Novel uric acid-based nano organocatalyst with phosphorous acid tags: Application for synthesis of new biologically-interest pyridines with indole moieties via a cooperative vinylogous anomeric based oxidation

Design, synthesis and application of a magnetic H-bond catalyst in the preparation of new nicotinonitriles via cooperative vinylogous anomeric-based oxidation

Herein, we designed and synthesized a new H-bond magnetic catalyst with 2-tosyl-N-(3-(triethoxysilyl)propyl)hydrazine-1-carboxamide as a sensitive H-bond donor/acceptor. We created an organic structure with a urea moiety on the magnetic nanoparticles, which can function as a hydrogen bond catalyst. Hydrogen bond catalysts serve as multi-donor/-acceptor sites. Additionally, we utilized magnetic nanoparticles in the production of the target catalyst, giving it the ability to be recycled and easily separated from the reaction medium with an external magnet. We evaluated the catalytic application of Fe3O4@SiO2@tosyl-carboxamide as a new magnetic H-bond catalyst in the synthesis of new nicotinonitrile compounds through a multicomponent reaction under solvent-free and green conditions with high yields (50-73%). We confirmed the structure of Fe3O4@SiO2@tosyl-carboxamide using various techniques. In addition, the structures of the desired nicotinonitriles were confirmed using melting point, 1H-NMR, 13C-NMR and HR-mass spectrometry analysis. The final step of the reaction mechanism was preceded via cooperative vinylogous anomeric-based oxidation (CVABO).

Application of Functionalized Zn-Based Metal-Organic Frameworks (Zn-MOFs) with CuO in Heterocycle Synthesis via Azide-Alkyne Cycloaddition

The main goal of this article is to discuss the expansion of click chemistry. A new catalyst composed of CuO nanoparticles embedded in Zn-MOF with the ligand 2,4,6-tris(4-carboxyphenoxy)-1,3,5-triazine (H3L) is presented. The incorporation of CuO nanoparticles into the Zn-MOF structure led to desirable morphology and catalytic properties. The designed catalyst was evaluated for its catalytic role in the multicomponent reaction and copper-catalyzed azide-alkyne cycloaddition (CuAAC) for preparation of triazole rings with 80-91% yield. The catalyst demonstrated an appealing architecture and exhibited robustness, high efficiency, and environmental friendliness. Characterization of the catalyst was performed using various techniques, including Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopes (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), elemental mapping, and X-ray diffraction (XRD). The results suggest that this novel catalyst has the potential to be a valuable tool in the development of new synthetic approaches for a wide range of applications.

Synthesis of picolinates via a cooperative vinylogous anomeric-based oxidation using UiO-66(Zr)-N(CH2PO3H2)2 as a catalyst

The anomeric effect highlights the significant influence of the functional group and reaction conditions on oxidation-reduction. This article successfully investigates the anomeric effect in the synthesis of picolinate and picolinic acid derivatives through a multi-component reaction involving 2-oxopropanoic acid or ethyl 2-oxopropanoate, ammonium acetate, malononitrile, and various aldehydes. To facilitate this process, we employed UiO-66(Zr)-N(CH₂PO₃H₂)₂ as a novel nanoporous heterogeneous catalyst. The inclusion of phosphorous acid tags on the UiO-66(Zr)-N(CH₂PO₃H₂)₂ offers the potential for synthesizing picolinates at ambient temperature.

Catalytic Application of Functionalized Bimetallic-Organic Frameworks with Phosphorous Acid Tags in the Synthesis of Pyrazolo[4,3-e]pyridines

Combining two different metals for the synthesis of a metal-organic framework (MOF) is a smart strategy for the architecture of new porous materials. Herein, a bimetal-organic framework (bimetal-MOFs) based on Fe and Co metals was synthesized. Then, phosphorous acid tags were decorated on bimetal-MOFs via a postmodification method as a new porous acidic functionalized catalyst. This catalyst was used for the synthesis of pyrazolo[4,3-e]pyridine derivatives as suitable drug candidates. The present study provides new insights into the architecture of novel porous heterogeneous catalysts based on a bimetal-organic framework (bimetal-MOFs). The type of final structures of catalyst and pyrazolo[4,3-e]pyridine derivatives were determined using different techniques such as fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), SEM-elemental mapping, N₂ adsorption-desorption isotherm, Barrett-Joyner-Halenda (BJH), thermogravimetry/differential thermal analysis (TG/DTA), ¹H NMR, and ¹³C NMR.

Chemistry of 3-cyanoacetyl indoles: synthesis, reactions and applications: a recent update

Indole is a significant nitrogen-based heterocycle with particular importance in the synthesis of heterocyclic scaffolds. Indole based compounds have been recently attracting much attention due to their biological and pharmaceutical activities. 3-Substituted indoles such as cyanoacetyl indoles (CAIs) are nitrogen-heterocyclic compounds which are easily obtained from the reaction of indoles and cyanoacetic acid. They are versatile starting materials utilized for the construction of a wide variety of molecules containing indole moieties in organic synthesis. In this study, we provide an overview on the synthesis of 3-cyanoacetyl indoles (CAIs) and their recent applications in the multi-component reactions for the synthesis of various heterocyclic compounds such as pyranes, pyridines, dihydropyridines, pyrimidines, tetrahydropyrimidines, pyrazoles, pyrazolopyridines, pyrazolopyrimidines, pyridopyrimidines, tetrazolopyrimidines, triazolopyrimidines, furans, dihydrofurans, coumarins, pyrimido naphthyridines, chromenes, thiazoles, pyrimidoindazoles, pyrazoloquinolines, isoxazolopyridines, and carbazoles and their biological activities during the period of 2013 to 2022.

Application of Zr-MOFs based copper complex in synthesis of pyrazolo[3, 4-b]pyridine-5-carbonitriles via anomeric-based oxidation

In this research article, Zr-MOFs based copper complex as a novel heterogeneous and porous catalyst was designed and prepared. The structure of catalyst has verified by various techniques such as FT-IR, XRD, SEM, N₂ adsorption-desorption isotherms (BET), EDS, SEM-elemental mapping, TG and DTG analysis. UiO-66-NH₂/TCT/2-amino-Py@Cu(OAc)₂ was used as an efficient catalyst in the synthesis of pyrazolo[3,4-b]pyridine-5-carbonitrile derivatives. The aromatization of titled molecules is performed via a cooperative vinylogous anomeric-based oxidation both under air and inert atmospheres. The unique properties of the presented method are short reaction time, high yield, reusability of catalyst, synthesis of desired product under mild and green condition.

Application of Metal-Organic Frameworks with Sulfonic Acid Tags in the Synthesis of Pyrazolo[3,4-b]pyridines via a Cooperative Vinylogous Anomeric-Based Oxidation

Herein, we report the design and synthesis of Co-MOF-71/imidazole/SO₃H as a novel porous catalyst with sulfonic acid tags. The structure and morphology of the catalyst were investigated using various techniques such as Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction, scanning electron microscopy (SEM), SEM elemental mapping, energy-dispersive X-ray spectroscopy, Barret-Joyner-Halenda, and N₂ adsorption-desorption isotherms. Co-MOF-71/imidazole/SO₃H was studied in the preparation of novel pyrazolo[3,4-b]pyridines under mild and green conditions via a cooperative vinylogous anomeric-based oxidation. A wide range of mono and bis pyrazolo[3,4-b]pyridines were synthesized with good to excellent yields (65-82%). A hot filtration test for the heterogeneous nature of the catalyst indicated the high stability of the prepared catalyst. The recyclability of Co-MOF-71/imidazole/SO₃H is another advantage of the present methodology. The structures of the final products were confirmed using FT-IR, ¹H-NMR, and ¹³C-NMR spectroscopic techniques.

Application of Nanomagnetic Metal-Organic Frameworks in the Green Synthesis of Nicotinonitriles via Cooperative Vinylogous Anomeric-Based Oxidation

In the current study, we synthesized a new nanomagnetic metal-organic framework Fe₃O₄@MIL-53(Al)-N(CH₂PO₃)₂ and characterized it using various techniques. This nanomagnetic metal-organic framework was used for the synthesis of a wide range of nicotinonitrile derivatives as suitable drug candidates by a four-component reaction of 3-oxo-3-phenylpropanenitrile or 3-(4-chlorophenyl)-3-oxopropanenitrile, ammonium acetate (NH₄OAc), acetophenone derivatives, and various aldehydes including those bearing electron-donating, electron-withdrawing, and halogen groups, which afforded desired products (27 samples) via a cooperative vinylogous anomeric-based oxidation (CVABO) mechanism under solvent-free conditions in excellent yields (68-90%) and short reaction times (40-60 min). Increasing the surface-to-volume ratio, easy separation of the catalyst using an external magnet, and high chemical and temperature stability are the advantages of the described nanomagnetic metal-organic frameworks.

Phosphonic acid tagged carbon quantum dots encapsulated in SBA-15 as a novel catalyst for the preparation of N-heterocycles with pyrazolo, barbituric acid and indole moieties

Herein, we have presented a new insight for the synthesis of a hybrid heterogeneous catalyst. For this purpose, phosphonic acid tagged carbon quantum dots of CQDs-N(CH₂PO₃H₂)₂ encapsulated and assembled in channels of SBA-15 using a post-modification strategy. The mesoporous catalyst of functionalized carbon quantum dots (CQDs) was characterized by several techniques. CQDs-N(CH₂PO₃H₂)₂/SBA-15 as an excellent catalyst was applied for the preparation of novel pyrazolo[4',3':5,6]pyrido[2,3-d]pyrimidine derivatives by using pyrazole, barbituric acid and indole moieties at 100 °C under the solvent-free condition. The present work shows that a significant increase in the catalytic activity can be achieved by a rational design of mesoporous SBA-15 modified with CQDs for the synthesis of biological active candidates. The synthesized compounds did not convert to their corresponding pyridines via an anomeric-based oxidation mechanism.

Catalytic synthesis of new pyrazolo [3,4-b] pyridine via a cooperative vinylogous anomeric-based oxidation

In this study, a novel nano-magnetic metal–organic frameworks based on Fe3O4 namely Fe3O4@MIL-101(Cr)-N(CH2PO3)2 was synthesized and fully characterized. The prepared sample was used as catalyst in the synthesis of pyrazolo [3,4-b] pyridines as convenient medicine by condensation reaction of aldehydes, 5-(1H-Indol-3-yl)- 2H-pyrazol-3-ylamine and 3-(cyanoacetyl)indole via a CVABO. The products were obtained with high yields at 100 °C and under solvent-free conditions.

Application of novel metal-organic framework [Zr-UiO-66-PDC-SO3H]FeCl4 in the synthesis of dihydrobenzo[g]pyrimido[4,5-b]quinoline derivatives

In the current paper, we produce a new metal-organic framework (MOF) based on Zr metal, [Zr-UiO-66-PDC-SO₃H]FeCl₄, via an anion exchange method, which is fully characterized by FT-IR, SEM with elemental mapping and EDX, FE-SEM and TEM. Furthermore, the use of [Zr-UiO-66-PDC-SO₃H]FeCl₄ as a porous catalyst was examined for the one-pot synthesis of novel dihydrobenzo[g]pyrimido[4,5-b]quinoline derivatives by reaction of 6-amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione, 2-hydroxynaphthalene-1,4-dione and various aldehydes at 100 °C with good to excellent yields.

Applications of novel composite UiO-66-NH2/Melamine with phosphorous acid tags as a porous and efficient catalyst for the preparation of novel spiro-oxindoles

A new approach for the incorporation of phosphorous acid tags into a metal organic framework based on UiO-66-NH2/Melamine was introduced. This new catalyst was applied to the preparation of novel spiro-oxindoles under mild and green conditions.

Novel nano-architectured carbon quantum dots (CQDs) with phosphorous acid tags as an efficient catalyst for the synthesis of multisubstituted 4H-pyran with indole moieties under mild conditions

In this work, a new nano-structured catalyst with phosphorus acid moieties, synthesized by the reaction of carbon quantum dots (CQDs) and phosphorus acid under refluxing EtOH. The structure and morphology of CQDs–N(CH₂PO₃H₂)₂ were fully characterized using various techniques such as Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, thermogravimetric (TG) analysis, fluorescence and X-ray diffraction (XRD) measurements. The new CQDs–N(CH₂PO₃H₂)₂ catalyst was successfully used for the synthesis of 2-amino-6-(2-methyl-1H-indol-3-yl)-4-phenyl-4H-pyran-3,5-dicarbonitriles by the one-pot reaction of various aromatic aldehydes, 3-(1H-indol-3-yl)-3-oxopropanenitrile derivatives and malononitrile in refluxing EtOH and/or ultrasonic irradiation conditions.

A new nano-structured catalyst with phosphorus acid moieties, synthesized by the reaction of carbon quantum dots (CQDs) and phosphorus acid under refluxing EtOH.