Heteropoly-12-tungstophosphoric acid H3[PW12O40] over natural bentonite as a heterogeneous catalyst for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones

Synthesis and characterization of bentonite-based NiO nanoparticles as bi-functional heterogeneous catalyst for efficient synthesis of 1,8-dioxo-decahydroacridines

A straightforward, expeditious, robust, and efficient synthesis of NiO@Bentonite nanocatalyst was done using a simple microwave method. The X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET), thermal behavior analysis, and vibrating sample magnetometer (VSM) techniques were used to characterize the physicochemical properties of the NiO@Bentonite nanocomposites. The outcomes demonstrated that the NiO nanoparticles are evenly distributed throughout the Bentonite surface and that the NiO@Bentonite nanocomposites have a high specific surface area and rich pore structure. The following report details the investigation of this catalyst for the preparation of 1, 8-dioxodecahydroacridine heterocycles in a one-pot, three-component reaction of aromatic aldehydes, dimedone, and aniline. After the conditions were optimized, the results demonstrated that this reaction could be carried out in an aqueous medium with a good yield.

Halogenated dicyanobenzene-based photosensitizer (3DPAFIPN) as a thermally activated delayed fluorescence (TADF) used in gram-scale photosynthesis 3,4-dihydropyrimidin-2-(1H)-one/thione derivatives via a consecutive visible-light-induced electron-transfer pathway

Background: Organic dyes often have shorter lifetimes in the excited state, which is a major obstacle to the development of effective photoredox methods. The scientific community has shown a great deal of interest in a certain class of organic chromophores because of their unique characteristics and effectiveness. One characteristic of the molecules under research is thermally activated delayed fluorescence (TADF), which is only observed in molecules with a tiny energy gap (often less than 0.2 eV) between their lowest two excited states, i.e., singlet excited state (S1) and triplet excited state (T1). The extended singlet excited states arising from TADF and the simplicity with which their redox potentials may be altered make the isophthalonitrile family of chromophores an attractive option for organic photocatalyst applications. Methods: The Biginelli reaction between β-ketoesters, arylaldehydes, and urea/thiourea has been used to build a sustainable technique for the production of 3,4-dihydropyrimidin-2-(1H)-one/thione derivatives. In the present study, the development of a green radical synthesis approach for this class of compounds is addressed in depth. As a photocatalyst, a new halogenated dicyanobenzene-based photosensitizer was employed in this study. As a renewable energy source activated by a blue LED, it was dissolved in ethanol, at room temperature in air atmosphere. The primary objective of this research is to employ a novel donor-acceptor (D-A) based on halogenated cyanoarene that is affordable, easily available, and innovative. Findings: The 3DPAFIPN [2,4,6-tris(diphenylamino)-5-fluoroisophthalonitrile] photocatalyst, a thermally activated delayed fluorescence (TADF), induces single-electron transfer (SET) in response to visible light, offering a straightforward, eco-friendly, and highly efficient process. Additionally, we determined the 3,4-dihydropyrimidin-2-(1H)-one/thione derivatives turnover frequency (TOF) and turnover number (TON). It has also been demonstrated that gram-scale cyclization is a workable method for industrial purposes.

Clay based heterogeneous catalysts for carbon-nitrogen bond formation: a review

Clay and modified clay-based catalysts are widely used in organic transformation. Owing to the interlayer ions and good ion exchange capacity of clay, replacement with another ion and incorporation of different nanomaterials can be done. Due to these significant properties of clay, it can be utilized in the synthesis of various organic compounds. Carbon-nitrogen bonded compounds possess diverse applications in different fields. These compounds are prepared using different solid acid heterogeneous catalysts. This review presents a detailed discussion on clay used for the carbon-nitrogen bond formation reaction, such as the Biginelli reaction and A3 and KA2 coupling reactions. Additionally, other C-N bond formation reactions using various clay-based catalysts such as bentonite, montmorillonite, hydrotalcite and halloysite clay with various metals, metal oxides, Kegging type heteropoly acid and various nanomaterial incorporated clay heterogeneous catalysts are discussed.

Recyclable photocatalyst perovskite as a single-electron redox mediator for visible-light-driven photocatalysis gram-scale synthesis of 3,4-dihydropyrimidin-2-(1H)-ones/thiones in air atmosphere

Based on the Biginelli reaction of β-ketoesters, arylaldehydes, and urea/thiourea, we created a green radical synthesis procedure for 3,4-dihydropyrimidin-2-(1H)-ones/thiones. A single-electron redox mediator was applied to a solution of ethanol in an air environment, at room temperature, and with blue LEDs as a renewable energy source in order to create. The objective of this research is to create a halide perovskite that is widely available, affordable, recyclable, and economically feasible. A factor mentioned in the discussion is that the procedure tolerates a variety of donating and withdrawing functional groups while still offering a very fast rate and excellent yields. The range of yields is quite uniform (86-94%, average: 90.4%), and the range of reaction times is very quick (4-8 min, average: 5.8 min). Furthermore, gram-scale cyclization shows that it is applicable for use in industry. Additionally, CsPbBr₃ is quite stable and can be used six times in a row without experiencing significant structural changes or activity loss, which has been extremely helpful in meeting industrial needs and environmental issues.

Carbazole-based photocatalyst (4CzIPN) for novel donor-acceptor (D-A) fluorophore-catalyzed visible-light-induced photosynthesis of 3,4-dihydropyrimidin-2-(1H)-ones/thiones via a proton-coupled electron transfer (PCET) process

Based on the Biginelli reaction of β-ketoesters, arylaldehydes, and urea/thiourea, we created a green radical synthesis procedure for 3,4-dihydropyrimidin-2-(1H)-ones/thiones. A PCET (proton-coupled electron transfer) photocatalyst was used in an ethanol solution in an air environment and at room temperature and visible light to provide a renewable energy source. In this study, we seek to create a novel donor-acceptor (D-A) fluorophore that is affordable and widely available. The carbazole-based photocatalyst (4CzIPN), in addition to its time-saving capabilities and simplicity of use, exhibits excellent yields, is energy-efficient, and is ecologically friendly. This makes it possible to track the evolution of environmental and chemical factors throughout time. To determine the turnover number (TON) and turnover frequency (TOF) of 3,4-dihydropyrimidin-2-(1H)-ones/thiones, a study was done. Gram-scale cyclization demonstrates that it may be used in industry effectively.

Mild Acidic Charcoal Catalyzed Synthesis of 3,4-dihydropyrimidin-2(1H)-one/-thione Derivatives

A green and efficient method for the multicomponent synthesis of 3,4-dihydropyrimidin-2(1H)-ones and -thiones using acetic acid supported on activated charcoal as a mild acid catalyst in ethanol under both conventional as well as microwave irradiation conditions has been developed. The catalyst system found more efficient under microwave irradiation conditions than conventional conditions with shorter reaction times and excellent yields.

Visible-Light-Induced Radical Condensation Cyclization to Synthesize 3,4-Dihydropyrimidin-2-(1H)-ones/thiones Using Photoexcited Na2 Eosin Y as a Direct Hydrogen Atom Transfer (HAT) Catalyst

The data suggests that Na2 eosin Y-derived photoinduced states act as a HAT catalyst for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones/thiones in ethanol at room temperature. This research establishes a novel function for using a nonmetallic natural dye, Na2 eosin Y, available commercially and at a cheap cost in the photochemical synthesis using the least amount of catalyst, obtaining good results, speeding up the process, and achieving a high atom economy. The TON and TOF of 3,4-dihydropyrimidin-2-(1H)-ones/thiones are computed. Furthermore, this cycle runs on the gram scale as well, indicating the possibility of industrial purposes.

Waste-to-wealth transition: application of natural waste materials as sustainable catalysts in multicomponent reactions

Application of natural waste materials as sustainable catalysts in multicomponent reactions.