- Heterogeneous catalysts for the cyclization of dicarboxylic acids to cyclic anhydrides as monomers for bioplastic production
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Cyclic anhydrides, key intermediates of carbon-neutral and biodegradable polyesters, are currently produced from biomass-derived dicarboxylic acids by a high-cost multistep process. We present a new high-yielding process for the direct intramolecular dehydration of dicarboxylic acids using a reusable heterogeneous Lewis acid catalyst, Nb2O5·nH2O. Various dicarboxylic acids, which can be produced by a biorefinery process, are transformed into the corresponding cyclic anhydrides as monomers for polyester production. This method is suitable for the production of renewable polyesters in a biorefinery process.
- Rashed, Md. N.,Siddiki,Ali, Md. A.,Moromi, Sondomoyee K.,Touchy, Abeda S.,Kon, Kenichi,Toyao, Takashi,Shimizu, Ken-Ichi
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p. 3238 - 3242
(2017/07/28)
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- Succinic anhydrides from epoxides
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Catalysts and methods for the double carbonylation of epoxides are disclosed. Each epoxide molecule reacts with two molecules of carbon monoxide to produce a succinic anhydride. The reaction is facilitated by catalysts combining a Lewis acidic species with a transition metal carbonyl complex. The double carbonylation is achieved in single process by using reaction conditions under which both carbonylation reactions occur without the necessity of isolating or purifying the product of the first carbonylation.
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Page/Page column 24; 25; 26; 29; 30
(2013/07/25)
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- Catalytic, enantio- and diastereoselective synthesis of γ-butyrolactones incorporating quaternary stereocentres
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A new, highly enantio- and diastereoselective catalytic asymmetric formal cycloaddition of aryl succinic anhydrides and aldehydes which generates paraconic acid (γ-butyrolactone) derivatives is reported.
- Manoni, Francesco,Cornaggia, Claudio,Murray, James,Tallon, Sean,Connon, Stephen J.
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supporting information; experimental part
p. 6502 - 6504
(2012/07/31)
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- Electrocarboxylation of alkynes with carbon dioxide in the presence of metal salt catalysts
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With some common metal salts (CuI, FeCl3) as catalysts, alkynes can be effectively electrocarboxylated with CO2 (4 MPa) in an undivided cell with Ni cathode and Al sacrificial anode containing n-Bu4NBr-DMF as supporting el
- Li, Chuanhua,Yuan, Gaoqing,Jiang, Huanfeng
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experimental part
p. 1685 - 1689
(2011/07/07)
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- Synthesis, nicotinic acetylcholine receptor binding, antinociceptive and seizure properties of methyllycaconitine analogs
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A series of methyllycaconitine (1a, MLA) analogs was synthesized where the (S)-2-methylsuccinimidobenzoyl group in MLA was replaced with a (R)-2-methyl, 2,2-dimethyl-, 2,3-dimethyl, 2-phenyl-, and 2-cyclohexylsuccinimidobenzoyl (1b-f) group. The analogs 1b-f were evaluated for their inhibition of [125I]iodo-MLA binding at rat brain α7 nicotinic acetylcholine receptors (nAChR). In order to determine selectivity, MLA and the analogs 1b-f were evaluated for inhibition of binding to rat brain α,β nAChR using [3H]epibatidine. At the α7 nAChR, MLA showed a Ki value of 0.87 nM, analogs 1b-e possessed Ki values of 1.67-2.16 nM, and 1f showed a Ki value of 26.8 nM. Surprisingly, the analog 1e containing the large phenyl substituent (Ki = 1.67 nM) possessed the highest affinity. None of the compounds possessed appreciable affinity for α,β nAChRs. MLA antagonized nicotine-induced seizures with an AD50 = 2 mg/kg. None of the MLA analogs were as potent as MLA in this assay. MLA and all of the MLA analogs, with the exception of 1b, antagonized nicotine's antinociceptive effects in the tail-flick assay. Compound 1c (Ki = 1.78 nM at α7 nAChR) with an AD50 value of 1.8 mg/kg was 6.7 times more potent than MLA (AD50 = 12 mg/kg) in antagonizing nicotine's antinociceptive effects but was 5-fold less potent than MLA in blocking nicotine-induced seizures. Since MLA has been reported to show neuroprotection against β-amyloid1-42, these new analogs which have high α7 nAChR affinity and good selectivity relative to α,β nAChRs will be useful biological tools for studying the effects of α7 nAChR antagonist and neuroprotection.
- Ivy Carroll,Ma, Wei,Navarro, Hernan A.,Abraham, Philip,Wolckenhauer, Scott A.,Damaj,Martin, Billy R.
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p. 678 - 685
(2007/10/03)
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- Catalytic double carbonylation of epoxides to succinic anhydrides: Catalyst discovery, reaction scope, and mechanism
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The first catalytic method for the efficient conversion of epoxides to succinic anhydrides via one-pot double carbonylation is reported. This reaction occurs in two stages: first, the epoxide is carbonylated to a β-lactone, and then the β-lactone is subsequently carbonylated to a succinic anhydride. This reaction is made possible by the bimetallic catalyst [(CITPP)Al(THF)2]+[Co(CO)4]- (1; CITPP = meso-tetra(4-chlorophenyl)porphyrinato; THF = tetrahydrofuran), which is highly active and selective for both epoxide and lactone carbonylation, and by the identification of a solvent that facilitates both stages. The catalysis is compatible with substituted epoxides having aliphatic, aromatic, alkene, ether, ester, alcohol, nitrile, and amide functional groups. Disubstituted and enantiomerically pure anhydrides are synthesized from epoxides with excellent retention of stereochemical purity. The mechanism of epoxide double carbonylation with 1 was investigated by in situ IR spectroscopy, which reveals that the two carbonylation stages are sequential and non-overlapping, such that epoxide carbonylation goes to completion before any of the intermediate β-lactone is consumed. The rates of both epoxide and lactone carbonylation are independent of carbon monoxide pressure and are first-order in the concentration of 1. The stages differ in that the rate of epoxide carbonylation is independent of substrate concentration and first-order in donor solvent, whereas the rate of lactone carbonylation is first-order in lactone and inversely dependent on the concentration of donor solvent. The opposite solvent effects and substrate order for these two stages are rationalized in terms of different resting states and rate-determining steps for each carbonylation reaction.
- Rowley, John M.,Lobkovsky, Emil B.,Coates, Geoffrey W.
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p. 4948 - 4960
(2008/02/03)
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- "ONE-POT" SYNTHESIS OF DISYMMETRICALLY α,α'-DISUBSTITUTED SUCCINIC ANHYDRIDES PRECURSORS
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A "one-pot" synthesis for disymmetrically α,α'-disubstituted succinic anhydrides precursors isreported in the present paper.Substituents are aryl, primary or secondary alkyl groups.This reaction represents a simple and quick method with fair yields.
- Dana, A.,Campagnole, M.,Bourgeois, M.J.,Montaudon, E.
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p. 2981 - 2988
(2007/10/03)
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- Synthesis of Small-Medium Ring Thioanhydrides
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Reaction of five-membered ring anhydrides with sodium sulfide has previously been employed for synthesis of the corresponding thioanhydrides in low yields.Re-examination of the stoichiometry reveals reaction of cyclic anhydride with sodium sulfide (2:1 respectively), affords the thioanhydride accompanied by the corresponding dicarboxylate in a 1:1 molar ratio.The mechanistic pathway for this reaction has also been elucidated.Optimization of reaction conditions has resulted in the synthesis of a variety of four to seven-membered ring thioanhydride in yields approaching theoretical.
- Kates, Michael J.,Schauble, J. Herman
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p. 971 - 978
(2007/10/02)
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- TETRAHYDROISOQUINOLINES AS ALPHA-2 ANTAGONISTS AND BIOGENIC AMINE UPTAKE INHIBITORS
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The present invention provides a tetrahydroisoquinoline compound of the formula STR1 or a pharmaceutically acceptable salt thereof which is an antagonist for alpha-2 adrenoreceptors and/or which inhibits biogenic amine uptake.
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- The Ozonolysis of Alkenylidenecyclopropanes
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The ozonolysis of alkenylidenecyclopropanes has been shown to generate cyclobutane-1,2-diones by a novel ring-expansion process which occurs at some point during oxidative cleavage of the allene unit.
- Crandall, Jack K.,Schuster, Thomas
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p. 1973 - 1975
(2007/10/02)
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- On the regioselectivity of Wittig reactions with unsymmetrically substituted succinic anhydrides
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Phosphorane ylids react readily with succinic anhydrides to give enol-lactones.With highly substituted succinic anhydrides, condensation occur at the less substituted carbonyl group, suggesting that the reaction is sterically controlled.This, however, is
- Kayser, Margaret M.,Breau, Livain
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p. 1401 - 1410
(2007/10/02)
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- Facile and Efficient Syntheses of Carboxylic Anhydrides and Amides Using (Trimethylsilyl)ethoxyacetylene
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(Trimethylsilyl)ethoxyacetylene, a stable and easy-handling reagent, serves as an excellent dehydrating agent for the synthesis of carboxylic anhydrides and amides from the corresponding carboxylic acids.By means of this reagent, various types of acid-sensitive carboxylic anhydrides and amides were obtained almost in quantative yields.Twenty-two examples of carboxylic anhydrides and 12 examples of amides were presented.
- Kita, Yasuyuki,Akai, Shuji,Ajimura, Naomi,Yoshigi, Mayumi,Tsugoshi, Teruhisa,et al.
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p. 4150 - 4158
(2007/10/02)
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- QUANTITATIVE DETERMINATION OF THE ELECTRONIC EFFECTS OF 3- AND 4-PYRIDAZINYL GROUPS FROM NMR SPECTRAL DATA FOR ISOMERIC AMINOPHENYL- AND PHENYLPYRIDAZINES
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The previously unknown aminophenylpyridazines were synthesized.The inductive and resonance constants of 3- and 4-pyridazinyl groups were calculated on the basis of 1H and 13C NMR spectral data for isomeric aminophenyl- and phenylpyridazines in dimethyl sulfoxide (DMSO).
- Shkurko, O. P.,Kuznetsov, S. A.,Denisov, A. Yu.,Mamaev, V. P.
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p. 763 - 770
(2007/10/02)
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- A MILD AND FACILE SYNTHESIS OF CARBOXYLIC ANHYDRIDES
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Reaction of carboxylic acids with trimethylsilylethoxyacetylene in an inert solvent under mild conditions affords the corresponding carboxylic anhydrides in almost quantitative yields.
- Kita, Y.,Akai, S.,Yoshigi, M.,Nakajima, Y.,Yasuda, H.,Tamura, Y.
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p. 6027 - 6030
(2007/10/02)
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- Acid and Polarity Effects in Benzene Photoreactions with Alkenes and Alkynes
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The effects of polar solvents and proton donors on various photoreactions of the benzene ring with electron-acceptor alkenes and alkynes are described and discussed in relation to the various electronic excitation mechanisms involved.Proton donors prove valuable as mechanistic probes for polar intermediates in such processes, and can in some systems both initiate and divert reaction pathways. - Key words: Photoreactions, Benzene, Alkenes, Alkynes, Acid Effects
- Bryce-Smith, D.,Gilbert, A.,Al-Jalal, N.,Deshpande, R.R.,Grzonka, J.,et al.
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p. 1101 - 1112
(2007/10/02)
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- SYNTHESE DU METHOXYCARBONYL-3 INDENE ET DE METHOXYCARBONYL-4 DIHYDRO-1,2 NAPHTALENES. OBTENTION DES β-TETRALONES A PARTIR DES α-TETRALONES CORRESPONDANTES
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The synthesis of variously substituted 3-methoxycarbonylindene and 4-methoxycarbonyl-1,2-dihydronaphthalenes is described.A simple and efficient method for the transformation of 1-tetralone into 2-tetralone is reported.
- Vebrel, Joel,Carrie, Robert
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p. 161 - 166
(2007/10/02)
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- 2-Phenyl- and 2-benzyl-N-[(trichloromethyl)thio]succinimides, and fungicidal compositions thereof
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N-[(Trichloromethyl)thio]succinimides of the formula STR1 WHERE R1, R2 and R3 independently are hydrogen or alkyl having from 1 to 6 carbon atoms, and n is zero or the integer 1, having antifungal activity, a method of use thereof as antifungal agents, and antifungal compositions comprising them are disclosed.
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- Ashless additives for lubricating compositions
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Superior ashless additives for lubricants are prepared by a process comprising first introducing a petroleum sulfonic acid and a polyamine to a reaction zone and subsequently introducing a cyclic anhydride of a dicarboxylic acid into the reaction zone. In another embodiment, the solids content of the additives is reduced to acceptable levels by removal of free SO2 from the petroleum sulfonic acid prior to preparing the additive. Lubricating oil compositions containing these ashless additives are also provided.
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