Catalyst For Synthesis Of Pyrano Research Articles

Glucose-Decorated Silica-Molybdate Complex: A Novel Catalyst for Facile Synthesis of Pyrano[2,3-d]-Pyrimidine Derivatives.

This article describes the preparation and identification of SiO2@Glu/Si(OEt)2(CH2)3N=Mo[Mo5O18] as a new bifunctional acid-base catalyst (both acidic and basic Lewis sites). Aminopropyltriethoxysilane was first reacted with hexamolybdate anions and then treated with glucose to prepare Glu/Si(OEt)2(CH2)3N=Mo[Mo5O18]. Nano-silica was then modified by the prepared glucose/molybdate complex to obtain SiO2@Glu/Si(OEt)2(CH2)3N=Mo[Mo5O18]. The developed catalyst was characterized by FT-IR, EDX, XRD, FE-SEM and TGA analyzes. Its catalytic efficiency was investigated for the preparation of pyrano[2,3-d]pyrimidine derivatives by the reaction between various aldehydes, malononitrile and barbituric acid. The desired products were prepared in the presence of 0.004 g of the prepared catalyst in high to excellent yields.

Urea chelated autocombused synthesis of BiFeO3 nanoparticles: application as magnetically retriable heterogeneous catalyst for synthesis of pyrano[2,3-c] pyrazoles

Herein, BiFeO3 nanoparticles are successfully established as promising catalyst of heterogeneous nature for one pot production of pyrano[2,3-c] pyrazoles. The desired BiFeO3 nanoparticles were synthesized using a facile auto combustion route in the presence of urea as a fuel. Further, the production was carried out at diverse range of temperatures of calcination (150 °C–650 °C), in order to determine the optimal temperature required for development of pure, BiFeO3 nanoparticles. Each of the prepared, BiFeO3 nanoparticles were fully characterized using XRD, FT-IR, VSM, TEM and BET. The catalytic performance of as BiFeO3 nanoparticles was then investigated for the creation of pyrano[2,3-c] pyrazoles.

Ultrasound assisted synthesis of pyrano[3,2-b]pyran and 7-tosyl-4,7-dihydropyrano[2,3-e]indole scaffolds using barium titanate nanoparticles

Barium titanate nanoparticles (BaTiO3 NPs) were synthesized under sonochemical conditions. The synthesized BaTiO3 NPs was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry analysis (TGA), Brunauer–Emmett–Teller (BET), Field emission scanning electron microscopy (FE-SEM) and Transmission electron microscopy (TEM). Morphological study reveals that BaTiO3 NPs have spherical shape with particle size ranging between of 60 and 80 nm. BaTiO3 NPs were further utilized as an efficient and reusable heterogeneous catalyst for ultrasound assisted synthesis of pyrano[3,2-b]pyran. In addition, novel 7-tosyl-4,7-dihydropyrano[2,3-e]indole derivatives were also synthesized using ultrasonication. This new catalytic method displays several notable features such as simplicity, short reaction time, easy work up, easy purification, increased yield and green reaction conditions. The nanocatalyst was reusable up to five runs with marginal loss in its catalytic activity.

18-C-6H3O+]: an in-situ generated macrocyclic complex and an efficient, novel catalyst for synthesis of pyrano[2,3-c]pyrazole derivatives

Synthesis of small aromatic heterocycles is of greater importance in the organic chemistry due to their vibrant applications in pharmaceuticals, agrochemicals and veterinary products. Pyranopyrazoles are one such class of heterocycles associated with numerous applications. Hence herein we report a multicomponent crown ether catalyzed, ultrasound irradiated methodology to make different functionalized pyranopyrazoles in a single step. This technique involves the in-situ generation of [18-C-6H3O+][OH−] complex, which in turn activates the aromatic aldehyde and aids in the facile nucleophilic addition.

Fe3O4/GO@melamine-ZnO nanocomposite: A promising versatile tool for organic catalysis and electrical capacitance

Herein, an efficient versatile nanocomposite constructed of melamine-functionalized graphene oxide nano-sheets (GO@melamine), iron oxide nanoparticles (Fe3O4 NPs), and zinc oxide (ZnO NPs) is presented. Moreover, two different applications have been studied for the prepared Fe3O4/GO@melamine-ZnO nanocomposite: First, as a heterogeneous catalyst for synthesis of pyrano[2,3-c]pyrazole derivatives in short reaction time (10 min) with high yields (96 %), second, as a substantial electrical supercapacitor with typical capacitive behavior, high resistance, and excellent electrode stability. From the catalytic aspect, high effectiveness, convenient isolation, and significant reusability could be referred as the distinguished properties for the produced nanocomposite. Turn-over number (TON) and turn-over frequency (TOF) values for the presented catalytic system have been estimated 17.2 × 106 and 1.71 × 106 min−1, respectively, which revealed high catalytic performance of this catalytic system. From electrochemical aspect, economic benefits for fabrication of the introduced nanocomposite containing low-cost materials, make it as a suitable electrical supercapacitor for industrial applications.

Nano-cell-OBF2: an efficient and cheap catalyst for one-pot synthesis of pyrano[4,3-b]pyrans under mild and green condition

Newly synthesized nano-cell-OBF2 catalyst was produced via boron trifluoride as lewis acid and nano cellulose as substrate. The obtained novel nanostructure has been assessed using Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FE-SEM), and Energy dispersive X-ray spectroscopy (EDX) techniques. In addition, the decomposition steps and thermal stability of the nano-cellulose and nano-cell-OBF2 were investigated by thermal analysis techniques (TGA/DTG). The activity of solid acid catalyst has been effectively inspected in a one-pot, three-component condensation reaction of aromatic aldehydes, 4-hydroxy-6-methyl-2H-pyran-2-one and malononitrile under mild reaction conditions to afford pyrano [4,3-b] pyran derivatives in good to excellent yields.

TiCl4/nano Sawdust as a Biocatalyst for the Synthesis of Ethyl 2-Amino-5-Oxo-4H,5H-Pyrano[4,3-b]Pyran-3-Carboxylates

TiCl4/nano sawdust has been prepared from nano sawdust and TiCl4 in chloroform as solvent. Then TiCl4/nano sawdust has been applied as a catalyst for synthesis of pyrano [4,3-b] pyrans from the simple one-pot reaction between aryl aldehydes, ethyl 2-cyanoacetate and 4-hydroxy-6-methyl-2H-pyran-2-one. Cleanliness, good to excellent yields of products, simple methodology, and an eco-friendly catalyst are some advantages of this method.

Formamidinesulfinic Acid‐Functionalized Fe3O4@SiO2 as a Green and Magnetic Recyclable Catalyst for Synthesis of Pyrano[2, 3‐d] pyrimidinone Derivatives

AbstractFormamidine sulfonic acid (FSA) stabilized on silica‐coated Fe3O4 magnetic nanoparticles as an efficient and hydrogen bonding catalyst was employed for Knoevenagel condensation and synthesis of pyrano[2, 3‐d]pyrimidinone derivatives by the one‐pot three‐component condensation reaction in water at room temperature. The catalyst can be separated from the mixture reaction which is in close agreement with green chemistry disciplines.

Succinimide-N-sulfonic Acid as a Recyclable Brönsted Acid Catalyst for Synthesis of Pyrano[4,3-b]pyran Derivatives by Using Solar Energy Under Solvent-Free Conditions

ABSTRACTSuccinimide-N-sulfonic acid as an efficient Brönsted acid catalyzed the synthesis of pyrano[4,3-b]pyrans by using solar energy as a green source of energy under solvent-free conditions. This method has the advantages of high yield, short reaction time, and clean and simple methodology. The catalyst could be recycled without significant loss of activity.

Iron Ore Pellet, A Natural and Reusable Catalyst for Synthesis of Pyrano(2,3-d)pyrimidine and Dihydropyrano(c)chromene Derivatives in Aqueous Media

We wish to report a mild and efficient one-pot three-component reaction of an aryl aldehyde, malononitrile and barbituric acid or 4-hydroxycoumarinfor the synthesis ofpyrano[2,3-d]pyrimidine and dihydropyrano[c]chromene derivatives in the presence of iron ore pellet as a natural and reusable catalyst under heterogeneous and green conditions. The present methodology offers several advantages such as excellent yields, simple procedure and work up steps, short reaction times and easy recovery of the catalyst. We have also demonstrated that the catalyst can be reused successfully after six times using the same catalyst with high yields. Use of water as the reaction medium makes the process environmentally benign.

Synthesis and characterization of pyridine-4-carboxylic acid functionalized Fe3O4 nanoparticles as a magnetic catalyst for synthesis of pyrano[3,2-b]pyranone derivatives under solvent-free conditions

Pyridine-4-carboxylic acid (PYCA) functionalized Fe3O4 nanoparticles as an organic–inorganic hybrid heterogeneous catalyst was fabricated and characterized by FT-IR, XRD, TGA, TEM, SEM, and VSM techniques. The catalytic activity of the magnetic catalyst was probed through one-pot synthesis of pyrano[3,2-b]pyranone derivatives from three component reactions of aromatic aldehydes, kojic acid, and ethyl cyanoacetate under solvent-free conditions. Some advantages of this protocol are its environmentally benign method, simple procedure, high yields, and short reaction time. The catalyst was readily separated using an external magnet and reusable without significant loss of its catalytic efficiency.

ChemInform Abstract: 4‐(Succinimido)‐1‐butane Sulfonic Acid as a Broensted Acid Catalyst for Synthesis of Pyrano[4,3‐b]pyran Derivatives under Solvent‐Free Conditions.

AbstractThe title sulfonic acid (SBSA) efficiently catalyzes the three‐component reaction of 4‐hydroxypyranone (I), aromatic aldehydes, and malonitrile furnishing pyranopyran derivatives (IV) (14 examples) in good yield, in general.

4-(Succinimido)-1-butane sulfonic acid as a Brönsted acid catalyst for synthesis of pyrano[4,3-b]pyran derivatives under solvent-free conditions

4-(Succinimido)-1-butane sulfonic acid as an efficient and reusable Brönsted acid catalyzed the synthesis of pyrano[4,3-b]pyran derivatives under solvent-free conditions. The catalyst can be prepared by mixing succinimide and 1,4-butanesultone that is more simple and safer than the preparation of succinimide sulfonic acid. This method has the advantages of high yield, clean reaction, simple methodology and short reaction time. The catalyst could be recycled without significant loss of activity.

ChemInform Abstract: Alum [KAl(SO4)2·12H2O]: A Green and Efficient Catalyst for Synthesis of Pyrano[4,3‐b]pyrans in Water under Conventional and Microwave Conditions.

One-pot synthesis of pyrano[4,3-b]pyrans by condensation of 4-hydroxy-6-methylpyran-2-one, aromatic aldehydes, and malononitrile or cyanoacetates in water using alum as a non-toxic, readily available, and reusable catalyst at 80 °C under conventional conditions and also under microwave irradiation is described.

H6P2W18O62·18H2O: A green and reusable catalyst for one-pot synthesis of pyrano[4,3-b]pyrans in water

A convenient, efficient and environmentally benign procedure has been developed for the synthesis of pyrano[4,3-b]pyran derivatives via a one-pot, three-component reaction of 4-hydroxy-6-methylpyran-2-one, aldehydes and malononitrile in water using H6P2W18O62·18H2O as catalyst. Reusability of the catalyst and reaction media, short reaction times and easy isolation of products are some added advantages of the present methodology.

Alum [KAl(SO4)2·12H2O]: a green and efficient catalyst for synthesis of pyrano[4,3-b]pyrans in water under conventional and microwave conditions

One-pot synthesis of pyrano[4,3-b]pyrans by condensation of 4-hydroxy-6-methylpyran-2-one, aromatic aldehydes, and malononitrile or cyanoacetates in water using alum as a non-toxic, readily available, and reusable catalyst at 80 °C under conventional conditions and also under microwave irradiation is described.