- Sequential Kinetic Resolution of (+/-)-2,3-Butanediol in Organic Solvent Using Lipase From Pseudomonas cepacia.
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Lipase from Pseudomonas capacia (PCL, Amano PS) catalyzed the enantioselective diacetylation of (+/-)-2,3-butanediol in vinyl acetate.Both acetylation steps favored the (R)-enantiomer (E1 = 12, E2 = 34), thus the reaction is a sequential kinetic resolution.The enantioselectivities of the two steps reinforced one another because both steps proceeded at comparable rates (S = 3) yielding an overall enantioselectivity of approximately 200.A synthetic-scale resolution starting from 2.7 g of (+/-)-2,3-butanediol yielded the diacetate ester of (R)-(-)-butanediol with 96percent ee (1.6 g, 30percent yield) and (S)-(+)-butanediol with 99percent ee (0.63 g, 23percentyield).This preparation is carried out entirely in organic solvent, thereby avoiding the difficult and low yield extraction of 2,3-butanediol from aqueous solution.
- Caron, Gaetan,Kazlauskas, Romas J.
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- METHOD FOR ESTERIFICATION OF A DIOL USING A REACTIVE DISTILLATION
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The invention relates to a conversion method that is fed with a diol feedstock that comprises at least 90% by weight of diol and a carboxylic acid feedstock that comprises at least 80% by weight of carboxylic acid. The method comprising at least: An esterification step which is fed with at least the diol feedstock and at least the carboxylic acid feedstock, wherein the carboxylic acid/diol molar ratio at the inlet of the esterification step is between 2 and 6, the esterification step comprises at least one reactive distillation column that has a mixed reaction/separation zone located between two separation zones; andA water elimination step that is fed with distillate from the esterification step that comprises water and producing at least one water effluent.
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Paragraph 0083-0091
(2018/02/28)
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- METHOD FOR PRODUCING 1,3-BUTADIENE FROM 1,4-BUTANEDIOL
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A method for producing 1,3-butadiene from a 1,4-butanediol feedstock: One step for esterification of 1,4-butanediol,One step for pyrolysis of 1,4-butanediol diester, producing butadiene.
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Paragraph 0076-0080
(2018/03/01)
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- Selective production of 1,3-butadiene using glucose fermentation liquor
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The production of 2,3-butanediol from glucose fermentation products and its subsequent esterification and conversion to 1,3-butadiene is reported. The addition of formic acid and acetic acid (C1-C2 acids) to the esterification reaction mixture resulted in yields of the diesters of 70% and 85%, without the loss of C1-C2 acids during the reaction. In the pyrolysis step, a highly selective (94% and 82% for formic acid 2-formyloxy-1-methyl-propyl ester and acetic acid 2-acetoxy-1-methyl-propyl ester, respectively) C-O cleavage to 1,3-butadiene over diesters was achieved without a catalyst. In the case of acetic acid, 100% was recovered, whereas in the case of formic acid, only 20% was recovered. Based on these results, it can be concluded that using glucose fermentation liquor as the starting material with external addition of acetic acid (2,3-butanediol:formic acid:acetic acid = 1:0.5:2.5), 70% yield of 1,3-butadiene can be achieved where the loss of formic acid is compensated by the acid in the starting material. This journal is the Partner Organisations 2014.
- Baek, Jayeon,Kim, Tae Yong,Kim, Wooyoung,Lee, Hee Jong,Yi, Jongheop
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p. 3501 - 3507
(2014/07/08)
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- Adrenaline profiling of lipases and esterases with 1,2-diol and carbohydrate acetates
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The adrenaline test for enzymes is a general back-titration procedure to detect 1,2-diols, 1,2-aminoalcohols and α-hydroxyketones reaction products of enzyme catalysis by colorimetry. The method was used to profile a series of esterases and lipases for their esterolytic activity on a series of carbohydrate and polyol acetates. Substrates were prepared by peracetylation and used for parallel microtiter-plate analysis of enzyme activities. This method can be used to achieve a rapid and automated characterization of a set of enzymes during HTS screening.
- Wahler, Denis,Boujard, Olivier,Lefèvre, Fabrice,Reymond, Jean-Louis
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p. 703 - 710
(2007/10/03)
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- Photochemical dimerization of organic compounds
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At least one of selectivity and reaction rate of photosensitized vapor phase dimerizations, including dehydrodimerizations, hydrodimerizations and cross-dimerizations of saturated and unsaturated organic compounds is improved by conducting the dimerization in the presence of hydrogen or nitrous oxide.
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- Hydrogen Atoms as Convenient Synthetic Reagents: Mercury-Photosensitized Dimerization of Functionalized Organic Compounds in the Presence of H2
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Hydrogen atoms are generated by mercury photosensitization in an unexceptional apparatus that makes them readily available for organic chemistry on a preparatively useful scale at 1 atm of pressure and temperatures from 0-150 °C. The H atoms add to CH2=CH-CH2X to give the intermediate radical CH3-(?CH)-CH2X, which dimerizes to give CH3CH(CH2X)-CH(CH2X)CH3. The saturated substrates CH3CH2CH2X undergo H abstraction to give CH3CH2(?CH)X as intermediates and CH3CH2CH(X)-CH(X)CH2CH3 as final products. The reaction shows a tolerance for different functional groups, X, which may be an alkyl or fluoroalkyl chain or contain vinyl, epoxy, ester, ketone, nitrile, and silyl groups. Radical disproportionation products are also formed but are easily separated. H atoms attack the weakest C-H bonds of the substrates with high selectivity. In our earliest direct mercury photosensitization, Hg* often failed to attack the substrate C-H bonds to give dimers; the presence of H2 strongly suppresses direct Hg* chemistry. H atoms are not sensitive to steric or polar effects Radical fragmentation is avoided by using "high" pressures (1 atm). Intramolecular radical additions to C=C bonds and methyl group 1,2-shift were also seen in some cases. Exceptional product ratios are observed for cross-reactions involving hydroxyalkyl radicals where H-bonding favors the homodimers in certain cases. Several bond strengths of C-H bonds α to CO were determined: EtCO2Me, 94.5; i-PrCO2Me, 92.7; cyclopentanone, 94.3; (i-Pr)2CO, 91.9 kcal/mol.
- Muedas, Cesar A.,Ferguson, Richard R.,Brown, Stephen H.,Crabtree, Robert H.
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p. 2233 - 2242
(2007/10/02)
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- DEHYDRODIMERIZATION OF KETONES, CARBOXYLIC ACIDS, AMIDES, ESTERS, ALCOHOLS, AND AMINES, VIA MERCURY-PHOTOSENSITIZATION
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Selective dehydrodimerization of the title compounds can be carried out on a preparative scale at 1 atm. and at 25-110 deg C in a simple apparatus by Hg-photosensitized reaction under H2.
- Boojamra, Constantine G.,Crabtree, Robert H.,Ferguson, Richard R.,Muedas, Cesar A.
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p. 5583 - 5586
(2007/10/02)
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- Studies on the Synthesis of Heterocyclic Compounds. VII. Action of Acyl Halides on Heterocyclic Compounds Containing the O-M-O (M = P, As, Sb) Bond in the Ring
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The action of acyl halides on heterocyclic compounds of five-membered rings containing an O-M-O (M = P, As, Sb) linkage is described.The reactions were either carried out in the presence of a solvent (benzene or toluene) or by direct heating of the reagent with the substrate.In the case of arsole, stibole and stannole derivatives, the cleavage of O-M bond and the formation of the respective mono- and diesters were always obtained, while with the phospholes, no cleavage of the compounds was observed.The products IIa-c (M = Sb) have been obtained in excellent yields starting from VIa-c and antimony trichloride.The structure of the compounds which were prepared was determined by analytical and spectroscopic methods and also by comparations with authentic samples where possible.
- Anchisi, Carlo,Corda, Luciana,Maccioni, Antonio,Podda, Gianni
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p. 141 - 144
(2007/10/02)
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- Production of esters from monoolefins and diolefins
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Monoolefins and diolefins are converted to corresponding esters in a process by contacting together at least one monoolefin, diolefin or mixture thereof, oxygen, at least one iodosoaryl dicarboxylate and at least one carboxylic acid, carboxylic acid anhydride or mixture thereof.
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- Linear-reactor-infrared-matrix and Microwave Spectroscopy of the cis-2-Butene Gas-phase Ozonolysis
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Investigation of the formation of complex products in the gas-phase ozonolysis of cis-2-butene by linear-reactor-infrared-matrix and linear-reactor-microwave spectroscopy is reported.The following species have been unequivocally detected: secondary 2-butene ozonide, acetic acid, peracetic acid, glycolaldehyde, dimethyl ketene, the simple mixed anhydrides of formic and acetic acid, 2,3-epoxy-butane and 2-butanone, besides polyatomic products alredy known.In contrast, the primery ozonide has been detectable neither by LR.-MW. nor by LR.-IR.Observation of both stereoisomeric epoxides and kinetic modelling are used to support the intermediate formation of the O'Neal-Blumstein radical CH3CH(O2)CH(O)CH3 and the existence of a reaction channel in which the two carbon atoms of the C,C double bond of the olefin remain connected.As the dominant reaction path a mechanism with a Criegee type split into methyldioxirane (ethylidene peroxide) and acetaldehyde is considered and subsequently proposed to explain formation of many complex products by either unimolecular or bimolecular processes of the peroxide.For the reactions considered, thermochemical estimates of reaction enthalpies and activation data are included.Kinetic modelling for a partial reaction mechanism involving at least two different paths of decay of the O'Neal-Blumstein biradical into Criegee-type intermediates and the 2,3-epoxy-butanes is discussed.
- Kuehne, Heinz,Forster, Martin,Hulliger, Juerg,Ruprecht, Heidi,Bauder, Alfred,Guenthard, Hans-Heinrich
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p. 1971 - 1999
(2007/10/02)
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