- METHOD FOR PREPARING ALKYL HYDROXYL ACID ESTER AND USE THEREOF
-
Provided is a method for preparing an alkyl hydroxyl acid ester, the product and use thereof. The method has advantages of high yield, not producing waste water, gas, or solid, low cost, and is green and environment friendly.
- -
-
Page/Page column 4; 5
(2021/09/17)
-
- Method for preparing lactate by catalyzing pyruvic aldehyde
-
The invention relates to a method for preparing lactate by catalyzing pyruvic aldehyde. The method comprises the following steps: contacting pyruvic aldehyde and alcohol with a catalyst in a reactor,and reacting to obtain a lactate-containing product, wherein the molar ratio of pyruvic aldehyde to alcohol is 1:(50-225), the reaction temperature is 30-180 DEG C, the reaction time is 1-10 h, the reaction pressure is 0.1-3 MPa, the catalyst contains a tin-titanium-silicon molecular sieve, and the weight ratio of pyruvic aldehyde to the tin-titanium-silicon molecular sieve based on dry basis weight is 1:(1-6). According to the method, the catalyst containing the binary tin-titanium-silicon molecular sieve is adopted, framework tin atoms and framework titanium atoms of the molecular sieve synergistically catalyze pyruvic aldehyde and alcohol to generate lactate, and the reaction efficiency is improved.
- -
-
Paragraph 0191; 0192; 0210
(2020/07/02)
-
- Preparation method and application of hydroxy acid alkyl ester
-
The invention relates to a preparation method of a green solvent hydroxy acid alkyl ester, which comprises the following steps: (1) an alkyl alcohol and a hydroxy acid methyl ester or an ethyl ester are mixed under normal pressure or micro-positive pressure in the presence of a catalyst and reacted at the temperature of 50-200 DEG C, and the molar ratio of alkyl alcohol to the hydroxy acid methylester or ethyl ester is greater than 1; (2) at the temperature of 135-170 DEG C, a product methanol or ethanol is fractionated for the first time, and the top temperature of a fractionating column isthe boiling point temperature of methanol or ethanol; (3) atmospheric pressure or reduced pressure distillation is carried out for the second time to obtain redundant reactants alkyl alcohol and unreacted hydroxy acid methyl ester or ethyl ester, and the distillation temperature is controlled to be the boiling point temperature of the alkyl alcohol and the hydroxy acid methyl ester or ethyl ester;and (4) the remaining product hydroxy acid alkyl ester is collected. The method has the advantages of high yield, no generation of any three wastes, low production cost, greenness and environmental protection.
- -
-
Paragraph 0025-0027
(2020/06/16)
-
- Robust acidic pseudo-ionic liquid catalyst with self-separation ability for esterification and acetalization
-
The novel acidic pseudo-ionic liquid catalyst with self-separation ability has been synthesized through the quaternization of triphenylphosphine and the acidification with silicotungstic acid. The pseudo-IL showed high activities for the esterification with average conversions over 90%. The pseudo-IL showed even higher activities for acetalization than traditional sulfuric acid. The homogeneous catalytic process benefited the mass transfer efficiency. The pseudo-IL separated from the reaction mixture automatically after reactions, which was superior to other IL catalysts. The high catalytic activities, easy reusability and high stability were the key properties of the novel catalyst, which hold great potential for green chemical processes.
- Shi, Yingxia,Liang, Xuezheng
-
p. 1413 - 1421
(2019/05/04)
-
- Retention Characteristics and Sorption Enthalpies of Esters of Natural Hydroxycarboxylic Acids on DB-1 Stationary Phase
-
Abstract: Sorption characteristics and retention of esters of glycolic, lactic, malic, and tartaric acids with C1?C8 alcohols of linear structure are studied by gas-liquid chromatography in the temperature range of 90?260°C on DB-1 nonpolar phase. The values of the retention indices of the compounds studied are obtained. On the basis of experimentally determined retention times, the thermodynamic characteristics of sorption under the conditions of limiting dilution are estimated. The dependences of the change in sorption enthalpies on the length of the linear alkyl substituent and on the value of the logarithmic retention index are found. The possibility of estimating the energy of intermolecular interactions of lactic acid esters in the liquid phase is shown on the basis of the obtained values of sorption enthalpies and vaporization enthalpies.
- Portnova,Yamshchikova, Yu. F.,Krasnykh
-
p. 577 - 583
(2019/06/03)
-
- Method for directly preparing lactate from 1,2-propanediol and short-chain alkyl alcohols
-
The invention belongs to the technical field of organic matter synthesis, and particularly relates to a method for directly preparing lactate from 1,2-propanediol and short-chain alkyl alcohols, and the method comprises the following steps: using a sodium stannate loaded rare noble metal as a catalyst, adding C1-C4 alkyl alcohols and the 1,2-propanediol into a high-pressure reaction kettle, usingnitrogen for purging air in the kettle, heating and stirring while the temperature is maintained to promote esterification of the 1,2-propanediol with the C1-C4 alkyl alcohols after oxidation of the 1,2-propanediol to produce the lactate. The method has mild reaction conditions and simple reaction steps, the 1,2-propanediol is completely converted, and the highest selectivity of the lactate can reach 78%. Meanwhile, the synthesized sodium stannate loaded rare noble metal has high catalytic activity and reusability.
- -
-
Paragraph 0050; 0053
(2019/10/15)
-
- Application of tungsten-based solid acid in lactic acid and lactate preparation using biomass and saccharides
-
The invention relates to the technical field of chemical catalyzing, in particular to application of tungsten-based solid acid in lactic acid and lactate preparation using biomass and saccharides. Tungsten-containing salt is allowed to have hydro-thermal synthesis reaction with the chlorine salt, sulfate, nitrate, phosphate and oxalate of barium, calcium, lead, aluminum, chromium, erbium, tin, germanium, niobium and tantalum to prepare a multiple-component tungsten-based solid acid catalyst. The multiple-component tungsten-based solid acid catalyst is simple to prepare, cheap, good in hydrothermal stability, easy to recycle, capable of catalyzing monosaccharides such as fructose and glucose to convert into the lactic acid or lactate, capable of catalyzing polysaccharides such as sucrose, maltose, starch and cellulose even biomass such as wood and corn straw containing cellulose to have hydrolysis reaction so as to prepare the lactic acid or lactate, promising in application prospect and the like, multi-step reaction catalyzing by one single catalyst is achieved, and the range of the biomass and the saccharides which can be converted by the catalyst is wide.
- -
-
Paragraph 0038; 0040
(2018/11/03)
-
- Quantitative NMR Approach to Optimize the Formation of Chemical Building Blocks from Abundant Carbohydrates
-
The future role of biomass-derived chemicals relies on the formation of diverse functional monomers in high yields from carbohydrates. Recently, it has become clear that a series of α-hydroxy acids, esters, and lactones can be formed from carbohydrates in alcohol and water solvents using tin-containing catalysts such as Sn-Beta. These compounds are potential building blocks for polyesters bearing additional olefin and alcohol functionalities. An NMR approach was used to identify, quantify, and optimize the formation of these building blocks in the Sn-Beta-catalyzed transformation of abundant carbohydrates. Record yields of the target molecules can be achieved by obstructing competing reactions through solvent selection.
- Elliot, Samuel G.,Tolborg, S?ren,Sádaba, Irantzu,Taarning, Esben,Meier, Sebastian
-
p. 2990 - 2996
(2017/07/25)
-
- Development of lactic ester as bifunctional additive of methanol-gasoline
-
In this paper, lactic esters were synthesized and used as phase stabilizer and saturation vapor pressure depressor of methanol-gasoline. The results show that the stabilities of the methanol-gasoline depend on the length of the lactic esters' alkoxy group. Several lactic esters were found to be effective in various gasoline-methanol blends, and the lactic esters display high capacity to depress the saturation vapor pressure of methanol-gasoline. According to the results, it can be concluded that the lactic esters have the great potential to be bifunctional gasoline-methanol additives.
- Zhang, Jie,Yang, Changchun,Tang, Ying,Xu, Lianghong,Wang, Xiaoting
-
p. 4827 - 4829
(2014/12/10)
-
- MONOMER, POLYMER, RESIST COMPOSITION, AND PATTERNING PROCESS
-
A polymer comprising recurring units derived from a (meth)acrylate monomer of tertiary ester type having branched alkyl on alicycle is used to form a resist composition. When subjected to exposure, PEB and organic solvent development, the resist composition is improved in dissolution contrast.
- -
-
-
- Bridging racemic lactate esters with stereoselective polylactic acid using commercial lipase catalysis
-
A productive and enantioselective hydrolysis of racemic mixtures of lactate esters with commercial Candida rugosa lipase was performed. This step contributes to a novel envisioned route for stereoselective PLA production by combining recent chemocatalytic developments with this biocatalytic contribution, foreseeing two separate l- and d-lactate enantiomer streams. A study of the hydrolysis kinetics identified an unexpected rate determining step at the origin of an unprecedented ester reactivity order.
- Van Wouwe, Pieter,Dusselier, Michiel,Basic, Aurelie,Sels, Bert F.
-
supporting information
p. 2817 - 2824
(2013/10/08)
-
- Poly(3-hydroxyoctanoate) depolymerase from Pseudomonas fluorescens GK13: Catalysis of ester-forming reactions in non-aqueous media
-
Several industrial processes based on lipase catalysis have been established. However, since there are still a vast number of catalytic processes that lack a suitable enzyme, the discovery of new biocatalysts is required to fulfil this purpose. The potential of using the medium-chain-length (mcl)-PHA depolymerase from Pseudomonas fluorescens GK13 in anhydrous media to catalyze ester-forming reactions has been investigated and compared with that of Novozyme 435. The mcl-PHA depolymerase catalyzes the ring-opening polymerization of racemic β-butyrolactone (β-BL), l- and d-lactide (LLA, DLA) with high yield resulting in low molecular weight polymers. On the other hand, ε-caprolactone and pentadecalactone, which show high polymerizability using Novozyme 435 as catalyst, were not polymerized by mcl-PHA depolymerase. Besides, the activity of mcl-PHA depolymerase toward transesterification and esterification of ethyl-3-hydroxyoctanoate, lauric acid, (R,S)-β-BL, LLA and DLA has been studied.
- Santos, Marta,Gangoiti, Joana,Llama, Maria J.,Serra, Juan L.,Keul, Helmut,Moeller, Martin
-
experimental part
p. 81 - 86
(2012/06/29)
-
- Synthesis and characterization of chiral mono N-heterocyclic carbene-substituted rhodium complexes and their catalytic properties in hydrosilylation reactions
-
Different chiral mono-substituted N-heterocyclic carbene complexes of rhodium were prepared, starting from [Rh(COD)Cl]2 (COD = cyclooctadiene) by addition of free N-heterocyclic carbenes (NHC), or an in-situ deprotonation of the corresponding iminium salt. All new complexes were characterized by spectroscopy methods. In addition, the structures of chloro(η4-1,5-cyclooctadiene)(1,3-di-[(1R,2R,3R,5S)-2,6, 6-trimethylbicyclo[3.1.1]hept-3-yl] imidazolin-2-ylidene)rhodium(I) (5a), chloro(η4-1,5-cyclooctadiene)(1,3-di-[(1R,2S,5R) -2-isopropyl-5-menthylcyclohex-1-yl]imidazol-2-ylidene)rhodium(I) (5b) and chloro(η4-1,5-cyclooctadiene)(1,3-di-[(2R,4S,5S) -2-methyl-4-phenyl-1,3-dioxacyclohex-5-yl]imidazolin-2-ylidene)rhodium(I) (5i) were analyzed by DFT-calculations. The enantioselective hydrosilylation of acetophenone, ethylpyruvate and n-propylpyruvate with diphenylsilane and hydrolysis was carried out with chiral C2-symmetrical mono-substituted N-heterocyclic carbene rhodium complexes giving for the first time an enantioselective excess of up to 74% ee in the case of the n-propylpyruvate.
- Steinbeck, Martin,Frey, Guido D.,Schoeller, Wolfgang W.,Herrmann, Wolfgang A.
-
scheme or table
p. 3945 - 3954
(2011/12/22)
-
- Lipase-catalyzed oligomerization and hydrolysis of alkyl lactates: Direct evidence in the catalysis mechanism that enantioselection is governed by a deacylation step
-
Lipase-catalyzed oligomerization of alkyl d-and l-lactate monomers (RDLa and RLLa, respectively) was studied for the first time. It has been found that the oligomerization occurs enantioselectively only for d-lactates to give oligomers up to heptamers of lactic acid (LA) in good to high yields by using primary C1 to C8 alkyl groups and sec-butyl group for d-lactate monomers. No reaction happened for all l-lactates in similar conditions. Lipase-catalyzed hydrolysis of alkyl d-and l-lactates was also examined, revealing that the hydrolysis took place for both d-and l-lactates, although l-lactates proceeded a couple of times slower. The hydrolysis results clearly demonstrate that the lipase catalysis mechanism involves an acyl-enzyme intermediate (EM) formation via the acylation step from both d-and l-lactates as a rate-determining step, and the subsequent deacylation step, a nucleophilic attack of water to the EM, takes place to produce free LA. On the other hand, in the oligomerization of d-lactates, the deacylation step, in which a sec-alcohol group of the monomer or of the propagating chain-end attacks to the EM, is only allowed for the sec-d-alcohol group to give a one-LA-unit-elongated oligomer. l-Lactates form the EM; however, the subsequent deacylation reaction with both the sec-l-and sec-d-alcohol groups does not take place, failing in the oligomerization to occur. These results provide with the first direct evidence in the lipase catalysis that the enantioselection is governed by the deacylation step. In the co-oligomerization between l-and d-lactates, the l-isomer retarded the reaction rate of the d-isomer, which was found due to the function of the former as a competitive inhibitor in the acylation step toward the latter.
- Ohara, Hitomi,Onogi, Akihisa,Yamamoto, Masafumi,Kobayashi, Shiro
-
experimental part
p. 2008 - 2015
(2011/03/22)
-
- Zeolite-catalysed conversion of C3 sugars to alkyl lactates
-
The direct conversion of C3 sugars (or trioses) to alkyl lactates was achieved using zeolite catalysts. This reaction represents a key step towards the efficient conversion of bio-glycerol or formaldehyde to added-value chemicals such as lactate derivatives. The highest yields and selectivities towards the desired lactate product were obtained with Ultrastable zeolite Y materials having a low Si/Al ratio and a high content of extra-framework aluminium. Correlating the types and amounts of acid sites present in the different zeolites reveals that two acid functions are required to achieve excellent catalysis. Bronsted acid sites catalyse the conversion of trioses to the reaction intermediate pyruvic aldehyde, while Lewis acid sites further assist in the intramolecular rearrangement of the aldehyde into the desired lactate ester product. The presence of strong zeolitic Bronsted acid sites should be avoided as much as possible, since they convert the intermediate pyruvic aldehyde into alkyl acetals instead of lactate esters. A tentative mechanism for the acid catalysis is proposed based on reference reactions and isotopically labelled experiments. Reusability of the USY catalyst is demonstrated for the title reaction.
- Pescarmona, Paolo P.,Janssen, Kris P. F.,Delaet, Chloe,Stroobants, Christophe,Houthoofd, Kristof,Philippaerts, An,De Jonghe, Chantal,Paul, Johan S.,Jacobs, Pierre A.,Sels, Bert F.
-
experimental part
p. 1083 - 1089
(2010/08/20)
-
- Poly(3-hydroxybutyrate)-depolymerase from Pseudomonas lemoignei: Catalysis of esterifications in organic media
-
Lipase catalysis in nonaqueous media is recognized as a powerful tool in organic and more recently polymer synthesis. Even though none of the currently known polyhydroxyalkanoate (PHA) depolymerases have lipase activity, they do have a catalytic center that resembles that of lipases. Motivated by the above, the potential of using the poly(3-hydroxybutyrate), PHB, depolymerase from Psuedomonas lemoignei in organic media to catalyze ester-forming reactions was investigated. The effect of different organic solvents (benzene-d6, cyclohexane-d12, and acetonitrile-d3) on the activity of the PHB-depolymerase toward propylation of L-lactide was studied. A significant difference in the catalytic rate was observed as a function of solvent polarity. The selectivity of the PHB-depolymerase (P. lemoignei) to catalyze the propylation of a series of different lactones including ε-caprolactone, δ-butyrolactone, γ-butyrolactone, and D, L, meso, and racemic lactides has been studied with the PHB-depolymerase (P. lemoignei) in organic solvents. Important differences in the reactivity of these lactones, as well as selective hydrolysis of stereochemically different linear lactic acid dimers, were observed. Moreover, the ability of the PHB-depolymerase to catalyze the solventless polymerization of ε-caprolactone and trimethylene carbonate was investigated.
- Kumar,Gross,Jendrossek
-
p. 7800 - 7806
(2007/10/03)
-
- Enantioselective hydrogenation of pyruvates over polymer-stabilized and supported platinum nanoclusters
-
The cinchonidine-modified enantioselective hydrogenation of pyruvates has been studied over polyvinylpyrrolidone-stabilized platinum (PVP-Pt) and the corresponding alumina-supported platinum (Al2O3-Pt) clusters. It is shown that the catalysts with particle size less than 2.0 nm demonstrate >90% enantioselectivity in favor of (R)-lactates. The solvent effect is similar to that over the conventional supported platinum catalyst except for tetrahydrofuran. These colloidal and supported clusters are stable with no obvious loss of activity and enantioselectivity even after 18 months standing in air at room temperature. Molecular mechanics calculations of the modifier- reactant interaction on the platinum surface suggest that it is possible to obtain good enantioselectivity on the small clusters.
- Zuo, Xiaobin,Liu, Hanfan,Guo, Dawei,Yang, Xiaozhen
-
p. 7787 - 7804
(2007/10/03)
-
- A boron analog of DIOP: Synthesis and properties
-
A rhodium complex of a boron analog of DIOP, which is a model for a tailored bimetallic catalyst possessing dual functions, is an active catalyst for hydrogenation and hydrosilylation.
- Borner,Ward,Kortus,Kagan
-
p. 2219 - 2228
(2007/10/02)
-
- Alpha-hydroxy carboxylic acid derivates suitable for use in liquid crystal materials and devices
-
Compounds which may be used as a dopant or host in a ferroelectric chiral smectic liquid crystal mixture. The compounds are characterized in that they are derivates of an X-hydroxy carboxylic acid and contain the chiral unit (I), in which Ro may be alkyl, alkoxy, halogen, formula (II), where b may be 0 to 3 and the phenyl ring may be substituted, and a is 0 or 1. The chiral unit is combined with a range of mesogenic combinations of groups. Lactic acid derivatives are described in detail (i.e. Ro=methyl) together with various preparative routes, for example the compound formula (III), which has dopant properties in a range of hosts.
- -
-
-
- Chiral phosphinopyrrolidine compounds and their use for asymmetric synthesis of optically active compounds
-
New chiral phosphinopyrrolidine compounds of the general formula: STR1 wherein R1 is a hydrogen atom, --COR, --COOR, --CONHR or --SO2 --R where R is an alkyl or aryl group, R2 and R3 each represents independently an aryl group which may have a substituent or substituents, and R4 and R5 each represents independently an aliphatic or cycloaliphatic hydrocarbyl group which may have a substituent or substituents, as well as the use of these compounds as ligand for a metal complex catalyst for asymmetric synthesis of optically active compounds. The new chiral phosphinopyrrolidine compounds are useful ligands which attain both of high optical yield and high reaction efficiency in catalytic asymmetric reduction.
- -
-
-
- Compounds for ferroelectric liquid crystal devices
-
STR1 Ferroelectric smectic liquid crystal mixtures are provided consisting of two constituents; a smectic host and another containing a chiral compound in which rotation of the chiral center relative to the molecular core is sterically hindered, so that the chiral compound induces a high Ps in the mixture. A preferred class of chiral compounds is those derived from naturally occurring compounds with chiral groups, especially α-hydroxycarboxylic acids, amino acids and terpenoids, e.g. with chiral groups (I), (II), (III). The chiral group is incorporated into a compound containing a mesogenic combination of groups, e.g. with chains of cyclic groups and some mesogenic combinations are described.
- -
-
-
- Highly Effective Catalytic Asymmetric Hydrogenations of α-Keto Esters and an α-Keto Acetal with New Neutral Chiral Pyrrolidinebisphosphine-Rhodium Complexes
-
Synthesis of new chiral pyrrolidinebisphosphine-rhodium complexes and their application to the asymmetric hydrogenations of α-keto esters and an α-keto acetal are described.Among them, MCCPM-Rh gave the highest optical yield (87 percent) of the α-hydroxy ester and MCPM-Rh gave the 75 percent optical yield of the α-hydroxy acetal at the substrate to catalyst ratio (1000 : 1).
- Takahashi, Hisashi,Morimoto, Toshiaki,Achiwa, Kazuo
-
p. 855 - 858
(2007/10/02)
-
- THE ASYMMETRIC HYDROGENATION OF α-KETO ESTERS CATALYZED BY RHODIUM(I) COMPLEXES WITH CHIRAL DIPHOSPHINE LIGANDS. ON THE CATALYTIC CYCLES AND THE MECHANISM OF ASYMMETRIC INDUCTION
-
Asymmetric hydrogenations of n-propyl pyruvate and ketopantoyl lactone catalyzed by rhodium complexes with (-) DIOP and BPPM were carried out under a variety of conditions.It was found that i) the Schrock-Osborn mechanism was not operative in these reactions at all since no acceleration of the reaction rate by the addition of water (1percent) was observed, ii) there was a clear difference between cationic and neutral (in situ) rhodium catalysts in their enantioslectivity, and iii) there was a remarkable solvent effect on the extent and direction of asymmetric induction.Possible mechanisms are discussed on the basis of these results.
- Ojima, Iwao,Kogure, Tetsuo
-
p. 239 - 248
(2007/10/02)
-