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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]

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]

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]

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 systematically 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. [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]

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]

Comprehensive Summary: An efficient electrochemical approach has been developed for the construction of 3‐sulfanylquinoline derivatives by treating phenylethynylbenzoxazinanones with disulfides in an undivided cell. The protocol provided a convenient route to functionalized quinolines with good functional group tolerance. Moreover, it does not require any metal catalysts or additives, furnishing a series of biological quinolines in moderate to good yields. [ABSTRACT FROM AUTHOR]

Ferrocenyl conjugated oxazepine/quinoline derivatives were presented through the reaction of hexadehydro-Diels-Alder (HDDA) generated arynes with ferrocenyl oxazolines under mild conditions via ring-expanding or rearrangement processes. Water molecule participated in this unexpected rearrangement process to produce quinoline skeletons, and DFT calculations supported a ring-expanding and intramolecular hydrogen migration process for the formation of oxazepine derivatives. Two variants of this chemistry, expanded the reactivity between ferrocenyl conjugated substances and arynes, further providing an innovative approach for the synthesis of ferrocene derivatives. [ABSTRACT FROM AUTHOR]

The first molybdenum triazolylidene complexes catalyzing the atom‐economical synthesis of quinolines through acceptorless dehydrogenative coupling of alcohols is reported. A new family of Mo(0) complexes bearing chelating bis‐1,2,3‐triazolylidene, pyridyl‐1,2,3‐triazolylidene, and bis‐triazole ligands have been prepared and applied as catalysts for the synthesis of quinolines. Interestingly, Mo complexes bearing bis‐1,2,3‐triazolylidene ligands with alkyl groups (Et, n‐Bu) displayed superior catalytic activities than those containing aryl substituents on the triazolylidene rings. Control experiments corroborated that the catalytic reaction involves the dehydrogenation pathway. [ABSTRACT FROM AUTHOR]

An iron(III)‐promoted radical fluoroalkylation of o‐alkenylaryl isocyanides has been developed using readily available perfluoroalkyl iodides as fluoroalkyl source. This cyclization reaction features broad substrate scope and provides a simple and efficient approach for regioselective construction of biologically important 2‐fluoroalkylated quinolines in 38–81 % yields. [ABSTRACT FROM AUTHOR]

A domino reaction comprising four consecutive steps based on the strategy of isomerization of allylic alcohols was developed. This base‐catalyzed protocol provided an approach for constructing polysubstituted quinolines without additional additives. A wide range of di‐ or trisubstituted γ‐aminoaryl allylic alcohols bearing alkyl or (hetero)aryl substituents were transformed to a range of structurally diverse quinolines. The utility of this transformation was demonstrated by the application in the concise synthesis of several polysubstituted quinoline derivatives, including natural products and pharmacological agents. Preliminary mechanistic experiments suggest that the isomerization of γ‐aminoaryl allylic alcohol proceeds via an intramolecular 1,3‐hydrogen shift whereas for the aromatization of the dihydroquinoline intermediate two possible pathways exist: acceptorless dehydrogenation and transfer hydrogenation. [ABSTRACT FROM AUTHOR]

Phenotypic assays detect small‐molecule bioactivity at functionally relevant cellular sites, and inherently cover a variety of targets and mechanisms of action. They can uncover new small molecule‐target pairs and may give rise to novel biological insights. By means of an osteoblast differentiation assay which employs a Hedgehog (Hh) signaling agonist as stimulus and which monitors an endogenous marker for osteoblasts, we identified a pyrrolo[3,4‐g]quinoline (PQ) pseudo‐natural product (PNP) class of osteogenesis inhibitors. The most potent PQ, termed Tafbromin, impairs canonical Hh signaling and modulates osteoblast differentiation through binding to the bromodomain 2 of the TATA‐box binding protein‐associated factor 1 (TAF1). Tafbromin is the most selective TAF1 bromodomain 2 ligand and promises to be an invaluable tool for the study of biological processes mediated by TAF1(2) bromodomains. [ABSTRACT FROM AUTHOR]

Retrosynthetic simplicity is introduced as a metric by which methods can be evaluated. An argument in favor of reactions which are retrosynthetically simple is put forward, and recent examples in the context of skeletal editing from my own laboratory as well as contributions from others are analyzed critically through this lens. 1 Introduction 2 Example 1: Quinoline to Quinazoline (One Product, Two Starting Materials) 3 Example 2: Benzene to Pyridine (Two Products, One Starting -Material) 4 Caveats, Counterarguments, and Conclusions [ABSTRACT FROM AUTHOR]

A novel synthesis strategy to access 2-alkoxyquinoline derivatives via a palladium-driven cascade reaction is disclosed. Unlike classic methods based on the alkylation of 2-quinolones with alkyl halides, the present method benefits from the de novo assembly of the quinoline core starting from 1,3-butadiynamides. Palladium-catalyzed reaction cascades with N-(2-iodophenyl)-N-tosyl-1,3-butadiynamides and primary alcohols as external nucleophiles proceed under mild reaction conditions and selectively deliver a variety of differently functionalized 4-alkenyl 2-alkoxyquinolines in a single batch transformation. [ABSTRACT FROM AUTHOR]

In this paper, we have established an operationally convenient protocol for the rapid construction of polysubstituted methyleneindene and quinoline derivatives under mild conditions. This new synthetic method is achieved through the conversion of acetyl‐substituted methylenecyclopropanes with TsOH ⋅ H2O and ortho‐amino‐substituted methylenecyclopropanes with aromatic aldehyde and TsOH ⋅ H2O, respectively. A variety of transformations of the obtained products was demonstrated. The plausible reaction mechanisms were also proposed. [ABSTRACT FROM AUTHOR]

Simple Summary: Squamous cell carcinoma of the penis is a rare yet distressing condition representing less than 1% of cancer diagnoses in the United States annually. It is largely associated with human papillomavirus infection, lack of circumcision, and poor hygiene, among other factors. When detected early, local therapies for penile cancer offer robust response and cure rates, but they can be disfiguring, leading to psychologic, social, and functional distress. Herein, we explore local therapies, including topical drugs, laser therapy, and excisional procedures, and more radical surgeries for squamous cell carcinoma of the penis as well as advanced reconstructive techniques, including skin grafting and the creation of a new penis to maintain functional status and cosmesis. Local therapy for penile cancer provides robust survival and can preserve the penis functionally and cosmetically. Interventions must target the appropriate clinical stage. We reviewed studies regarding the primary therapy in penile cancer, from topical therapy to radical penectomy, and reconstructive techniques. Topical therapy (5-FU or Imiquimod) provides a robust oncologic response in patients with Ta or Tis disease. Multiple laser therapies are available for localized patients and those with low-grade T1 disease. There is a non-trivial risk of progression and nodal metastases in poorly selected patients. Wide local excision provides an oncologically sound option in patient with up to T1 disease; less evidence exists for Mohs microsurgery in the setting of penile cancer. Increasingly aggressive approaches include glansectomy and partial/radical penectomy, which provide 5- and 10-year cancer-specific survival rates of over 80%. Meticulous reconstruction is necessary for the durable function of the remaining penis. Preservation of voiding and sexual function occurs via penile skin grafting, glans resurfacing, creation of a functional penile stump, and phalloplasty with a penile implant. Perineal urethrostomy provides an alternative in pathology demanding extensive partial or radical penectomy, and a durable option for seated voiding. Clinical suspicion and timely diagnosis are paramount in terms of management as less-invasive options for earlier-stage disease develop. [ABSTRACT FROM AUTHOR]

This work aims to explore the catalytic potential of manganese oxide (MnO2) supported on (Fe3O4‐MWCNT) nano‐composite, which is composed of iron oxide and multi‐walled carbon nanotubes. The nano‐composite was synthesized using a simple impregnation technique. The catalyst material was extensively characterized using a variety of possible analytical methods, including X‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X‐ray spectroscopy (EDS). Then, utilizing a multi‐component condensation protocol comprising substituted aldehydes, cyclohexadione, ethylacetoacetate, and NH4OAc, the catalytic efficacy of the Fe3O4‐MWCNT@MnO2 nano‐composite was assessed for synthesizing novel hexahydro‐quinoline analogues. The catalyst was found to be effective because of its huge specific surface area, stability, porosity, and distinctive exposed surfaces. The catalyst's surface exhibited an exceptionally active nature, as seen by the notably high turnover frequency. Herein, we present a reusable and effective catalytic method that produces outstanding product yields (93%–97%) under mild reaction conditions, using ethanol as a green solvent. Cost‐effectiveness, environmental safety, and high atom efficiency are achieved using the nano‐composite. [ABSTRACT FROM AUTHOR]

NADPH oxidases (NOXs) are the sole enzyme in the human body that can directly produce reactive oxygen species. Recent studies have shown that NOXs is a very promising target for the treatment of diabetic nephropathy (DN). Here, a series of quinoline(quinolinone) derivatives have been designed based on pharmacophore strategy, synthesized and evaluated. Among them, 19d exhibits potent antiproliferative and NOXs inhibitory activities, and is worthy for further investigation. [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. [ABSTRACT FROM AUTHOR]

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Summary: Radioresistance is an inevitable obstacle in the clinical treatment of inoperable patients with non-small cell lung cancer (NSCLC). Combining treatment with radiosensitizers may improve the efficacy of radiotherapy. Previously, the quinoline derivative 10E as new exporter of Nur77 has shown superior antitumor activity in hepatocellular carcinoma. Here, we aimed to investigate the radiosensitizing activity and acting mechanisms of 10E. In vitro, A549 and H460 cells were treated with control, ionizing radiation (IR), 10E, and 10E + IR. Cell viability, apoptosis, and cycle were examined using CCK-8 and flow cytometry assays. Protein expression and localization were examined using western blotting and immunofluorescence. Tumor xenograft models were established to evaluate the radiosensitizing effect of 10E in vivo. 10E significantly inhibited cell proliferation and increased their radiosensitivity while reducing level of p-BCRA1, p-DNA-PKs, and 53BP1 involved in the DNA damage repair pathway, indicating that its radiosensitizing activity is closely associated with repressing DNA damage repair. A549 cells showed low level of Nur77 and a low response to IR but 10E-treated A549 cells showed high level of Nur77 indicating that Nur77 is a core radiosensitivity factor and 10E restores the expression of Nur77. Nur77 and Ku80 extranuclear co-localization in the 10E-treated A549 cells suggested that 10E-modulated Nur77 nuclear exportation inhibits DNA damage repair pathways and increases IR-triggered apoptosis. The combination of 10E and IR significantly inhibits tumor growth in a tumor xenograft model. Our findings suggest that 10E acts as a radiosensitizer and that combining 10E with radiotherapy may be a potential strategy for NSCLC treatment. [ABSTRACT FROM AUTHOR]

The effects of three preservation methods (ultrasound, ZnO NPs, and ultrasound combined with ZnO NPs) on the odor, microstructure, and edible quality of fresh-cut lettuce were investigated in this study. When stored for 8 days, significant improvements were observed in the following when using ultrasound combined with ZnO NP treatment to better preserve fresh-cut lettuce (and were reduced when compared with the control group): the color (L* value (34.53); a* value (−5.89); b* value (15.00); browning index (40.63); firmness (25.66); propectin (2.12%); chlorophyll (2.75 mg/100 g); cellulose (20.35%); total phenolic content (0.95 mg/100 g); PAL activity (54.91 U·h−1·g−1); CAT activity (41.78 U·min−1·mg−1); ABTS free-radical scavenging ability (137.62 µmol/L); FRAP total reducing ability (94.42 µmol/L) (p < 0.05), PPO activity (0.85 U·min−1·g−1); MDA (1.97 µmol/g); and H2O2 (54.26 µmol/g). In addition, the results of the volatile components indicated that the use of ultrasound combined with ZnO NP treatment decreased the production of adverse flavor compounds by inhibiting the generation of aldehydes and ketones, as well as by promoting the generation of olefins, nitriles, and quinolines, and the contents of nitriles and quinolines were 20.07% and 2.07% of the total components, respectively. The resultant microstructure indicated that the microchannels generated by ultrasound allowed for the ZnO NPs to enter the intracellular cavity of the fresh-cut lettuce more efficiently; such a finding could serve as a basis for a hypothesis on the mechanism of ultrasound combined with ZnO NP treatment. The results of fresh-cut lettuce preservation when using ultrasound combined with ZnO NPs were better than those that were obtained when using ultrasound and ZnO NP treatment alone. And, using ultrasound combined with ZnO NP treatment as a new preservation method for fresh-cut lettuce provides a promising preservation idea for other fresh-cut fruits and vegetables. [ABSTRACT FROM AUTHOR]

A general and atom-efficient synthesis of quinoline-C2-substituted β-hydroxyarylethylamino derivatives was achieved by copper-catalyzed [3+3]-cycloaddition reaction of N -oxide with N -Ts aziridines. Notably, temperature has a huge impact on this transformation as evidenced by the fact that, at 80 °C, exclusively the [3+3] cycloadduct was isolated whereas, at elevated temperature (140 °C), it has been converted into the aminated product with good yield. Notably, there is no byproduct in the overall process. The use of base-free conditions, excellent site selectivity, and good functional group tolerance are the important features of the process. [ABSTRACT FROM AUTHOR]

An operationally simple approach to azolo[4,5‐b]quinolines based on the condensation of 2‐aminobenzaldehydes with various azolones is developed. A series of 22 compounds was synthesized typically in good yields (40–92 %). [ABSTRACT FROM AUTHOR]

Chromenes are an essential class of oxygen‐containing heterocyclic compounds with intriguing biological activity. It is an important moiety for the discovery of new drug candidates. Chromenes are naturally abundant as alkaloids, tocopherols, flavones, and anthocyanins. The incorporation of 4H‐chromene, along with various bioactive heterocycles such as indole, pyrazole, kojic acid, pyran‐2‐one, quinoline, pyridine, pyrimidine, coumarin, sesamol, furan, uracil, benzoimidazole, benzotriazole, thiazole, isoxazole and barbituric acid moieties, into a molecular scaffold has the potential to combine the properties of both components. The synergistic effect of combining different heterocyclic moieties within a 4H‐chromene nucleus results in the formation of valuable compounds with significant biological importance. This review summarizes the different synthetic techniques used for preparing 4H‐chromene‐embedded heterocycles. The common mechanisms of key reactions and the significance of the method are discussed. [ABSTRACT FROM AUTHOR]

AbstractA new library of quinoline–natural product conjugates bearing 1,2,3-triazole moiety as a linker has been synthesized using the copper(I) catalyzed azide-alkyne [3 + 2] cycloaddition reaction (CuAAC) methodology. The structure characterization of the synthesized compounds was achieved using NMR and HRMS analysis. The compounds were subsequently screened for their antimicrobial efficacies against methicillin resistant Staphylococcus aureus (MRSA), MDR Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, and Cryptococcus neoformans. The studied compounds generally displayed stronger inhibition of microbial cell growth compared to their parent phenolic natural products. Eugenol, thymol, guaiacol, and o-vanillin based 1H-1,2,3-triazole compounds exhibited the best antimicrobial profiles while the pathogen, A. baumannii showed the highest susceptibility to the hybrids. Precisely, hybrids 19a, 20b, and 25b derived from eugenol, thymol, and o-vanillin, respectively, exhibited over 50% growth inhibition of the pathogen. K. pneumoniae was however strongly resistant to the compound series. In silico docking studies of the representative compounds further explored the characteristic binding orientations of these compounds in the active sites of the bacterial and fungal proteins. Overall, we perceive that rational scaffold hopping of these compounds holds promise to offer novel antimicrobial agents with enhanced potency. [ABSTRACT FROM AUTHOR]

Visible-light photocatalysis has evolved as a powerful technique to enable controllable radical reactions. Exploring unique photocatalytic mode for obtaining new chemoselectivity and product diversity is of great significance. Herein, we present a photo-induced chemoselective 1,2-diheteroarylation of unactivated alkenes utilizing halopyridines and quinolines. The ring-fused azaarenes serve as not only substrate, but also potential precursors for halogen-atom abstraction for pyridyl radical generation in this photocatalysis. As a complement to metal catalysis, this photo-induced radical process with mild and redox neutral conditions assembles two different heteroaryl groups into alkenes regioselectively and contribute to broad substrates scope. The obtained products containing aza-arene units permit various further diversifications, demonstrating the synthetic utility of this protocol. We anticipate that this protocol will trigger the further advancement of photo-induced alkyl/aryl halides activation. Visible-light photocatalysis has evolved as a powerful technique to enable controllable radical reactions and the exploration of new photocatalytic mode for product diversity is of great significance. Herein, the authors present a photo-induced chemoselective 1,2-diheteroarylation of unactivated alkenes utilizing halopyridines and quinolines. [ABSTRACT FROM AUTHOR]

An electrochemical method with high faradaic efficiency was developed for the ruthenium‐catalyzed C8‐regioselective aroylation of quinoline N‐oxides under oxidant‐free conditions by using aryl α‐ketoacids as the aroylation reagent. A series of 8‐aroylquinoline N‐oxides were effectively synthesized in moderate‐to‐excellent yields. Furthermore, the proposed method was successfully applied to the gram‐scale synthesis of a tubulin polymerization inhibitor. Additionally, a plausible reaction mechanism for the decarboxylation radical acylation was proposed on the basis of the results of cyclic voltammetry and control experiments. Overall, this method provides a novel solution for the C8‐regioselective aroylation of quinoline N‐oxides. [ABSTRACT FROM AUTHOR]

The document is the contents list for an issue of the journal Chemical Communications. It includes articles on various topics such as AI-assisted chemistry research, modification strategies of lead halide perovskite nanocrystals, gold catalysis in quinoline synthesis, and rapid production of H2O2 in a photocatalyst suspension. The journal is published by The Royal Society of Chemistry and aims to connect the world with the chemical sciences. [Extracted from the article]

Quinolines are biologically and pharmaceutically important N-heterocyclic aromatic compounds, which have broad applications in medicinal chemistry. Thus, their efficient synthesis has attracted extensive attention, and a broad range of synthetic strategies have been established. Of note, gold-catalyzed methodologies for the synthesis of quinolines have greatly advanced this field. Various gold-catalyzed intermolecular annulation reactions, such as annulations of aniline derivatives with carbonyl compounds or alkynes, annulations of anthranils with alkynes, and annulations based on A3-coupling reactions, as well as intramolecular cyclization reactions of azide-tethered alkynes, 1,2-diphenylethynes, and 2-ethynyl N-aryl indoles, have been developed. This review provides an overview of this exciting research area. Typical achievements in reaction methodologies and plausible reaction mechanisms are summarized. [ABSTRACT FROM AUTHOR]

A new cobalt-based metal–organic framework with the chemical formula of [Co2(DClTPA)2(DABCO)]·(DMF)4 (MUT-16) containing 1,4-diazabicyclo[2.2.2]octane (DABCO) and 2,5-dichloroterephthalic acid (DClTPA) has been designed and prepared through a solvothermal method. MUT-16 (MUT = Materials from University of Tehran) crystallized in a tetragonal system with I41/acd space group, based on single-crystal X-ray analysis. The Ag@MUT-16 nanocomposite was prepared using Ag nanoparticles (NPs) loaded into/onto porous MUT-16via photoreduction route (PR). The MUT-16 and Ag@MUT-16 were characterized using various techniques, such as PXRD, FT-IR, FE-SEM, TEM, EDX, N2 adsorption–desorption isotherms, TGA, DRS, PL, EIS, and Mott–Schottky measurements. The Ag@MUT-16 nanocomposite showed photocatalytic activity of 87.75% in the degradation of Quinoline Yellow (QY) after 30 min under visible light irradiation. The distinctive characteristics of the Ag@MUT-16 nanocomposite, such as the Fenton-like effect of Co2+ ions, surface plasmon resonance (SPR) of Ag NPs, Schottky junction at interfaces between Ag NPs and MUT-16, and reduction of electron–hole recombination through electron trapping by Ag NPs as co-catalyst, all play significant roles in the photocatalytic degradation of Quinoline Yellow (QY). [ABSTRACT FROM AUTHOR]

We describe herein the additive‐controlled divergent [4+2] cycloaddition and 1,4‐Michael addition reaction of benzofuran‐derived azadienes (BDAs) with enamides. An unprecedented [4+2] cycloaddition reaction of BDAs and enamide compounds was developed in the presence of 4 Å MS, providing a variety of structurally complex decahydrobenzofuro[3,2‐b]quinolines (13 examples) in moderate to excellent yields (59–98 % yields) with single diastereoisomer obtained. While employing MgSO4 as desiccant, the chemoselectivity was switched to the 1,4‐addition reactions, leading to a wide range of highly functionalized hybrids of benzofurans and enamide compounds (25 examples) in 25–94 % yields under mild conditions. [ABSTRACT FROM AUTHOR]

A one‐pot Kabachnik‐Fields reaction is used in the presence of magnesium triflate [Mg(OTf)2] as a catalyst between quinoline, diethyl phosphite (DEP), and substituted aldehydes to synthesize quinoline thioacetohydrazide α‐aminophosphonates (5 a‐f). Analytical and spectroscopic techniques identify the novel compounds. The cytotoxicity properties of the synthesized compounds were examined against HepG2 and MCF7 human cancer cells using the MTT assay. Some of the synthesized compounds exhibit potent anticancer activities. Compounds 5 e and 5 b exhibited the most promising activity against MCF7 human cancer cells, while compounds 5 c and 5 e were potent against HepG2 human cancer cells. Molecular docking experiments on the active compounds showed ring‐stacking interactions between compounds 5 b, 5 c, and 5 e with other proteins, which are compatible with other results. [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]

Imidazo[1,5‐a]quinolines emit intense blue luminescence, suggesting their possible use as emitter molecules in organic light‐emitting diodes. We synthesized several new imidazo[5,1‐a]isoquinolines and found they possessed a characteristic hypsochromic effect and even increased quantum efficiency compared to the homolog imidazo[1,5‐a]quinolines, as measured by UV‐vis‐ and fluorescence spectroscopy in solution. The energies of the highest occupied and lowest unoccupied molecular orbitals were calculated using density functional theory and experimentally determined by cyclic voltammetry in solution. We obtained a maximum fluorescence quantum yield of 48 % at 446 nm for the newly synthesized 3‐(4‐cyanophenyl)‐1‐(pyridyl)imidazo[5,1‐a]isoquinoline with an optimized substitution pattern. For 1‐phenyl‐3‐(2‐pyridinyl)imidazo[5,1‐a]isoquinoline, a quantum yield of 33 % was obtained at an even shorter emission wavelength of 431 nm. [ABSTRACT FROM AUTHOR]

A series of benzoquinoline-employing heterocycles was synthesized by treating 3-chlorobenzo[f]quinoline-2-carbaldehyde with N-phenyl-3-methylpyrazolone, 4-aminoacetophenone, 1,2-diaminoethane, and 2-cyanoethanohydrazide. Also, pyridine, chromene, α,β-unsaturated nitrile, thiosemicarbazone, and 1,2-bis-aryl hydrazine derivatives were prepared from the cyanoethanohydrazone obtained. The DFT calculations and experiment outcomes were consistent. In vitro screening of their antiproliferative efficacy was examined against HCT116 and MCF7 cancer cell lines. The pyrazolone 2 and cyanoethanohydrazone 5 derivatives exhibited the most potency, which was demonstrated by their molecular docking towards the CDK-5 enzyme. The binding energies of compounds 2 and 5 were − 6.6320 kcal/mol (with RMSD of 0.9477 Å) and − 6.5696 kcal/mol (with RMSD of 1.4889 Å), respectively, which were near to that of co-crystallized ligand (EFP). This implies a notably strong binding affinity towards the CDK-5 enzyme. Thus, pyrazolone derivative 2 would be considered a promising candidate for further optimization to develop new chemotherapeutic agents. In addition, the ADME (absorption, distribution, metabolism, and excretion) analyses displayed its desirable drug-likeness and oral bioavailability properties. [ABSTRACT FROM AUTHOR]

We previously reported on the interaction of 10-chloro-7H-benzo[de]benzo[4,5] imidazo[2,1-a]isoquinolin-7-one (10-Cl-BBQ) with the Aryl hydrocarbon Receptor (AhR) and selective growth inhibition in breast cancer cell lines. We now report on a library of BBQ analogues with substituents on the phenyl and naphthyl rings for biological screening. Herein, we show that absence of the phenyl Cl of 10-Cl-BBQ to produce the simple BBQ molecule substantially enhanced the growth inhibitory effect with GI50 values of 0.001-2.1 ^iM in select breast cancer cell lines MCF-7, T47D, ZR-75-1, SKBR3, MDA-MB-468, BT20, BT474 cells, while having modest effects of 2.1-7 ^iM in other cell lines including HT29, U87, SJ-G2, A2780, DU145, BE2-C, MIA, MDA-MB-231 or normal breast cells, MCF10A (3.2 ^iM). The most potent growth inhibitory effect of BBQ was observed in the triple negative cell line, MDA-MB-468 with a GI50 value of 0.001 ^M, presenting a 3,200-fold greater response than in the normal MCF10A breast cells. Additions of Cl, CH3, CN to the phenyl ring and ring expansion from benzoimidazole to dihydroquinazoline hindered the growth inhibitory potency of the BBQ analogues by blocking potential sites of CYP1 oxidative metabolism, while addition of Cl or NO2 to the naphthyl rings restored potency. In a cell-based reporter assay all analogues induced 1.2 to 10-fold AhR transcription activation. Gene expression analysis confirmed the induction of CYP1 oxygenases by BBQ. The CYP1 inhibitor a-naphthoflavone, and the SULT1A1 inhibitor quercetin significantly reduced the growth inhibitory effect of BBQ, confirming the importance of both phase I and II metabolic activation for growth inhibition. Conventional molecular modelling/docking revealed no significant differences between the binding poses of the most and least active analogues. More detailed DFT analysis at the DSD-PBEP86/Def-TZVPP level of theory could not identify significant geometric or electronic changes which would account for this varied AhR activation. Generation of Fukui functions at the same level of theory showed that CYP1 metabolism will primarily occur at the phenyl head group of the analogues, and substituents within this ring lead to lower cytotoxicity. [ABSTRACT FROM AUTHOR]

The building of N-heterocyclic cores endures an influential area of research due to their ubiquitous presence in natural products, agrochemicals, and small bioactive molecules. Over the past two decades, the synthesis of N-heterocycles via C-H activation comes out as a dominating synthetic protocol in atom-economic manner. The creation of C-C/C-N bonds acts as a key determining step for the building of nitrogen-based heterocycles via direct C-H activation protocol, which could serve as a fascinating concept. In recent years, Group 9 (Co, Rh & Ir) transition metal emerged as a robust catalytic system for the development of valuable N-heterocyclic scaffolds among other transition metals due to their mild reaction conditions, high reactivity, and functional group tolerance. A diverse type of arenes such as anilines/anilides, benzamides, hydrazones, ketoximes, benzylamine, and N-aryl nitrones were subjected to the C-H bond activation for the annulation reaction. Moreover, unsaturated compounds such as alkyne and olefin as coupling partners are again the most used companions for the same purpose, i.e., formation of N-heterocycles. Therefore, this review centers on the up-to-date reports on N-heterocycles synthesis by implementing alkynes and olefins as coupling partners through Group 9 transition metals' catalysis. The methodologies will be based on the coupling of alkynes and olefin, which preferably react in an intermolecular fashion. The scope, limitation, and mechanistic investigation of the Group 9 metal-activated C-H functionalization for the access of N-containing heterocycles with unsaturated reacting partners are the primary focus of the current review. [ABSTRACT FROM AUTHOR]

A series of quinoline-thiazole appended 1,4-disubstituted 1,2,3-triazole were synthesized by performing Cu(I) catalyzed 1,3-dipolar cycloaddition reaction ("Click" reaction) and fully characterized by various spectral techniques like FTIR, NMR and HRMS. These compounds were evaluated for in vitro antimalarial activity against plasmodium falciparum. All the compounds (7a–7y) exhibited moderate to good activity in comparison to standard drug Quinine. Compound 7r (IC50 0.19 µg/mL) displayed appreciable activity comparable to Quinine (IC50 0.268 µg/mL). Further antimicrobial screening of the synthesized substituted triazoles were also carried out against two gram (+) bacteria (Staphylococcus aureus, Bacillus subtilis), two gram (–) bacteria (Escherichia coli, Klebsiella pneumonia) and two fungi (Candida albicans, Aspergillus niger). Results revealed that compound 7r reflected promising antimicrobial activity among the synthesized library of molecules. Molecular docking studies of broadly active antimalarial disubstituted triazoles 7m and 7r were explored in the active site of enzyme dihydroorotate dehydrogenase (DHODH) to have the probable mode of action. [ABSTRACT FROM AUTHOR]

Herein, the synthesis of homoallylic amines, quinolines, and tetrahydroquinolines has been demonstrated. The domino one‐pot multi‐component approach has been accomplished using Lewis acid‐catalyzed conditions. A useful scaffold construction strategy can be achieved by controlling the electronic effect of aniline rather than relying on reaction conditions. The described method applies to a wide variety of substrates embedded with diverse functional groups and can be extended toward the synthesis of natural products. Suitable control experiments, real‐time NMR studies, and DFT calculations have validated the reported process. The protocol outlines a strategy for synthesizing homoallylic amines and quinolines, controlled by the electronic properties of anilines. [ABSTRACT FROM AUTHOR]

The effect of periodic acid on oxidation of the quinoline alkaloids bucharaine, foliosidine, evoxine, and dubinidine was studied as a function of their structures and the reaction conditions. Periodic acid in dilute aqueous solutions was shown to form stable gem-diols. The use of a large excess of HIO4 formed gem-diols and aldehydes. O-Methyl derivatives were obtained in aqueous MeOH solutions. [ABSTRACT FROM AUTHOR]

A novel 8-hydroxy quinoline-derived amide receptor, in conjunction with its Cu (II) and Zn (II) complexes, has been strategically developed to function as remarkably efficient fluorescent receptors with a distinct capability for anion sensing. The comprehensive characterization of the synthesized compounds were achieved through UV-Vis, IR, NMR, and HRMS spectroscopic techniques. Among the Cu (II) and Zn (II) complexes, the latter exhibits superior selectivity for anions, specifically dihydrogen phosphate and hydrogen sulfate, as their tetrabutylammonium salts in a 9:1 acetonitrile-water (v/v) mixture. The Cu (II) complex demonstrates enhanced anion binding compared to the amide ligand, albeit with reduced selectivity. Furthermore, the affinity was evaluated using the Benesi-Hildebrand plot. The binding constants and Limit of Detection (LOD) for both complexes were precisely quantified. The Job plot illustrates a clear 1:1 binding interaction between the metal complexes and the guest anions. Significantly, both metal-complex receptors display a broad spectrum of antibacterial activity, against both gram-positive and gram-negative bacteria. It is worth highlighting that the Zn (II) complexed receptor outperforms the Cu (II) complexed receptor, as evidenced by its considerably lower Minimum Inhibitory Concentration (MIC) value against both bacterial strains. [ABSTRACT FROM AUTHOR]

A novel series of imidazole appended quinoline derivatives (6a–j) have been synthesized using the one-pot three-component reaction that occurred between the starting materials of substituted 2-phenoxyquinolin-3-carbaldehydes (3a-j), benzil (4), and ammonium acetate (5) by taking equimolar ratio. The newly synthesized imidazole-appended quinolines were subjected to probable inhibition against the anti-diabetic drug target maltase enzyme. The efficacy was tested using in-silico molecular docking analysis and molecular dynamics simulation. The studies revealed that the test 6f ligand (3-(4,5-diphenyl-1H-imidazol-2-yl)-2-phenoxy quinoline) is a strong inhibitor of the target protein maltase when compared with the known inhibitor acarbose and sheds new light on the medicinal chemistry research for the application of the synthesized 6f ligand in the pharmaceutical industry. [ABSTRACT FROM AUTHOR]

Heterocyclic amines (HAs) are a group of mutagenic and carcinogenic compounds produced from the processing of high‐protein foods, which include 2‐amino‐3‐methylimidazo[4, 5‐f]quinoline (IQ) showing the strongest carcinogenic effect. Camels are able to digest HAs in foods, which provide rich microbial resources for the study. Thus, camel rumen and intestinal microbiota were used to degrade IQ, and the dominant microorganisms and their degradation characteristics were investigated. After three generations of culture with IQ as the sole carbon source, the highest abundance in rumen and intestinal microbes was found in the Proteobacteria phylum. The strains of third generation of the rumen contents were mainly attributed to the genera Brevundimonas and Pseudomonas, and the dominant genera in intestine were Ochrobactrum, Bacillus, and Pseudomonas. Microorganisms were further isolated and purified from the third generation cultures. These 27 strains from the rumen (L1–L27) and 23 strains from the intestine (C1–C23) were obtained. Among them, four strains with the most effective degrading abilities were as follows: L6 (28.55% of IQ degrading rate) and C1 (25.19%) belonged to the genus Ochrobactrum, L15 (23.41%) belonged to the genus Pseudomonas, and C16 (20.89%) were of the genus Bacillus. This study suggested the application of abundant microbial resources from camels' digestive tract to biodegrade foodborne toxins. [ABSTRACT FROM AUTHOR]

The work is devoted to the study of the influence of nitrogenous bases on the composition of oil and the structure of asphaltenes on their colloidal stability in solution. Model petroleum systems with a basic nitrogen content of 1, 2, and 3% wt. were used as objects of study. Asphaltene-like nitrogenous bases were obtained by thermolysis of model petroleum systems with different nitrogen contents. The results were obtained using elemental analysis, non-aqueous potentiometric titration, spectrophotometry, 1H NMR spectroscopy, and liquid adsorption chromatography. It was established that the content of Nbas in asphaltenes increases by 0.3–1.3% wt. with the increase in quinoline content in petroleum components. Quinoline is incorporated into the supramolecular structure of asphaltenes and increases their average molecular weight by 650 amu. and aromaticity by 2%. The aggregative stability of asphaltenes decreases by 1.5–6 times with an increase in their average molecular weight and an increase in Nbas in their composition as a component of a dispersion medium. The colloidal stability of synthetic asphaltene-like substances, on the contrary, is due to the appearance of their molecular sequence of fragments containing Nbas in aromatic rings. [ABSTRACT FROM AUTHOR]

Attempts to carry out intramolecular annulation of 9,10‐diarylbenzo[h]quinolines and 9,10‐di(hetero)arylphenanthrenes to aromatics with expanded π‐conjugated systems by using different methods are described. The starting compounds (9,10‐diarylbenzo[h]quinolines and 9,10‐di(hetero)arylphenanthrenes) were prepared by C−C bond activation in 1‐azabiphenylene or biphenylene followed by insertion of internal alkynes. Interestingly, unlike in purely carbon‐based aromatics, the course of the annulation turned out to be highly dependent on the structure of maternal compounds. In a handful of cases were obtained the expected or desired products. In others, unexpected rearrangements of the basic molecular frameworks were observed. [ABSTRACT FROM AUTHOR]