1195-59-1Relevant articles and documents
A new synthetic method of cyclic nitrogenous compounds. XV. Syntheses of 1,2,4,4a,5,6,7,7a-octahydropyrrolo [2,1,5-cd]indolizine derivatives
Murakoshi,Takada,Haginiwa
, p. 1661 - 1663 (1969)
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Brown et al.
, p. 387 (1975)
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Photocatalytic CO2 Reduction by Trigonal-Bipyramidal Cobalt(II) Polypyridyl Complexes: The Nature of Cobalt(I) and Cobalt(0) Complexes upon Their Reactions with CO2, CO, or Proton
Shimoda, Tomoe,Morishima, Takeshi,Kodama, Koichi,Hirose, Takuji,Polyansky, Dmitry E.,Manbeck, Gerald F.,Muckerman, James T.,Fujita, Etsuko
, p. 5486 - 5498 (2018)
The cobalt complexes CoIIL1(PF6)2 (1; L1 = 2,6-bis[2-(2,2′-bipyridin-6′-yl)ethyl]pyridine) and CoIIL2(PF6)2 (2; L2 = 2,6-bis[2-(4-methoxy-2,2′-bipyridin-6′-yl)ethyl]pyridine) were synthesized and used for photocatalytic CO2 reduction in acetonitrile. X-ray structures of complexes 1 and 2 reveal distorted trigonal-bipyramidal geometries with all nitrogen atoms of the ligand coordinated to the Co(II) center, in contrast to the common six-coordinate cobalt complexes with pentadentate polypyridine ligands, where a monodentate solvent completes the coordination sphere. Under electrochemical conditions, the catalytic current for CO2 reduction was observed near the Co(I/0) redox couple for both complexes 1 and 2 at E1/2 = -1.77 and -1.85 V versus Ag/AgNO3 (or -1.86 and -1.94 V vs Fc+/0), respectively. Under photochemical conditions with 2 as the catalyst, [Ru(bpy)3]2+ as a photosensitizer, tri-p-tolylamine (TTA) as a reversible quencher, and triethylamine (TEA) as a sacrificial electron donor, CO and H2 were produced under visible-light irradiation, despite the endergonic reduction of Co(I) to Co(0) by the photogenerated [Ru(bpy)3]+. However, bulk electrolysis in a wet CH3CN solution resulted in the generation of formate as the major product, indicating the facile production of Co(0) and [Co-H]n+ (n = 1 and 0) under electrochemical conditions. The one-electron-reduced complex 2 reacts with CO to produce [Co0L2(CO)] with νCO = 1894 cm-1 together with [CoIIL2]2+ through a disproportionation reaction in acetonitrile, based on the spectroscopic and electrochemical data. Electrochemistry and time-resolved UV-vis spectroscopy indicate a slow CO binding rate with the [CoIL2]+ species, consistent with density functional theory calculations with CoL1 complexes, which predict a large structural change from trigonal-bipyramidal to distorted tetragonal geometry. The reduction of CO2 is much slower than the photochemical formation of [Ru(bpy)3]+ because of the large structural changes, spin flipping in the cobalt catalytic intermediates, and an uphill reaction for the reduction to Co(0) by the photoproduced [Ru(bpy)3]+.
Synthesis of pyridine acrylates and acrylamides and their corresponding pyridinium ions as versatile cross-linkers for tunable hydrogels
Mateescu, Markus,Nuss, Isabell,Southan, Alexander,Messenger, Hayley,Wegner, Seraphine V.,Kupka, Julia,Bach, Monika,Tovar, Guenter E. M.,Boehm, Heike,Laschat, Sabine
, p. 1243 - 1253 (2014)
A small library of cross-linkers for hydrogels was synthesized. The cross-linkers consisted of 2,6- and 3,5-diacylpyridine or 2,4,6-triacylpyridine as the core unit, which were tethered via ethylene glycol, amino ethanol, and 1,n-diamine spacers to terminal acrylate or acrylamide moieties. Esterification and amide formation of the terminal acryl units were found to be dependent on the ratio of NH/O in the spacer, the constitution pattern of the pyridine ring, and the total number of acryl groups. Thus, esters generally gave higher yields than amides decreasing with increasing number of NH in the spacer and with increasing number of acryl units. In the case of 3,5-diacylpyridine derivatives, these trends were less prominent as compared to the 2,6-diacylpyridine series, indicating that steric hindrance and unfavorable hydrogen bonding interaction of the spacers might influence the observed reactivity differences. The 3,5-diacylpyridines were converted to the N-methylpyridinium salts and selected members of both neutral and cationic 3,5-diacylpyridinium derivatives were submitted to hydrogelations with synthetic polymer poly(1-glycidylpiperazine) via aza-Michael addition and thiolated natural hyaluronan via thio-Michael reaction, respectively. Rheological properties of the resulting hydrogels were studied, revealing that both spacer type as well as charge affected elastic moduli and degree of swelling. Georg Thieme Verlag Stuttgart New York.
Synthesis and fluorescence properties of lanthanide(III) complexes of a novel bis(pyrazolyl-carboxyl)pyridine-based ligand
Shi, Xiao-Ming,Tang, Rui-Ren,Gu, Guo-Liang,Huang, Ke-long
, p. 198 - 203 (2009)
A novel bis-pyrazolyl-carboxyl ligand, 2,6-bis(5-methyl-3-carboxypyrazol-1-ylmethyl)pyridine (L), was designed and synthesized and its several lanthanide(III) complexes Eu(III), Tb(III), Sm(III) and Gd(III) were successfully prepared and characterized in detail based on elemental analysis, infrared, mass, proton nuclear magnetic resonance spectroscopy and TG-DTA studies. Analysis of the IR spectra suggested that each of the lanthanide metal ions coordinated to the ligand via the carbonyl oxygen atoms and the nitrogen atom of the pyridine ring and pyrazole rings. The fluorescence spectra exhibits that the Tb(III) complex and the Eu(III) complex display characteristic metal-centered fluorescence in solid state while ligand fluorescence is completely quenched. However, the Tb(III) complex displays more effective fluorescence than the other complexes, which is attributed to especial effectivity in transferring energy from the lowest triplet energy level of the ligand (L) onto the excited state (5D4) of Tb(III).
Synthesis of bis(amidoxime)s and evaluation of their properties as uranyl-complexing agents
Stemper, Jérémy,Tuo, Wei,Mazarío, Eva,Helal, Ahmed S.,Djurovic, Alexandre,Lion, Claude,El Hage Chahine, Jean-Michel,Maurel, Fran?ois,Hémadi, Miryana,Le Gall, Thierry
, p. 2641 - 2649 (2018)
Uranium pollution involves high toxicity and radioactivity and, therefore, constitutes a grave threat to human health and the environment. Chelation is an effective method for sequestering uranium. It is well known that chelators based on oxime groups are able to complex uranyl cations efficiently. To this end, various bis(amidoxime)s were synthesized by reaction of hydroxylamine with the corresponding dinitriles. In these compounds the amidoximes are separated by chains of various lengths, some including a heterocycle (pyridine or 1,3,5-triazine). The abilities of these bis(amidoxime)s to complex uranyl cation in water were evaluated by determining their affinity constants and thermodynamic parameters by means of Isothermal Titration Calorimetry (ITC). DFT calculations were also performed, to determine the optimum structures of the complexes formed between uranyl cations and the oximate groups. A tetrakis(amidoxime), also synthesized in this work, shows good affinity for uranium, and a single molecule is able chelate several uranyl cations. These results are of importance for the remediation of uranium-polluted wastewaters, and open up several perspectives for the design and synthesis of new amidoxime compounds.
Design, synthesis, and biological characterization of a new class of symmetrical polyamine-based small molecule CXCR4 antagonists
An, Jing,Fang, Xiong,Huang, Lina S.,Huang, Ziwei,Liang, Boqiang,Meng, Qian,Schooley, Robert T.,Wang, Juan,Xu, Yan,Zhang, Chaozai,Zhang, Huijun,Zhang, Xingquan,Zhu, Siyu
, (2020)
CXCR4, a well-studied coreceptor of human immunodeficiency virus type 1 (HIV-1) entry, recognizes its cognate ligand SDF-1α (also named CXCL12) which plays many important roles, including regulating immune cells, controlling hematopoietic stem cells, and directing cancer cells migration. These pleiotropic roles make CXCR4 an attractive target to mitigate human disorders. Here a new class of symmetrical polyamines was designed and synthesized as potential small molecule CXCR4 antagonists. Among them, a representative compound 21 (namely HF50731) showed strong CXCR4 binding affinity (mean IC50 = 19.8 nM) in the CXCR4 competitive binding assay. Furthermore, compound 21 significantly inhibited SDF-1α-induced calcium mobilization and cell migration, and blocked HIV-1 infection via antagonizing CXCR4 coreceptor function. The structure-activity relationship analysis, site-directed mutagenesis, and molecular docking were conducted to further elucidate the binding mode of compound 21, suggesting that compound 21 could primarily occupy the minor subpocket of CXCR4 and partially bind in the major subpocket by interacting with residues W94, D97, D171, and E288. Our studies provide not only new insights for the fragment-based design of small molecule CXCR4 antagonists for clinical applications, but also a new and effective molecular probe for CXCR4-targeting biological studies.
Rigid Mn(II) chelate as efficient MRI contrast agent for vascular imaging
Su, Hongying,Wu, Changqiang,Zhu, Jiang,Miao, Tianxin,Wang, Dan,Xia, Chunchao,Zhao, Xuna,Gong, Qiyong,Song, Bin,Ai, Hua
, p. 14480 - 14483 (2012)
The aza-semi-crown pentadentate ligand rigidified by pyridine and piperidine rings was designed and synthesized. It can react with Mn(II) in water to form complex with improved longitudinal relaxivity, leading to efficient signal intensity enhancement of vascular vessels under a clinical magnetic resonance imaging scanner.
Amino-acid templated assembly of sucrose-derived macrocycles
Lewandowski, Bartosz,Jarosz, Slawomir
, p. 2532 - 2535 (2010)
C2-Symmetrical chiral macrocyles containing two sucrose units were prepared by an amino acid templated macrocyclization reaction between appropriate sucrose-based linear precursors and ethylenediamine.
Metal organic complex with near-infrared absorption and emission properties and preparation method thereof
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Paragraph 0110; 0113-0114, (2021/02/24)
The invention discloses a metal organic complex with near-infrared absorption and emission properties and a preparation method thereof. The metal organic complex is prepared by the following steps of:carrying out condensation reaction on an aldehyde group-containing ligand precursor and thiophene or furan or pyrrole or benzene ring or selenophen to obtain a ligand, and carrying out coordination reaction on the ligand and Pd(DMSO)2Cl2 or Pt(DMSO)2Cl2 to obtain a complex monomer, and carrying out condensation dimerization reaction on the complex monomer to obtain the metal organic complex. Themetal organic complex with near-infrared absorption and emission properties has near-infrared absorption and emission properties, and can be used as a wave-absorbing material in the fields of near-infrared imaging, invisible ink and anti-counterfeiting printing, near-infrared bar code invisible identification, plasma display panels, dye-sensitized solar cells, near-infrared light emitting diodes and the like.
Preparation method of 2,6-chloromethylpyridine hydrochloride (by machine translation)
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Paragraph 0018; 0021; 0024; 0026; 0029; 0031; 0034, (2020/03/03)
The invention belongs to the field, of organic synthesis, and particularly relates to 2,6 -chloromethylpyridine hydrochloride, preparation method :(1), which comprises the following steps 2,6 - reacting,dimethylaminopyridine as a raw material 2,6 - to prepare ;(2)2,6 -picolinic acid dimethyl 2,6 -picolinic acid dimethyl ;(3)2,6 -pyridine dimethanol and thionyl chloride to obtain a target product 2,6 -dichloromethylpyridine dihydrochloride with methanol in an acidic condition ;(4)2,6 - The method comprises the following steps: reacting 2,6 - with a commonly-used chemical raw material containing a pyridine ring and methanol in an acidic condition. The method disclosed by the invention is suitable for industrial, production : (by machine translation)
