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Advantages of the employed method are clean reaction with high yields in short reaction time and easy purification.

Fe3O4-CTAB NPs have been applied as a competent catalyst for one-pot synthesis of nitriles directly from aldehydes. The present investigation describes the synthesis of nitriles by combination of aromatic/aliphatic/heterocyclic aldehydes and hydroxylamine hydrochloride in the presence of iron oxide nanocatalyst in DMF under reflux condition. Fe3O4-CTAB NPs were prepared by reported method and characterized by FE-SEM, TEM, and XRD analysis. The amount of Fe in Fe3O4-CTAB was quantified by Atomic Absorption Spectroscopy (AAS). The protocol endow with excellent yield of products along with simple reaction set up and economically adept alternative approach.

The new title catalyst is prepared and used for the one-pot reductive amination of ketones affording a diverse range of secondary amines in predominantly excellent yields.

An efficient, one-pot, three-component protocol for the synthesis of a small library of chiral isoxazolidines and spiroisoxazolidines with high diastereoselectivity, from the reaction of N-arylhydroxylamines, arylaldehydes, isatins, and α,β-unsaturated aldehydes is described. l-Proline functionalized Fe3O4 nanoparticles as a magnetic organocatalyst gave isoxazolidine products in high yields as single isomers with an endo-configuration. Notable features of this methodology were: short reaction time, good to excellent yields, and use of an easily recovered heterogeneous catalyst that could be reused many times without significant loss of its catalytic activity.

Aggregates of the perylene bisimide derivatives act as reactors and stabilizers for the preparation of superparamagnetic Fe3O4 nanoparticles.

Using an efficient and eco-friendly approach, title compounds and some 2-thione analogues are prepared in good yields and in short reaction times by a three-component reaction of aromatic aldehydes with dimedone and (thio)urea using Fe3O4 nanoparticles in aqueous ethanol under reflux conditions.

The title compounds (IV) are obtained by one-pot three-component condensation between 4-hydroxycoumarin (I), various aryl glyoxals (II), and malononitrile (III), using magnetically recyclable Fe3O4 nanoparticles as catalyst.

Phosphotungstic acid supported on nanoparticles of Fe3O4—SiO2 is an efficient catalyst for the solvent-free hydrophosphonylation of aldehydes (I) and isatins (VIII) leading to corresponding α-hydroxyphosphonates (III) and (IX), respectively.

The Pd-catalyzed Sonogashira reaction is a powerful method for the formation of Csp2–Csp bonds and has found application in a wide variety of areas including medicinal chemistry, agrochemistry, materials and electronics. Development of competent catalysts for the Sonogashira reaction is a particular scientific challenge since it is traditionally a di-metallic-mediated homogeneous catalytic process including some major drawbacks. This review provides a concise overview of the mechanistic aspects of the Cu co-catalyzed, Cu-free and Au-catalyzed Sonogashira coupling processes. More recent developments and next generation catalysts for the Sonogashira reaction are also presented. These include non transition-metal catalysts, metal free couplings and photo-induced protocols. Finally, the application of metal nanoparticles in Sonogashira reactions is presented. These include Pd nanoparticles, Pd bi- and tri-metallic nanoparticles, magnetically separable Pd/Fe3O4 nanoparticles, Ru nanoparticles and Au nanoparticles.

Magnetic Fe3O4 nanoparticles can be easily recovered and reused up to 6 times without any significant loss in activity.

A magnetically recoverable and biodegradable heterogeneous nanocatalyst is prepared and characterized.

We present herein a new and efficient methodology for the synthesis of alkynyl chalcogenides from terminal acetylenes and diorganyl dichalcogenides, catalyzed by Fe3O4 nanoparticles. This new approach provided the desired products in good to excellent yields. Moreover, the catalyst was easily recoverable using an external magnet and reused for further experiments without loss of catalytic activity.

Pyranopyrazoles are prepared within a few minutes via a four-component reaction of malononitrile, hydrazine hydrate, ethyl acetoacetate and carbonyl compounds in water as green solvent.

A new methodology for the oxidation of aldehydes promoted by commercially available Fe3O4 nanoparticles (Fe3O4 NPs) activated by ethyl acetoacetate was developed. The use of ethyl acetoacetate as additive was crucial to achieve high reactivities. All reactions were realized under solvent free conditions, using air or tBuOOH as oxidants. Finally, the separation and reuse of the magnetically recoverable nanoparticles make this methodology very practical, simple and economical.

A novel Pd(0) compound immobilized on the surface of hollow magnetic mesoporous spheres, with Fe3O4 nanoparticles embedded in the mesoporous shell is prepared.

A Broensted acidic ionic liquid imidazolium hydrogen sulfate immobilized on magnetic Fe3O4 nanoparticles exhibits excellent catalytic activity in the Biginelli-type synthesis of a diverse range of pyrimidine derivatives (IV).

Cu(acac)2 immobilized on the surface of amine-terminated silica-coated Fe3O4 nanoparticles appears to be an efficient catalyst for the synthesis of α-aminoacyl amides (V) (14 examples) Using an Ugi four-component reaction.

Imidazole-coated magnetic Fe3O4 nanoparticles work as an effective, reusable and easily available catalyst for the one-pot three-component condensation reaction of aldehydes, 1,3-dicarbonyl compounds, and urea under solvent-free conditions.

A new, one-pot condensation of aldehydes, enolizable ketones and esters, AcCl, and MeCN, in the presence of Fe3O4 nanoparticles (nano-Fe3O4) as an efficient catalyst, for the preparation of β-acetamido carbonyl compounds at room temperature is described.

ortho-Benzoylation of phenols with aryl aldehydes to afford the substituted 2-hydroxybenzophenones can be catalyzed efficiently by Fe3O4 nanoparticles under ligand-free conditions. This method is useful for the preparation of xanthones in good yields. The catalyst can be magnetically removed and recycled easily over four cycles without a significant decrease in activity.

An efficient and green procedure has been developed for the synthesis of monoarylidenes of cyclic and heterocyclic ketones. The reaction was carried out under solvent-free conditions in the presence of a catalytic amount of nanosized magnetite (Fe3O4). The catalyst was easily removed by using an external magnet. The structures of the products were deduced from their 1H NMR, 13C NMR, and infrared spectroscopy and mass spectrometry. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]

The ionic liquid 1-methyl-3-(3-trimethoxysilylpropyl)imidazolium chloride was immobilized on Fe3O4 nanoparticles and used as an efficient and reusable catalyst for the one-pot synthesis of 1,2,4,5-tetrasubstituted imidazoles at room temperature under ultrasonic irradiation. The immobilized ionic liquid catalysts proved to be effective and easily separated from the reaction media by applying an external magnetic field. This procedure has many obvious advantages compared to those reported in the previous literatures, including avoiding the use of harmful catalysts, reacting at room temperature, high yields, and simplicity of the methodology.

A three-component, one-pot synthesis of 2,4,5-trisubstituted imidazoles by condensation of 1,2-diketones, aromatic aldehydes, and ammonium acetate is developed.

We report here on the preparation of an efficient, easily recoverable and reusable Fe3O4 magnetic nanoparticle-supported Cu(II)-β-cyclodextrin complex catalyst for the synthesis of symmetrical biaryls and 1,2,3-triazoles from arylboronic acids. The presented Fe3O4 magnetic nanoparticle-supported Cu(II)-β-cyclodextrin complex catalyst was characterized by TEM, XRD, VSM, TGA, and FT-IR spectrometer. By using the catalyst, we have developed an efficient protocol for the homocoupling of aryl boronic acids for the synthesis of biaryls. The catalyst is also active in the synthesis of 1,2,3-triazoles via a one-pot reaction of an arylboronic acid with sodium azide in water followed by a click cyclization reaction with an alkyne at room temperature in air without any additives. The reusability of the prepared nanocatalyst was successfully examined four times with only a very slight loss of catalytic activity.

A new, efficient, one-pot multicomponent reaction for the synthesis of diazepine derivatives in excellent yields is described. The reactions of various 1,2-diamines, terminal alkynes, and an isocyanide take place in the presence of a catalytic amount of magnetically recoverable silica-supported superparamagnetic Fe3O4 nanoparticles in ethanol (as a green reaction medium) at ambient temperature.

Application of Fe3O4 nanoparticles (NPs) as a robust, very efficient, and magnetically recoverable catalyst was investigated in Friedel–Crafts acylation (FCA) of ferrocene and aromatic compounds. This reaction was performed with acid chlorides in solvent-free conditions at room temperature. The catalyst was easily separated by an external magnetic field from the reaction mixture. The separated catalyst was recycled for several consecutive runs without appreciable loss of its catalytic activity. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.

The use of Fe3O4 nanoparticles as magnetically separable catalyst for the three-component, one-pot synthesis of 1,4-dihydropyridines is described.

The catalyst is found to be reusable for five cycles without any appreciable loss of its activity.

A highly air- and moisture-stable supported Pd catalyst is prepared by reaction of palladium acetate with phosphinylethyl-functionalized silica-coated Fe3O4 nanoparticles.

The system exhibits high chemoselectivity for nitro group reduction in the presence of hydrogenation-labile functional groups.

Three-dimensional flowerlike hierarchical Fe3O4@Bi2O3 core—shell particles are solvothermally synthesized from Bi(NO3)3 and magnetic Fe3O4 nanoparticles in a mixture of ethylene glycol and EtOH (autoclave, 160 °C, 5 h).

A chiral rhodium catalyst anchored on SiO2-coated Fe3O4 magnetic nanoparticles is synthesized, which exhibits excellent catalytic activity and enantioselectivity in asymmetric transfer hydrogenation reactions of aryl methyl ketones in aqueous medium.

The catalyst exhibits excellent reactivity to afford the propargyl amines with high yields and enantioselectivities.

An efficient one-pot procedure is developed for the synthesis of the title compounds (IV), (VI), and (VII).

A robust, safe and magnetically recoverable Fe3O4 nanoparticle catalyzed three-component coupling of aldehyde, alkyne, and amine (A3-coupling) was developed. A diverse range of propargylamines were obtained in moderate to high yield under mild conditions in air. The separation and reuse of the magnetic Fe3O4 nanoparticles were very simple, effective and economical.

Magnetically separable Fe 3 O 4 nanoparticles endow with an efficient and economic route for the synthesis of propargylamines by the three-component coupling of aldehyde, amine, and alkyne through C–H activation. The reaction is especially effective for reactions involving aliphatic aldehydes and no additional co-catalyst or activator is required. High catalytic activity and ease of recovery using an external magnetic field are additional eco-friendly attributes of this catalytic system. The catalyst was recycled for five times without a significant loss of catalytic activity.