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The irreversible locking of reversible imine linkages in COFs into quinoline-4-carboxylic esters has been achieved for the first time through the Doebner–von Miller reaction. The high conversion efficiency and broad scope were demonstrated by synthesizing four quinoline-4-carboxylic ester-linked COFs (QCE-COFs). Subsequently, this approach was applied to create the chiral QCE-COF-Men containing L -menthol. Remarkably, QCE-COF-Men was found to release the flavorant L -menthol at elevated temperature by cleaving the weak ester bond without destroying the quinoline skeleton. [ABSTRACT FROM AUTHOR]

Quinoline is a N-containing heterocyclic organic compounds with significant biological importance in pharmaceuticals field as well as natural products. They exhibit excellent pharmacological activities. To synthesize quinoline and their derivatives several synthetic methods have reported, such as conventional method, ultrasonic method, microwave (MW) irradiation method, with or without catalytic reaction, which have various pharmacological and biological activities, such as antibacterial, antifungal, anticancer, anti-HIV, antimalarial, antitumor, and anti-inflammatory activity. The objective of this review is to compile various synthetic methods were used for the formation of the Quinoline derivatives and their biological importance, such as antibacterial, anticancer, anti-microbial, antimalarial, antileishmanial, antifungal, and anti-inflammatory during 2010–2023, which will help the researchers how are working in this area. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) remains a global health concern, necessitating the continuous search for novel therapeutic agents to combat drug-resistant strains and enhance treatment efficacy. The present study focuses on designing, synthesizing, and exploring quinoline analogues as potential anti-tubercular agents. Quinoline scaffolds like bedaquiline inhibit the ATP synthase enzyme involved in energy production. A diverse library of 19 quinoline derivatives was sys tematically synthesized through rational structural modifications. The quinoline analogues were evaluated for their anti-tubercular activity against Mycobacterium tuberculosis (M.tb). Furthermore, the study delves into the molecular interactions between the synthesized quinoline derivatives and M.tb ATP synthase, shedding light on the underlying mechanisms of their anti-tubercular activity. The initial in-vitro screening revealed that some of the designed molecules were active against M.tb, making them potential candidates for further development. A diverse library of 19 quinoline derivatives was systematically synthesized through rational structural modifications. Molecular docking studies showed to target the ATP synthase protein of Mycobacterium tuberculosis (MtB). The quinoline analogs were found to have good anti-tubercular activity again Mtb. [ABSTRACT FROM AUTHOR]

Cancer affects millions of people worldwide. PDK1 enzyme (co-crystallized with BIM-1) controls the proliferation of breast cancer cells. Aiming to resemble BIM-1's binding, quinoline-based pyrimidinediones and thiazolidinediones were synthesized starting from 2-chloro-3-formylquinoline. Compared with doxorubicin (reference), in vitro antiproliferative activity against MCF7 and HCT116 cancer cell lines showed the most potency of thiobarbiturate 3 and thiazolidinedione 4. In silico molecular docking, DFT, and pharmacokinetics simulations supported the findings. The docking analysis toward PDK1 enzyme showed that most amino acids interacting with co-crystallized ligand (BIM-1) were successfully bonded to our docked substances, especially thiobarbiturate 3 with highest S-score closer to BIM-1. In DFT calculations, this compound exhibited the lowest energy gap and highest softness leading to more response to radical surface interactions. The compounds with significant antiproliferative activity exhibited high electrophilicity values. ADME analysis showed its desirable drug-likeness and oral bioavailability. This work may contribute to developing new potent antiproliferative agents. [ABSTRACT FROM AUTHOR]

In this study, electrochemical copolymerization of 6,7-diphenyl-4,9-di(selenophen-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline and 3,3'-didecyl-3,4-propylenedioxythiophene is carried out to obtain a copolymer namely poly(6,7-diphenyl-4,9-di(selenophen-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline-co-3,3'-didecyl-3,4-propylenedioxythiophene). Two distinct copolymers, PC1 and PC2, were produced as a result of the utilization of two different feed ratios. Copolymers were examined electrochemically and spectroelectrochemically after the copolymerization procedure. This study's major goal is to combine the exceptional characteristics of homopolymers P1 and P2 (P1 has a low band gap but is not soluble, and P2 is soluble and has a larger band gap) into a single copolymeric material. [ABSTRACT FROM AUTHOR]

Aberrant activation of the cGAS-STING signaling results in innate immune response induction. Herein, we report HSKB142, an orally bioavailable compound containing the 3H-pyrazolo [4,3-f]quinoline synthesized via a Povarov–Doebner MCR. HSKB142 is non-cytotoxic towards immune cells and suppresses type-1 interferon expression in human THP-1 monocytes upon treatment with 2′3′-cGAMP. [ABSTRACT FROM AUTHOR]

The syntheses of the tripodal tetraamine ligands 2‐(pyridin‐2‐yl)‐N,N‐bis(quinolin‐2‐ylmethyl)ethan‐1‐amine (DQPEA), N‐(pyridin‐2‐ylmethyl)‐2‐(quinolin‐2‐yl)‐N‐(2‐(quinolin‐2‐yl)ethyl)ethan‐1‐amine (DQEPMA), 2‐(pyridin‐2‐yl)‐N,N‐bis(2‐(quinolin‐2‐yl)ethyl)ethan‐1‐amine (DQEPEA), N,N‐bis(pyridin‐2‐ylmethyl)‐2‐(quinolin‐2‐yl)ethan‐1‐amine (QEDPMA), and 2‐(pyridin‐2‐yl)‐N‐(2‐(pyridin‐2‐yl)ethyl)‐N‐(2‐(quinolin‐2‐yl)ethyl)ethan‐1‐amine (QEDPEA) containing mixed quinolyl and pyridyl moieties are reported, with 2‐vinylquinoline being used to attach quinolylethyl arms to the aliphatic N atom. X‐ray crystal structures of [(Mn(DQPEA))2O2](ClO4)2 ⋅ (CH3CN)2, [Cu(DQPEA)NCCH3](ClO4)2, [Zn(DQPEA)NCCH3](ClO4)2, [Pd(DQEPEA)Cl]Cl ⋅ 11H2O are detailed, with four, five, and six‐coordination observed. In addition, the dimeric complex [(DPEA)Co(μ‐OH)3Co(DPEA)](ClO4)3 ⋅ 0.5H2O ⋅ MeCN containing the tridentate DPEA ligand formed by N‐dealkylation of QEDPEA is reported. Calculations suggest that the very short Co…Co distance of 2.5946(6) Å in this complex is unlikely to be due to a Co−Co bond. [ABSTRACT FROM AUTHOR]

8‐Methylquinoline is regarded as an ideal substrate to participate in diversely C(sp3)−H functionalization reactions. The presence of the chelating nitrogen atom enables 8‐methylquinoline to easily form cyclometallated complexes with various transition metals, leading to the selective synthesis of functionalized quinolines. Considering the great importance of quinoline cores in medicinal chemistry, in this review article, we have covered the publications related to the C−H activation and functionalization of 8‐methylquinoline under transition metal catalysis during the last decade. [ABSTRACT FROM AUTHOR]

Enantiopure chiral-at-metal rhodium(III) unsaturated 16e complexes have been obtained from racemic [Rh(SiN)2Cl] (SiN= 8-(dimethylsilyl)quinoline) using a readily accessible chiral spiroborate as chiral resolution agent. This strategy allows an easy access to enantiopure neutral Δ/Λ-Rh(SiN)2Cl and cationic Δ/Λ-Rh(SiN)2[BAr4F] unsaturated complexes, wherein rhodium(III) is coordinated to two inert silylquinoline ligands in a propeller-like arrangement. [ABSTRACT FROM AUTHOR]

This report outlines the evolution and recent progress about the different protocols to synthesize the N‐heterocycles fused hybrids, specifically [1,2,3]triazolo[1,5‐a]quinoline. This review encompasses a broad range of approaches, describing several reactions for obtaining this since, such as dehydrogenative cyclization, oxidative N−N coupling, Dieckmann condensation, intramolecular Heck, (3+2)‐cycloaddition, Ullman‐type coupling and direct intramolecular arylation reactions. We divided this review in three section based in the starting materials to synthesize the target [1,2,3]triazolo[1,5‐a]quinolines. Starting materials containing quinoline or triazole units previously formed, as well as starting materials which both quinoline and triazole units are formed in situ. Different methods of obtaining are described, such as metal‐free or catalyzed conditions, azide‐free, using conventional heating or alternative energy sources, such as electrochemical and photochemical methods. Mechanistic insights underlying the reported reactions were also described in this comprehensive review. [ABSTRACT FROM AUTHOR]

Spiro-heterocycles have attracted significant interest due to their unique biological properties with fewer side effects compared to traditional drugs. Herein, a novel method is reported for the synthesis of a series of spiro-heterocycles possessing a quinoline motif. The strategy utilizes rhodanine derivatives, hydrazonoyl chlorides, and 2-chloroquinoline-3-carbaldehyde, and proceeds via a one-pot sequential pseudo-five-component reaction. The reactions are found to proceed in a regioselective and chemoselective manner. [ABSTRACT FROM AUTHOR]

Organic molecular cages with low symmetry are promising to generate complex chemical environments for molecular recognition and catalysis. Herein, a new triangular prism cage with three rigid 8‐aminoquinoline‐2‐carboxylic acid derivatives as edges were synthesized. This molecular cage possesses reduced symmetry and contains both secondary amine and amide as hydrogen donating groups for molecular recognition. It could bind anions, such as NO3−, AcO−, and F− with moderate affinity. [ABSTRACT FROM AUTHOR]

The rapid emergence of various forms of drug‐resistant tuberculosis (TB) has massively impacted people's health globally. According to the WHO, TB care and facilities have been downgraded by 21% since the COVID‐19 pandemic, which has further slowed down the progress toward the "End TB Strategy." Multiple studies have shown drug‐resistant tuberculosis to be resilient to front‐line antituberculosis drugs, including isoniazid (INH), thus constantly prompting researchers worldwide to probe new potent chemical entities to replace/supplement the current artillery of anti‐TB therapeutics. The molecular hybridization (MH) technique has recently been adopted by many synthetic and medicinal chemists to combine different pharmacophoric units into a single molecular architecture which in most cases has been reported to exhibit a better pharmacological profile as compared to its precursors. The present review provides a concise account of the MH hybridization strategies directed at the structural manipulations of isoniazid to develop new anti‐TB agents and their structure‐activity relationships. Furthermore, their toxicity profiles and docking studies with relevant receptors are also briefly discussed. [ABSTRACT FROM AUTHOR]

N‐heterocyclic compounds have a broad range of applications and their selective synthesis is very appealing for the pharmaceutical and agrochemical industries. Herein we report the usage of the flavin‐dependent nitroreductase BaNTR1 for the photoenzymatic synthesis of various anthranils and quinolines from retro‐synthetically designed o‐nitrophenyl‐substituted carbonyl substrates, achieving high conversions (up to >99 %) and good product yields (up to 96 %). Whereas the effective production of anthranils required the inclusion of H2O2 in the reaction mixtures to accumulate the needed hydroxylamine intermediates, the formation of quinolines required the use of anaerobic or reducing conditions to efficiently generate the essential amine intermediates. Critical to our success was the high chemoselectivity of BaNTR1, performing selective reduction of the nitro group without reduction of the carbonyl moiety or the activated carbon‐carbon double bond. The results highlight the usefulness of an innocuous chlorophyll‐ and nitroreductase‐based photoenzymatic system for the tailored synthesis of diverse N‐heterocycles from simple nitro compounds. [ABSTRACT FROM AUTHOR]

Crystallization of 5-nonanoyl-8-hydroxyquinoline in the presence of InCl3 in acetonitrile yields a dinuclear InIII complex crystallizing in the space group P1. In this complex, [In2(C18H22NO2)2Cl4(H2O)2], each indium ion is sixfold coordinated by two chloride ions, one water molecule and two 8-quinolinolate ions. The crystal of the title complex is composed of two-dimensional supramolecular aggregates, resulting from the linkage of the Owater—H...O C and Owater—H...Cl hydrogen bonds as well as bifurcated Carene—H...Cl contacts. [ABSTRACT FROM AUTHOR]

A KOtBu‐promoted robust strategy has been described for the regioselective synthesis of pyrrolo[3,4‐b]quinolin‐1‐one and naphthyridin‐1(2H)‐one derivatives from o‐alkynylquinolinecarbonitriles in good to excellent yields. The reaction proceeds through in situ transformation of the nitrile moiety into an amide group followed by the selective C−N bond formation through a 5‐exo‐dig or 6‐endo‐dig annulation reaction. Among the synthesized derivatives, 6‐endo‐dig naphthyridin‐1(2H)‐ones displayed good photophysical properties. The present approach is superior to other established methodologies as it avoids use of transition metals and column chromatographic purification and affords the products in high yields. Additionally, the current methodology provides several additional advantages, such as one‐pot operation, high atom economy, broad substrate scope and a step‐economical process. [ABSTRACT FROM AUTHOR]

ABSTRACT A method for efficient synthesis of quinolines via acceptorless dehydrogenative condensation is presented. A series of quinolines are obtained by the coupling reaction of 2‐aminobenzyl alcohols with secondary alcohols in the presence of bidentate terpyridine Mn(I) complex in good to excellent yields. Pleasantly, various substituted secondary alcohols and substituted aminobenzyl alcohols all provide quinolines with good functional group tolerance. Importantly, this investigation also provides a green and environmentally friendly protocol for constructing heterocyclic compounds. [ABSTRACT FROM AUTHOR]

A novel catalyst of cesium-loaded boron nitride (Cs-BNT) was synthesized by stirring the materials at room temperature and was subsequently characterized by the spectroscopic techniques SEM, SEM-EDX, SEM-Mapping, TEM, Brunauer–Emmett–Teller (BET), DSC-TGA, Fourier transform infrared spectroscopy (FT-IR), and Raman spectrum. Furthermore, the catalyst of CsBN layer theoretically analyzed. The microwave method by Cs-BNT was used to synthesize novel heterocyclic quinoline-bearing dihydropyridines 5a-l and subsequently characterized using FT-IR, 1H NMR, 13C NMR, and mass spectrometry. An efficient, recyclable property of the catalyst was recognized, and it was observed that it could show more than five times efficiency in reusability without significant loss of its catalytic activity. The compound diethyl-6-amino-5-cyano-1-(4-fluorophenyl)-4-(2-methoxyquinolin-3-yl)-1,4-dihydropyridine-2,3-dicarboxylate hit compound revealed EHOMO-ELUMO as 4.00 eV indicating high stability of the molecule. The band structure, geometry, DOS, PDOS and Mulliken population based on DFT studies complemented the experimental results. [ABSTRACT FROM AUTHOR]

We herein report the synthesis, spectral analysis, DFT calculations, in vitro and in silico biological activities of novel N'-((2-thioxo-1,2-dihydroquinolin-3 yl)methylene)isonicotinohydr-azide with its Cu(II), Co(II), Ni(II), and Zn(II) complexes have been successfully prepared. The ligand and the complexes were characterized by analytical, FT-IR, 1H NMR, mass, UV–visible spectroscopy, molar conductivity, and magnetic susceptibility measurements. Density Functional Theory (DFT) estimations for the ligand at the DFT/B3LYP level via 6-31 G++ (d, p) replicate the structure and geometry. Furthermore, molecular docking and ADME calculations were also performed to correlate and interpret the experimental results. The antimicrobial activity study illustrated enhancement in the activity of the free ligand upon complex formation, and the Cu(II) complex (MIC 25 µg mL−1) may be considered a promising antibacterial agent, and Ni(II) and Zn(II) complexes (MIC 25 µg mL−1) as promising antifungal agent. Also, synthesized Ni(II) and Zn(II) metal complexes (MIC 3.125 µg mL−1) showed promising anti-TB activity against Mycobacterium tuberculosis. In the antioxidant activity, the Cu(II) complex showed excellent activity as compared to standard drugs and in silico docking studies were carried out against Cytochrome c Peroxidase (PDB ID: 2X08). [ABSTRACT FROM AUTHOR]

Under solvent-free conditions and with the help of ultrasonic irradiation, the synthesis of pyrano[3,2-c]chromen and pyrano[3,2-c]quinolin derivatives was promoted by four different ionic liquids. All reaction was performed at 100 °C and had good to excellent yields. 1-butyl-1-methylpyrrolidin-1-ium acetate (A), 1-butyl-1-methylpiperidin-1-ium acetate (B), N,N,N-triethylbutan-1-aminium acetate (C), and tetrabutylammonium acetate (D) as perfect ionic liquids for this reaction show remarkable catalytic activity. The work was simply developed for the reaction of chalcones with 4-hydroxy-1-methylquinolin-2(1H)-one/4-hydroxycoumarin to perform pure products of pyran heterocycles. [ABSTRACT FROM AUTHOR]

Quinolines are very important materials in organic synthesis due to their wide range of biological activities as well as representing one of the most research area in medicinal chemistry. Quinolines have many applications in design and synthesis of multiple heterocyclic compounds with a wide variety of biological significance. Quinolines fused heterocycles at face b using different synthetic methodologies as well as variable precursors and reaction conditions were the aim of the current review. [ABSTRACT FROM AUTHOR]

We report a convergent synthesis of heteroaryl/aryl-annulated pyridine and quinoline derivatives by a metal-free Povarov reaction. para -Toluene sulfonic acid was used as the catalyst in this reaction, which produced the products in good yields from the corresponding aromatic amines and ethyl vinyl ether. A pyridocoumarin and a pyridopyrimidine product were evaluated for their mosquito larvicidal activity against the third instar larvae of the dengue vector mosquito Aedes aegypti. Examination of morphological changes in the larvae showed damage to the target body part after treatment with both the pyridocoumarin and pyridopyrimidine products at the LC50 concentrations. [ABSTRACT FROM AUTHOR]

Chromenes and 2H‐Chromenes are vital components of natural products, pharmaceuticals, and agrochemicals that have captured the attention of researchers worldwide. These heterocyclic compounds represent an essential class of structural scaffolds, and the quest for their synthesis in a mild and straightforward way has gained significant momentum. Chromenes are oxygen‐containing heterocycles that have been widely studied due to their potential medicinal properties. In the last two decades, researchers have made remarkable progress towards the synthesis of chromene based heterocyclic compounds using O‐propargylated benzaldehydes as a substrate. These substrates are highly versatile and contain functional groups that make them ideal for a wide range of reactions. This review article provides an in‐depth analysis of the latest advances in alkynes' functionalization, emphasizing the substrate scope, limitations, regioselectivity control, and applications of these reactions. The review also covers a range of critical methods and strategies, including multicomponent reactions, used for the general synthesis of numerous types of chromene derivatives. [ABSTRACT FROM AUTHOR]

Background Currently, treatment options for patients with advanced melanoma who experience failed immunotherapy or targeted therapy are lacking. Recent studies suggest the antitumor activity of combined pembrolizumab and lenvatinib in patients with advanced melanoma progressing on immunotherapy. Herein, we report the clinical outcomes of combined lenvatinib and a programmed cell death protein-1 inhibitor (PD-1) in this population. Materials and Methods This French multicenter real-world study was conducted between September 2020 and July 2023. The primary endpoint was the objective response rate (ORR) according to the Response Evaluation Criteria in Solid Tumours (version 1.1). Secondary variables were treatment-related adverse events (TRAEs), progression-free survival (PFS), overall survival (OS), and duration of response (DOR). Results Of the 67 patients included (median age, 69 years; median follow-up, 5.0 months), 85% had stage IV-M1c or M1d disease. The overall ORR was 28.4% (95% CI, 18%-41%), including 3 complete (4.5%) and 16 partial (23.9%) responses. Median DOR was 3.1 (interquartile range, 1.3-4.3) months. Median PFS and OS were 3.1 (95% CI, 2.5-3.7) and 9.8 (95% CI, 5.6-13.9) months, respectively. Grades 3-5 TRAEs occurred in 16 (24%) patients; common TRAEs were fatigue (43.3%), nausea/vomiting (26.8%), diarrhea (20.9%), and hypertension (20.9%). No treatment-related deaths occurred. Conclusion Our real-world study demonstrates an interesting response rate and acceptable safety profile in a population with poor prognostic factors. Our data support this treatment option for refractory melanoma, as it is not approved by the Food and Drug Administration or European Medicines Agency, and highlight the need for new strategies. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) is a contagious disease caused by M. tuberculosis (Mtb) affecting people across the globe. Quinoline and chalcone cores have good anti-tubercular properties; thus, we have designed a hybrid scaffold containing quinoline and chalcone. A series of 3-(quinolin-3-yl)-1-phenylprop-2-en-1-one analogs 7a-p and 8a-k were synthesized through different reactions involving nucleophilic substitution, Vilsmeier Haack formylation, Claisen Schmidt condensation, and demethylation. Spectroscopic methods, including 1H NMR, 13C NMR, IR, and HRMS, were used to characterize all synthesized compounds. The anti-tubercular activity of compounds 7a-p and 8a-k was assessed against Mtb H37Rv (ATCC 27294). These compounds demonstrated anti-tubercular activity against H37Rv in the range of 6.25–50 μM. Swiss ADME's in silico computational studies showed that the ADME parameters were better and had a good pharmacokinetic profile. The compounds 8a, 7a, and 7p showed the most potential as anti-TB activity against Mtb H37Rv in this study, with MIC values of 6.25 μM, 12.5 μM, and 10 μM, respectively. [ABSTRACT FROM AUTHOR]

Herein we first report the unprecedented synthesis of tetrazene‐based cobalt complexes using unusual coupling of amines via dehydrogenation. These cobalt complexes were employed for dehydrogenative coupling reactions to synthesize N‐heterocycles (quinoline, and quinazolinone). Based on control experiments and IR identification of intermediates, we proposed a plausible reaction mechanism. Synthesis protocols were utilized for preparative scale synthesis and biologically active molecule (±)‐galipinine synthesis. [ABSTRACT FROM AUTHOR]

Quinoline is one of the most important nitrogen containing heterocycles, being widespread in nature and present in a broad variety of pharmacologically active compounds. Specifically, several quinoline based renowned antimalarial agents have served the mankind for several past decades and showed strong potential applications in other field also. 3‐Formyl‐quinoline is a versatile precursor which can be transformed using several easy methods into a wide range of biologically valuable scaffolds. The exploration of 3‐formyl‐quinolines have gained much more attention to medicinal chemists in the field of drug discovery to design and synthesize new fused/tethered quinolines as potent therapeutical agents. This manuscript summarizes the reports (from 2011 to 2023) which showing the synthetic potential of quinoline‐3‐carbaldehydes. [ABSTRACT FROM AUTHOR]

The rising antimicrobial resistance crisis has diminished the effectiveness of traditional antibiotics against pathogenic bacteria. This study addresses this urgent challenge by exploring the antibacterial potential of novel quinolone derivatives (1–33). Using computational in silico modeling to simulate biological interactions, we aimed to identify candidates with potent antibacterial activity. A total of 33 quinolone derivatives were assessed for their physicochemical properties and effectiveness against a range of clinically relevant pathogens, including methicillin‐resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, Streptococcus pneumoniae, and Enterococcus faecalis. Molecular docking studies identified compounds 28, 29, 32, and 33 as having notable binding affinities, particularly against MRSA. Further molecular dynamics simulations of compound 29 confirmed its favorable stability and potential for disrupting MRSA, reinforcing the docking results and showing strong alignment with in vitro findings. These findings position compound 29 as a promising lead for developing alternative MRSA therapies and underscore the need for further in vivo studies to evaluate its therapeutic potential. [ABSTRACT FROM AUTHOR]

A Pd-catalyzed regioselective H/D exchange at the α-position of pyridines was achieved by employing secondary phosphine oxide as an internal base. The proposed five-membered structure enabled the reaction to overcome its conventional ortho-directing feature, allowing the efficient deuteration of pyridines and quinolines at adjacent sites of N-atoms. [ABSTRACT FROM AUTHOR]

ABSTRACT We have described herein a simple and formal two‐step synthesis of 3‐(4,6‐diaryl‐1,3,5‐triazin‐2‐yl)‐2‐aryl quinolines from 2‐chloro‐3‐(4,6‐diaryl‐1,3,5‐triazin‐2‐yl) quinolines and boronic acids under the Suzuki–Miyaura conditions. This protocol provides the C‐2 arylation of 2‐chloro‐3‐(4,6‐diaryl‐1,3,5‐triazin‐2‐yl) quinolines under the mild reaction conditions. These newly formed chemo‐types may be useful in drug discovery programs or in material chemistry. [ABSTRACT FROM AUTHOR]

The hydrogenation of nitrogen‐containing heterocyclic precursors in aqueous medium is challenging, especially at ambient temperature and pressure. Electrochemical hydrogenation (ECH) of quinoline to 1,2,3,4‐tetrahydroquinoline (THQ) at mild conditions using water as the hydrogen source is demonstrated with splendid activity on a Cu‐based nonprecicous catalyst. The yield of THQ is up to ≈100% with ≈100% selectivity at −1.275 V vs Hg/HgO. The real active sites and key intermediates are deciphered, where the Lewis acid‐base sites on the heterointerface of Cu/Cu2O are beneficial to the quinoline adsorption in a dual‐site coordination configuration and water dissociation to afford H*. The presence of Cu0 plays a vital role in inhibiting the binding of H*, which ensures good Faradaic efficiency. In addition, a novel co‐production system by coupling benzyl alcohol oxidation at the anode is established, achieving dual benefits in both energy utilization efficiency and economic benefits. [ABSTRACT FROM AUTHOR]

A series of novel quinoline-isoxazole hybrids 6a–o has been synthesized via multistep synthetic approach involving hetero Diels-alder reaction strategy. The target compounds were obtained in good yield, using low-cost readily available starting materials using simple reaction conditions. The newly synthesized compounds were confirmed using 1H NMR,13C NMR, and Mass spectroscopic analysis techniques. Further, compounds 6a–o were subjected to in vitro antimicrobial screening against various bacterial and fungal strains, such as Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella typhi, Aspergillus niger, and Candida albicans. Among these, compounds 6i, 6j, and 6 l were found most active having equally potent compared to standard drug Ampicillin and Gentamycin. Moreover, in silico studies of 6a–o with E. coli DNA gyrase through molecular docking and MD simulations showed excellent binding properties of these derivatives with protein site. [ABSTRACT FROM AUTHOR]

A new ligand architecture based on quinoline/pyridine attached ortho to the amine functionality on an aniline, which is coupled to another quinoline unit has been prepared. Ligands L1 and L2 have been complexed with CF3 and C2F5 ligated nickel centers. The resulting complexes have been extensively studied by NMR spectroscopy (on 1H, 13C{1H}, and 19F nuclei) and single‐crystal X‐ray crystallography. A poorly defined mixture of complexes obtained from L1 and nickel bis‐trifluoromethyl complex was moderately active in C−H trifluoromethylation with the Umemoto I reagent. [ABSTRACT FROM AUTHOR]

Nine quinoline‐1,2,4‐triazine hybrids (5 a–5 i) were designed, synthesized, and subjected to evaluation as potential anti‐cancer agents. Structures validation of the synthesized analogues was accomplished through comprehensive analysis employing NMR, HRMS, and IR spectroscopy techniques. Furthermore, the molecular structures of compounds 5 a, 5 d and 5 h were authenticated via single crystal X‐ray diffraction. In an extensive screening process against the human pancreatic cancer PANC‐1 cell line utilizing the MTT assay, all quinoline‐1,2,4‐triazine hybrids (5 a–5 i) manifested significant anti‐proliferative activity. Compound 5 g demonstrated a significant anti‐proliferative effect with an IC50 value of 26.8 μM, similar to the positive control, 5‐Fu. Subsequent investigations revealed varying degrees of cell viability in MDA‐MB‐231, A549, and UM‐UC‐3 cell lines upon exposure to different concentrations of compound 5 g. These findings lead us to postulate that compound 5 g may impede the migration, invasion, and adhesion of PANC‐1 cells, similar to the effects observed with 5‐Fu. [ABSTRACT FROM AUTHOR]

A regioselective synthesis of 4H‐pyrano[2,3‐b]quinoline derivatives via DABCO‐mediated Knoevenagel condensation/heterocyclization sequence has been executed. In this way some new fused heterocyclic compounds were synthesized from 2‐chloroquinoline‐3‐carbaldehyde as a versatile and efficient synthetic building block. The one‐pot three‐component reaction of 2‐chloroquinoline‐3‐carbaldehyde and diverse cyclic active methylenes for construction of highly substituted quinolines scaffold has been accomplished under mild condition. The strategy included herein shows significant advantages, including a facile process with easy purification, excellent yields, wide applicability, available substrates, and cost‐effective/eco‐friendly solvent and catalyst. [ABSTRACT FROM AUTHOR]

The present work focuses on the synthesis of novel heterocycles 2-(aryloxy)-3-(4,5-diaryl-1H-imidazol-2-yl)quinolines (6k-v) by an effective condensation reaction. These molecules exhibited fluorescent properties and hence for the proper understanding of their optical behavior and quantum yields, solvatochromic studies have been carried out. Further, frontier molecular orbitals, molecular electrostatic potential (MEP), and geometrical structure optimization have been investigated using the B3LYP/6-311G ++ (d, p) method. The energy gap between the HOMO, LUMO of the optical and energy band gap is determined by DFT and UV–visible spectra for TD-DFT studies are done. The screening of these compounds for in vitro COX-1 and COX-2 inhibition and DPPH free radical scavenging ability assays produced promising results. The binding interactions of these molecules against the COX-2 enzyme (PDB: 5IKR) were validated by docking studies. [ABSTRACT FROM AUTHOR]

For very first time, we report the synthesis of 8-(2-methoxyphenyl)-6-methyl-2-(1-methyl-1H-benzo[d]imidazol-2-yl)quinoline 1. This was achieved in several steps, including usage of the Suzuki reaction for functionalization of 2-(1H-benzo[d]imidazol-2-yl)quinoline moiety. The new compound exhibits blue fluorescence. Its structure was confirmed with 1D and 2D NMR spectroscopy, IR spectroscopy, high-resolution mass spectrometry and X-ray analysis. [ABSTRACT FROM AUTHOR]

Forced intercalation peptide nucleic acids (FIT-PNAs) are DNA mimics that act as RNA sensors. The sensing event occurs due to sequence-specific RNA hybridization, leading to a substantial increase in fluorescence. The fluorophore in the FIT-PNA is termed a surrogate base. This molecule typically replaces a purine in the PNA sequence. BisQ is a surrogate base that connects two quinolines via a monomethine bond. BisQ-based FIT-PNAs have excellent biophysical features that include high brightness and red-shifted emission (λem, max = 613 nm). In this report, we detail two chemical approaches that allow for the facile synthesis of the BisQ PNA monomer. In both cases, the key compound used for the synthesis of BisQ-CH2COOH is the tBu-ester-modified quinoline synthon (compound 5). Subsequently, one method uses the Alloc acid-protected PNA backbone, whereas the other uses the tBu ester-protected PNA backbone. In the latter case, the overall yield for BisQ acid (compound 7) and BisQ PNA monomer syntheses was 61% in six synthetic steps. This is a substantial improvement to the published procedures to date (7% total yield). Lastly, we have prepared an 11-mer FIT-PNA with either BisQ or thiazole orange (TO) and studied their photophysical properties. We find superior photophysical properties for the BisQ FIT-PNA in terms of the brightness and selectivity, highlighting the added value of using this surrogate base for RNA sensing. [ABSTRACT FROM AUTHOR]

Simple Summary: Imiquimod (IMQ) is clinically used in the treatment of various skin malignancies. We previously showed that IMQ-induced apoptosis and autophagic cell death in skin cancer cells are ROS-dependent. Additionally, IMQ-induced apoptosis is associated with a decrease in Mcl-1 levels. However, the exact role of Mcl-1 in IMQ-induced apoptosis, including its protective mechanisms and physiological function in cancer cells, remains unclear. This study demonstrated that the overexpression of Mcl-1 or IL-6-induced Mcl-1 upregulation reversed mitochondrial dysfunction, mitochondrial fission, and mitophagy in IMQ-treated cancer cells and protected them from IMQ-induced apoptosis. These results provide significant insights supporting the role of Mcl-1 in mitochondria and suggest that it may be a potential target for cancer research and therapy. Mitochondria, vital organelles that generate ATP, determine cell fate. Dysfunctional and damaged mitochondria are fragmented and removed through mitophagy, a mitochondrial quality control mechanism. The FDA-approved drug IMQ, a synthetic agonist of Toll-like receptor 7, exhibits antitumor activity against various skin malignancies. We previously reported that IMQ promptly reduced the level of the antiapoptotic Mcl-1 protein and that Mcl-1 overexpression attenuated IMQ-triggered apoptosis in skin cancer cells. Furthermore, IMQ profoundly disrupted mitochondrial function, promoted mitochondrial fragmentation, induced mitophagy, and caused cell death by generating high levels of ROS. However, whether Mcl-1 protects mitochondria from IMQ treatment is still unknown. In this study, we demonstrated that Mcl-1 overexpression induced resistance to IMQ-induced apoptosis and reduced both IMQ-induced ROS generation and oxidative stress in cancer cells. Mcl-1 overexpression maintained mitochondrial function and integrity and prevented mitophagy in IMQ-treated cancer cells. Furthermore, IL-6 protected against IMQ-induced apoptosis by increasing Mcl-1 expression and attenuating IMQ-induced mitochondrial fragmentation. Mcl-1 overexpression ameliorates IMQ-induced ROS generation and mitochondrial fragmentation, thereby increasing mitochondrial stability and ultimately attenuating IMQ-induced cell death. Investigating the roles of Mcl-1 in mitochondria is a potential strategy for cancer therapy development. [ABSTRACT FROM AUTHOR]

The new methacrylic azomethine-containing monomers with side chain quinoline moiety were synthesized by reaction of their corresponding alcohols with methacryloyl chloride. The polymers based on new monomers were synthesized by free radical polymerization. Polymers were characterized by 1HNMR spectroscopy, and the results of their photochemical and optical activities are presented. [ABSTRACT FROM AUTHOR]

[Display omitted] Quinoline is high toxicity and difficult biodegradation in oil washing wastewater. Therefore, efficient removal of quinoline contaminant from water bodies poses a major challenge. Hence, Co quantum dot loaded N-doped porous carbon (CoNC) nanosheets grown in situ on carbon cloth were fabricated as cathode for the degradation of quinoline in electro-Fenton system. Under optimal conditions (c(Fe2+) = 0.5 mM, U = -0.3 V, pH = 3), quinoline was completely degraded within 15 min with superior apparent rate constant of 0.385 min−1, which was 19.6 times higher than that of the ZIF-L precursor, due to the abundance of Co QDs active sites and hydrophilicity and electrical conductivity of N-doped porous carbon. In addition, three reaction pathways for quinoline were deduced by combining Density Functional Theory (DFT) calculation and Liquid Chromatography-Mass Spectrometry (LC-MS). More importantly, in situ FTIR and free energy calculations were analyzed to reveal that pathway Ⅰ as spontaneous reaction was the main reaction pathway. Finally, the toxicity of the intermediates was assessed with ECOSAR software and E. coli experiments, and the overall toxicity decreased during the degradation reactions. This work provides novel perspectives on environmental protection by designing in-situ grown cathodes through self-assembly method, thereby effectively purifying pollutants from wastewater. [ABSTRACT FROM AUTHOR]

An efficient nickel‐catalyzed sequential one‐pot strategy for the synthesis of coumarin‐appended quinolines and bis‐quinolines has been developed under mild reaction conditions in moderate to good yields (up to 84 %) via dehydrogenative Friedlander annulation followed by C(sp3)−H functionalization. The use of a cost‐effective Ni catalyst, environmentally friendly solvents and simple operating procedures are the attractive attributes of this method. Additionally, the photophysical properties of the synthesized derivatives were explored utilizing UV‐vis absorption and fluorescence emission studies. Furthermore, the large‐scale synthesis and the synthetic utility of the derivatives highlight the potential applicability of this strategy in synthetic organic chemistry. Moreover, A plausible reaction mechanism is supported by the control experiments and reaction monitoring by 1H NMR analysis. [ABSTRACT FROM AUTHOR]

Crystallization of 5-nonanoyl-8-hydroxyquinoline in the presence of InCl3 in acetonitrile yields a dinuclear InIII complex crystallizing in the space group P\overline{1}. In this complex, [In2(C18H22NO2)2Cl4(H2O)2], each indium ion is sixfold coordinated by two chloride ions, one water molecule and two 8-quinolinolate ions. The crystal of the title complex is composed of two-dimensional supramolecular aggregates, resulting from the linkage of the Owater—H...O=C and Owater—H...Cl hydrogen bonds as well as bifurcated Carene—H...Cl contacts.

The adsorption capacity and removal rate of quinoline by AgY, ZnY and CrY zeolites from model fuel at different adsorption times were investigated by experiments. The order of adsorption capacity and removal rate of quinoline was AgY>CrY>ZnY. Theoretical study on the mechanism of adsorption of quinoline on AgY, CrY and ZnY was made by using the theory of Grand Canon Monte Carlo (GCMC) and density functional theory (DFT) in Materials Studio software. The experiment results indicated that modified Y zeolites for N2 adsorption-desorption and simulated calculation of specific surface area and pore volume of AgY, ZnY and CrY are consistent. It is found that the adsorption capacity of modified Y zeolites has little relationship with specific surface area and pore volume; based on Fukui function, Mulliken and Hirshfeld are used to analyze the relative electrophilicity and Lewis acid of three modified Y zeolites and the order of Lewis acidity is as follows: AgY>CrY>ZnY. The adsorption mode is the π-complexed adsorption. The simulation and calculation of the adsorption energy of three modified Y zeolites suggest that the order of adsorption energy is: AgY>CrY>ZnY. All results of simulation are in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

A set of Pd-containing composites was prepared by the deposition of Pd on the following carriers: polyaniline (PANI); PANI doped by H2SO4; Norit GSX activated carbon or Aerosil (SiO2) coated by PANI or by H2SO4-doped PANI; PANI after thermal treatment at 300 °C in an atmosphere of H2. One sample was also prepared by the in situ polymerization of aniline in the presence of Pd2+· The decomposition of Pd was carried out via deposition from the solutions of Pd2+ salts or decomposition of Pd0 complex Pd2(dba)3, where dba is dibenzylideneacetone. The composites were studied by powder X-ray diffraction, transmission electron microscopy, IR and Raman spectroscopy. The hydrogenation of quinoline in the presence of composites was carried out; the catalytic performance of the composites was evaluated by the yield of 1,2,3,4-tetrahydroquinoline. It was found that the doping of PANI by H2SO4, inclusion of Norit GSX activated carbon as a component of the carrier or thermal treatment of PANI prior to the deposition of Pd led to significant increase in the catalytic performance of the composites in the hydrogenation of quinoline.

An electrocatalytic hydrogenation of cyanoarenes, nitroarenes, quinolines, and pyridines using a proton-exchange membrane (PEM) reactor was developed. Cyanoarenes were then reduced to the corresponding benzylamines at room temperature in the presence of ethyl phosphate. The reduction of nitroarenes proceeded at room temperature, and a variety of anilines were obtained. The quinoline reduction was efficiently promoted by adding a catalytic amount of p-toluenesulfonic acid (PTSA) or pyridinium p-toluenesulfonate (PPTS). Pyridine was also reduced to piperidine in the presence of PTSA.

Three organoplatinum(II) complexes bearing natural arylolefin and quinoline derivatives, namely, [4-methoxy-5-(2-methoxy-2-oxoethoxy)-2-(prop-2-en-1-yl)phenyl](quinolin-8-olato)platinum(II), [Pt(C13H15O4)(C9H6NO)], (I), [4-methoxy-5-(2-oxo-2-propoxyethoxy)-2-(prop-2-en-1-yl)phenyl](quinoline-2-carboxylato)platinum(II), [Pt(C15H19O4)(C10H6NO2)], (II), and chlorido[4-methoxy-5-(2-oxo-2-propoxyethoxy)-2-(prop-2-en-1-yl)phenyl](quinoline)platinum(II), [Pt(C15H19O4)Cl(C9H7N)], (III), were synthesized and structurally characterized by IR and 1H NMR spectroscopy, and by single-crystal X-ray diffraction. The results showed that the cycloplatinated arylolefin coordinates with PtII via the carbon atom of the phenyl ring and the C=Colefinic group. The deprotonated 8-hydroxyquinoline (C9H6NO) and quinoline-2-carboxylic acid (C10H6NO2) coordinate with the PtII atom via the N and O atoms in complexes (I) and (II) while the quinoline (C9H7N) coordinates via the N atom in (III). Moreover, the coordinating N atom in complexes (I)–(III) is in the cis position compared to the C=Colefinic group. The crystal packing is characterized by C—H...π, C—H...O [for (II) and (III)], C—H...Cl [for (III) and π–π [for (I)] interactions.

Synthesis of novel (E)‐N‐(4‐(substituted)benzylidene)‐6‐substituted‐1H‐pyrazolo[3,4‐b]quinoline‐1‐carbothioamides/carboxamides was achieved by the condensation of 6‐substituted‐1H‐pyrazolo[3,4‐b]quinoline‐1‐carbothioamides/carboxamides with substituted benzaldehydes in alcoholic medium in the presence of acetic acid. The structures of synthesized compounds are assigned on the basis of FT IR, 1H NMR, 13C NMR and Mass Spectral data. The compounds are subjected for their antibacterial, antifungal and DFT studies. Compounds, (E)‐6‐chloro‐N‐(4‐(dimethylamino)benzylidene)‐1H‐pyrazolo[3,4‐b]quinoline‐1‐carbothioamide (5 b), (E)‐6‐chloro‐N‐(4‐(dimethylamino)benzylidene)‐1H‐pyrazolo[3,4‐b]quinoline‐1‐carboxamide (5 f), and (E)‐6‐chloro‐N‐(4‐hydroxybenzylidene)‐1H‐pyrazolo[3,4‐b]quinoline‐1‐carboxamide (5 j) possessed pronounced antibacterial and antifungal activities due to their chemical structure. [ABSTRACT FROM AUTHOR]

The reaction between 6‐aminouracils and isatins having no substitution on nitrogen was carried out in acetic acid at 80 °C. This was followed by the oxidative decarboxylation of the resulting intermediates in the presence of Pb(OAc)4, resulting in the synthesis of the corresponding 6‐aminouracil substituted pyrimido[4,5‐b]quinolines with good to excellent yields. Additionally, the reaction of 6‐aminouracils, isatin derivatives, and 1,3‐dimethylbarbituric acid yielded similar results, and the corresponding products were efficiently obtained with symmetric and asymmetric structures. Furthermore, N‐substituted isatins were also subjected to the reaction conditions and the resulted spirooxindoles prepared, showing resistance against oxidation with (Pb(OAc)4. Notably, the condensation reaction of N‐substituted isatins with N‐arylaminouracils was also investigated, leading to spiro[indoline‐3,5′‐pyrimido[4,5‐b]quinoline] derivatives. [ABSTRACT FROM AUTHOR]

The spread of drug-resistant tuberculosis strains has become a significant economic burden globally. To tackle this challenge, there is a need to develop new drugs that target specific mycobacterial enzymes. Among these enzymes, InhA, which is crucial for the survival of Mycobacterium tuberculosis, is a key target for drug development. Herein, 24 compounds were synthesized by merging 4-carboxyquinoline with triazole motifs. These molecules were then tested for their effectiveness against different strains of tuberculosis, including M. bovis BCG, M. tuberculosis, and M. abscessus. Additionally, their ability to inhibit the InhA enzyme was also evaluated. Several molecules showed potential as inhibitors of M. tuberculosis. Compound 5n displayed the highest efficacy with a MIC value of 12.5 μg/mL. Compounds 5g, 5i, and 5n exhibited inhibitory effects on InhA. Notably, 5n showed significant activity compared to the reference drug Isoniazid. Molecular docking analysis revealed interactions between these molecules and their target enzyme. Additionally, the molecular dynamic simulations confirmed the stability of the complexes formed by quinolinetriazole conjugate 5n with the InhA. Finally, 5n underwent in silico analysis to predict its ADME characteristics. These findings provide promising insights for developing novel small compounds that are safe and effective for the global fight against tuberculosis. [ABSTRACT FROM AUTHOR]