Ti-based MOFs with acetic acid pendings as an efficient catalyst in the preparation of new spiropyrans with biological moieties

The strategy of designing heterogeneous porous catalysts by a post-modification method is a smart strategy to increase the catalytic power of desired catalysts. Accordingly, in this report, metal-organic frameworks based on titanium with acetic acid pending were designed and synthesized via post-modification method. The structure of the target catalyst has been investigated using different techniques such as FT-IR, XRD, SEM, EDX, Mapping, and N2 adsorption/desorption (BET/the BJH) the correctness of its formation has been proven. The catalytic application of Ti-based MOFs functionalized with acetic acid was evaluated in the preparation of new spiropyrans, and the obtained results show that the catalytic performance is improved by this modification. The strategy of designing heterogeneous porous catalysts through post-modification methods presents a sophisticated approach to enhancing the catalytic efficacy of desired catalysts. In this context, our study focuses on the synthesis and characterization of metal-organic frameworks (MOFs) based on titanium, functionalized with acetic acid pendants, using a post-modification method. Various characterization techniques, including Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), mapping, and N2 adsorption/desorption (BET/BJH), were employed to investigate the structure and composition of the synthesized catalyst. These techniques collectively confirmed the successful formation and structural integrity of the target catalyst. The structure of the synthesized products was confirmed by melting point, 1H-NMR and 13C-NMR and FT-IR techniques. Examining the general process of catalyst synthesis and its catalytic application shows that the mentioned modification is very useful for catalytic purposes. The presented catalyst was used in synthesis of a wide range of biologically active spiropyrans with good yields. The simultaneous presence of several biologically active cores in the synthesized products will highlight the biological properties of these compounds. The present study offers a promising insight into the rational design, synthesis, and application of task-specific porous catalysts, particularly in the context of synthesizing biologically active candidate molecules.

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).

Synthesis and Application of Task-Specific Bimetal-Organic Frameworks in the Synthesis of Biological Active Spiro-Oxindoles

The use of click chemistry as a smart and suitable method for the development of new heterogeneous catalysts is based on metal-organic frameworks as well as the production of organic compounds. The development of the click chemistry method can provide a new strategy to achieve superior properties of MOFs. Here, the two metals Co and Fe are used to create a bimetallic-organic framework. In the following, the click chemistry and postmodification method are well organized and an acidic heterogeneous porous catalyst is developed. This prepared catalyst was used as a highly efficient catalyst for the preparation of new spiro-oxindoles obtained through click chemistry with good to excellent yields (80-94%). This presented catalytic system can compete with the best reported catalytic systems. The findings showed that the presence of Co and Fe metals in the MOF, and the presence of the triazole ring on the catalyst, can increase the catalytic efficiencies. This study offers novel insights into the architecture of Metal-Organic Frameworks (MOFs), click chemistry, and biologically active compounds. Additionally, the research explores the antibacterial properties of the synthesized spiro-oxindoles and catalysts. The findings reveal significant antibacterial activities of the synthesized compounds against S. aureus, MRSA, and E. coli bacteria.

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.

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.

A convenient catalytic method for preparation of new tetrahydropyrido[2,3-d]pyrimidines via a cooperative vinylogous anomeric based oxidation

In this study, a novel functionalized metal-organic frameworks MIL-125(Ti)-N(CH₂PO₃H₂)₂ was designed and synthesized via post-modification methodology. Then, MIL-125(Ti)-N(CH₂PO₃H₂)₂ as a mesoporous catalyst was applied for the synthesis of a wide range of novel tetrahydropyrido[2,3-d]pyrimidines as bioactive candidate compounds by one-pot condensation reaction of 3-(1-methyl-1H-pyrrol-2-yl)-3-oxopropanenitrile, 6-amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione and aromatic aldehydes at 100 °C under solvent-free condition. Interestingly, the preparation of tetrahydropyrido[2,3-d]pyrimidine was achieved via vinylogous anomeric based oxidation mechanism with a high yield and short reaction time.