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In this investigation, we present synthesis and characterized of three new heteropolynuclear cyanide complexes with 2- (Hydroxymethyl)pyridine (hmpH) of [M(H2O)(hmpH)Ni(CN)4]2·nH2O, (M(II) = Fe, Co and Ni); n = 12 for Fe, 2 for Co and Ni). The obtained complexes have been studied by elemental, thermal analysis, FT-IR, and Raman spectroscopic measurement techniques. Considering the alterations in characteristic peaks of cyanide, aqua, and hmpH ligands, general knowledge about the structural features of the complexes was detected from the vibrational spectra. The Ni(II) ion is coordinated by four cyanidecarbon atoms forming a square planar geometry. In addition, thermal analyses and electrical features of the complexes were investigated. [ABSTRACT FROM AUTHOR]

This article provides a detailed account of the synthesis and characterization of pyridinium salts derived from hydroxymethyl-containing compounds. The researchers conducted bioactivity tests on the synthesized salts and found that some of them exhibited strong antimicrobial activity against bacteria and fungi. The study suggests that these salts have the potential to be developed into new antimicrobial drugs, but further research is needed to fully explore their properties. The research was conducted by scientists from Kazan Federal University and Kazan State Medical Academy in Russia. [Extracted from the article]

The resulting mixture was purified by flash column chromatography on silica gel (gradient elution: 5% to 45% EtOAc in hexanes) to afford the desired product B 17 b (0.872 g, 4.77 mmol, 72% yield) as a yellow solid. Keywords: 1,4-oxazinones; cycloaddition; cycloreversion; pyridine synthesis; domino reaction; Diels-Alder reaction; natural product synthesis EN 1,4-oxazinones cycloaddition cycloreversion pyridine synthesis domino reaction Diels-Alder reaction natural product synthesis 2319 2324 6 07/14/23 20230801 NES 230801 Graph Guaipyridine sesquiterpene alkaloids are a family of nearly 20 structurally related natural products characterized by a 2-methylpyridine fused to a saturated seven-membered ring (Figure 1). NEt SB 3 sb (0.35 mL, 2.58 mmol), pyridine (0.21 mL, 2.58 mmol), and Ac SB 2 sb O (0.24 mL, 2.58 mmol) were added to the reaction mixture. 1,4-oxazinones, cycloaddition, cycloreversion, domino reaction, Diels-Alder reaction, natural product synthesis, pyridine synthesis. [Extracted from the article]

Methods for the preparation of pinopyridines from pinocarvone oxime or its ethers and alkenes (alkynes) using the C–H activation reaction were studied. Palladium complexes and Wilkinson's catalyst were chosen as the catalytic systems. [ABSTRACT FROM AUTHOR]

The gas phase pyridine synthesis process is usually carried out in a fluidized bed reactor. The contact efficiency between the reactants and the catalysts has great influence on the reactor performance. In this paper, three fluidized bed reactors with different flow patterns were used to investigate the contact efficiency. The superficial contact efficiency index (SCEI) was defined and used in this paper to quantify the contact efficiency inside these reactors. To obtain the values of the SCEI, the ideal reactor model was constructed. The results showed that the SCEI average value decreased as the flow pattern shifted from fast fluidization to bubbling fluidization; these values were 0.86, 0.55, and 0.19 for the fast fluidized bed reactor, turbulent fluidized bed reactor, and bubbling fluidized bed reactor, respectively. An empirical correlation was proposed in this paper to predict the SCEI under different operating conditions. The model prediction results agreed well with experimental results with an average prediction error of 8%. [ABSTRACT FROM AUTHOR]

A Co‐catalyzed enantioselective desymmetric [2+2+2] cycloaddition for synthesis of pyridines with all‐carbon quaternary carbon centers has been developed. The regio‐ and enantioselectivities are controlled by the inherent nature of terminal alkynes and the substituents on the bisoxazolinephosphine ligands. Pyridines with 5‐substitutents could be obtained with >20:1 regioselectivity and up to 94 % ee when terminal alkyl, alkenyl or silyl alkynes and DTBM/Ph‐based NPN* ligand L6 were used. Terminal aryl alkynes and Ph/Bn‐based ligand L4 leads to formation of pyridines with 6‐substitutents in up to 99 % ee. [ABSTRACT FROM AUTHOR]

A library of new spiro[diindeno[1,2-b:2′,1′-e]pyridine-11,3′-indoline]-2′,10,12-trione derivatives has been prepared in an efficient, one-pot pseudo four-component method mediated by a reusable heterogeneous nano-ordered mesoporous SO3H functionalized-silica (MCM-41-SO3H) catalyst. Excellent yields, short reaction times, as well as convenient non-chromatographic purification of the products and environmental benefits such as green and metal-free conditions constitute the main advantages of the developed synthetic methodology. The obtained fused indole-indenone dyes would be of interest to pharmaceutical and medicinal chemistry. Furthermore, due to their sensitivity to pH changes, they could be used as novel pH indicators. [ABSTRACT FROM AUTHOR]

In this study was preparation heterocyclic compounds of seven ring know Oxazepine compounds through reaction of schiff base compounds with cyclic anhydride (phthalic anhydride, malic anhydride, succinic anhydride), schiff base compound synthesis by reaction between pyridine derivatives and different aldehyde compound and the prepare compounds were identification by infrared technology as well as the use of carbon magnetic resonance spectroscopy (13C-NMR) as well as the hydrogen nuclear resonance spectroscopy (1H-NMR). The biological activity of the prepared compounds was studied and its effect on two bacteria gram negative bacteria (Escherichia coli) and gram-positive bacteria (Staphylococcus aureus), which causes many diseases as well as the biological activity of the prepared compounds was studied on two Fungi (Penicillium, Aspergillus). The compound (9) studied its effect on breast cancer cells. [ABSTRACT FROM AUTHOR]

Pyrido[1,2-a]pyrimidin-4-one and their derivatives are found to be key intermediates in the synthesis of medicinally active compounds. Therefore an efficient and convenient procedure has been developed for the synthesis of some novel pyrido[1,2-a]pyrimidin-4-one derivatives like aryl-N-(2-(2-methyl-4-oxo-8-(trifluoromethyl)-4H-pyrido[1,2-a]pyrimidin-3-yl)ethyl) carboxamide and alkyl-N-(2-(2-methyl-4-oxo-8-(trifluoromethyl)-4H-pyrido[1,2-a]pyrimidin-3-yl)ethyl)carboxamide. The structures of the new compounds have been evaluated on the basis of FT-IR, ¹H NMR and Mass spectroscopy data. They have also been screened for their antimicrobial activities against various strains of bacteria and fungi. [ABSTRACT FROM AUTHOR]

The reactions of 2,6-bis(1,4-diphenyl-5-hydroxy-1H-pyrazol-3-yl)pyridine (L), which is the first representative of a series of 2,6-bis(pyrazol-3-yl)pyridine ligands bearing substituents in positions 1 and 4 of the pyrazol-3-yl ring, with the divalent iron and cobalt salts afford new Со(II) and Fe(II) complexes: [Co(L)2](ClO4)2 (I) and [Fe(L)2](ClO4)2 (II). The compounds are isolated in the individual state and characterized by elemental analysis, NMR spectroscopy, and X-ray diffraction analysis (CIF files CCDC nos. 1967892 (I) and 1967893 (II)). According to the data obtained, the transition metal ion in complexes I and II exists in the high-spin state (S = 3/2 for Co(II) and S = 2 for Fe(II)) in a range of 120–345 K, and the proposed modification of the ligand does not lead to the temperature-induced spin transition in both the solution and crystalline state. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride as an interesting sustainable soft nanomaterial has drawn broad interdisciplinary attention because of unique electronic structure and chemical stability. An ultrasound-assisted preparation of a series of polysubstituted pyridines in the presence of a polar and strongly acidic sulfonated magnetic graphitic carbon nitride (Fe3O4@g-C3N4-SO3H) under milder and faster reaction conditions in water as a green medium was reported. One-pot sequential multicomponent reaction of aromatic aldehydes with acyclic and cyclic ketones, malononitrile and ammonium acetate was afforded the pyridine derivatives in good-to-excellent yields. In view of eco-friendly and economic considerations, this approach offers a straightforward and convenient route to generate biologically active pyridine derivative in an environmentally friendly manner. The Fe3O4@g-C3N4-SO3H showed high stability and reusability over several reaction sets without noteworthy loss of activity, and thus, this method is a cheap and eco-friendly procedure. [ABSTRACT FROM AUTHOR]

A transition-metal-free synthesis of pyridine derivatives by 6- endo - dig cyclization of N -propargyl enamines was developed. This method is environmentally friendly and is a high atom economy reaction that is easily accessed to provide pyridine derivatives in moderate to good yield by heating N -propargyl enamines in solvent without additives. The total synthesis of onychine was achieved in 51% yield in only two steps by using this method. [ABSTRACT FROM AUTHOR]

Pyridine-3-carbaldehyde reacted with 1-(aryl)ethan-1-ones to give 1,5-diaryl-3-(pyridin-3-yl)pentane-1,5-diones, which were further converted to 2′,6′-bis-aryl-3,4′-bipyridines. [ABSTRACT FROM AUTHOR]

N‐heterocyclic carbene‐catalyzed activation of ynals for rapid synthesis of pyridine derivatives with important utilities has been reported. This successful strategy using NHC‐bound alkynyl acyl azolium as the key intermediate further improved the application of N‐Ts 2‐aminoacrylate as a nucleophile. Importantly, this work introduces an ester substituent to pyridines that could be easily transformed to other functional groups. [ABSTRACT FROM AUTHOR]

We synthesised palladium and platinum complexes possessing cyclic and acyclic pincer‐type polyaromatic ligands and investigated their structural effect on the catalysis. The pincer‐type bis(6‐arylpyridin‐2‐yl)benzene skeleton was constructed via Kröhnke pyridine synthesis under transition metal‐free conditions on gram‐scale quantity. Ligand structure significantly influenced catalytic activity toward the platinum‐catalysed hydrosilylation of diphenyl acetylenes, despite the ligand‐independence of the conformations and electronic properties of these complexes. [ABSTRACT FROM AUTHOR]

The catalytic effects of two forms of nano‐TiO2, which are prepared via an ordinary or a magnetized process, are investigated in the synthesis of pyridine dicarbonitriles by one‐pot multicomponent reaction of 4‐methyl thiophenol, malononitrile, and aryl aldehydes. The results have shown that both prepared nano‐TiO2 exhibited high catalytic activities toward the synthesis of pyridine dicarbonitrile derivatives but the nano‐TiO2, which is prepared via a magnetized process, has shown better catalytic activity. Furthermore, this new catalytic method for the synthesis of pyridine dicarbonitriles provides rapid access to the desired compounds in high yields and so a simple work‐up procedure in the presence of water at room temperature. Therefore, this method represents a significant improvement incompatible of the other methods that are available for the synthesis of pyridine dicarbonitriles. [ABSTRACT FROM AUTHOR]

A convenient and efficient strategy has been devised for the synthesis of bipyrido‐fused coumarins employing Kröhnke's pyridine synthesis approach. In the present work, 4‐hydroxycoumarins 1a–d were reacted with appropriate chalcones 2a–c to afford desired bipyridyl‐fused coumarins 3a–l. The structures of all the newly synthesized compounds 3a–l were ascertained by IR, 1H NMR, 13C NMR, mass spectral data, and elemental analyses. The compounds were further evaluated for their antimicrobial response against representative panel of pathogens, and the results thus obtained were compared with those of standard drugs. Few of the derivatives 3c, 3f, and 3i exhibited promising potency. [ABSTRACT FROM AUTHOR]

An efficient copper‐catalyzed cyclization of acetophenone and ammonium acetate with release of methane has been developed for the synthesis of polysubstituted pyridines. A series of 2,4,6‐triphenyl‐pyridines has been produced in good yields. This synthetic method is sustainable, simple, and environment‐friendly. [ABSTRACT FROM AUTHOR]

A facile approach to access polysubstituted pyridine derivatives starting from Baylis‐Hillman adducts is disclosed. The reactions proceeded smoothly by sequential AlCl3‐catalyzed condensation/aza‐Wittig/isomerization reactions, leading to the target products at room temperature within 24 h in moderate to good yields. Furthermore, the final products were evaluated in mycelial growth tests against Pythium dissimile, Botryotinia fuckeliana and Zymoseptoria tritici and showed potential activities. [ABSTRACT FROM AUTHOR]

• Two silver(I) complexes bearing mefenamic acid and pyridine derivatives were synthesized and characterized. • Antiproliferative activity towards MCF-7, HT-29, HepG2 and 3T3L1 cell lines was investigated. • The Ag(I) complexes exhibited considerably higher selectivity between the tested cancer and healthy cell lines than carboplatin. • Induction of apoptosis and ROS production were measured in MCF-7 cell line. Two Ag(I) complexes [Ag 2 (μ-mef) 2 (2-pymet) 2 ] 1 , [Ag 2 (μ-mef) 2 (2-pyet) 2 ] 2 containing mefenamic acid, 2-pyridinemethanol and 2-pyridineethanol were synthesized and characterized by using SCXRD, FT-IR, elemental and thermal analysis techniques. The complex 1 was synthesized as a single crystal whereas the complex 2 was obtained as a microcrystalline powder. The complex 1 consists of binuclear structure. The argentophilic interaction occurs among silver(I) ions due to the short Ag⋯Ag distance (2.8710(10) Å). Two Ag(I) centers are connected by carboxylato oxygen-bridge to form the binuclear metal core. The FT-IR spectra and thermal analysis studies confirmed that both complexes exhibited similar structures. In vitro antiproliferative activity of both complexes were evaluated against MCF-7, HT-29 and HepG2 cancer cell lines. The apoptotic effects and intracellular ROS generation from both complexes were investigated in MCF-7 cell line by flow cytometry analysis. The XTT and LDH assays revealed that both complexes showed strong antiproliferative activity with higher selectivity towards cancer cells compared to the normal cells. In addition, Annexin V/propidium iodide assay exhibited that apoptotic cell number was increased in MCF-7 cells with increasing concentrations of Ag(I) complexes. Furthermore, both complexes induced the ROS generation considerably in MCF-7 cells suggesting the possible pro-oxidant activity of the novel synthesized Ag(I) complexes. Taken together, these findings provide a notable support for potential utility of Ag(I) complexes as novel anticancer agents against numerous kind of carcinogenesis. [ABSTRACT FROM AUTHOR]

2,2′‐Bipyridyls have been utilized as indispensable ligands in metal‐catalyzed reactions. The most streamlined approach for the synthesis of 2,2′‐bipyridyls is the dehydrogenative dimerization of unfunctionalized pyridine. Herein, we report on the palladium‐catalyzed dehydrogenative synthesis of 2,2′‐bipyridyl derivatives. The Pd catalysis effectively works with an AgI salt as the oxidant in the presence of pivalic acid. A variety of pyridines regioselectively react at the C2‐positions. This dimerization method is applicable for challenging substrates such as sterically hindered 3‐substituted pyridines, where the pyridines regioselectively react at the C2‐position. This reaction enables the concise synthesis of twisted 3,3′‐disubstituted‐2,2′‐bipyridyls as an underdeveloped class of ligands. [ABSTRACT FROM AUTHOR]

Abstract Herein, a new metal-organic framework based on Cu(II) and 3-bromo-5-(4-carboxyphenyl)pyridine (HL) was obtained under hydrothermal condition, namely, CuL 2 (1). Its structure was characterized by single-crystal X-ray diffraction and further determined by IR spectroscopy as well as thermogravimetric analysis (TGA) and differential thermoanalysis (DTA). In 1 , every L anion links three Cu(II) ions to generate a three-dimensional (3D) framework with a 3,6-connected (4⋅62) 2 (42⋅610⋅83) topology. Meanwhile, the photoluminescent and magnetic properties of 1 were investigated. Graphical abstract A three-dimensional 3,6-connected metal-organic framework based on Cu(II) and 3-bromo-5-(4-carboxyphenyl)pyridine has been successfully constructed under hydrothermal condition. The metal-organic framework displays a dual property of photoluminescence and magnetism. Image 1 Highlights • A 3D 3,6-connected metal-organic framework was obtained under hydrothermal condition. • The metal-organic framework displays the photoluminescent and magnetic properties. • 3-bromo-5-(4-carboxyphenyl)pyridine was first utilized to construct metal-organic framework. [ABSTRACT FROM AUTHOR]

Pseudomonas sp. JY-Q was isolated from nicotine-rich environment and could degrade and tolerate high-content nicotine. Its specific genetic architecture comprised duplicated homologous nicotine-degrading clusters for different functional modules on the whole pathway. Its adaptive and genomic properties caused our concern whether the duplicated homologous gene clusters confer additive effects on nicotine degradation and result in strain JY-Q strong capability. After deletion of representative genes from duplicated homologous gene clusters of upstream module Nic1, midstream module Spm, and downstream module Nic2, the nicotine degradation efficiency of the wild type and mutant strains were examined. As the first genes of clusters Nic1-1 and Nic1-2, nicA2 and nox are both involved in nicotine degradation, but nox exhibited more contribution to nicotine metabolism due to the higher transcriptional amount of nox than that of nicA2. Likewise, the sub-clusters spm1 and spm2 showed additive effect on nicotine metabolism. As two hpo-like genes of clusters Nic2-1 and Nic2-2, hpo1, and hpo2 also showed additive effect on the nicotine degrading, but hpo1 provided more contribution than hpo2. The third hpo-like gene in cluster NA (nicotinic acid degrading), nicX is not necessary for 2,5-dihydroxypyridine transformation when hpo1 and hpo2 exist. A variety of transposases and integrases observed around Nic1 and Nic2 cluster genes suggests that the duplicated genes could evolve from horizontal gene transfer (HGT)-related dissemination. This study provide an insight into a novel adaptability mechanism of strains in extreme environment such as high nicotine concentration, and potential novel targets to enhance strain synthesis/degradation ability for future applications. [ABSTRACT FROM AUTHOR]

In this work, a calixarene based ionic liquid was successfully prepared and characterized by different techniques. This ionic liquid was used as an efficient catalyst for the synthesis of a series of polysubstituted pyridines from aldehydes, malononitrile, 1,3‐diketones and arylamines in water as a green solvent. Also, for the first time, symmetric and unsymmetric polysubstituted bis‐pyridines were obtained in high yields from diamines using this catalyst. Mild reaction conditions, high to excellent yields, easy work‐up, excellent activity and reusability of the catalyst are the key features of this method which make it an interesting and novel alternative for the synthesis of the above mentioned important heterocyclic compounds. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Synthesis of novel pyridines with tricyanobutadienes fragment was described. • A plausible mechanism for the reaction was proposed. • The oxygen of air as a dehydrogenation reagent was used. • The optical and electrochemical properties of synthesized compounds were studied. Abstract The synthesis of pyridine derivatives containing a buta-1,3-diene-1,1,3-tricarbonitrile fragment via the base-promoted reaction of benzalacetones and malononitrile dimer with subsequent oxidation is described. The influence of the substituents on the spectral-luminescent and electrochemical properties was also investigated. [ABSTRACT FROM AUTHOR]

A highly efficient and flexible protocol for intramolecular annulation of exocyclic β‐enaminones has been disclosed for the synthesis of carbazolones and imidazo[1,2‐a]pyridines through a counter‐anion‐controlled free‐radical mechanism promoted by hypervalent iodine(III). The cooperative behavior of HTIB and AgSbF6 plays a crucial role in the intramolecular annulation process through C−C and C−N bond formation to give the desired products. The mechanistic insights suggest that the two competitive reactions involved in the system are guided by the nature of the counteranion, which determines the formation of the final products. A wide variety of carbazolones and imidazo[1,2‐a]pyridine molecules have been prepared and isolated in good to excellent yields. [ABSTRACT FROM AUTHOR]

Abstract The synthesis and structural characterization of novel mixed ligand complexes derived from 9-anthraldehyde, 2-amino-3-hydroxy pyridine, 1,10-phenanthroline and metal chlorides are reported. The synthesized mixed ligand complexes are characterized by multispectral techniques such as UV‐Visible, FT-IR, EPR, NMR, ESI-mass analysis and other physicochemical analysis like elemental analysis, molar conductivity, magnetic susceptibility measurements. Moreover, the mixed ligand complexes have strived for their biological future. The biological studies involved are DNA interaction (binding and damage), antimicrobial, antiproliferative studies and free radical scavenging ability studies. The DNA interaction studies are accomplished by UV‐Visible absorption titration, viscosity measurement, which exposed that the synthesized compounds could interplay with CT-DNA through non-covalent interaction of phenanthroline co-ligand by the way of intercalative binding mode. Additionally, the antimicrobial assay specified that the mixed ligand complexes are excellent antimicrobial agents against various pathogens. The gel electrophoresis scrutiny clearly evinced that the prominent DNA cleavage activity of the mixed ligand complexes to divide the supercoiled pUC 19 DNA. The in-vitro antiproliferative activities of the mixed ligand complexes are explored on MCF-7, Hep G2, HBL-100 cell lines using an MTT assay. The morphological changes of the nucleus are explored using Hoechst 33258 staining apoptosis assay. The antioxidant possessions manifest that the mixed ligand complexes have desirable proficiency to scavenge the hydroxyl radical than the ligand. The prediction of in-silico ADMET property revealed that the Schiff base ligand possesses appreciable drug-likeness characters according to Lipinski's regulations. The prediction of PASS biological activity explains that the synthesized ligand holding the excellent biological potential against various diseases. Eventually, the molecular docking studies are achieved to comprehend the nature of binding of the synthesized ligand and mixed ligand complexes with COX-2 protein and DNA. Graphical abstract Unlabelled Image Highlights • Synthesis and characterization of the novel mixed ligand complexes • Substantial antimicrobial, antiproliferative and antioxidant nature of complexes • The remarkable drug-like character of synthesized compound • The doping of the synthesized compounds with protein and DNA using HEX-8 software [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Racemic 3,4-dihydroferroceno[ c ]pyridines were obtained via the Ritter reaction. • MsOH-catalysed reaction of 2-methyl-1-ferrocenylpropan-1-ol with nitriles. • Preparative chiral HPLC resolution of the racemic 3,4-dihydroferroceno[ c ]pyridines. • Assignment of absolute configuration of (R p)- and (S p)-enantiomers by X-ray. Abstract A new approach for the synthesis of functionalized racemic 3,4-dihydroferroceno[ c ]pyridines via the Ritter reaction of 2-methyl-1-ferrocenylpropan-1-ol with nitriles in the presence of methansulfonic acid was developed. The scope and limitations of the reaction were evaluated. Selected racemic 3,4-dihydroferroceno[ c ]pyridines were successfully separated by preparative HPLC on a Chiralcel OD-H column. The absolute configuration of the enantiomers was determined by X-ray crystal structure analysis. [ABSTRACT FROM AUTHOR]

A palladium‐catalyzed coupling between aryl halides and monocyclopropanated pyrroles or furans has been developed, leading to valuable six‐membered N‐ and O‐heterocycles. As the key step, a selective cleavage of the non‐activated endocyclic C−C bond of the 2‐heterobicyclo‐[3.1.0]hexane framework is achieved. The developed method offers access to highly functionalized piperidines, pyridines, and pyrans that are challenging to access by traditional methods. Heck‐type arylation of cyclopropanated furans and pyrroles proceeds with ring expansion via the unactivated cyclopropyl bond, giving rise to arylated diyhdropyridines, pyridines, and 2H‐pyrans. [ABSTRACT FROM AUTHOR]

With the aim of discovering a lead compound for pyridine‐based fungicide bearing adamantane moiety, a series of novel O‐alkyl/benzyl‐1‐(adamantan‐1‐yl)‐2‐(pyridin‐3‐yl)ethan‐1‐one oximes were synthesized from 3‐methylpyridine, ethyl (adamantan‐1‐yl)carboxylate, and alkoxyamine or benzoxyamine hydrochloride. The in vitro antifungal activity against four pathogenic fungi was evaluated, and some compounds exhibited good antifungal activity. Compounds 3d and 3f demonstrated strong activity against Sclerotinia sclerotiorum, with EC50 values of 11.25 and 12.87 μg/mL, respectively; 3b, 3c, and 3k had notable activity against Botrytis cinerea, with EC50 values of 12.78, 12.57, and 11.97 μg/mL, respectively. For Rhizoctonia Solani, 3d and 3g showed sufficient activity with EC50 values of 9.66 and 8.90 μg/mL, respectively. In addition, 3d and 3g demonstrated moderate activity against Colletotrichum orbiculare, with EC50 values of 14.32 and 15.83 μg/mL, respectively. A series of novel O‐alkyl/benzyl‐1‐(adamantan‐1‐yl)‐2‐(pyridin‐3‐yl)ethan‐1‐one oximes were synthesized, and their in vitro antifungal activities against four pathogenic fungi were evaluated. Compounds 3d and 3f possessed strong activity against Sclerotinia sclerotiorum; and 3b, 3c, and 3k had notable activity against Botrytis cinerea. For Rhizoctonia Solani, 3d and 3g showed sufficient activity. [ABSTRACT FROM AUTHOR]

A new coordination polymer {[Cd(H2dmbpzp)I2]·CH3CH2OH}n (H2dmbpzp = 2,6-dimethyl-3,5-bis(pyrazo-3-yl)pyridine) has been prepared by the reaction of H2dmbpzp in aqueous ethanolic solution at room temperature with CdI2. The compound has been characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA) and single crystal X-ray diffraction. Photoluminescence properties have also been examined. The complex exhibits a 1D chain structure. [ABSTRACT FROM AUTHOR]

Abstract In this report the thirteen new compounds including five new heterocyclic ligands and eight complexes with Cu(II), Zn(II) and Ni(II) ions are presented. The investigation of subsequent amide derivatives of picolinic and isonicotinic acid was performed to compare the coordination affinity for this carboxamide series. Moreover the magnetic properties of the obtained complexes were studied and revealed to be in good correspondence with the last achieved results. All synthesized ligands were characterized in detail with the use of 1H, 13C, COSY 2D, HSQC, HMBC NMR spectroscopy and TG-DTA analysis. Obtained compounds were investigated via FT-IR, excitation and emission spectra and elemental analysis. In addition, for the selected compounds the crystal structures were determined by X-Ray single crystal analysis. Graphical abstract Image 1 Highlights • Five new heterocyclic ligands and eight complexes were obtained. • A comparison of coordination affinity for carboxamide series was performed. • Complexes with Cu(II) and Ni(II) ions presented revealed magnetic properties. • Complex with Zn(II) revealed luminescent properties. [ABSTRACT FROM AUTHOR]

The structure of the cadmium(II) iodide complex with 3,4-diphenyl-1-(pyridin-2-yl)-6,7-dihydro-5H-cyclopenta[c]pyridine is studied and determined by X-ray diffraction analysis (СIF file CCDC no. 1833097). The problem about the possibility of coordination of the phenyl substituents of the ligands to the central cadmium atom is examined. The degree of participation of the π system of the phenyl substituent of the ligand in the coordination to the central ion is analyzed using quantum chemical calculations. [ABSTRACT FROM AUTHOR]

The reaction of (ethoxymethylidene)cyanoacetic ester with arylamides of acetoacetic acid proceeds under heating in the presence of triethylamine or at room temperature in the presence of sodium ethoxide. According to the NMR and IR data, the intermediate adduct undergoes no other transformations but azacyclization which predominantly involves the cyano group and forms ethyl 5-acetyl-1-aryl-6-hydroxy-2-imino-1,2-dihydropyridine-3-carboxylates in yields of 30–78%. In some cases, 5-acetyl-1-aryl-2-hydroxy-6-oxo-1,6-dihydropyridine-3-carbonitriles resulting from cyclization involving the ethoxycarbonyl group were isolated as minor products (3–12%). [ABSTRACT FROM AUTHOR]

Facile and efficient protocols for the synthesis of 2‐R‐6,8‐dinitro[1,2,4]triazolo[1,5‐a]pyridines from commercially available starting materials have been developed. The reactions proceed via cyclization of corresponding 3,5‐dinitropyridine‐2‐yl hydrazides or aldehyde 3,5‐dinitropyridine‐2‐yl hydrazones followed by in situ Dimroth rearrangement to provide these triazole fused bicyclic heterocycles in good yields under mild conditions. Another synthetic route to target N‐bridged dinitro[1,2,4]triazolo[1,5‐a]pyridines includes arylation of 5‐aryltetrazoles with 2‐chloro‐3,5‐dinitropyridine and subsequent thermal decomposition/cyclization. A series of 6,8‐dinitro[1,2,4]triazolo[1,5‐a]pyridines with variety of substituents in position 2 have been synthesized from readily available starting materials. General methods include acid‐catalysed cyclization of 3,5‐dinitropyridine‐2‐yl hydrazides and oxidation of aldehyde 3,5‐dinitropyridine‐2‐yl hydrazones to give mentioned dinitro compounds in moderate to excellent yields. [ABSTRACT FROM AUTHOR]

A general and efficient protocol was developed for the synthesis of polysubstituted pyridines from propargyl amines and unsaturated carbonyl compounds through a tandem condensation/alkyne isomerization/6π 3‐azatriene electrocyclization sequence. This process was found to be applicable to a wide range of readily available substrates (30 examples, up to 95 % yield) and could be readily performed on a preparative (20 g) scale. By taking advantage of this method for late‐stage pyridine incorporation, we successfully completed the collective total synthesis of suveoline, norsuveoline, and macrophylline. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A one-pot synthetic process of 2-substituted benzo[ b ]furan/hetero-benzo[ b ]furan. • Starting from 2-iodo-phenol and 1-alkynes. • Catalyzed by CuI/proline in mild condition, Palladium and Phosphorus free. Abstract CuI/proline-catalyzed coupling reaction of 2-iodo-phenols with terminal alkynes and the following cyclization process is carried out successively in DMSO at 80 °C. Under this tandem process, 2-substituted benzo[ b ]furans/furo-pyridines were synthesized in good to excellent yields with a great diversity. [ABSTRACT FROM AUTHOR]

Abstract An octahedral zinc(II) complex of 2,2′:6′,2″-terpyridine (Tpy) and pyridine-2,6-dicarboxylate (Pydc), [Zn(II)(Tpy)(Pydc)·4H 2 O] was synthesized and its structure was determined by a single-crystal X-ray diffraction. The ligand pyridine-2,6-dicarboxylate coordinated to the zinc(II) ion via two pairs of carboxylate oxygens and one nitrogen atom, whereas 2,2′:6′,2″-terpyridine also contributed three coordination bonds through its nitrogen atoms. [Zn(II)(Tpy)(Pydc)·4H 2 O] showed luminescence properties between 412 and 435 nm in DMSO. The solid-state octahedral geometry of [Zn(II)(Tpy)(Pydc)·4H 2 O] was also preserved in solution as confirmed by the observed UV λ ex = 346. Experimental and theoretical studies indicated that [Zn(II)(Tpy)(Pydc)·4H 2 O] interacted with amoxicillin. Density functional theory calculations at B3LYP/LanL2dz level of theory suggested that [Zn(II)(Tpy)(pydc)·4H 2 O] dimer interacts with (2 S ,5 R ,6 R)-6-{[(2 R)-2-amino-2-(4-hydroxyphenyl)-acetyl]amino}-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-24-carboxylic acid (amoxicillin) via highest occupied molecular orbital and lowest unoccupied molecular orbital, π–π interaction, hydrogen bond interaction, and van der Waals forces, thus influencing [Zn(II)(Tpy)(Pydc)·4H 2 O] properties. [ABSTRACT FROM AUTHOR]

Abstract Solid-state acidochromic (SSAC) molecules often exhibit dual-coloured rather than multi-coloured stimuli-responsive properties. To obtain the molecule possessing a multi-coloured emission switching based on one specific solid-state of a single molecule, a new D-π-A type 1,4-dihydropyridine derivative 4a containing barbituric acid and N , N -dimethylaniline unit, which contains multiple sites that can be combined with H+, is designed and synthesized. Compound 4a is confirmed to have twisted molecular conformation by crystallographic data and exhibits aggregation-induced emission characteristic. Upon the stimuli of acid-base system, 4a exhibits rare seven-coloured emission switching in solid-state. Another 1,4-dihydropyridine derivative 4b based on 1,3-dimethylbarbituric acid is synthesized for comparison. Compared with 4b which only displays three-coloured solid-state emission switching, 4a exhibits a more abundant colour change, which might be attributed that the nitrogen atoms on the N H bonds are also involved in the process of protonation and deprotonation, slowing down the transformation between D-π-A and A-π-A structures. The results provide a new idea for the development of multicolour SSAC materials. Graphical abstract Image 1 Highlights • Synthesis and characterization of two new 1,4-dihydropyridine derivatives. • These AIE-active compounds exhibit solid-state acidochromism. • Barbituric acid-based compound shows rare seven-coloured emission switching in solid-state. [ABSTRACT FROM AUTHOR]

The article reports on the latest research and development in the synthesis of pyrazolopyridines and their derivatives.

The novel 1,4-bis(2,6-dibromo-4-formylphenoxy)butane (3), prepared from 3,5-dibromobenzaldehyde (1), reacted with different hydrazines 4a–4d and active methylene containing compounds 9a–9d to give the corresponding bis(hydrazones) 5a–5d and bis(cinnamonitriles) 11a–11d, respectively. Both bis(2-cyanoacetic acid hydrazide) derivative 5d and bis(thioacrylamide) derivative 11a were taken as synthetic precursors for the synthesis of the target molecules bis(pyridine-2(1H)-thione) derivative 10 and 13a–13c and their bis(2-methylsulfanylpyridine) derivative 14 and 17a–17c. Another synthetic route was designed to prepare the target molecules 14 and 17a–17c in a better yield using pyridine-2(1H)-thione) derivative 15 and 19a–19c. Characterization of the newly prepared compounds via elemental analyses and spectral data are established. [ABSTRACT FROM AUTHOR]

Methods for synthesizing new condensed pyrano[4, 3-b]pyridine derivatives from 2-methyl-2-ethyltetrahydropyran-4-one were developed. The neurotropic activities of the compounds were studied. [ABSTRACT FROM AUTHOR]

Organometallic precatalysts play a pivotal role in organic synthesis. However, their preparation often relies on multiple time, energy, and solvent intensive steps, including the synthesis of supporting organic ligand structures, and finally installation on the desired metal centres. We report the sustainable mechanochemical synthesis of acetyl- and bis-(imino)pyridine pincer complexes, a ubiquitous ligand class for organometallic precatalysts. The approach is extended to the one-pot synthesis of acetyl(imino)pyridine-CoCl2, where the ligand is formed in situ. [ABSTRACT FROM AUTHOR]

Abstract A simple and effective fluorescent sensor bearing pyridine units was designed and synthesized. The sensor can detect Zn2+ with high selectivity accompanied by a distinct fluorescence turn-on response, inducing the fluorescent color markedly changed from darkness to bright green. The limit of detection (LOD) was calculated as 8.56 × 10−9 M with a good linearity (R = 0.95943). In addition, the chelate of sensor with Zn2+ can further recognize H 2 PO 4 −/HSO 4 − with notable fluorescence quenching behaviors over other anions and the LODs were as low as 3.44 × 10−6 M (R = 0.99762) and 3.84 × 10−6 M (R = 0.99315), respectively. Graphical abstract Image 1 Highlights • An effective and simple chemosensor T bearing pyridine units was successfully synthesized for the first time. • Probe T can detect the presence of Zn2+ with high sensitivity in nM level. • A unique fluorescence turn-on signal was observed only when Zn2+ was added to T. • Complex T -Zn2+ can further explore the existence of HSO 4 −/H 2 PO 4 − with notable fluorescence turn-off behaviors. [ABSTRACT FROM AUTHOR]

Reaction of 2-nitroacetophenone, furfurol, β-dicarbonyl compounds, and ammonium acetate led to 3-substituted 4-(2-furyl)-5-nitro-6-phenyl-1,4-dihydropyridines, which were oxidized with potassium nitrate in the presence of copper(II) nitrate (10 mol %), leading to the respective 5-nitro-6-phenylpyridines. The performed multicomponent reactions met the general principles of green chemistry. Synthesis of these unsymmetrical 5-nitro-6-phenylpyridines via the formation of 1,4-dihydropyridine intermediates under the conditions of multicomponent reaction significantly shortened the overall reaction time, decreased the number of steps, and improved the yield. [ABSTRACT FROM AUTHOR]

A series of pyridine derivatives containing a 2-hydroxybenzyl or (2-hydroxynaphthalen-1-yl)methyl substituent were obtained by treating carbonyl-substituted 4Н-chromenes and 1Н-benzo[f]chromenes with ammonia and 1,3-dicarbonyl compounds or aromatic ketones as a result of the carbo-Michael reaction, chromane ring opening, and cyclodehydration. [ABSTRACT FROM AUTHOR]

Here we describe the synthesis, antioxidant and anti-inflammatory activity of the novel N3 substituted 5,7-dimethyl-6-phenylazo-3Н-thiazolo[4,5-b]pyridin- 2-ones, who were synthesized in reactions aminomethylation, cyanoethylation, hydrolysis and under the reaction of nucleophilic substitution. The antioxidant activity of the synthesized compounds was evaluated in vitro by the method of scavenging effect on 2,2 diphenyl-1-picrylhydrazyl (DPPH) radicals. The anti-inflammatory action was evaluated in vivo employing the carrageenan-induced rat paw edema method. [ABSTRACT FROM AUTHOR]

Graphical abstract A procedure for preparing a 4′-triphenylborate-substituted derivative of the 2,2′:6′,2″-terpyridine ligand is described. Such a modification renders the terpyridine ligand anionic, which enables unique design possibilities for coordination chemistries involving metal ions relative to the unsubstituted parent ligand. Abstract A procedure for preparing a 4′-triphenylborate-substituted derivative of the 2,2′:6′,2″-terpyridine ligand is described. Such a modification renders the terpyridine ligand anionic, which enables unique design possibilities for coordination chemistries involving metal ions relative to the unsubstituted parent ligand. Proof-in-principle that this new ligand can coordinate to transition metals was provided through the synthesis of a novel nickel complex. [ABSTRACT FROM AUTHOR]