hydroxy-substituted naphthalene-1,4-dione derivatives, using silica-bonded propylpiperazine-N-sulfamic acid as a solid acid, green, heterogeneous catalyst, under ambient and solvent-free conditions, is described. A simple procedure, high yields, short reaction time, safety, and reusability of the catalyst are advantages of these protocols.     

二氧化硅键合丙基哌-N-氨基磺酸作为可回收固体酸催化剂制备2-氨基-3-氰基-4-芳基-5,10-二氧代-5,10-二氢-4H-苯并[g]苯并吡喃和羟基取代的萘-1,4-二酮衍生物FahimeKhorami,HamidRezaShaterian简

An efficient method for the synthesis of 2-amino-3-cyano-4-aryl-5,10-dioxo-5,10-dihydro-4H-benzo[g]chromenes and hydroxy-substituted naphthalene-1,4-dione derivatives, using silica-bonded propylpiperazine-N-sulfamic acid as a solid acid, green, heterogeneous catalyst, under ambient and solvent-free conditions, is described. A simple procedure, high yields, short reaction time, safety, and reusability of the catalyst are advantages of these protocols.     

Reusable montmorillonite-entrapped organocatalyst for asymmetric Diels-Alder reaction

A chiral organocatalyst was successfully entrapped by montmorillonite clay using the cation-exchange method. The mont-entrapped organocatalyst acted as a highly efficient and reusable heterogeneous catalyst for the asymmetric Diels-Alder reaction, without loss of its initial activity.     

Mild,four-component synthesis of 6-amino-4-aryl-3-methyl-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles catalyzed by titanium dioxide nano-sized particles

A convenient and efficient solvent-free procedure is described for preparation of 6-amino-4-aryl-3-methyl-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles by four-component reaction of hydrazine hydrate, ethyl acetoacetate, aryl aldehyde, and malononitrile in the presence of a catalytic amount of titanium dioxide nano-sized particles. Short reaction times, high yields under ambient conditions, simple reaction, clean work-up, and reusability of the nano heterogeneous catalyst are the advantages of this method.     

Stereoselective C-glycoside formation by a rhodium(I)-catalyzed 1,4-addition of arylboronic acids to acetylated enones derived from glycals

[reaction: see text] A new method for the formation of C-glycosides has been developed employing a cationic rhodium(I)-catalyzed 1,4-addition of arylboronic acids to enones derived from glycals. The reaction is stereoselective for the alpha-anomer and is highly dependent on the nature of the rhodium catalyst.     

Copper-catalyzed aerobic oxidative dehydrogenation for conversion of 2-(alkylthio)-1,4-dihydropyrimidines to 2-(alkylthio)pyrimidines

A simple and efficient aerobic oxidative dehydrogenation reaction method for the conversion of 2-(alkylthio)-1,4-dihydropyrimidines to 2-(alkylthio)pyrimidines using copper catalyst with no additives, such as an oxidant, acid, or base, has been developed. The reaction was successful with a wide range of 2-(alkylthio)-1,4-dihydropyrimidine substrates.     

A copper(I) isonitrile complex as a heterogeneous catalyst for azide-alkyne cycloaddition in water

A structurally well-defined copper(I) isonitrile complex is shown to be an efficient, heterogeneous catalyst for the Huisgen azide-alkyne 1,3-dipolar cycloaddition under mild conditions in water. Notably, this catalyst can also be utilized in a three-component reaction of halides, sodium azide and alkynes to form 1,4-disubstituted 1,2,3-triazoles in high yields. Furthermore, it can be readily recovered by precipitation and filtration and recycled for at least five runs without significant loss of activity.     

One-pot,solvent-free and efficient synthesis of 2,4,6-triarylpyridines catalyzed by nano-titania-supported sulfonic acid as a novel heterogeneous nanocatalyst

Nano titania-supported sulfonic acid (n-TSA) has found to be a highly efficient, eco-friendly and recyclable heterogeneous nanocatalyst for the solvent-free synthesis of 2, 4, 6-triarylpyridines through one-pot three-component reaction of acetophenones, aryl aldehydes and ammonium acetate. This reported method illustrates several advantages such as environmental friendliness reaction conditions, simplicity, short reaction time, easy work up, reusability of catalyst and high yields of the products. One new compound is reported too. Furthermore, the catalyst could be recycled after a simple work-up, and reused at least six times without substantial reduction in its catalytic activity.     

Silica sulfuric acid as a highly efficient catalyst for the synthesis of diarylacetic acids

An efficient heterogeneous method for the synthesis of diarylacetic acids was developed utilizing silica sulfuric acid as a catalyst. The reaction is highly efficient with a small amount of catalyst for the combination of a variety of electron-neutral to electron-rich arenes with glyoxylic acid. The reaction can also be utilized to synthesize unsymmetric derivatives from activated mandelic acids in good to excellent yields.     

Efficient and green synthesis of dihydropyrimido[4,5-b]quinolinetriones using MWCNTs@TEPA/Co (II) as a novel and eco-friendly catalyst

A new heterogeneous nanocatalyst [MWCNTs@TEPA/Co (II)] was successfully prepared using multiwall carbon nanotubes (MWCNTs) as a suitable and efficient support for covalent anchoring of tetraethylene pentaamine (TEPA)/Co (II). The new heterogeneous catalyst was prepared through an easy and applicable method, and characterized by various techniques such as Fourier transform-infrared, thermogravimetric analysis, energy-dispersive X-ray spectroscopy, mapping, field emission-scanning electron microscopy, inductively coupled plasma-optical emission spectrometry and Brunauer−Emmett−Teller. Synthesized catalyst was used efficiently for the preparation of dihydropyrimido [4,5-b]quinolinetrione derivatives via the four-components reaction of barbituric acid, dimedone, aryl aldehyde and amines under thermal conditions. The nanostructure catalyst was easily recovered by filtration and reused several times without noticeable loss of its catalytic activity. Low amounts of catalyst (0.005 g), short reaction times and green conditions are some merits of the presented method.     

Iron‐catalyzed cross‐coupling reaction: Heterogeneous palladium and copper‐free Heck and Sonogashira cross‐coupling reactions catalyzed by a reusable Fe(III) complex

An interesting silica‐supported iron catalyst was successfully prepared and demonstrated as an efficient heterogeneous catalyst for cross‐coupling reactions of aryl halides. The as‐prepared nanocatalyst was well characterized and found to be highly efficient in Heck reaction under mild and sustainable conditions (water as solvent at 80 °C in short reaction time). Furthermore, the obtained catalyst was used as an efficient, inexpensive and green heterogeneous catalyst for Sonogashira cross‐coupling reactions of various aryl iodides and provided the corresponding products with moderate to good yields. This phosphine, copper and palladium‐free catalyst was simply recovered from the reaction mixture and recycled five times without substantial decrease in its catalytic activity.     

New method for post-processing crosslinking reaction

A new processing method to process functionalized polymer materials that are able to crosslink has been developed. The crosslinking reaction occurs after the melt processing stage at moderate temperature and without the addition of external reagents. Maleic anhydride-ethylene copolymer was processed with 1,4-butanediol in the presence of para-toluene sulfonic acid as catalyst. To prevent the reaction in the melt, it was chosen to trap the 1,4-butanediol onto vector particles. The extent of the crosslinking reaction during the mixing at 110 °C has been studied for three different particles taken as vector particles. It was found that Orgasol^® polyamide particles are efficient to inhibit the crosslinking reaction in the mixer. The reaction then takes place at 40 °C and after 100 h the cured samples appeared to be highly and homogeneously crosslinked with a gel content above 90%.     

One-pot synthesis of 1,4-dihydropyridines and N-arylquinolines in the presence of copper complex stabilized on MnFe2O4 (MFO) as a novel organic–inorganic hybrid material and magnetically retrievable catalyst

In this work, the design and synthesis of a heterogeneous catalyst based on functionalization of manganese ferrite nanoparticles encapsulated in a silica layer with Schiff base and subsequent incorporation of copper is presented. The fabricated hybrid material was characterized by employing Fourier-transform infrared spectroscopy, X-ray powder diffraction, field emission scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, differential thermal gravimetric analysis, vibrating sample magnetometry and inductively coupled plasma-optical emission spectrometry techniques. The prepared organic–inorganic hybrid material was successfully used as an efficient and recoverable catalyst for the synthesis of 1,4-dihydropyridines and N-arylquinolines under mild and green reaction conditions. The results showed that the catalyst exhibited excellent catalytic activity under optimum reaction conditions and the desired products were obtained in good to excellent yields. The new 1,4-dihydropyridines and N-arylquinolines were characterized by Fourier-transform infrared spectroscopy, ¹H NMR and Elemental analysis of Carbon, Hydrogen and Nitrogen (CHN) analyses. Study of the catalyst reusability confirmed that the catalyst could be recycled for five reaction runs with slight loss of the catalytic activity and negligible copper leaching.     

Pd/Cu-free Heck and Sonogashira coupling reactions applying cobalt nanoparticles supported on multifunctional porous organic hybrid

A new heterogeneous cobalt catalyst has been synthesized by immobilizing Co species onto a nitrogen-rich porous organic polymer (Co@imine-POP). The heterogeneous catalyst synthesized was efficient in Heck and Sonogashira cross-coupling reactions in green media under mild reaction conditions without inert air and phase transfer agents. This phosphine-, copper-, and palladium-free catalyst was stable under the reaction conditions and could be reused for at least eight successive runs without a discernible decrease in its catalytic activity.     

A simple and efficient one-pot synthesis of Hantzsch 1,4-dihydropyridines using silica sulphuric acid as a heterogeneous and reusable catalyst under solvent-free conditions

A simple, inexpensive and efficient one-pot synthesis of 1,4-dihydropyridine derivatives under solvent-free conditions using silica sulphuric acid (SSA) as a heterogeneous and recyclable catalyst is reported.