Efficient Recyclable Catalyst Research Articles

A Novel Trihybrid Material Based on Renewables: An Efficient Recyclable Heterogeneous Catalyst for C-C Coupling and Reduction Reactions.

The generation of organic-inorganic hybrid materials from renewable resources and their utilization in basic and applied areas has been at the forefront of research in recent years for sustainable development. Herein, a novel organic-inorganic trihybrid material was synthesized by in situ generation of palladium nanoparticles (PdNPs) in a hybrid gel matrix based on renewable chemicals. Constituents of the hybrid gel included a pentacyclic triterpenoid arjunolic acid extractable from Terminalia arjuna and the leaf extract of Chrysophyllum cainito rich in flavonoids. We took advantage of the presence of flavonoid molecules in this hybrid gel to generate an advanced trihybrid gel through in situ reduction of doped Pd(II) salts to stable PdNPs. The xerogel of this trihybrid material was used as a recyclable heterogeneous catalyst for C-C coupling and reduction reactions in aqueous media. We also demonstrated that the in situ generated PdNPs containing trihybrid material was a more efficient catalyst than the trihybrid material generated with presynthesized PdNPs.

Environmental and safety aspects of tertiary amino-functionalized ILs’ use as efficient recyclable catalysts for direct α-bromination of cyclic conjugated enones

To develop chemical processes, according to Green Chemistry and Engineering principles, the use of solvents must be greatly reduced or eliminated. This paper focuses on the use of a new generation of amino-functionalised ionic liquids, which enclose both solvent and catalytic properties for the bromination of cycloenones characterised by a conjugative endo-cyclic CC bond of various nature. These procedures represent an interesting approach to the environmental sustainability of bromination reactions, even if liquid Br2 is toxic and awkward. Given the large uses of brominated compounds in chemical industry, this procedure could be specially appreciated.

Magnetically Recyclable Cufe2o4 Nanoparticles as an Efficient and Reusable Catalyst for the Green Synthesis of 2,4,6,8,10,12-Hexabenzyl-2,4,6,8,10,12-hexaazaisowurtzitane as CL-20 Explosive Precursor

ABSTRACTMagnetic nanoparticles of copper ferrite (CuFe2O4 MNPs) have been simply prepared and applied as an efficient recyclable and reusable catalyst for the green synthesis of 2,4,6,8,10,12-hexabenzyl-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.05,9.03,11]dodecane (HBIW). The structure of the synthesized pure HBIW (recrystallization from ethanol) was confirmed by using various spectral techniques like infrared (IR), 1H-NMR, 13C-NMR and some of its physical properties. The prepared catalyst was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR). In addition, CuFe2O4 MNPs could be reused up to seven runs without any significant loss of activity. Finally, the remarkable advantages of this method are the simple experimental procedure, shorter reaction times, simple workup, and green aspects by avoiding toxic catalysts and high yield of product.

Aqueous biphasic hydroformylation of higher alkenes and highly efficient catalyst recycling in the presence of a polar low boiling solvent

The hydroformylation of higher alkenes under aqueous biphasic reaction conditions with a rhodium catalyst derived from BISBIS (sodium salt of sulfonated 2,2′-bis (diphenylphosphinomethyl)-1,1′-biphenyl) in the presence of a polar low boiling point solvent was studied. The addition of ethanol greatly accelerated hydroformylation, such that the turnover frequency (defined as the moles of converted alkene per mole of Rh per hour) and the selectivity for linear aldehyde were up to 2095 h−1 and 99 %, respectively. The catalytic system could be recycled for at least five runs without significant loss of activity in the aqueous biphasic hydroformylation of 1-octene; the rhodium content leaching in product mixtures detected by inductively coupled plasma atomic emission spectroscopy was < 0.1 ppm.

One‐step synthesis of Pt@three‐dimensional graphene composite hydrogel: an efficient recyclable catalyst for reduction of 4‐nitrophenol

A Pt@three‐dimensional graphene (Pt@3DG) composite hydrogel with a unique porous nanostructure was prepared and used as an efficient, recyclable and robust catalyst for the reduction of 4‐nitrophenol to 4‐aminophenol under mild conditions. The influence of graphene architecture on catalytic activities was comparatively investigated by loading the same amount of Pt on reduced graphene oxide. Pt@3DG exhibits a very high catalytic activity owing to the three‐dimensional macroporous framework with high specific surface area, numerous activation sites and efficient transport pathways. Moreover, catalyst separation can be easily achieved by simple filtration, and the catalyst can be reused for at least five runs, maintaining its high catalytic activity. Copyright © 2016 John Wiley &amp; Sons, Ltd.

Sulfonic acid–functionalized magnetic Fe3-xTixO4 nanoparticles: New recyclable heterogeneous catalyst for one-pot synthesis of tetrahydrobenzo[b]pyrans and dihydropyrano[2,3-c]pyrazole derivatives

ABSTRACTIn this work, titanomagnetite nanoparticles (Fe3-xTixO4) have been used as a novel suppport for the synthesis of a magnetic acidic catalyst. These nanoparticles were functionalized with sulfonic acid groups to prepare the Fe3-xTixO4@SO3H nanoparticles. The synthesized acidic nanoparticles have been explored as new and efficient recyclable heterogeneous catalyst for a one-pot, three-component synthesis of tetrahydrobenzo[b]pyrans known as 4H-chromenes and 1,4-dihydropyrano[2,3-c]pyrazoles. The structure of the catalyst was established by infrared, energy dispersive x-ray (EDX), and scanning electron microscopy analyses. The reactions proceed smoothly to furnish the respective products in excellent yields and short reaction times. The facile reaction conditions, easy isolation of the products, versatility, and easy magnetic separation and reusability of the catalyst with no significant loss of activity are the main merits of the present method.

Pyridinium saccharinate salts as efficient recyclable acylation catalyst: a new bridge between heterogeneous and homogeneous catalysis

It is important to find a way for separation of concerned chemicals from product mixture after reaction, in order to avoid spreading harmful chemicals to society. The homogeneous nature of DMAP-catalyzed acylation still suffers from the problems of catalyst separation and/or residual DMAP contamination. DMAP causes acute dermal toxicity, whereas the corresponding DMAP salt exhibits only slight irritation to the skin. Very recently, we found that the DMAP saccharinate salt is also great recyclable catalyst, whose acylation of alcohols has been successfully and effectively carried out 10 times without loss in activity. This report covers our comprehensive studies on using the pyridinium saccharinate salts as efficient recyclable acylation catalysts including 4-N,N-dimethylaminopyridinium saccharinate (A), 4-(1-pyrrolidinyl) pyridinium saccharinate (B), 2-N,N-dimethylaminopyridinium saccharinate (C), and pyridinium saccharinate (D). Their structure and reactivity have been studied. The salts A, C, and D contain very interesting seven-membered synthon showing multiple H-bonding interactions for pair of pyridinium cation and saccharinate anion in the solid state. The salt B exhibits H-bonding interaction of N(sac) … H–N(py) in the solid state, instead of seven-membered synthon. The catalytic reactivity studies show that salts A and B are both very effective, with salt B even better in reactivity, and are both recyclable in the esterification of a variety of alcohols, under solvent-free and base-free conditions at room temperature.

Another application of (NH4)42[MoVI72MoV60O372(CH3COO)30(H2O)72] as a highly efficient recyclable catalyst for the synthesis of dihydropyrano[3,2‐c]chromenes

In continuation of our previous works on the application of (NH4)42[MoVI72MoV60O372(CH3COO)30(H2O)72], a Keplerate‐type giant‐ball nanoporous isopolyoxomolybdate, as a catalyst for the synthesis of heterocyclic compounds, in this paper, we report another application of this attractive catalyst in the synthesis of 2‐amino‐5‐oxo‐4,5‐dihydropyrano[3,2‐c]chromene‐3‐carbonitriles via a one‐pot three‐component reaction of 4‐hydroxycoumarin, aldehydes and malononitrile. The reactions occur in ethanol–water as solvent at room temperature and the process is operative with various aldehydes, giving the corresponding products in high yields. Other beneficial features of this protocol include short reaction times, simple work‐up and the recyclability and reusability of the catalyst for up to five consecutive runs. Copyright © 2016 John Wiley &amp; Sons, Ltd.

Magnetic iron oxide nanoparticles–N‐heterocyclic carbene–palladium(II): a new, efficient and robust recyclable catalyst for Mizoroki–Heck and Suzuki–Miyaura coupling reactions

A new and efficient nanoparticle–N‐heterocyclic carbene–palladium complex was synthesized and characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, field emission scanning electron microscopy, energy‐dispersive X‐ray analysis, X‐ray diffraction, transmission electron microscopy, elemental analysis, inductively coupled plasma analysis and vibrating sample magnetometry. This catalytic system was found to be a highly active catalyst in the Mizoroki–Heck and Suzuki–Miyaura cross‐coupling reactions. These reactions were best performed in dimethylformamide and water, respectively, in the presence of only 0.054 mol% of palladium under mild conditions. Moreover, the catalyst could be recovered easily and reused at least ten times without any considerable loss of its catalytic activity. Copyright © 2016 John Wiley &amp; Sons, Ltd.

Immobilization Na7PW11O39 on quanternary ammonium functionalized chloromethylated polystyrene by electrostatic interactions: An efficient recyclable catalyst for alcohol oxidation

Na7PW11O39 (PW11) was immobilized on quanternary ammonium functionalized chloromethylated polystyrene (DMA16/CMPS) in a facile method and used as efficient recyclable catalyst in oxidation of alcohol. Commercially available mesopores and macropores CMPS was quaternized by N, N- dimethylhexadecylamine (DMA16) followed by immobilization of PW11 onto the pore of CMPS by electrostatic interaction. The synthesized catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), thermo gravimetric analyzer (TGA), ultraviolet–visible (UV–vis), N2 adsorption–desorption, X-ray photoelectron spectroscopy (XPS), zeta potential, contact angle, 31P nuclear magnetic resonance (31P NMR), scanning electron microscope (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The results indicated that Na7PW11O39 was successfully immobilized by electrostatic interaction and finely dispersed on quaternary ammonium functionalized CMPS. PW11-DMA16/CMPS showed a similar catalytic activity to that of homogeneous PW11, which was attributed to the hydrophobic nature of the PW11-DMA16/CMPS and facile diffusion of reactant to the active sites provided by widely opened mesopores and macropores. The present approach provides a promising and universal strategy for the construction of hybrid catalysts based on POMs and mesopores and macropores materials.

ChemInform Abstract: Fe3O4@MgO Nanoparticles as an Efficient Recyclable Catalyst for the Synthesis of Phosphoroamidates via the Atherton—Todd Reaction.

AbstractA simple, and convenient method for the synthesis of phosphoroamidates via the Atherton—Todd coupling reaction of amines with dialkyl phosphites is reported.

Catalytic performance of a Keplerate-type, giant-ball nanoporous isopolyoxomolybdate as a highly efficient recyclable catalyst for the synthesis of biscoumarins

AbstractIn continuation of our previous works on the application of (NH4)42[MoVI72MoV60O372(CH3COO)30(H2O)72], a Keplerate-type giant-ball nanoporous isopolyoxomolybdate, as a catalyst for a series of organic transformations, in this paper, we discovered that this new attractive catalyst has high catalytic activity in the synthesis of biscoumarins prepared by the reaction of 4-hydroxycoumarin and aromatic or aliphatic aldehydes in refluxing ethanol. The catalyst was prepared according to a previously published literature procedure using inexpensive and readily available starting materials. Furthermore, the catalyst could be recovered conveniently and reused efficiently such that a considerable catalytic activity still could be achieved after fifth run. Other beneficial features of this new synthetic approach include short reaction time, high yields, clean reaction profiles, and a simple work-up procedure.

Copper supported β-cyclodextrin grafted magnetic nanoparticles as an efficient recyclable catalyst for one-pot synthesis of 1-benzyl-1H-1,2,3-triazoldibenzodiazepinone derivatives via click reaction

Cu immobilized into β-cyclodextrin covalently attached to magnetic nanoparticles (denoted as [Cu@β-CD@SPIONs]) is reported as an efficient and recoverable catalyst for “click” and multicomponent reactions.

Succinimide-N-sulfonic acid as an efficient recyclable catalyst for the synthesis of some fused indolo pyrano pyrimidinone derivatives

A new, simple, thermally efficient and solvent-free condensation of 2-amino-4,5-dihydro-4-phenylpyrano[3,2-b]indole-3-carbonitrile derivatives with coumarin-3-carboxylic acid employing succinimide-N-sulfonic acid (SuSA) as catalyst for the synthesis of a series of 5,6-dihydro-2-(2-oxo-2H-chromen-3-yl)-5-phenyl-indolo[2',3':5,6]pyrano[2,3-d]pyrimidin-4(3H)-one derivatives is described. This method has the advantages of high yield, simple methodology, and short reaction time, as well as being green in terms of avoiding the use of toxic catalysts and solvents. Furthermore, the catalyst could be recycled and reused four times without significant loss of activity. Thiourea dioxide (TUD) catalyzed efficient three-component coupling reactions of aromatic aldehydes, 3-hydroxyindole and malononitrile in water at 70 ºC was described as the preparation of 2-amino-4,5-dihydro-4-phenylpyrano[3,2-b]indole-3-carbonitrile derivatives. KEY WORDS: Succinimide-N-sulfonic acid, Thiourea dioxide, Coumarin-3-carboxylic acid, Indolo pyrano pyrimidineone derivatives Bull. Chem. Soc. Ethiop. 2015, 29(3), 457-471.DOI: http://dx.doi.org/10.4314/bcse.v29i3.14

Fe3O4@MgO nanoparticles as an efficient recyclable catalyst for the synthesis of phosphoroamidates via the Atherton–Todd reaction

A simple and efficient method is presented for the synthesis of phosphoroamidates in moderate to good yield via the Atherton–Todd coupling of primary amines with H-dialkyl phosphites using Fe3O4@MgO nanoparticles as a recyclable catalyst.

Biopolymeric alginic acid: an efficient recyclable green catalyst for the Friedel–Crafts reaction of indoles with isoquinoline-1,3,4-triones in water

A very cheap, naturally available, nontoxic and biopolymeric alginic acid has been found to be an efficient, recyclable and heterogeneous green catalyst for the Friedel–Crafts reactions of indoles at C-3 and C-2 positions with isoquinoline-1,3,4-triones and hydroxyindolyl derivatives in water under mild conditions. These operational simple procedures furnish good to high yields of corresponding synthetically as well as biologically interesting functionalized 4-hydroxy-4-indolylisoquinoline-1,3(2H,4H)-diones and 4,4-diindolylisoquinoline-1,3(2H,4H)-diones, respectively. Moreover, alginic acid could be recovered and reused several times (up to 5 times) without significant loss in activity.

Regioselective Synthesis of 1,2,3-Triazoles Catalyzed Over ZnO Supported Copper Oxide Nanocatalyst as a New and Efficient Recyclable Catalyst in Water.

The CuO/ZnO nanocatalysts are reported as efficient and recyclable catalysts for the regioselective synthesis of 1,2,3-triazoles from benzyl halides and terminal alkynes in water. The catalysts are synthesized by a co-precipitation method and characterized by BET surface area, XRD, SEM, TEM and EDS analysis. The effect of CuO loading, catalyst amount and solvent was investigated. The catalyst can be recovered by a simple filtration and applied in consecutive runs with no loss of activity.

ChemInform Abstract: A Magnetic Solid Sulfonic Acid Modified with Hydrophobic Regulators: An Efficient Recyclable Heterogeneous Catalyst for One‐Pot Aza‐Michael‐Type and Mannich‐Type Reactions of Aldehydes, Ketones, and Amines.

Two convenient green protocols for the synthesis of β-amino ketones have been developed which involve one-pot aza-Michael-type and Mannich-type reactions of a series of aldehydes, ketones, and amines in the presence of a catalytic amount of the magnetic solid sulfonic acid catalyst, Fe3O4@SiO2@Me&Et-PhSO3H, at room temperature. The catalyst can be reused four times without loss of activity.

Rhodium catalyzed hydroformylation of 1-dodecene using an advanced solvent system: Towards highly efficient catalyst recycling

The challenging task of rhodium catalyzed hydroformylation with higher olefins is the efficient combination of the reaction and separation step for catalyst recovery and recycling. One promising concept is the use of organic solvent systems, which use a strong polar organic phase for the catalyst and allow a liquid/liquid-separation of product and catalyst after the reaction step. In this work, the hydroformylation reaction with 1-dodecene is presented in discontinuous lab-scale investigations as well as continuously driven in a miniplant. The hydroformylation reaction is carried out in a two-component solvent system containing propylene carbonate as polar catalyst solvent and decane as apolar product solvent.

ChemInform Abstract: ZnS Nanoparticles as an Efficient Recyclable Heterogeneous Catalyst for One‐Pot Synthesis of 4‐Substituted‐1,5‐benzodiazepines.

An efficient and novel method was developed for the synthesis of 4-substituted-1,5-benzodiazepine derivatives via a one-pot three-component catalytic reaction. The o-phenylenediamine and dimedone were reacted with aldehyde derivatives in the presence of ZnS nanoparticles as a heterogeneous catalyst under thermal conditions. The reaction was completed with high to excellent product yields and short reaction times. Simplicity of operation, high yields, easy work-up, easily accessible catalyst and purification of products through a crystallization method (non-chromatographic) are the key advantages of this work.