- ELECTROCHEMICAL OXIDATION OF 1,3-DIKETONES IN THE PRESENCE OF HYDROHALIC ACID SALTS
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In the presence of a mediator (sodium iodide) acetylacetone dimerizes with the formation of 3,4-diacetylhexane-2,5-dione, with a yield up to 90percent.Salts of 2-halosubstituted 1,3-diketones form more highly enolized cyclic 1,3-diketones - 1,3-cyclohexanedione and dimedone under analogous conditions, with a yield up to 90percent. Keywords: electrolysis, electrochemical oxidation, 1,3-diketones, 3,4-diacetylhexane-2,5-dione, sodium salt of 2-halosubstituted 1,3-diketones.
- Elinson, M. N.,Lizunova, T. L.,Nikishin, G. I.
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- Direct Synthesis of Bis(acetylacetonato)nickel(II) Dihydrate and Isolation of α,α,β,β-Tetra-acetylethane as the Oxidation Product of Acetylacetone
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NiO(OH) undergoes a facile reaction with acetylacetone affording a very high yield of bis(acetylacetonato)nickel(II) dihydrate, (Ni(acac)2)2H2O, and giving α,α,β,β-tetra-acetylethane as the oxidation product of acetylacetone.
- Bhattacharjee, Manabendra N.,Chaudhuri, Mihir K.,Ghosh, Soumitra K.,Hiese, Zavei,Roy, Nirmalendu
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- Chiral bead-like trimer of tris(2,4-pentanedionato)ruthenium(III)
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A chiral tri-nuclear metal complex, ΔΔΔ- or ΛΛΛ-[Ru(acac)2(taet)Ru(acac)(taet)Ru(acac) 2] (acac = acetylacetonato and taet = tetraacetylethanato), was prepared and its monolayer behavior was investigated, leading to the conclusion that the bead-like character of the trimer was an essential factor in achieving stable two-dimensional molecular packing. Copyright
- Sato, Hisako,Kameda, Jun,Fukuda, Yutaka,Haga, Masa-Aki,Yamagishi, Akihiko
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- Alkylation of 3,4-dibromo-4-methyltetrahydropyran with diethyl malonate as a key to understanding the electronic nature of chemo- and regioselectivity of molecules
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The reaction of 3,4-dibromo-4-methyltetrahydropyran with diethyl malonate in the presence of sodium butoxide leads to formation of the corresponding cross-coupling product rather than of tetraethyl ethane-1,1,2,2-tetracarboxylate (product of dehydrodimerization of diethyl malonate) which is formed in the presence of sodium ethoxide. An explanation was proposed, which may be regarded as a key to understanding the nature of the driving force for one- and two-electron transfer, as well as chemo- and regioselectivity of organic molecules. 2005 Pleiades Publishing, Inc.
- Gevorkyan,Arakelyan,Dzhandzhulyan,Mikaelyan,Petrosyan,Panosyan
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- Design and Solvothermal Synthesis of Polyoxometalate-Based Cu(II)-Pyrazolate Photocatalytic Compounds for Solar-Light-Driven Hydrogen Evolution
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Polyoxometalates (POMs) are known for their photocatalytic hydrogen production activity, but their solubility and limited stability often restrict their practical applications. Herein, we designed and solvothermally synthesized two new Cu-H2bpz (3,3′,5,5′-tetramethyl-4,4′-bipyrazole, abbreviated as H2bpz) compounds, namely, Cu0.5(H2bpz)(NO3) (1) and Cu(Hbpz)(Cl)DMF (2), and three new polyoxometalate-based Cu(II)-pyrazolate compounds, namely, Cu(PW12O40)0.5(H2bpz)2(H2O)(OH)0.5(H2O)5.5 (3), Cu(HPMo12O40)(H2bpz)2(H2O)2(H2O)4 (4), and Cu2(SiW12O40)(H2bpz)3(H2O)3(H2O)6 (5). Compound 3 (Cu(PW12O40)0.5(H2bpz)2(H2O)(OH)0.5(H2O)5.5) exhibits the best photocatalytic activity of 44.4 μ L h-1 g-1, which may be related to the stability of compounds. Herein, the solvothermal method has been proven to be an effective method in synthesizing stable organic-inorganic hybrid compounds with soluble POMs, metal ions, and organic ligands. Thus, heterogeneous catalysts with outstanding solar-light-driven photocatalytic properties were obtained.
- Chen, Yan-Xin,Hu, Ting,Liao, Mingyue,Meng, Lingyi,Wang, Tianming,Xie, Yiming,Yang, Mingxue,Zuo, Tao
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supporting information
p. 13136 - 13149
(2021/09/03)
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- Modular construction of 3D coordination frameworks incorporating SiF 62- links: Accessing the significance of [M(pyrazole) 4{SiF6}] synthon
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Rational combination of Cd2+ cations, bitopic pyrazole ligands, bridging SiF62- and terminal NCS- anions provide generation of 3D frameworks and precise control over connectedness of the net nodes: two-fold interpenetrated 4-connected NbO-like net (nbo) in [Cd(Me4bpz)2{NCS}2]·CH 2Cl2 (1), uninodal 5-connected noz framework in [Cd 2(Me4bpz)4{SiF6}{NCS} 2]·6CHCl3 (2), novel 5-connected binodal topology (with a point symbol of {42.55.62.7}{4 2.56.62}) in [Cd2(Me 4bpz)4{SiF6}{NCS}2]·2CH 2Cl2 (3) and 6-connected α-Po cubic nets (pcu) in [Cd(Me4bpz)2{SiF6}]·6H2O (4) and [Cd(Me4bpz)2{SiF6}]·1.5CH 2Cl2 (5) (Me4bpz = 3,3′,5,5′- tetramethyl-4,4′-bipyrazole). Hexafluorosilicate anions act as bridges between Cd ions yielding further linkage of 4-connected [Cd(Me 4bpz)2] subtopologies. Characteristic and specific interaction between SiF62- and the metal-organic portion is conditioned by a synergy of coordination and multiple strong NH...F bonds, which suggests perfect compatibility of the bipyrazole and SiF 62- linkers for the construction of 3D structures, either by pillaring of 2D layers or cross-linking of 3D frameworks. Two observed motifs, 1D [M(pyrazole)4{μ-SiF6}]n (in 4 and 5) and discrete [{M{NCS}(pyrazole)4}2{μ-SiF 6}] (in 2 and 3) are discussed as special supramolecular synthons for the framework solids. An improved large-scale and cost-effective procedure for the synthesis of the organic ligand Me4bpz is also described.
- Ponomarova, Vira V.,Komarchuk, Vasiliy V.,Boldog, Ishtvan,Krautscheid, Harald,Domasevitch, Konstantin V.
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p. 8280 - 8287
(2013/10/22)
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- Bromophilic substitution/carbophilic substitution cascade reactions of α,α-dibromo-2-methoxyacetophenone with C-, N- and O-nucleophiles
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α,α-Dibromo-2-methoxyacetophenone reacts, under mild reaction conditions, with C-, N- and O-nucleophiles via a bromophilic substitution/protonation/carbophilic substitution cascade process to afford α-monosubstituted-2-methoxyacetophenones in moderate to good yield. The only exception from this reaction pathway is the reaction with the anion derived from malononitrile in which 2-aroyl-1,1,3,3-tetracyanopropene is obtained.
- Tatar, Jovana,Markovi?, Rade,Stojanovi?, Milovan,Baranac-Stojanovi?, Marija
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experimental part
p. 4851 - 4855
(2010/10/02)
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- Oxidative Coupling of 1,3-Dicarbonyl Compounds by Cerium(IV) Ammonium Nitrate
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A fast, mild, and highly efficient method for the intermolecular coupling of 1,3-dicarbonyl compounds using cerium ammonium nitrate in CH 3CN/CH3OH/H2O has been described. The procedure provided a convenient method for the synthesis of 1,4-diketone derivatives with excellent yields (up to 96%) and powerful evidence for the oxidation mechanism mediated by cerium ammonium nitrate. Copyright
- Song, Jianan,Zhang, Hao,Chen, Xianjun,Li, Xinsheng,Xu, Dongcheng
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experimental part
p. 1847 - 1855
(2010/07/02)
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- Efficient selective formation of C-C single bonds and C=C double bonds by NBS-promoted oxidative coupling of β-keto esters
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A new application of NBS, which results in the oxidative coupling of β-keto esters to selectively form C-C single and C=C double bonds, can be controlled by the amount of NBS and t-BuOK employed. This methodology adds a new entry to C-C single and C=C double-bond formation between active methylene groups under mild conditions with high selectivity. Copyright Taylor & Francis Group, LLC.
- Wang, Zhiguo,Yin, Guodong,Chen, Aihua,Hu, Shengli,Wu, Anxin
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p. 4399 - 4405
(2008/03/14)
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- One-step preparation of symmetrical 1,4-diketones from α-halo ketones in the presence of Zn-I2 as a condensation agent
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Eleven 1,4-diphenylbutane-1,4-diones have been prepared in one step from the corresponding α-halo acetophenones under the action of Zn-I 2 as a condensation agent with moderate to high yields. The mechanistic pathway of the reaction can be explained by the Wurtz-like self-condensation of α-halo ketones. Similarly, 3-chloropentane-2,4-dione gave 3,4-diacetylhexane-2,5-dione, a Wurtz-like condensation product.
- Ceylan, Mustafa,Guerdere, M. Burcu,Budak, Yakup,Kazaz, Cavit,Secen, Hasan
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p. 1750 - 1754
(2007/10/03)
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- ELECTROLUMINESCENT MATERIALS AND DEVICES
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An electroluminescent compound is an organic diiridium acatylacetonate complex.
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Page/Page column 18-19
(2008/06/13)
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- Cooperative association of pyrazoles and phenols: A versatile binary system
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The ability of self-complementary H-bond donor/acceptor phenol (OH/O) and pyrazole (NH/N) molecules for cooperative association allowed the developing of a range of binary compounds, in which the molecular counterparts are integrated by hydrogen bonding. Complexes involving either monofunctional 3,5-dimethylpyrazole and phenol and polyfunctional 3,3′,5,5′- tetramethyl-4,4′-bipyrazole, hydroquinone and phloroglucinol are based on mixed phenol-pyrazole chains. They reveal common features allowing high level of control over the entire connectivity and dimensionality. Unprecedented NH...π pyrazole hydrogen bonding was essential for the structure of the resorcinol complex.
- Boldog, Ishtvan,Rusanov, Eduard B.,Sieler, Joachim,Domasevitch, Konstantin V.
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p. 756 - 759
(2007/10/03)
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- Tetranuclear copper(n) complexes incorporating short and long metal-metal separations: Synthesis, structure and magnetism 1
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Synthesis, structural and magnetic characterization of tetranuclear [(Cu2L2B] complexes [where H3L is the Schiffs-base ligand, l,3-bis(salicylideneamino)propan-2-of; B is the dipyrazolate entities: methylenebis(3,5-dimethylpyrazolate) (mbdpz) or 4,4′-bi-3,5-dimethylpyrazolate (mdpz)] are reported. The structures reveal short intra- and inter-molecular Cu ... Cu separations (ca. 3.4 A), in combination with long intramolecular copper distances (ca. 10 A). The magnetic behaviour of [(Cu2L)2(mbdpz)] (1) is indicative of an intramolecular antiferromagnetic interaction between the copper(n) centres [2J = -460 cm-1], whilst that of [(Cu2L)2(mdpz)] (2) is characteristic of an antiferromagnetically coupled system with intramolecular coupling in the order of 2J= -380 cm-1, with the presence of a further intermolecular interaction indicated. The Royal Society of Chemistry 2000.
- Kruger, Paul E.,Moubaraki, Boujemaa,Fallen, Gary D.,Murray, Keith S.
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p. 713 - 718
(2007/10/03)
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- Chemical and Electrochemical Oxidative Dimerization of Carbonyl Compounds by Cerium(IV) Salts. A Comparative Study
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β-dicarbonyl and β-cyanocarbonyl compounds were dimerized chemically by CAN or by electrocatalysis using cerous nitrate as mediator.The saturated and unsaturated products of these oxidations are presented.
- Cho, Liu Yao,Romero, Jose Ricardo
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p. 8757 - 8760
(2007/10/02)
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- β-Diketone Interactions Part 8. The Hydrogen Bonding of the Enol Tautomers of Some 3-Substituted Pentane-2,4-diones
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Three new derivatives of pentane-2,4-dione (PD) have been synthesized: 3-(4-nitrophenyl), 3-(4-phenoxyphenyl) and 3-(4-isopropylphenyl).The X-ray crystal structures of these compounds show them to have very short hydrogen bonds with R(O...O) = 2.445, 2.443, and 2.419 Angstroem, respectively.Those parameters most sensitive to hydrogen bonding - 1H chemical shift, change in chemical shift on deuteration , and streching frequencies C=O and νmax.(OHO)> - have been measured for these, and other 3-derivatives of PD, with a view to probing the potential energy well of this type of bond.The conclusion is that in all of the compounds with R(O...O) 2.45 Angstroem, the hydrogen bonding is very strong with the proton zero point energy above the internal barrier.
- Emsley, John,Ma, Lewina Y. Y.,Bates, Paul A.,Motevalli, Majid,Hurtshouse, Michael B.
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p. 527 - 534
(2007/10/02)
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- Hypervalent Iodine Oxidation: α-Functionalization of β-Dicarbonyl Compounds Using Iodosobenzene
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Hypervalent iodine oxidation of β-diketones and β-ketoesters with iodosobenzene-boron trifluoride etherate in chloroform using appropriate nucleophiles results in α-functionalization.Benzoylacetone on reaction with iodosobenzene or iodosobenzene boron trifluoride-etherate in methanol yields α-methoxyacetophenone (9) and methyl phenylacetate (10).The possible mechanisms for these reactions are discussed.
- Moriarty, Robert, M.,Vaid, Radhe K.,Ravikumar, Vasulinga T.,Vaid, Beena K.,Hopkins, Thomas E.
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p. 1603 - 1608
(2007/10/02)
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- Electrosynthesis of organic compounds. XII. Synthesis of some arylacetylacetone derivatives
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Electrosynthesis of some arylacetylacetone derivatives was carried out by the anodic oxidation of acetylacetone in absolute methanol containing 0.8 gm atom l-1 sodium metal in the presence of selected aromatic compounds (benzene, toluene, o-xylene, naphthalene and anthracene) at platinum anode under controlled anodic potential value of +1.1 +/-0.03 V vs SCE at 20 deg C.The synthesized compounds were 3-phenyl-2,4-pentanedione, 3-(p-tolyl)2,4-pentanedione, 3-(o-xylyl)2,4-pentanedione, 3-(α-naphthyl)2,4-pentanedione and 3-(9-anthryl)2,4-pentanedione.In addition a small amount of dimerized and polymerized products was obtained.A suitable mechanism involving the formation of acetylacetone radical intermediates CH3COC.HCOCH3 is suggested.Potentiostatic studies of the anodic oxidation of acetylacetone were also carried out and the anodic oxidation potential was determined.
- Ismail, M. T.
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p. 438 - 440
(2007/10/02)
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- 2,5-Di-lower-alkyl-3,4-di-(2-hydroxy-2-propyl)furan compounds
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2,5-Di-lower-alkyl-3,4-disubstituted-furans have anti-secretory activity.
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