Solid Acid Nanocatalyst Research Articles

Mesoporous SBA‐15 Silica Phenylsulfonic Acid (SBA‐15‐Ph‐SO3H) as Efficient Nanocatalyst for One‐pot Three‐component Synthesis of 3‐Methyl‐4‐aryl‐2,4,5,7‐tetrahydropyrazolo[3,4‐b]pyridine‐6‐ones

A simple, economical, and efficient approach to the one‐pot synthesis of 3‐methyl‐4‐aryl‐2,4,5,7‐tetrahydropyrazolo[3,4‐b]pyridine‐6‐ones by multicomponent assembling of 5‐methylpyrazol‐3‐amine, aldehydes, and Meldrum's acid using mesoporous silica phenylsulfonic acid (SBA‐15‐Ph‐SO3H) as recyclable and heterogonous solid acid nanocatalyst has been described. This protocol has the advantages of high yields, wide application scope, and an environmental benign procedure.

Direct Synthesis of Nitriles from Aldehydes and Hydroxylamine Hydrochloride Catalyzed by a HAP@AEPH2-SO3H Nanocatalyst

We describe an efficient method for the direct preparation of nitriles from aldehydes and hydroxylamine hydrochloride catalyzed by sulfonated nanohydroxyapatite functionalized by 2-aminoethyl dihydrogen phosphate (HAP@AEPH2-SO3H) as an eco-friendly and recyclable solid acid nanocatalyst. In this protocol the use of a solid acid nanocatalyst provides a green, useful, and rapid method for the preparation of nitriles in excellent yields. In addition, the notable feature of this methodolgy is that the synthesized nanocatalyst can be recovered and reused five times without any noticeable loss of efficiency.

ChemInform Abstract: Nano‐Zirconia as an Excellent Nano Support for Immobilization of Sulfonic Acid: A New, Efficient and Highly Recyclable Heterogeneous Solid Acid Nanocatalyst for Multicomponent Reactions.

AbstractHexahydroquinolines, dioxodecahydroacridines, polyhydroquinolines, and dioxooctahydroxanthenes are prepared by multicomponent cyclocondensations using the title catalyst.

Synthesis, characterization and application of sulfonic acid supported on ferrite–silica superparamagnetic nanoparticles

In this study, the synthesis of sulfonic acid supported on ferrite–silica superparamagnetic nanoparticles (Fe3O4@SiO2@SO3H) as a nanocatalyst with large density of acidic groups is suggested. This nanocatalyst was prepared in three steps: preparation of colloidal iron oxide magnetic nanoparticles (Fe3O4 MNPs), coating of silica on Fe3O4 MNPs (Fe3O4@SiO2) and incorporation of sulfonic acid as a functional group on the surface of Fe3O4@SiO2 nanoparticles (Fe3O4@SiO2@SO3H). The properties of the prepared magnetic nanoparticles were characterized using transmission electron microscopy, infrared spectroscopy, vibrating sample magnetometry, X‐ray diffraction and thermogravimetric analysis. Finally, the applicability of the synthesized magnetic nanoparticles was tested as a heterogeneous solid acid nanocatalyst for one‐pot synthesis of diindolyloxindole derivatives in aqueous medium. Oxindole derivatives were produced by the coupling of indole and isatin compounds with good to high yields (60–98%). Copyright © 2016 John Wiley & Sons, Ltd.

Synthesis of sulfonated carbon-based solid acid as a novel and efficient nanocatalyst for the preparation of highly functionalized piperidines and acylals: a DFT study

A novel carbon-based solid-acid nanocatalyst (Sta-SO3H) was simply prepared for the first time by the thermal treatment of sulfuric acid with starch at 180 °C in a sealed autoclave. The catalytic activities of Sta-SO3H as an efficient and reusable catalyst were investigated by the condensation reaction of aldehyde, amine and β-keto ester for the synthesis of functionalized piperidines under solvent-free conditions at room temperature in good to high yields. Density functional theory calculations were used to study the structure of methyl 1,2,6-triphenyl-4-(phenylamino)-1,2,5,6-tetrahydropyridine-3-carboxylate (MPPC) as well as the thermochemistry of the multicomponent reaction. The theoretically calculated infrared and 1H nuclear magnetic resonance spectra of MPPC were compared to the experimental data. It was found that the synthesis of MPPC is exothermic accompanied by a decrease in entropy, internal energy and Gibbs free energy of reaction. Good consistency between the calculated and observed spectral data was found. Also, Sta-SO3H has been developed for the synthesis of acylals (1,1-diacetate) in high yields through the reaction of aldehydes with acetic anhydride at room temperature under solvent-free conditions. The mild conditions, eco-friendliness, excellent yields, short reaction times and use of an inexpensive and reusable catalyst are important features of this method.

A highly efficient magnetic solid acid nanocatalyst for the synthesis of new bulky heterocyclic compounds

Fe3O4nanoparticles were coated with 3-aminopropyltriethoxysilane and further chemically modified with maleic anhydride to generate Fe3O4@APTES·MAH NPs. Then some new bulky heterocyclic compounds were synthesized using this catalyst.

A new type of SO3H-functionalized magnetic-titania as a robust magnetically-recoverable solid acid nanocatalyst for multi-component reactions

This paper highlights a novel synthetic strategy for the preparation of robust and magnetically-recoverable solid acid nanocatalysts.

Sulfamic acid-functionalized nano-titanium dioxide as an efficient, mild and highly recyclable solid acid nanocatalyst for chemoselective oxidation of sulfides and thiols

A highly efficient and retrievable titanium dioxide-based nanocatalyst has been synthesized by covalent grafting of chlorosulfonic acid on amine-functionalized titania as a novel inorganic–organic hybrid heterogeneous nanocatalyst, which was characterized by Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The acid strength of the catalyst was determined by pH analysis and the Hammett acidity function. The potential of the resultant nanocatalyst was effectively evaluated for the chemoselective oxidation of sulfides to sulfoxides and thiols to disulfides using 30% H2O2 as an oxidant at room temperature under solvent-free conditions, which led to high conversion rates and yields. Optimization of the reaction conditions was studied by central composite design (CCD), which is one of the most widely used response surface methodologies. The catalyst can be easily recycled up to 10 times without significant decrease in catalytic activity, which makes it a promising catalyst for practical and large-scale applications. This work is the first report that uses 2,4-toluene diisocyanate as a linker for immobilizing liquid acid on a support.

Nano-zirconia as an excellent nano support for immobilization of sulfonic acid: a new, efficient and highly recyclable heterogeneous solid acid nanocatalyst for multicomponent reactions

Nano-zirconia-supported sulfonic acid as a novel, highly efficient and recyclable heterogeneous nanocatalyst is reported for the synthesis of multicomponent reactions.

A waste to wealth approach through utilization of nano-ceramic tile waste as an accessible and inexpensive solid support to produce a heterogeneous solid acid nanocatalyst: to kill three birds with one stone

Waste minimization through the utilization of cost-effective, available, and nontoxic nano-ceramic tile wastes for the heterogenization of sulfuric acid.

PEG-SANM nanocomposite: a new catalytic application towards clean and highly efficient Biginelli-like reaction under solvent-free conditions

The poly (ethylene glycol)-sulfonated sodium montmorillonite (PEG-SANM) nanocomposite with various ratios was prepared and used as a highly efficient and reusable solid acid nanocatalyst for synthesis of pyrimidinone derivatives under solvent-free conditions.

A convenient, simple and one-pot synthesis of dibenzoxanthenes and tetrahydrobenzoxanthenes by nanotitania-supported sulfonic acid as an efficient and highly reusable nanocatalyst

Nanotitania-supported sulfonic acid (n-TSA) as a highly powerful solid acid nanocatalyst has been successfully applied for the rapid and green synthesis of dibenzoxanthenes and tetrahydrobenzoxanthenes via one-pot condensation–cyclization reactions of aldehydes with β-naphthol, on the other hand with β-naphthol and 1,3-cyclic diketones. The ease of preparation and handling of the catalyst, operational simplicity, short reaction time, mild reaction conditions, and environmentally benign conditions are the main advantages of these protocols, which led to high yields of products, 70–96 % for dibenzoxanthenes and 65–98 % for tetrahydrobenzoxanthenes. Furthermore, the catalyst could be recycled after a simple work-up, and reused at least five times without substantial reduction in its catalytic activity, confirming the stability of the covalent bonding of acidic centers.

Efficient N-Boc protection of amines by a reusable heterogeneous solid acid nanocatalyst at room temperature

An efficient and rapid protocol for chemoselective N-Boc protection of various structurally different aryl, aliphatic, and heterocyclic amines is reported with (Boc)2O using mesoporous silica phenylsulfonic acid (SBA-15-Ph-SO3H) as a recyclable and heterogeneous solid acid nanocatalyst under solvent-free condition at ambient temperature. The catalyst can be easily recovered and reused for ten reaction cycles for protection of amines without considerable loss of activity. The advantages of this green method are simplicity, easy workup, chemoselectivity, short reaction time, and excellent yield.

Sulfonic acid-functionalized ordered nanoporous Na+-montmorillonite (SANM) as an efficient and recyclable catalyst for the tetrahydropyranylation and detetrahydropyranylation of alcohols and phenols

Sulfonic acid-functionalized ordered nanoporous Na+-montmorillonite, as a newly reported solid acid nanocatalyst, was efficiently used for the tetrahydropyranylation and detetrahydropyranylation of alcohols and phenols. All reactions were performed at room temperature in high to excellent yields. Ease of preparation and handling of the catalyst, heterogeneous reaction conditions, easy work-up of the products, high reaction rates and reusability of the catalyst are the main advantages of this method.

An efficient and one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles catalyzed via solid acid nano-catalyst

A simple highly versatile and efficient synthesis of 2,4,5-trisubstituted imidazoles is achieved by three component cyclocondensation of 1,2-dicarbonyl compounds, aldehydes and NH4OAc, as ammonia source using clays, zeolite, nano-crystalline sulfated zirconia (SZ) as catalyst in ethanol at moderate temperature. Moreover, the utility of this protocol was further explored conveniently for the one-pot, four component synthesis of 1,2,4,5-tetrasubstituted imidazoles in high yields, short reaction times and milder conditions, easy work-up and purification of products by non-chromatographic methods. The catalysts can be recovered for the subsequent reactions and reused without any appreciable loss of their efficiency.

A mild and highly efficient Friedländer synthesis of quinolines in the presence of heterogeneous solid acid nano-catalyst

A simple highly versatile and efficient synthesis of various poly-substituted quinolines in the Friedländer condensation of 2-aminoarylketones with carbonyl compounds and β-keto esters using Montmorrilonite K-10, zeolite, nano-crystalline sulfated zirconia (SZ) as a catalyst in ethanol at moderate temperature. The advantages of methods are short reaction times and milder conditions, easy work-up and purification of products by non-chromatographic methods. The catalysts can be recovered for the subsequent reactions and reused without any appreciable loss of efficiency.