- Synthesis of indenes by intramolecular morita-baylis-hillman reaction in aqueous media catalyzed by resin-supported proline
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Novel synthesis of indene derivatives has been developed in an organocatalytic way. Although homogeneous proline showed low catalytic efficiency, resin-supported proline effectively catalyzed the intramolecular Morita-Baylis-Hillman reaction to afford the
- Akagawa, Kengo,Sakamoto, Seiji,Kudo, Kazuaki
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- Organocatalytic regiospecific synthesis of 1H-indene-2-carbaldehyde derivatives: suppression of cycloolefin isomerisation by employing sterically demanding catalysts
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The regiospecific synthesis of 1H-indene-2-carbaldehyde derivatives was achieved through transition-metal-free, reductive cyclisation of ortho-formyl trans-cinnamaldehydes with Hantzsch ester in the presence of an aminocatalyst. In particular, cycloolefin isomerisation of the resulting products could be inhibited efficiently by the introduction of a sterically demanding stereo-defined aminocatalyst.
- Mao, Hui,Kim, Dong Wan,Shin, Hun Yi,Song, Choong Eui,Yang, Jung Woon
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p. 1355 - 1362
(2017/02/15)
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- Simple one-pot conversion of aldehydes and ketones to enals
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A simple and efficient method to convert aldehydes into α,β-unsaturated aldehydes with a two-carbon homologation is presented. Hydroboration of ethoxy acetylene with BH3·SMe 2 generates tris(ethoxyvinyl) borane. Transmetalation with
- Valenta, Petr,Drucker, Natalie A.,Bode, Jeffrey W.,Walsh, Patrick J.
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supporting information; experimental part
p. 2117 - 2119
(2009/10/18)
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- An efficient palladium-catalyzed synthesis of cinnamaldehydes from acrolein diethyl acetal and aryl iodides and bromides
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(Matrix presented) The reaction of aryl iodides and bromides with acrolein diethyl acetal in the presence of Pd(OAc)2, nBu 4NOAc, K2CO3, KCl, and DMF, at 90°C until the disappearance of the acetal followed by the addition of 2 N HCl to the crude reaction mixture, affords cinnamaldehydes in good to high yields. A variety of functional groups are tolerated in the aryl halides, including ether, aldehyde, ketone, ester, dialkylamino, nitrile, and nitro groups. The presence of substituents close to the oxidative addition site does not hamper the reaction.
- Battistuzzi, Gianfranco,Cacchi, Sandro,Fabrizi, Giancarlo
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p. 777 - 780
(2007/10/03)
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- Titanium dioxide photocatalyzed oxygenation of naphthalene and some of its derivatives
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The titanium dioxide photocatalyzed oxygenation of naphthalene in water gives (E,Z)-2-formylcinnamaldehydes and 1,4-naphthoquinone besides traces of naphthols. 1-Substituted naphthalenes (both with an electron-withdrawing and -donating group) are likewise oxidised at about the same rate with a similar product distribution. The evidence obtained supports the hypothesis that the reaction involves transfer of a hydroxy group to naphthalene and reduction of oxygen to superoxide followed by coupling of the two species. In organic solvents the reaction is slower, more selective (a cyano group inhibits the reaction) and leads to phthalic anhydride and 1,4-naphthoquinone. The relation with the solvent-dependent course of the ozonation of the same substrates is commented upon.
- Soana, Federica,Sturini, Michela,Cermenati, Laura,Albini, Angelo
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p. 699 - 704
(2007/10/03)
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- Reaction of naphthalene and its derivatives with hydroxyl radicals in the gas phase
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Naphthalene is the most abundant polycyclic aromatic hydrocarbon (PAH) found in urban air. It is reactive in the atmosphere under ambient conditions, its chief reaction partner being the hydroxyl radical, OH·. In this work, the reactions of OH· with naphthalene, 1- and 2-naphthol, and 1- and 2-nitronaphthalene were studied in a 9.4 m3 smog chamber. Relative rates of reaction accorded well with previous studies and allowed estimates to be made of the atmospheric lifetimes of these compounds. Numerous oxidation products were identified, and mechanisms proposed for their formation were based on the further transformation of benzocyclohexadienyl radicals formed by addition of OH· to naphthalene. The naphthols and nitronaphthalenes were deduced not to be on the major reaction pathway to the more oxidized products. Because of the high reactivity of PAH in air, we suggest that priority be given to identifying and quantitating their reaction products, some of which may be relatively persistent air toxics. Naphthalene is the most abundant polycyclic aromatic hydrocarbon (PAH) found in urban air. It is reactive in the atmosphere under ambient conditions, its chief reaction partner being the hydroxyl radical, OH·. In this work, the reactions of OH· with naphthalene, 1- and 2-naphthol, and 1- and 2-nitronaphthalene were studied in a 9.4 m3 smog chamber. Relative rates of reaction accorded well with previous studies and allowed estimates to be made of the atmospheric lifetimes of these compounds. Numerous oxidation products were identified, and mechanisms proposed for their formation were based on the further transformation of benzocyclohexadienyl radicals formed by addition of OH· to naphthalene. The naphthols and nitronaphthalenes were deduced not to be on the major reaction pathway to the more oxidized products. Because of the high reactivity of PAH in air, we suggest that priority be given to identifying and quantitating their reaction products, some of which may be relatively persistent air toxics.
- Bunce, Nigel J.,Liu, Lina,Zhu, Jiang,Lane, Douglas A.
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p. 2252 - 2259
(2007/10/03)
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- Uranyl-Sensitized Photochemical Oxidation of Naphthalene by Molecular Oxygen. Role of Electron Transfer
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Naphthalene quenches the excited state *UO2(2+) in two parallel pathways: oxidation to naphthalene radical cation, C10H8(.+) (Φ = 0.3), and exciplex formation.The overall rate constant in aqueous acetonitrile containing 0.1 M H3PO4 has a value kq = 2.20E9 M-1 s-1.In the presence of O2, a portion of c10H8(.+) is converted to 2-formylcinnamaldehyde and several other products, the rest reacting with UO2(1+) by back electron transfer.
- Mao, Yun,Bakac, Andreja
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p. 7929 - 7933
(2007/10/03)
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- Catalytic Oxidation of Naphthalene on Palladium in Cooperation with Copper(I)/(II) Redox Couple
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Catalytic oxidation of naphthalene in moist acetic acid solutions has been studied.The catalyst used was a silica-supported palladium which works in cooperation with the Cu(1+)/Cu(2+) redox couple.Products were 1-naphthol, 1,4-naphthoquinone and (E)-2-formylcinnamaldehyde with a total yield of more than 78percent in which naphthoquinone shared 40percent.Reaction mechanism has been discused in comparison with that of benzene.
- Kuroda, Yasushi,Kunai, Atsutaka,Hamada, Michiyuki,Kitano, Tomoyuki,Ito, Sotaro,Sasaki, Kazuo
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p. 3089 - 3093
(2007/10/02)
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- Preparation and Photoisomerization of 2-Formylcinnamaldehyde in Solution
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Naphthalene, in dilute aqueous solution, reacts with ozone to form one or both isomers of 2-formylcinnamaldehyde; an equilibrium mixture of the isomers also results upon irradiation of the E-isomer with long wavelength ultraviolet light.
- Larson, Richard A.,Garrison, Wendy J.,Marley, Karen A.
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p. 3987 - 3990
(2007/10/02)
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- OZONOLYSIS BY MICROWAVE DISCHARGE OF OXYGEN OF NAPHTHALENE ADSOBED ON FLORISIL
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Microwave discharge of O2 produces O(3P) atoms which form O3 on florisil surface.Reaction with adsorbed naphthalene results in o-formylcinnamaldehydes as the main product.
- Zadok, Elazar,Rubinraut, Sara,Mazur, Yehuda
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p. 4175 - 4176
(2007/10/02)
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