- The special role of B(C6F5)3 in the single electron reduction of quinones by radicals
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In the presence of two molar equiv. of B(C6F5)3p-benzoquinone reacts with persistent radicals TEMPO, trityl or decamethylferrocene by single electron transfer to give doubly O-borylated benzosemiquinone radical anions with
- Tao, Xin,Daniliuc, Constantin G.,Knitsch, Robert,Hansen, Michael Ryan,Eckert, Hellmut,Lübbesmeyer, Maximilian,Studer, Armido,Kehr, Gerald,Erker, Gerhard
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p. 8011 - 8018
(2018/11/03)
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- Degradation of acenaphthylene and anthracene by chemically modified laccase from Trametes versicolor
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We are studying the chemically modified laccase from Trametes versicolor for use in the in vitro oxidation of two polycyclic aromatic hydrocarbons (PAHs), acenaphthylene and anthracene, in combination with 2,2′-azino-bis- (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as a redox mediator. The results indicate that the maleic anhydride modified laccase (MA-Lac) improved the stability of laccase to temperature, pH and storage time compared with the free enzyme. After incubation for 72 h, the MA-Lac-ABTS system oxidized acenaphthylene and anthracene to more than 70% from the reaction mixture. This journal is the Partner Organisations 2014.
- Liu, Yulong,Hua, Xiufu
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p. 31120 - 31122
(2014/08/05)
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- Kinetic studies of acenaphthene oxidation catalyzed by N-Hydroxyphthalimide
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The acenaphthene oxidation with molecular oxygen in the presence of N-hydroxyphthalimide (NHPI) has been investigated. It is shown that the main oxidation product is acenaphthene hydroperoxide. The phthalimide-N-oxyl (PINO) radical has been generated in situ from its hydroxyimide parent, NHPI, by oxidation with iodobenzenediacetate. The rate constant of H-abstraction (k H) from acenaphthene by PINO has been determined spectroscopically in acetonitrile. The kinetic isotope effect and the activation parameters have also been measured. On the basis of the results of our studies and available published literature data, a plausible mechanism for the oxidation process of acenaphthene with dioxygen catalyzed by NHPI was discussed.
- Opeida,Litvinov,Kushch,Kompanets,Shendrik
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p. 515 - 524
(2013/07/26)
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- Design, synthesis and characterization of a modular bridging ligand platform for bio-inspired hydrogen production
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Synthesis and characterization of a novel type of ambident bridging ligands joining together the functional prerequisites for visible-light absorption, photoinduced electron transfer and catalytic proton reduction is presented. This class of compounds consists of a chromophoric 1,2-diimine-based π-acceptor site and a rigid polyaromatic dithiolate chelator. Due to the presence of a common conjugated linker moiety with an intrinsic two-electron redox reactivity and a suitable orbital coupling of the subunits, a favourable situation for vectorial multielectron transfer from attached electron donors to a catalytic acceptor site is provided. As an example for the application of this kind of bifunctional ligand systems, a [FeFe]-hydrogenase enzyme model compound is prepared and structurally characterized. Electrocatalytic hydrogen formation with this complex is demonstrated.
- Topf, Christoph,Monkowius, Uwe,Kn?r, Günther
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scheme or table
p. 147 - 150
(2012/08/27)
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- New recoverable organoselenium catalyst for hydroperoxide oxidation of organic substrates
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New benzisoselenazol-3(2H)-one covalently bounded to a silica support was synthesized and characterized. It was used as an effective, selective, and easy-to-regenerate catalyst for t-BuOOH and H2O2 oxidation of alkyl arenes to alkyl aryl ketones, aromatic aldehydes to arene carboxylic acids, and sulfoxides and/or sulfones. Copyright Taylor & Francis Group, LLC.
- Wojtowicz, Halina,Soroko, Grazyna,Mlochowski, Jacek
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p. 2000 - 2010
(2008/09/21)
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- Oxidative cleavage of vicinal diols: IBX can do what Dess-Martin periodinane (DMP) can
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A study was conducted to demonstrate the similarity of reactivity between o-iodoxybenzoic acid (IBX), an oxidative agent of vicinal diols and Des-Martin periodinane (DMP). The study examined IBX-mediated oxidative cleavage of tert,tert-1,2-diols and discovered pathways that favored fragmentation of sec,sec-1,2-diols, which produce non-cleavage products. It was observed that IBX can be employed to perform oxidative cleavage of 1,2-diols similar to DMP by simple variation of solvent and temperature. It was also observed that protonation of 10-1-4 species of diols may suppress the nucleophilic attack, leading to the production of ketol to achieve oxidative cleavage of sec,sec-1,2-diols that yield non-cleavage products with IBX in DMSO. TFA was used as a significant source of protons and a better solvent of IBX to conduct protonation of diols. A variety of sec,sec,tert,tert and sec,tert syn-1,2-diols underwent oxidative cleavage effectively, using TFA as a solvent.
- Moorthy, Jarugu Narasimha,Singhal, Nidhi,Senapati, Kalyan
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p. 767 - 771
(2008/03/27)
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- Oxidations with IBX: Benzyl halides to carbonyl compounds, and the one-pot conversion of olefins to 1,2-diketones
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A variety of benzyl halides were converted to the corresponding aldehydes/ketones in respectable yields by IBX in DMSO at 65°C. The bromohydrin reaction of olefins using NBS-H2O in DMSO can be nicely adapted to IBX-mediated oxidation of benzyl halides in such a way that olefins are converted to the corresponding 1,2-diketones in good isolated yields in one-pot.
- Moorthy, Jarugu Narasimha,Singhal, Nidhi,Senapati, Kalyan
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p. 1757 - 1761
(2007/10/03)
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- Therapeutics for chemokine mediated diseases
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The invention provides therapeutic and biological uses of chemokine-receptor-binding compounds (including chemokine receptor ligands such as chemokine receptor agonists or antagonists), such as tricyclic phenanthrene derivatives, including uses in the treatment of disease states mediated by chemokines. The relevant chemokines may for example be monocyte chemoattractant protein-one (MCP-1) or interleukin-8 (IL-8), and the relevant chemokine receptors may for example be corresponding chemokine receptors (CCR-2, CCR-4, CXCR-1, and CXCR-2). In other aspects, the invention provides corresponding pharamaceutical compositions and therapeutic methods. In one aspect, for example, the invention provides for the use of phenanthrene-9,10-dione in the treatment of multiple sclerosis.
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- Catalytic oxidation of acenaphthene and its derivatives in acetic acid
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The chemistry of formation of products of acenaphthene oxidation in the presence of the catalyst containing both manganese and cobalt bromides under batch conditions is discussed. The main reaction products are acenaphthene quinone, acenaphthenol-9, trans-acenaphthylene glycol, naphthalide, and naphthalic anhydride. The sequence of reactions leading to the final products is established. It is shown that the main oxidation product in the presence of the manganese-based catalyst is naphthalic anhydride, and the main product in the presence of the cobalt-based catalyst is acenaphthene quinone. The process and engineering techniques providing for the high overall and fractional yields of the desired products are discussed.
- Bukharkina, Tatiana V.,Grechishkina, Olga S.,Digurov, Nikolai G.,Kon'kov, Ivan I.
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p. 394 - 400
(2013/09/06)
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- Reactions of hydroxyl radicals and ozone with acenaphthene and acenaphthylene
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Acenaphthene and acenaphthylene are polycyclic aromatic hydrocarbons (PAHs) emitted into the atmosphere from a variety of incomplete combustion sources such as diesel exhaust. Both PAHs are present in the gas phase under typical atmospheric conditions and
- Reisen, Fabienne,Arey, Janet
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p. 4302 - 4311
(2007/10/03)
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- Decomposition of acenaphthylene by ultrasonic irradiation
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Polycyclic aromatic hydrocarbons were extracted from a soil sample using ultrasound and dichloromethane-, cyclohexane-, and toluene-water mixtures. It was found that when dichloromethane is used as an extractant, acenaphthylene reacts with the solvent Several chlorinated and oxygenated derivatives were identified. The results show that chlorinated solvents should be avoided because of their sonolytic decomposition. Particularly unsaturated nonaromatic compounds might react with intermediate decomposition radicals of the solvent
- Leonhardt,Stahl
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p. 1228 - 1230
(2007/10/03)
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- Benzeneseleninic anhydride oxidation of 1,2-diarylethanes and 1,2- diarylethylenes to 1,2-diaryldiketones
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1,2-Diarylethanes and 1,2-diarylethylenes can be oxidized directly to 1,2-diaryldiketones in good yields by reaction with benzeneseleninic anhydride (BSA) at 120°C in chlorobenzene.
- Clayton, Mark D.,Marcinow, Zbigniew,Rabideau, Peter W.
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p. 9127 - 9130
(2007/10/03)
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- Acenaphthene Oxidation in the Presence of Tetraethylammonium and Tetrabutylammonium Perchlorates
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Liquid-phase oxidation of acenaphthene in the presence of tetraethylammonium and tetrabutylammonium perchlorates proceeds with chain initiation by degenerate branching through 9-acenaphthyl hydroperoxide the secondary hydroxide that is the main reaction product. In addition, 9-acenaphthenone, 9-acenaphthenol, and acenaphthenequinone are formed as the main reaction products. A simulation of this process showed that the perchlorate catalysis was weakened in the course of oxidation because of deactivation of the perchlorates. The rate of molecular decomposition of the hydroperoxide is higher than that of radical decomposition by a factor of 2 to 3. The initiation rate constant in the catalysis with tetrabutylammonium perchlorate is six times as high as that with tetraethylammonium perchlorate.
- Opeida,Zalevskaya,Vasil'ev
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p. 328 - 335
(2007/10/03)
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- Oxidation of cumene and acenaphthene by oxygen in the presence of tetraalkylammonium perchlorates
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Tetraalkylammonium perchlorates catalyze oxidation of cumene and acenaphthene by oxygen. The perchlorates are more stable in these reactions than halides with the same cations. The perchlorate-initiated decomposition of hydroperoxides depends on the structure of the latter: secondary acenaphthyl hydroperoxide reacts with perchlorates more readily than does tertiary cumyl hydroperoxide. 1996 MAEe Cyrillic signΚ Hayκa/Interperiodica Publishing.
- Opeida,Zalevskaya
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p. 524 - 529
(2007/10/03)
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- Oxidation by DMSO. II. An efficient synthesis of α,β-diketones from α,β-dibromides
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α,β-Dibromides refluxed in DMSO are oxidised into α,β-diketones. The reaction takes place rapidly under microwave irradiation.
- Villemin,Hammadi
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p. 3145 - 3148
(2007/10/02)
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- CATALYSIS OF THE OXIDATION OF ACENAPHTHENE BY TETRAETHYL AND TETRABUTYL AMMONIUM HALIDES
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A liquiud-phase oxidation of acenaphthene in the presence of tetraethyl and tetrabutyl ammonium halides proceeds with chain initiation via degenerate branching on a secondary hydroperoxide-acenaphthyl-9-hydroperoxide (AHP-9).In the series of salts investigated, change in the cation had virtually no effect on the activity of the salt, while variation in the anion indicates that, under identical oxidation conditions (a constant concentration of the catalyst and acenaphthene and a constant reaction time), the degree of conversion of the hydrocarbon increases in the order iodidebromidechloride with an almost identical selectivity of the reaction with respect to the hydroperoxide formed.When halides of quaternary ammonium salts are used, oxidation begins to develop actively from almost the first minutes, and in most cases the maximum rate of the reaction is rapidly attained.The selectivity of the process with respect to the hydroperoxide depends on the conditions and varies in a wide range (from 5 to 70percent).
- Opeida, I. A.,Zalevskaya, N. M.,Vasil'yev, A. Yu.
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p. 535 - 543
(2007/10/03)
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- Syntheses and Photophysical Properties of Some 5(2)-Aryl-2(5)-(4-pyridyl)oxazoles and Related Oxadiazoles and Furans
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A number of 5-aryl-2-(4-pyridyl)oxazoles, a 2-aryl-5-(4-pyridyl)oxazole, the related oxadiazole and furan, several 2-(4-pyridyl)cycloalkanooxazoles, and many of their quaternary salts were prepared.No single standard synthesis was effective for preparation of more than a few of the 25 free bases described; methods often unique to a base were employed.Minor variations in structure sometimes produced large differences in absorption and emission wavelengths, as well as in the magnitude of the extinction coefficient.The salts are of interest as laser dyes, scintillation fluors, biological stains, and shifters for luminescent solar concentrators.
- Hall, J. Herbert,Chien, Joseph Yuming,Kauffman, Joel M.,Litak, Peter T.,Adams, Jeffrey K.,et al.
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p. 1245 - 1273
(2007/10/02)
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- Photochemical Reaction between Acenaphthene and Arenecarbonitriles
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Various aromatic nitriles have been irradiated in acetonitrile in the presence of acenaphthene.The observed reactions involve electron-transfer quenching of the singlet excited state of the nitriles, and lead to replacement of a cyano group with an acenaphthenyl when starting from 1,4-dicyanobenzene and 1,2,4,5-tetracyanobenzene .While 9,10-dicyanoanthracene (DCA) only biacenaphthenyls and reduced DCA are formed.With 1,4-dicyanonaphthalene the reaction is more complex, and both substitution of a cyano group and addition to yield 1- or 2-(acenaphthen-1-yl)-1,2-dihydro derivatives are obtained; furthermore, a product resulting from both reaction at the benzylic position and cycloaddition onto the 2a,3 bond of acenaphthene is isolated, and shown to be formed independently from the above adducts.
- Boggeri, Enrico,Fasani, Elisa,Mella, Mariella,Albini, Angelo
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p. 2097 - 2102
(2007/10/02)
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- Preparation and Catalytic Hydrogenation of Spiro and Sprio
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Wittig monoolefination of acenaphthylene-1,2-quinone (1) with ethyl (triphenylphosphoranylidene)acetate yields the o-quinomethane derivative 2 which by 1,3-dipolar cycloaddition reactions with aromatic nitrile oxides affords regioselectively the spiro 3 and 4.Reaction between 1 and benzonitrile oxide gives the spiro 5 which by treatment with ethyl(triphenylphosphoranylidene)acetate gives compound 6.Reaction between 6 and benzonitrile oxide gives regioselectively the diastereomeric dispiro compounds 7 and 7'.Catalytic hydrogenation of the spiro compounds 6,7, and 7' over 10percent Pd/C results in the cleavage of the dioxazole ring while cleavage of the isoxazole ring of compound 3 is achieved either by reduction over Raney nickel or by treatment with sodium ethoxide.Reduction of products prepared according Scheme 1 affords the acenaphthylene derivatives 8,9 and 12-15.
- Lefkaditis, Demetrios A.,Argyropoulos, Nicolaos G.,Nicolaides, Demetrios N.
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p. 1863 - 1871
(2007/10/02)
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- A Convenient One-Pot Synthesis of Acenaphthenequinones from 1-Acenaphthenones by NBS-DMSO Oxidation
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Acenaphthenequinone was obtained in 95percent yield whwn the teaction of 1-acenaphthenone with N-bromosuccinimide was carried uot in dimethyl sulfoxide at room temperature.Under similar conditions, several acenaphthenequinones were prepared from the corresponding 1-acenaphthenones in good yield.
- Tatsugi, Jiro,Okumura, Shigeo,Izawa, Yasuji
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p. 3311 - 3313
(2007/10/02)
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- Nitrosamine Photolysis as a Synthetic Method: The Addition of Aminium Radicals to Unsaturated Carbon-Carbon Bonds
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Acid complexed nitrosamines decompose from their lowest singlet excited state to gine aminium radicals and nitric oxide radical transients.Aminium radicals initiate addition of various unsaturated groups to give 1-amino-2-nitroso compounds under an inert atmosphere, or 1-amino-2-nitrates under oxygen.In this report, photoaddition of nitroamines to olefins, acetylenes and fused aromatic hydrocarbons, and the subsequent transformations of the intermediates are described.Aminium radical initiated intramolecular cyclization to prepare tetracyclic aza compounds is also described.While photoaddition of nitrosamines to 4-propenylanisole or 3-butenol wes efficient, that to 3-butenyl benzoates under oxidative conditions was only fair, obviously due to the presence of a benzene ring.The oxidative photoaddition to 3-butenyl halide was followed by spontaneous cyclization to an azaspiro compound.The photoaddition to phenyl-substituted acetylenes gave β-nitroso enamines which hydrolyzed to diketomonoximes under neitral conditions but decomposed extensively under acidic conditions.Certain fused aromatic hydrocarbons acted as singlet sensitizers as well as substrates to induce similar addition giving amino nitroso adducts.These adducts took different courses of conversion dependent on reaction conditions, and on steric and electronic factors.
- Chow, Yuan L.,Colon, Carlos J.,Chang, Dawid W. L.,Pillay, K. Somasekharen,Lochart Robert D.,Tezuka, Takahiro
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p. 622 - 634
(2007/10/02)
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- PHOTOSENSITIZED OXYGENATION OF 3-DIAZOCAMPHOR
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Photosensitized oxygenation of 3-diazocamphor gave camphorquinone and camphoric anhydride in benzene.The yield of camphoric anhydride did not depend on the concentration of added camphorquinone or of diazocamphor.When the reaction was carried out in acetonitrile or benzonitrile, amide 7 or 8 was produced.The formation of amide strongly supports the intermediacy of carbonyl oxide.
- Okada, Keiji,Mukai, Toshio
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p. 359 - 360
(2007/10/02)
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