One-pot Three-component Reaction Research Articles

Recent Progress in Synthetic Chemistry and Biological Activities of Pyrimido[ 4,5-b] Quinoline Derivatives (Part III)

Abstract: Amongst heterocyclic compounds, quinoline and pyrimidine are advantaged scaffolds that appear as significant assembly motifs for the development of new drug entities. Moreover, quinolinepyrimidine- inspired hybrids have a number of biological characteristics that are known. In addition, many pyrimido[4,5-b]quinoline ring systems (PyQs4,5-b), specifically concerning medicinal chemistry, have been reported over the past decade. The synthesis of (PyQs4,5-b) using barbituric acid, thiobarbituric acid, pyrimidine, and their derivatives is presented in this review. The preparation of PyQs4,5-b was clarified through the following chemical reactions: Friedländer, Vilsmeier-Haack formylation, Hantzsch-like reaction, and one-pot three-component reaction.

Photocatalytic One-Pot Three-Component Reaction for the Regioselective Synthesis of Bromo-Substituted Pyrazoles.

A photocatalytic three-component cascade reaction of readily available enaminones, hydrazines, and CBr4 for the synthesis of bromo-substituted pyrazoles in one pot has been demonstrated. This strategy involves intermolecular C-N/C-Br bond formation and represents an efficient approach to the construction of 4-bromo-substituted pyrazoles with high regioselectivity, broad substrate scope, good functional group tolerance, convenient operation, and mild reaction conditions. Mechanistic investigations show that this reaction proceeds via intermolecular cyclization of enaminones with hydrazines, followed by a regioselective bromination of pyrazoles using CBr4 as a "Br" source.

Construction of pyrrolo[3,2-b]pyrrolyl-linked covalent organic polymers to promote continuous overall H2O2 production

Sacrificial agent-free, solar-driven photocatalytic oxygen reduction holds promise for hydrogen peroxide production. However, the rapid recombination of electron–hole pairs in catalysts and the slow diffusion rate of oxygen on the catalyst surfaces significantly hinder the efficiency of hydrogen peroxide production. To address these issues, we developed a novel class of pyrrolo[3,2-b]pyrrolyl-linked covalent organic polymers (COPs) combined with microreactor technology to enhance hydrogen peroxide synthesis. These structurally well-defined polymers feature photoactive pyrrolo[3,2-b]pyrrolyl units were assembled from aldehyde, aniline, and 2,3-butanedione through a one-pot three-component reaction. Integrating pyrrolo[3,2-b]pyrrolyl moieties into the COPs creates donor–acceptor structures that facilitate the separation of photogenerated electrons and holes. Among them, COP-2 achieved the highest H2O2 yield of 5446 μmol g−1 h−1. Furthermore, we designed a coiled tube photomicroreactor to improve mass transfer efficiency in the gas–liquid–solid triphase system, boosting the H2O2 yield to 20285 μmol g−1h−1 without the need for a sacrificial agent. This study offers new insights into integrating polymer photocatalysts with microflow technology, underscoring the potential for future green and continuous H2O2 production.

Synthesis of Hetaryl Substituted Pyrazolo[3,4-b]Quinolinone Systems by Multicomponent Cyclocondensation Reaction

In this study, the synthesis of pyrazolo[3,4-b]quinolinone compounds was carried out via one-pot three-component reactions. These reactions proceed as domino processes, making them easier to occur than the conventional multistep organic reactions. By employing this method, new organic molecules can be synthesized in a single step, using minimal time and number of trials. In the first phase of this two-step study, heteroaromatic carbaldehydes (quinoline-8-carboxaldehyde and quinoline-4-carboxaldehyde) were prepared to be used as substrates in subsequent reactions by oxidation of 8-methylquinoline and 4-methylquinoline with selenium dioxide, a mild oxidant. In the second step, heteroaromatic carbaldehyde reacted with aminopyrazole and dimedone in anhydrous ethanol by one-pot multicomponent condensation method to synthesize six new compounds with heteryl-substituted pyrazolo[3,4-b]quinolinone ring system. The crude products were obtained in excellent yields and further purified by crystallization. The structures of the compounds, which were found to be completely pure as a result of chromatographic studies, were elucidated by spectroscopic methods and elemental analysis.

Marine-derived magnetic nanocatalyst in sustainable ultrasound-assisted synthesis of 2,3-diphenyl-2,3-Dihydroquinazolin-4(1H)-One derivatives

This research presents a sustainable approach to fabricate iron oxide nanoparticles by employing phytochemicals derived from marine grass extract as both reducing and stabilizing agents. Formation of magnetic nanoparticles (MNPs) initially confirmed by ultraviolet–visible spectroscopy (UV–vis) showing absorption peak at 370 nm. X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques unveiled magnetic iron oxide NPs with a rod shape, an average size of 21 nm, and an inverse spinel crystal structure. The participation of organic compounds in the production and stabilization of MNPs was evidenced through Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). A vibrating sample magnetometer (VSM) demonstrated the magnetic properties of iron oxide NPs showing a saturation magnetization value of 21.46 emu/g. The catalytic efficiency of these marine-assisted MNPs was evaluated in a one-pot three-component reaction involving isatoic anhydride, aromatic aldehydes, and amines under ultrasonic conditions. Under optimal conditions, a low dose of 1.5 mg of biobased magnetite nanoparticles yielded dihydroquinazolin-4(1H)-One products with up to 95 % efficiency in a brief duration of 15 min at an ultrasonic power intensity of 130 W. Different directing groups were investigated, and control experiments were carried out to enhance the understanding of the reaction mechanism. The obtained results highlight the synergistic effect of marine grass-mediated magnetic nanocatalysts combined with ultrasonic-assisted synthesis in developing sustainable green methodologies in organic synthesis.

One-pot Three-component Synthesis of Fully and Diversely Functionalized Pyrans and Spiropyrans Using Sodium Formate as Catalyst in Aqueous Ethanol at Room Temperature

Abstract: A convenient and general method has been developed for the synthesis of fully and diversely functionalized pyrans via one-pot three-component reactions of various aryl or heteroaryl aldehydes, malononitrile, and 1,3-dimethyl/1,3-diethyl-acetonedicarboxylates in the presence of a catalytic amount of sodium formate as an efficient organocatalyst in aqueous ethanol at room temperature. All the scaffolds were synthesized in excellent yields within 2.5 hours. Under the same reaction conditions, fully and diversely functionalized spiro-pyrans were also synthesized in excellent yields from the reaction of isatin, malononitrile, and 1,3-dimethyl/1,3-diethylacetonedicarboxylates. All the products were isolated pure just by simple filtration. Synthesis of fully and diversely functionalized biologically promising pyrans, excellent yields, use of organocatalyst, less toxic solvent, no column chromatographic purification, and energy efficiency are some of the major advantages of this newly developed protocol. method: In a clean test tube a magnetic stir bar, 0.5 mmol of aldehydes (1a-1i), 0.5 mmol of malononitrile (2; 0.033 g) and 0.5 mmol of 1,3-dimethylacetonedicarboxylate (3a; 0.087 g) or 1,3-diethylacetonedicarboxylate (3b; 0.101 g), 4 ml aqueous ethanol (1:1 v/v) and 20 mol% sodium formate were taken sequentially. The whole reaction mixture was stirred at room temperature for the time mentioned in Table 2. The progress of reaction was monitored by TLC. By using the same amount of catalyst and solvent the synthesis of methyl/ethyl-2'-amino-3'-cyano-6'-(2-meth/ethoxy-2-oxoethyl)-2-oxospiro[indoline-3,4'-pyran]-5'-carboxylate (6a/6b) was achieved from the reactions of 0.5 mmol of isatin (5; 0.0735 g), 0.5 mmol of malononitrile (2; 0.033 g) and 0.5 mmol of 1,3-dimethylacetonedicarboxylate (3a; 0.0871 g) or 1,3-diethylacetonedicarboxylate (3b; 0.1011 g). After the completion of each reaction, the desired products were isolated simply by filtration and subsiquent washing with aqueous ethanol (EtOH:H2O = 1:1).

MPC@But-SO3H a mesoporous heterogeneous organocatalyst in one-pot tandem synthesis of dihydroindeno[1,2-b]pyrrole derivatives

A sustainable, metal-free, and highly efficient protocol for the synthesis of dihydroindeno[1,2-b]pyrrole derivatives via a tandem one-pot three-component reaction in aqueous medium at room temperature using an effective and reusable mesoporous heterogeneous organocatalyst, MPC@But-SO3H has been developed. MPC@But-SO3H was easily synthesized using a melamine-based covalent organic polymer and 1,4-butane sultone. The organocatalyst was well characterized by numerous spectroscopic techniques such as Fourier Transform Infrared (FTIR), Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), Powder X-ray diffraction (PXRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), elemental mapping, and Thermal Gravimetric (TG) analyses. The catalyst displayed excellent catalytic potential, high thermochemical stability, and reusability for up to eight catalytic cycles. It offered the title compounds in excellent yields (˃90%) in a short reaction time (9-14 min). The synthesized compounds were characterized through FTIR, 1H, and 13C Nuclear Magnetic Resonance (NMR), and the molecular structure of 2-(benzylamino)-3a,8b-dihydroxy-1-methyl-3-nitro-3a,8b-dihydroindeno[1,2-b]pyrrol-4(1H)-one (4a) was confirmed by the Single Crystal XRD (SC-XRD) analysis. The key features of the present protocol include the use of water as a green solvent, zero involvement of any metal, sustainable reaction conditions, easy catalyst recovery, and a simple work-up procedure. The calculations for green metrics parameters further supported the greenness and sustainability of the protocol.

One-pot three-component synthesis of 2,4-dimethoxy-5,8,9,10-tetrahydropyrimido[4,5-b]quinolinone derivatives along with in silico and in vitro investigation of their antimalarial activity

Pyrimidoquinolinone-derived compounds have exhibited a broad spectrum of biological activities and have been acknowledged as a potential antimalarial scaffold through multiple conventional strategies. In the present study, a novel series of 2,4-dimethoxy-5,8,9,10-tetrahydropyrimido[4,5-b]quinolinones 4(a-m) were synthesized via a one-pot three-component reaction of cyclohexane-1,3‑dione, 4-amino-2,6-dimethoxypyrimidine and various aldehyde with l-proline as the catalyst and acetic acid as the solvent under reflux condition. In vitro antimalarial activity toward P. falciparum 3D7 strain cultures were investigated. Compounds 4b and 4m demonstrated significant efficacy against strains of P. falciparum, with IC50 values of 0.63 and 0.65 μg/mL, respectively. The results were also supported by molecular docking and ADME assays.

“In-Water” Three-Component One-Pot Reaction for the Facile Synthesis of Densely Functionalized 2,3-Dihydro-1H-pyrrol-2-ols and Mechanistic Insight

“In-Water” Three-Component One-Pot Reaction for the Facile Synthesis of Densely Functionalized 2,3-Dihydro-1<i>H</i>-pyrrol-2-ols and Mechanistic Insight

Rapid and selective detection of Gram-positive bacteria using new dual emissive and non-cytotoxic organoboron esters

In this work, we report the green synthesis of five emissive organoboron esters, obtained by a condensation reaction via one-pot three-component reaction under microwave irradiation in just 5 min, yielding quantitative yields. The molecular structure proposed in solution (1H, 11B and high-resolution mass spectrometry) was corroborated through X-ray diffraction analysis for 3c, where the boron ion resides in distorted tetrahedral geometry. The photophysical properties of organoboron esters were obtained in solution state, revealing that these molecular materials could be classified as semiconductors with a fluorescence quantum yield in the 0.70–32 % range. Furthermore, organoboron ester 3a demonstrated a non-hazardous selective fluorescent yellow stain against Staphylococcus aureus and Bacillus subtills strains. To the best of our knowledge, this is the first report of the use of a non-toxic organoboron ester compound as a selective fluorescent dye against Gram-positive bacterial.

Blue luminescent pyridine-tethered quinazoline framework: Highly selective and sensitive picric acid chemosensor

The microwave-assisted one-pot three-component reaction of 2-phenyl-7,8-dihydroquinazolin-5(6H)-one, 2-arylidenemalononitrile and ammonium acetate under solvent-free conditions occurred through a five-step multiple bond-forming transformation to afford 2-amino-8-phenyl-4-aryl-5,6-dihydropyrido[2,3-f]quinazoline-3-carbonitriles in excellent yields. All the quinazoline-3-carbonitriles exhibited bright blue fluorescence under a UV lamp and were found to be efficient chemosensors of picric acid with detection limits in the nano-molar range.

Evaluation of Spirooxindole-3,3'-pyrrolines-incorporating Isoquinoline Motif as Antitumor, Anti-Inflammatory, Antibacterial, Antifungal, and Antioxidant Agents.

A series of novel 2-(isoquinolin-1-yl)-spiro[oxindole-3,3'-pyrrolines] were synthesized by a one-pot three-component reaction involving dimethyl acetylenedicarboxylate, 3- phenylimidazo[5,1-a]isoquinoline and N-alkylisatins in chloroform at ∼60 °C for 24 h. This study aimed at the synthesis of novel spirooxindole-3,3'-pyrrolines derivatives and in vitro evaluation of cytotoxicity affinities in cross-correlations with their antiinflammation and radical scavenging capacities. The objective of this study was to use a one-pot, three-component reaction to synthesize a novel set of spirooxindole-3,3'-pyrrolines derivatives. A novel set of spirooxindole-3,3'-pyrrolines (8a-i) was synthesized by a one-pot threecomponent reaction involving dimethyl acetylenedicarboxylate, 3-phenylimidazo[5,1-a]isoquinoline and N-alkylisatins in chloroform at ∼60 °C for 24 h. These new compounds were characterized by 1HNMR, 13C-NMR, and HRMS spectral data and screened for their antitumor, anti-inflammatory, antibacterial, antifungal, and antioxidant activities. The new synthetic spirooxindole-3,3'-pyrrolines (8a-i)-tested compounds displayed significant anti-inflammatory properties and were noncytotoxic on PDL fibroblasts. However, they lacked antioxidative-DPPH radical scavenging capabilities. Notably, Doxorubicin and cisplatin demonstrated antiproliferative effects on various cancer monolayers. Moreover, compounds 8b, 8d, 8f, 8h, and 8i exhibited pronounced viability reduction properties in colorectal and pancreatic cancer monolayers, as well as across skin, lung, prostate, and cervical adenocarcinomas, with higher cytotoxicity in mammary cancer cells MCF7 and T47D. None of the tested compounds had significant antibacterial activity against S. aureus or E. coli. However, compounds 8c, 8d, and 8f exhibited notable antifungal properties, indicating potential for further investigation. Eight new synthetic spiro[indoline-3,3-pyrroles] were prepared, characterized, and evaluated for their anti-inflammatory and cytotoxic properties. The compounds showed significant anti-inflammatory effects and promising cytotoxicity against various cancer monolayers, especially in colorectal and pancreatic cancers. Some compounds also exhibited antifungal properties. However, they did not exhibit significant antibacterial activity.

Multicomponent Synthesis of New Fluorescent Boron Complexes Derived from 3-Hydroxy-1-phenyl-1H-pyrazole-4-carbaldehyde.

Novel fluorescent pyrazole-containing boron (III) complexes were synthesized employing a one-pot three-component reaction of 3-hydroxy-1-phenyl-1H-pyrazole-4-carbaldehyde, 2-aminobenzenecarboxylic acids, and boronic acids. The structures of the novel heterocyclic compounds were confirmed using 1H-, 13C-, 15N-, 19F-, and 11B-NMR, IR spectroscopy, HRMS, and single-crystal X-ray diffraction data. The photophysical properties of the obtained iminoboronates were investigated using spectroscopic techniques, such as UV-vis and fluorescence spectroscopies. Compounds display main UV-vis absorption maxima in the blue region, and fluorescence emission maxima are observed in the green region of the visible spectrum. It was revealed that compounds exhibit fluorescence quantum yield up to 4.3% in different solvents and demonstrate an aggregation-induced emission enhancement effect in mixed THF-water solutions.

One-step construction of indolo[2,1-a]isoquinolines using solid calcium carbide as an alternative to gaseous acetylene

An efficient method for the synthesis of indolo[2,1-a]isoquinolines using calcium carbide as an alkyne source, 2-(2-bromophenyl)-1H-indoles as starting materials, and copper as a catalyst is described. The target products are synthesized via Sonogashira cross-coupling/nucleophilic addition tandem reactions. The advantages of this protocol include the use of inexpensive and easy-to-handle solid alkyne source instead of flammable and explosive gaseous acetylene, cheap and readily available raw materials, wide range of substrates, and simple reaction procedure. The method can also be extended to gram scale. In addition, the desired product can also be obtained by one-pot three-component reaction of phenylhydrazine hydrochlorides, o-bromoacetophenones and calcium carbide.

1,2,4-Triazolo-quinazolinones as Effective Antifoulants: Molecular Design, Synthesis, and Biological Evaluation.

A series of 1,2,4-triazolo-quinazolinones and 1,2-benzisothiazolone derivatives (S1-S12) were successfully synthesized as environmentally friendly alternatives to copper-based antifouling paints using N-alkylation, cyclocondensation, and one-pot three-component and amide coupling reactions. The monoclinic structure of single-crystal 1,2,4-triazolo-quinazolin-acetic acid (S8) was confirmed by single-crystal X-ray diffraction analysis. All the synthesized molecules were studied for their in silico molecular docking interactions with three target proteins, namely, RbmA, ToxR, and Bap. Following that, the antialgal activity was assessed against two types of marine algae: Chlorella sp. and Chaetoceros curvisetus. The minimal inhibitory concentration and zone of inhibition have been used to evaluate the antibacterial activities of S1-S12 against both marine Gram-positive (Staphylococcus aureus) and Gram-negative (Vibrio parahemolyticus and Vibrio vulnificus) bacteria. Additionally, antifouling studies have been done on all the compounds, and among them, 1,2,4-triazolo-quinazolinyl-acetate (S7), 1,2,4-triazolo-quinazolinyl-acetic acid (S8), 1,2,4-triazolo-quinazolinyl-oxobutanoate (S9), benzo[d]isothiazolyl butanoate (S10), benzo[d]isothiazolyl-acetic acid (S11), and 1,2,4-triazolo-quinazolinyl-acetyl-benzo[d]isothiazolone (S12) exhibited good antialgal, antibacterial, and antifouling activities.

Natural product synthesis by a nanoporous In-MOF Catalyst: Crystallographic insight by incorporating substrate inside its nanopores

Metal-organic frameworks (MOFs) are promising candidates as nanoporous heterogeneous catalysts over other solid catalysts. Herein, utilizing a new tetra-acid ligand and employing high-valent Indium metal source we have strategically developed a 3D robust nanoporous framework, IITKGP-53, which retained its crystallinity over a wide range of pH solutions (2–12). Considering the green synthesis approach IITKGP-53 was explored as a heterogeneous catalyst toward one-pot three-component Strecker reaction under solvent-free condition, with low catalyst loading for a broad range of substrates. Considering practical utility, biologically important natural product, Girgensohnine, was synthesized for the first time by using this catalyst with excellent conversion rate. The substrate binding sites inside the nanopores and host–guest interactions were verified crystallographically by obtaining a substrate inside nanopores of this MOF (aniline@IITKGP-53) and computational modeling. An in-depth theoretical investigation unveiled the most plausible transition states for the first time. This study inaugurates the usage of nanoporous MOFs as heterogeneous catalysts for natural product synthesis.

Synthesis and biological evaluation of 2-(2-hydrazinyl) thiazole derivatives with potential antibacterial and antioxidant activity

Heterocyclic systems containing 2-(2-hydrazinyl) thiazole moieties were synthesized by heterocyclization of thiosemicarbazones with arylglyoxals and Meldrum's acid in ethanol and water 1:1 (v/v) under reflux conditions. The paper reports an efficient, facile, and environmentally friendly protocol via a novel one-pot three-component reaction to access a broad range of 2-(2-Hydrazinyl) thiazole derivatives. Products were isolated by plate chromatography and their structures were established from their spectroscopic data, then the antibacterial and antioxidant activity of synthesized 2-(2-hydrazinyl) thiazole derivatives were evaluated, and demonstrated encouraging antibacterial activity against Staphylococcus aureus as a gram positive bacteria and Escherichia coli as a gram negative bacteria. Furthermore, when representative products were assessed for radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH0), high antioxidant effects were observed, indicating their potential safety for use in pharmacological studies.

Variation in Catalytic Efficacies of a 2D pH-Stable MOF by Altering Activation Methods.

Although it is well-known that the Lewis acidity of Metal-Organic Frameworks (MOFs) can effectively enhance their catalytic activity in organic transformations, access to these Lewis-acidic sites remains a key hurdle to widespread applications of Lewis-acidic catalysis by MOFs. Easy accessibility of strong Lewis acidic sites onto 2D MOFs by using proper activation methods can be a cornerstone in attaining desired catalytic performance. Herein, we report a new 2D chemically stable MOF, IITKGP-60, which displayed excellent framework robustness over a wide pH range (2-12). Benefiting from the abundant open metal sites (OMSs) and framework robustness, the catalytic activity of the developed material was explored in one-pot three-component Strecker reaction and Knoevenagel condensation reaction. Moreover, the developed catalyst is superior in catalyzing the reactions involving sterically hindered substrate (1-naphthaldehyde) with high turnover number. A comparative catalytic study was conducted using different activation methods (chloroform and methanol exchanged activated samples), highlighting the significant effect of activation methods on its catalytic performances. The sustainable synthetic pathway under solvent-free conditions for a broad scope of substrates using low catalyst loading and excellent recyclability made the developed pH-stable framework a promising heterogeneous catalyst.

One-Pot and Three-Component Coupling Synthesis of Novel p-[(Benzothiazolylamino)(aryl/heteroaryl)methyl]phenols and Its Corresponding O-Tosylates under Catalyst- and Solvent-Free Conditions

AbstractA catalyst- and solvent-free procedure has been developed for the synthesis of p-[( benzothiazolylamino)(aryl/heteroaryl)methyl]-functionalized phenols and its O-tosylates via one-pot three-component coupling reaction of thymol or carvacrol, aryl/heteroaryl aldehydes, and 2-aminobenzothiazoles with high selectivity. The present amino methylation process is convenient to perform even on large scale with a broad scope. The products were likely formed through the initial para attack of thymol on aldehydes to generate p-quinone methide intermediate and subsequent 1,6-aza-Michael addition of 2-aminobenzothiazoles on in-situ generated p-quinone methide intermediate.

Metal-Catalyzed Multi-Component Approach to Quinoline-Linked Covalent Organic Frameworks

The development of new reaction chemistry is highly desirable to construct new structural and functional covalent organic frameworks (COFs). Benefiting from the extremely large database of metal-catalyzed reaction database, we herein develop a new synthetic strategy that can generate quinoline-linked COFs via a silver-catalyzed three-component one-pot reaction and achieve functionalization by the simple replacement of alcohols. This metal-catalyzed approach to the construction of robust COF structures characterized by extended π-conjugation holds the potential to pave a novel pathway in the synthesis of COF materials endowed with both heightened stability and functionality.