- A novel one-pot synthesis of esters by exchange reactions between carbonates and anhydrides
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A new method for the synthesis of esters by exchange reaction between anhydrides and carbonates, without any solvent, in the presence of Ti or Sn based catalyst is presented.
- Berti, Corrado,Colonna, Martino,Marianucci, Elisabetta,Sweileh, Bassam,Pilati, Francesco
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- Biochemical and genetic evidence of benzylsuccinate synthase in toluene-degrading, ferric iron-reducing Geobacter metallireducens
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In vitro assays demonstrated that toluene-grown cells of Geobacter metallireducens catalyzed the addition of toluene to fumarate to form benzylsuccinate under anaerobic conditions. The specific in vitro rate of benzylsuccinate formation was ca. 45% of the specific in vivo rate of toluene consumption. In addition, bssA and bssB, which code for the α and β subunits of benzylsuccinate synthase (BSS), respectively, were found to have sequences in G. metallireducens similar to the only sequences heretofore available (for three denitrifying strains). This is the first report of the presence of BSS in a ferric iron-reducing bacterium; BSS activity has previously been reported in denitrifying, sulfate-reducing, and anoxygenic phototrophic toluene degraders, as well as in a highly enriched methanogenic, toluene-degrading culture.
- Kane, Staci R.,Beller, Harry R.,Legler, Tina C.,Anderson, Robert T.
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- Electrocatalytic Reduction of C-C π-Bonds via a Cobaltocene-Derived Concerted Proton-Electron Transfer Mediator: Fumarate Hydrogenation as a Model Study
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Reductive concerted proton-electron transfer (CPET) is poorly developed for the reduction of C-C π-bonds, including for activated alkenes that can succumb to deleterious pathways (e.g., a competing hydrogen evolution reaction or oligomerization) in a standard electrochemical reduction. We demonstrate herein that selective hydrogenation of the C-C π-bond of fumarate esters can be achieved via electrocatalytic CPET (eCPET) using a CPET mediator comprising cobaltocene with a tethered Br?nsted base. High selectivity for electrocatalytic hydrogenation is observed only when the mediator is present. Mechanistic analysis sheds light on two distinct kinetic regimes based on the substrate concentration: low fumarate concentrations operate via rate-limiting CPET followed by an electron-transfer/proton-transfer (ET/PT) step, whereas high concentrations operate via CPET followed by a rate-limiting ET/PT step.
- Derosa, Joseph,Garrido-Barros, Pablo,Peters, Jonas C.
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supporting information
p. 9303 - 9307
(2021/07/19)
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- Direct esterification of succinic acid with phenol using zeolite beta catalyst
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Direct esterification of succinic acid with phenol in the presence of zeolite catalysts was explored. H+-zeolite β (SiO2/Al2O3 = 150) has emerged as the most effective solid acid catalyst, affording 96% yield of
- Le, Son Dinh,Nishimura, Shun,Ebitani, Kohki
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- O-acylation of substituted phenols with various alkanoyl chlorides under phase-transfer catalyst conditions
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Esterification of several types of mono-and disubstituted phenols with various mono-and dialkanoyl chlorides was performed in phase-transfer catalysis conditions, using tetrabutylammonium chloride in a mixture of aqueous NaOH and dichloromethane. The process is particularly efficient (almost quantitative yields) as well as rapid (only 5 min reaction time, at a temperature of0°C). Taylor & Francis Group, LLC.
- Simion, Alina Marieta,Hashimoto, Iwao,Mitoma, Yoshiharu,Egashira, Naoyoshi,Simion, Cristian
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experimental part
p. 921 - 931
(2012/02/01)
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- SO42-/SnO2: Efficient, chemoselective, and reusable catalyst for acylation of alcohols, phenols, and amines at room temperature
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SO42-/SnO2 was employed for the acylation of a variety of alcohols, phenols, and amines under solvent-free conditions at room temperature. This method showed preferential selectivity for acetylation of the amino group in the presence of a hydroxyl group. The reported method is simple, mild, and environmentally viable, using several other acid anhydrides at room temperature. Copyright Taylor & Francis Group, LLC.
- Satam, Jitendra R.,Gawande, Manoj B.,Deshpande, Sameer S.,Jayaram, Radha V.
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p. 3011 - 3020
(2008/02/12)
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- Synthesis of 1,4-diketones: reaction of α-bromo ketones with tetrakis(dimethylamino)ethylene (TDAE)
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1,4-Diketones were prepared by the reaction of α-bromo ketones with tetrakis(dimethylamino)ethylene (TDAE) in moderate to good yields. Similarly, α-bromo esters were reductively coupled using TDAE to give the 1,4-diesters in moderate yields.
- Nishiyama, Yutaka,Kobayashi, Akihiro
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p. 5565 - 5567
(2007/10/03)
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- Montmorillonite clay catalysis. Part 10. K-10 and KSF-catalysed acylation of alcohols, phenols, thiols and amines: Scope and limitation
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Montmorillonite K-10 and KSF are highly efficient catalysts for the acetylation of a variety of alcohols, thiols, phenols and amines with acetic anhydride. Amino groups can be selectively acetylated in the presence of hydroxy groups, while the hydroxy groups can be preferentially acetylated in the presence of thiol groups. No selectivity is observed between primary and secondary hydroxy groups in the presence of K-10 and KSF. The catalysts are found not to be efficient for acetylation of tertiary alcohols. This method is simple and convenient with minimum environmental impact. The catalysts are also effective for the acylation of alcohols, thiols, phenols and amines with acetyl chloride and benzoyl chloride. Cyclic anhydrides such as succinic anhydride, maleic anhydride and phthalic anhydride and p-toluene sulfonyl chloride show less reactivity than acetic anhydride and acyl chlorides.
- Li, Tong-Shuang,Li, Ai-Xiao
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p. 1913 - 1917
(2007/10/03)
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- 2,4,4,6-Tetrabromocyclohexa-2,4-dienone: a New Electron Acceptor in the Photosensitized Oxidation of Unsaturated Substrates
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2,4,4,6-Tetrabromocyclohexa-2,4-dienone, usually used as a mild and selective brominating agent, acts as an electron acceptor in the sensitized photo-oxygenation of several unsaturated substrates; a mechanism is proposed.
- Lopez, Luigi,Calo, Vincenzo
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p. 1266 - 1268
(2007/10/02)
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