81998-03-0Relevant articles and documents
A series of dinuclear copper complexes bridged by phosphanylbipyridine ligands: Synthesis, structural characterization and electrochemistry
Lilio, Alyssia M.,Grice, Kyle A.,Kubiak, Clifford P.
, p. 4016 - 4023 (2013)
The phosphanylbipyridine ligands 6-(diphenylphosphanyl)-4,4'-dimethyl-2,2'- bipyridine (PPh2-Me2-bipy, a), 4,4'-di-tertbutyl-6- (diphenylphosphanyl)-2,2'-bipyridine (PPh2-t Bu2- bipy, b), and 6-(diisopropylphosphanyl)-2,2'-bipyridine (PiPr2bipy, c) and the corresponding dinuclear copper complexes [Cu2(μ-PPh 2-Me2-bipy)2(NCCH3) 2](PF6)2 (1), [Cu2(μ-PPh 2-t Bu2-bipy)2(NCCH3) 2](PF6)2 (2), [Cu2(μ-PiPr 2bipy)2(μ-NCCH3)](PF6) 2 (3), and [Cu2(μ-PiPr2bipy) 2{μ-CNCH(CH3)2}]-(PF6) 2 (4) were synthesized. The X-ray structures of 1-4 show that the complexes are dinuclear with the bidentate bipyridine coordinating to one copper atom and the phosphane moiety coordinating the other copper center. Complexes 3 and 4 possess short Cu-Cu distances with bridging acetonitrile and isocyanide ligands. The cyclic voltammograms of 1-4 were examined under N2 and CO2. Under N2, 1-3 show four quasi-reversible 1e - reductions, and under CO2, they show current enhancement at the second reduction. In comparison, complex 4 shows four irreversible reductions under N2 and no current enhancement under CO2.
Synthesis, characterization and crystal structure of 6-Chloro-4,4′-dimethyl-2,2′-bipyridine and 4,4′-Dimethyl 2,2′-bipyridine N-Oxide
Conterosito, Eleonora,Magistris, Claudio,Barolo, Claudia,Croce, Gianluca,Milanesio, Marco
, p. 337 - 343 (2016)
The synthesis, the NMR characterization and the crystal structure of 6-Chloro 4,4′-dimethyl 2,2′-bipyridine and of the reaction intermediate 4,4′-Dimethyl 2,2′-bipyridine N-Oxide are here reported. The target compound crystallizes in the orthorhombic system while the intermediate is monoclinic. In both structures, the molecules are linked by weak interactions. The structure of the reaction intermediate N-oxide is characterized by a dihedral angle between the two phenyl rings of 161.77° while the other is almost planar with a dihedral angle of 179.15°. The crystal packing was investigated, also with the aid of Hirshfeld surface analysis. In the N-oxide reaction intermediate the packing is governed by CH-O interactions, while in the product the packing is simply driven by minimizing the voids and thus maximizing the density, with a prevalence of H???H and C???H contacts, as indicated by fingerprint decomposition analysis.
Synthesis and catalytic water oxidation activities of ruthenium complexes containing neutral ligands
Xu, Yunhua,Duan, Lele,Akermark, Torbjoern,Tong, Lianpeng,Lee, Bao-Lin,Zhang, Rong,Akermark, Bjoern,Sun, Licheng
, p. 9520 - 9528 (2011)
Two dinuclear and one mononuclear ruthenium complexes containing neutral polypyridyl ligands have been synthesised as pre-water oxidation catalysts and characterised by 1H and 13C NMR spectroscopy and ESI-MS. Their catalytic water oxidation properties in the presence of [Ce(NH 4)2(NO3)6] (CeIV) as oxidant at pH 1.0 have been investigated. At low concentrations of Ce IV (5 mM), high turnover numbers of up to 4500 have been achieved. An 18O-labelling experiment established that both O atoms in the evolved O2 originate from water. Combined electrochemical study and electrospray ionisation mass spectrometric analysis suggest that ligand exchange between coordinated 4-picoline and free water produces Ru aquo species as the real water oxidation catalysts. Copyright
Deoxygenative Amination of Azine-N-oxides with Acyl Azides via [3 + 2] Cycloaddition
Ghosh, Prithwish,Han, Sang Hoon,Han, Sangil,Kim, Dongeun,Kim, In Su,Kim, Saegun,Kwon, Na Yeon,Mishra, Neeraj Kumar
, p. 2476 - 2485 (2020/03/13)
A transition-metal-free deoxygenative C-H amination reaction of azine-N-oxides with acyl azides is described. The initial formation of an isocyanate from the starting acyl azide via a Curtius rearrangement can trigger a [3 + 2] dipolar cycloaddition of polar N-oxide fragments to generate the aminated azine derivative. The applicability of this method is highlighted by the late-stage and sequential amination reactions of complex bioactive compounds, including quinidine and fasudil. Moreover, the direct transformation of aminated azines into various bioactive N-heterocycles illustrates the significance of this newly developed protocol.
IMMUNOSUPPRESSIVE AGENTS
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Page/Page column 26-27; 27, (2018/08/20)
Provided herein is a compound having the Formula 1, all of its related stereoisomers and their pharmaceutically acceptable salts with immunosuppressive property and process for preparation thereof. The said molecule provides potent anti-proliferative activity in lymphocyte proliferation assay and in mouse skin graft rejection assay. Further, the said molecule is a valuable lead compound in development of improved immunosuppressive agents.
Cobalt Complex with Redox-Active Imino Bipyridyl Ligand for Electrocatalytic Reduction of Carbon Dioxide to Formate
Liu, Fang-Wei,Bi, Jiaojiao,Sun, Yuanyuan,Luo, Shuping,Kang, Peng
, p. 1656 - 1663 (2018/05/08)
An imino bipyridine cobalt(II) complex was developed for the electrocatalytic reduction of CO2 to formate in acetonitrile with a faradaic efficiency of approximately 80 %. For comparison, a symmetric bis-imino pyridine complex showed lower catalytic activity because of less conjugation in the system. Cyclic voltammetry, electron paramagnetic resonance and IR spectroscopy studies provided mechanistic details and the structures of the key intermediates. DFT calculations confirmed the role of large π-conjugated groups for stabilizing key intermediates through electronic conjugation.
2,2′-Homocoupled Azine N,N′-Dioxides or Azine N-Oxides: CDC- or SNAr-Controlled Chemoselectivity
Jha, Abadh Kishor,Jain, Nidhi
, p. 4765 - 4772 (2017/09/07)
An unprecedented Cu(OAc)2- and LiOtBu-mediated homocoupling of azine N-oxides to yield 2,2′-azine N,N′-dioxides is reported. This is the first instance in which copper has been used to catalyze the homodimerization reaction, especially of 2-phenylpyridine N-oxides. In the absence of catalytic copper, the reaction follows an alternative pathway, and instead of dioxides it yields 2,2′-azine N-monoxides. This latter protocol works efficiently with a range of N-heterocyclic oxides of pyridine, 2-phenylpyridine, quinoline and N-aryl-1,2,3-triazole. It is scalable, offers high regioselectivity and gives the products in moderate to high yields. The observed chemoselectivity between the copper-assisted and copper-free protocols is routed through oxidative cross-dehydrogenative coupling (CDC) and nucleophilic aromatic substitution of hydrogen (SNAr) pathways, respectively.
Nitrogen-containing tooth heterocyclic ring substituted tetrazole rare earth complex and its preparation method
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Paragraph 0066-0068, (2016/11/24)
The invention provides a nitrogen-containing double-tooth heterocyclic ring substituted tetrazole type rare-earth complex LnL3 expressed by the formula I, wherein Ar is a nitrogen-containing double-tooth heterocyclic ring; the center rare-earth ion Ln is any one of yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. The preparation method of the nitrogen-containing double-tooth heterocyclic ring substituted tetrazole type rare-earth complex LnL3 is characterized in that a nitrogen-containing double-tooth heterocyclic ring substituted tetrazole type three-tooth compound, namely a dipyridyl tetrazole type three-tooth compound or phenanthroline tetrazole type three-tooth compound, is taken as a single ligand, and simultaneously, coordination saturation is satisfied, and the tetrazole group in the complex serves as negative irons to realize electrically neutral charge balance together with center rare-earth metal cations. The obtained rare-earth complex is high in thermal stability, can be prepared into a device through an evaporation film-forming process or a solution film-forming process. Besides, the preparation method has the advantages of high yield, of the product has high purity, reaction time is short and operation is simple; and as a result, the cost is greatly reduced.
BIPYRIDYL TRIAZOLE RARE EARTH COMPLEX AND PREPARATION PROCESS THEREFOR
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Paragraph 0051-0054, (2015/05/19)
The invention provides a novel bipyridine triazole rare earth complex LnL3 as shown in formula 1 and a preparation method thereof. The rare earth complex has high thermal stability and is suitable for manufacturing devices by an evaporation fil
Synthesis of novel tridentate pyrazole–bipyridine ligands for Co-complexes as redox-couples in dye-sensitized solar cells
Zavozin, Alexander G.,Ignat'ev, Nikolai V.,Schulte, Michael,Zlotin, Sergei G.
, p. 8551 - 8556 (2016/09/02)
Novel pyrazole bipyridine ligands have been synthesized from 4,4′-substituted bipyridines through oxidation, chlorination and non-catalyzed C–N coupling of potassium pyrazolate with 6-halogen-4,4′-bipyridines in diglyme. These tridentate pyrazole–bipyridine ligands are of interest as components of new redox systems for dye-sensitized solar cells.
