cas 617-51-6, ISOPROPYL (S)-(-)-LACTATE | Articles data

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Bi-Functional Magnesium Silicate Catalyzed Glucose and Furfural Transformations to Renewable Chemicals
Bio-refinery is attracting significant interest to produce a wide range of renewable chemicals and fuels from biomass that are alternative to fossil fuel derived petrochemicals. Similar to petrochemical industries, bio-refinery also depends on solid zeolite catalysts. Acid-base catalysis plays pivotal role in producing a wide range of chemicals from biomass. Herein, the Mg framework substituted MTW zeolite is synthesized and explored in the valorisation of glucose and furfural. Bi-functional (acidic and basic) characteristics are confirmed using pyridine adsorbed FT?IR analysis and NH3 and CO2 temperature-programmed desorption techniques. Textural properties and morphological information are retrieved from N2-sorption, X-ray photoelectron spectroscopy, and electron microscopy. The activity of the catalyst is demonstrated in the selective isomerisation of glucose to fructose in ethanol. Glucose is converted to methyl lactate in high yield using the same catalyst. Further, the bi-functional activity of this catalyst is demonstrated in the production of fuel precursor by the reaction of furfural and isopropanol. Mg?MTW zeolite exhibits excellent activity in the production of all these chemicals and fuel derivative. The catalyst exhibits no significant loss in the activity even after five recycles. One simple catalyst affording three renewable synthetic intermediates from glucose and furfural will attract significant attention to catalysis researchers and industrialists.
Kumar, Abhinav,Srivastava, Rajendra
p. 4807 - 4816
(2020/08/24)

ANTIVIRAL PRODRUGS OF TENOFOVIR
Compounds of Formula I: and pharmaceutically acceptable salts and co-crystals thereof are useful for the inhibition of HIV reverse transcriptase. The compounds may also be useful for the prophylaxis or treatment of infection by HIV and in the prophylaxis, delay in the onset or progression, and treatment of AIDS. The compounds and their salts can be employed as ingredients in pharmaceutical compositions, optionally in combination with other antiviral agents, immunomodulators, antibiotics or vaccines.
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Page/Page column 30; 34; 35

(2018/09/26)

Method of synthesizing acid ester
PROBLEM TO BE SOLVED: To provide a method for manufacturing lactate without the corrosion of a reactor nor trouble of waste liquid processing, using glycerol separated and generated from various oil-and-fats, including glycerol by-produced in the manufacture of a biodiesel fuel.SOLUTION: In the method, the lactate is synthesized from the glycerol in the presence of a solid basic catalyst, using alcohol in a high-temperature and high-pressure state as a reaction medium.
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Paragraph 0052-0054

(2017/02/23)

Dynamic kinetic resolution of α-substituted β-ketoesters catalyzed by Baeyer-Villiger monooxygenases: Access to enantiopure α-hydroxy esters
BVMOs make a play: The dynamic kinetic resolution of racemic α-alkyl-β-ketoesters was performed through a selective Baeyer-Villiger oxidation employing different Baeyer-Villiger monooxygenases (BVMOs) in mild basic media. The product diesters were obtained with excellent yields and enantioselectivities, and used as precursors for optically active α-hydroxy esters.
Rioz-Martínez, Ana,Cuetos, Aníbal,Rodríguez, Cristina,De Gonzalo, Gonzalo,Lavandera, Iván,Fraaije, Marco W.,Gotor, Vicente
supporting information; experimental part
p. 8387 - 8390
(2011/10/09)

Organosoluble zirconium phosphonate nanocomposites and their supported chiral ruthenium catalysts: The first example of homogenization of inorganic-supported catalyst in asymmetric hydrogenation
In this article, we report the synthesis, structure, morphologies, and asymmetric catalytic properties of a series of novel organosoluble zirconium phosphonate nanocomposites and their supported chiral ruthenium catalysts, which have a good organosolubility (0.1-0.5 g mL-1) in various solvents and mesoporous, filiform, and layered structures. Due to the organosoluble properties in various organic solvents, the first homogenization of zirconium phosphonate-supported catalyst was realized in the field of catalysis. In the asymmetric hydrogenation of substituted α-ketoesters, enantioselectivities (74.3-84.7% ee) and isolated yields (86.7-93.6%) were higher than the corresponding homogeneous Ru(p-cymene)(S-BINAP)Cl2 due to the confinement effect caused by the remaining mesopores in the backbone of the zirconium phosphonate. After completing the reaction, the supported catalyst can be readily recovered in quantitative yield by adding cyclohexane and centrifugation, and reused for five consecutive runs without significant loss in catalytic activity.
Chen, Taotao,Ma, Xuebing,Wang, Xiaojia,Wang, Qiang,Zhou, Jinqin,Tang, Qian
experimental part
p. 3325 - 3335
(2011/05/13)

Hydroxyapatite supported lewis acid catalysts for the transformation of trioses in alcohols
We prepared hydroxyapatite-supported tin(II) chloride and tin(IV) chloride Lewis acid catalysts. These catalysts showed catalytic activity for the transformation of trioses in alcohols to yield alkyl lactates. Under optimal conditions, n-butyl lactate was obtained in 73.5 yield when dihydroxyacetone and n-butanol were treated with hydroxyapatite-supported tin(II) chloride.
Zhang, Zehui,Zhao, Zongbao
experimental part
p. 70 - 73
(2011/10/05)

ZEOLITE-CATALYZED PREPARATION OF ALPHA-HYDROXY CARBOXYLIC ACIDS AND ESTERS THEREOF
A process for the production of lactic acid and 2-hydroxy-3-butenoic acid or esters thereof by conversion of glucose, fructose, sucrose, xylose and glycolaldehyde dissolved in a solvent in presence of a solid Lewis acidic catalyst.
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Page/Page column 3

(2010/06/11)

Zeolite-catalyzed preparation of alpha-hydroxy carboxylic acid compounds and esters thereof
A process for the production of lactic acid and 2-hydroxy-3-butenoic acid or esters thereof by conversion of glucose, fructose, sucrose, xylose and glycolaldehyde dissolved in a solvent in presence of a solid Lewis acidic catalyst.
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Page/Page column 6

(2010/06/11)

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)

Synthesis of alkyl (R)-lactates and alkyl (S,S)-O-lactyllactates by alcoholysis of rac-lactide using Novozym 435
Enzymatic alcoholysis of rac-lactide for kinetic resolution was carried out in organic solvents. Effects of organic solvent, reaction temperature, and alcohol as a nucleophile were also investigated in Novozym 435-catalyzed alcoholysis of rac-lactide. Both alkyl (R)-lactate and alkyl (S,S)-O-lactyllactate were simultaneously obtained in high yields (>45%) and high enantiopurities (>97% ee) through Novozym 435-catalyzed ring-opening of rac-lactide and subsequent enantioselective alcoholysis of the resultant alkyl O-lactyllactate.
Jeon, Nan Young,Ko, Sung-Jin,Won, Keehoon,Kang, Han-Young,Kim, Bum Tae,Lee, Yeon Soo,Lee, Hyuk
p. 6517 - 6520
(2007/10/03)

PROCESS FOR THE PRODUCTION OF METAL SALTS OF TRIFLUOROMETHANE SULPHONIC ACID AND THEIR USE AS ESTERIFICATION CATALYSTS
The subject matter of the invention is a process for the production of metal salts of trifluoromethane sulphonic acid by reacting trifluoromethane sulphonic acid with a metal alcoholate and the use thereof as esterification catalyst and/or transesterification catalyst for the production of hydroxycarboxylic acid esters.
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Page/Page column 12; 14

(2008/06/13)

A mild, efficient, and inexpensive protocol for the selective deprotection of TBDMS ethers using KHSO4
Potassium hydrogensulfate in 30% aq. methanol deprotects a variety of tert-butyldimethylsilyl ethers at room temperature in excellent yields.
Arumugam, Pandurangan,Karthikeyan, Ganesan,Perumal, Paramasivan T.
p. 1146 - 1147
(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)

Separation of methylene chloride from tetrahydrofuran by extractive distillation
Methylene chloride is difficult to separate from tetrahydrofuran by conventional distillation or rectification because of the proximity of their vapor pressures. Methylene chloride can be readily separated from tetrahydrofuran by extractive distillation. Effective agents are 1-pentanol, 1,2-butanediol and 3-nitrotoluene.
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(2008/06/13)

Chiral Synthesis via Organoboranes. 15. Selective Reductions. 42. Asymmetric Reduction of Representative Prochiral Ketones with Potassium 9-O-(1,2:5,6-Di-O-isopropylidene-α-D-glucofuranosyl)-9-boratabicyclononane
Potassium 9-O-(1,2:5,6-di-O-isopropylidene-α-D-glucofuranosyl)-9-boratabicyclononane (9-O-DIPGF-9-BBNH, K-glucoride), a new stable chiral borohydride reducing agent, was prepared by reaction of the corresponding borinic ester, 9-O-DIPGF-9-BBN, with potassium hydride in THF.The reagent provides high optical induction for asymmetric reduction of prochiral ketones, such as relatively hindered aliphatic ketones, alkyl aromatic ketones, and α-keto esters.In particular, the reduction of hindered α-keto esters provides the corresponding α-hydroxy esters with optical purities approaching 100percent ee.Moreover, the reduction of relatively hindered aliphatic ketones such as 3,3-dimethyl-2-butanone, 2,2-dimethylcyclopentanone, spirononan-1-one, and 2,2-dimethylcyclohexanone yields the corresponding alcohols in 70percent ee, 84percent ee, 82percent ee, and 64percent ee, respectively.The reduction of unhindered aliphatic ketones such as 2-butanone, 3-methyl-2-butanone, 2-octanone, and cyclohexyl methyl ketone provides the corresponding alcohols in relatively low optical purities, 3percent ee, 39percent ee, 27percent ee, and 23percent ee respectively.Alkyl aromatic ketones are reduced to the corresponding alcohols, providing products in 78percent ee for acetophenone, 92percent ee for propiophenone, 87percent ee for butyrophenone, 87percent ee for isobutyrophenone, 85,4percent ee for valerophenone, 97-100percent ee for pivalophenone, and 91percent ee for 2'-methylacetophenone.The reduction of α-keto esters provides the corresponding α-hydroxy esters in exceptionally high ee, such as 86percent ee for methyl pyruvate, 86percent ee for ethyl pyruvate, 87percent ee for isopropyl pyruvate, 81percent ee for tert-butyl pyruvate, 92percent ee for ethyl 2-oxobutanoate, 94percent ee for ethyl 2-oxopentanoate, 98percent ee for methyl 3-methyl-2-oxobutanoate, 97percent ee for ethyl 3-methyl-2-oxobutanoate, 97percent ee for methyl 3,3-dimethyl-2-oxobutanoate, 98percent ee for ethyl 3,3-dimethyl-2-oxobutanoate, 93percent ee for ethyl 4-methyl-2-oxopenyanoate, 92percent ee for methyl benzoylformate, 94percent ee for ethyl benzoylformate, 93percent ee for isopropyl benzoylformate, and 96percent ee for ethyl α-oxo-1-naphthaleneacetate.The reduction of relatively more hindered ketones such as 3,3-diethyl-2-pentanone, 2,2,2-triphenylacetone, 2,2,2-triethylacetophenone, 2,2,2-triphenylacetophenone, and 2',4',6'-trimethylacetophenone results in a serious decrease in optical purity, 25percent ee, 7percent ee, 34percent ee, 4percent ee, and 35percent ee, respectively. 4-Chlorobenzophenone is reduced to 4-chlorobenzhydrol in only 11,5percent ee.Ethyl 2,2-dimethylacetoacetate is reduced to ethyl 2,2-dimethyl-3-hydroxybutanoate in 43percent ee.The reductions of alkyl heterocyclic ketones such as 2-acetylfuran, 2-acetylthiophene, and 3-acetylpyridine afford the corresponding alcohols with 42percent ee, 42percent ee, and 70percent ee, respectively.The reductions of α-halo ketones, 2-chloroacetophenone and 2,2,2-trifluoroacetophenone, yield the corresponding halohydrins in 77percent ee and 48percent ee, respectively. trans-4-Phenyl-3-buten-2-one is reduced to the corresponding allylic alcohol in 60percent ee.The reduction of 4-phenyl-3-butyn-2-one provides the corresponding acetylenic alcohol in 61percent ee.The ...
Brown, Herbert C.,Cho, Byung Tae,Park, Won Suh
p. 1231 - 1238
(2007/10/02)

Selective Reductions. 37. Asymmetric Reduction of Prochiral Ketones with B-(3-Pinanyl)-9-borabicyclononane
The chiral trialkylborane B-(3-pinanyl)-9-borabicyclononane, either with the neat reagents or concentrated solutions, 2 M, reduces a wide range of prochiral carbonyl compounds with good to excellent asymmetric induction.Reduction of simple dialkyl ketones, 2-butanone, 2-octanone, 3-methyl-2-butanone, and 3,3-dimethyl-2-butanone, yields the corresponding alcohols with 43percent, 48percent, 62percent, and 0.7percent asymmetric induction.Acetophenone is reduced to 1-phenylethanol in 85percent ee.The α,β-unsaturated ketones 3-buten-2-one, 1-acetyl-1-cyclohexene, 3-methyl-2-cyclohexenone, and trans-4-phenyl-3-buten-2-one are reduced to the corresponding allylic alcohols with 57percent, 64percent, 11percent, and 97percent asymmetric induction, respecticvely.The α,β-conjugated acetylenic ketones 3-butyn-2-one, 4-methyl-1-pentyn-3-one, and 4-phenyl-3-butyn-2-one underwent a rapid reduction to afford the corresponding propargylic alcohols with 79percent, 99percent, and 91percent enantiomeric purities.The α-haloalkyl aromatic ketones α-chloroacetophenone, α-bromoacetophenone, α-iodoacetophenone, α,p-dibromoacetophenone, α-bromo-p-cyanoacetophenone,α-bromo-2'-acetonaphthone,and α,α,α-trifluoroacetophenone afforded the corresponding halohydrins with 96percent,93percent,93percent,96percent,96percent,90percent,and35percent enantiomeric purities, respectively.The corresponding aliphatic analogue 1-bromo-3-methyl-butanone gave the halohydrin in 66percent ee.The other isomer of this ketone, 3-bromo-3-methyl-2-butanone, failed to undergo reduction.Both the aliphatic and aromatic α-keto esters underwent rapid reduction to give the corresponding α-hydroxy esters with excellentenantiomeric excesses.Thus, methyl, ethyl, isopropyl, and tert-butyl pyruvates afforded the corresponding lactates with 86percent,83percent,78percent, and 92percent ee at 25 deg C,respectively.Lowering the reaction temperature to 0 deg C gave the tert-butyl lactate in 100percent ee.Other aliphatic α-keto esters such as metyl and ethyl 2-oxopentanoates, methyl 3-methyl-2-oxobutanoate, and ethyl 4-methyl-2-oxopentanoate were reduced to the corresponding α-hydroxy esters with 96percent, 96percent, 11percent, and 82percent ee.The methyl, isopropyl, and tert-butyl benzoylformates were reduced to the corresponding mendelic esters with 90percent, 96percent and 100percent ee, respectively.The reduction of the β-keto esters, however, proceeded slowly and ethyl acetoacetate gave the corresponding alcohol with 55percent ee.
Brown, Herbert C.,Pai, G. Ganesh
p. 1384 - 1394
(2007/10/02)

Remarkable Optical Induction in the Reduction of α-Keto Esters with B-(3-Pinanyl)-9-borabicyclononane. Synthesis of α-Hydroxy Esters of 100percent Optical Purity
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Brown, Herbert C.,Pai, Ganesh G.,Jadhav, Prabhakar K.
p. 1531 - 1533
(2007/10/02)