- Asymmetric hydrogenation reaction of alpha-ketoacids compound
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The invention relates to the technical field of organic chemistry, especially to an asymmetric hydrogenation reaction of an alpha-ketoacids compound. The asymmetric hydrogenation reaction comprises a scheme shown in the description. In the scheme, R1 is phenyl, substituted phenyl, naphthyl, substituted naphthyl, C1-C6 alkyl, or aralkyl; a substituent group is C1-C6 alkyl, C1-C6 alkoxy, or halogen; and the number of the substituent group is 1-3. In the scheme, M is a chiral spiro-pyridylamino phosphine ligand iridium complex having a structure shown in the description. In the structure, R is hydrogen, 3-methyl, 4-tBu, or 6-methyl.
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Paragraph 0037; 0045
(2016/10/10)
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- Direct asymmetric hydrogenation of α-keto acids by using the highly efficient chiral spiro iridium catalysts
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A new efficient and highly enantioselective direct asymmetric hydrogenation of α-keto acids employing the Ir/SpiroPAP catalyst under mild reaction conditions has been developed. This method might be feasible for the preparation of a series of chiral α-hydroxy acids on a large scale.
- Yan, Pu-Cha,Xie, Jian-Hua,Zhang, Xiang-Dong,Chen, Kang,Li, Yuan-Qiang,Zhou, Qi-Lin,Che, Da-Qing
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p. 15987 - 15990
(2015/02/19)
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- Carboxylation with CO2 via brook rearrangement: Preparation of α-hydroxy acid derivatives
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In the presence of CsF, a wide range of α-substituted α-siloxy silanes were carboxylated under a CO2 atmosphere (1 atm) via Brook rearrangement. A variety of α-substituents including aryl, alkenyl, and alkyl groups were tolerated to afford α-hydroxy acids in moderate-to-high yields. One-pot synthesis from aldehydes using PhMe2SiLi and CO 2 was also possible, providing α-hydroxy acids without the isolation of an α-hydroxy silane.
- Mita, Tsuyoshi,Higuchi, Yuki,Sato, Yoshihiro
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- SOLUBLE EPOXIDE HYDROLASE INHIBITORS
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Disclosed are alpha keto amide and alpha hydroxy amide compounds and compositions that inhibit soluble epoxide hydrolase (sEH), methods for preparing the compounds and compositions, and methods for treating patients with such compounds and compositions. The compounds, compositions, and methods are useful for treating a variety of sEH mediated diseases, including hypertensive, cardiovascular, inflammatory, pulmonary, and diabetic-related diseases.
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Page/Page column 114; 115
(2008/12/06)
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- An efficient new synthesis of racemic cetiedil and a novel route to α-ketocarboxylic acids utilising mild conditions
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We describe a new efficient synthesis of the prescribed racemic drug cetiedil [(±)-2-cyclohexyl-2-(3-thienyl)ethanoic acid 2-(hexahydro-1H-azepin-1-yl)ethylester], Additionally, we report herein a high yielding large scale, route to its acid precursor 7, subsequently enabling large-scale synthesis of the chiral forms of cetiedil, and detailed pharmacological investigations. Additionally, we describe a novel route to α-ketocarboxylic acids, starting from readily available or easily obtainable aldehydes: The mild conditions utilised opens up its applicability for use on molecules of biological interest. Georg Thieme Verlag Stuttgart.
- Roxburgh, Craig J.,Ganellin, C. Robin,Thorpe, Andrew J.
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p. 1211 - 1214
(2008/02/07)
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- Cyclic alkyl substituted glycolides and polylactides therefrom
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Cyclic alkyl, particularly cyclohexyl, substituted glycolides and polylactides are described. The polylactides have a high glass transition temperature and improved clarity.
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Page/Page column 6
(2008/06/13)
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- METHOD OF PREPARATION OF OPTICALLY ACTIVE ALCOHOLS
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The present invention relates to a method for preparing chiral alcohol having optical activity. More specifically, the present invention relates to a method for preparing (S)-chiral alcohol with a high yield and a high optical purity by mixing achiral substrates such as racemic alcohol or ketone with metal catalyst and protein hydrolase to perform a dynamic kinetic resolution reaction.
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Page/Page column 19
(2010/02/10)
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- Samarium diiodide-promoted diiodomethylation of carbonyl compounds with iodoform. Synthetic applications of diiodoalcohols
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A rapid and effective diiodomethylation of carbonyl compounds using SmI2 and iodoform is described. Transformations of the obtained diiodoalcohols 2 into α-iodoaldehydes 5 and α-hydroxyacids 6 is also reported.
- Concellon, Jose M.,Bernad, Pablo L.,Perez-Andres, Juan A.
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p. 1409 - 1412
(2007/10/03)
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- Reaction of carboxylic acids with diethyl phosphorocyanidate; a novel synthesis of homologated α-hydroxycarboxylic acids from carboxylic acids
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Carboxylic acids react with 2 equivalents of diethyl phosphorocyanidate in the presence of triethylamine to give dicyanophosphates in good yields; these dicyanophosphates can be hydrolyzed easily to give homologated α- hydroxycarboxylic acids.
- Mizuno, Masanori,Shioiri, Takayuki
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p. 9209 - 9210
(2007/10/03)
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- Enantioselective synthesis of α-hydroxy carboxylic acids: Direct conversion of α-oxocarboxylic acids to enantiomerically enriched α-hydroxy carboxylic acids via neighboring group control
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α-Oxocarboxylic acids can be reduced to the corresponding α-hydroxy carboxylic acids employing DIP-CI(TM) as a reducing agent. The α-carboxylic substituent exerts a remarkable neighboring group effect on the reduction. The reaction presumably proceeds in an intramolecular fashion through a 'rigid' bicyclic transition state assembly, which produces enantioselectivities approaching 99%.
- Wang, Zhe,La, Brittany,Fortunak, Joseph M.,Meng, Xian-Jun,Kabalka, George W.
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p. 5501 - 5504
(2007/10/03)
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- Dienediolates of Unsaturated Carboxylic Acids in Synthesis. Synthesis of Cyclohexenones and Polycyclic Ketones by Tandem Michael-Dieckmann Decarboxylative Annulation of Unsaturated Carboxylic Acids.
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Substituted 2-cyclohexenones 4 to 7 and hexahydronaphthalenones and hexahydroindenones 13 to 18 are prepared by tandem Michael-Dieckmann addition of lithium dienediolates of acyclic and alicyclic unsaturated carboxylic acids to the lithium salts of the same or other unsaturated carboxylic acids.
- Aurell, Maria J.,Gavina, Pablo,Mestres, Ramon
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p. 2571 - 2582
(2007/10/02)
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- A Novel Highly Diastereoselective Synthesis of Cyano Esters by Regioselective Ring Opening of Chiral Oxazolidinium Methiodides with Sodium Cyanide
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Sodium cyanide reacts with chiral oxazolidinium methiodides, prepared by quaternization of oxazolidines with methyl iodide, leading regio- and stereoselectively (d.e. 82-94percent) to cyano esters in moderate to good chemical yields (51-95percent).The open compounds are isolated as a pure diastereomer by a single recrystallization of their ammonium methiodides, and converted into enantiomerically pure α-hydroxy acids by heating with a concentrated solution of hydrochloric acid. - Key words: Chiral Oxazolidinium Iodides; alpha-Cyano ethers, Diastereoselective Ring Opening; alpha-Hydroxy Acids; Asymmetric Synthesis.
- Andres, Celia,Delgado, Manuel,Pedrosa, Rafael,Rodriquez, Raquel
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p. 8325 - 8328
(2007/10/02)
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- 1-Chloroalkyl p-Tolyl Sulfoxides as Useful Agents for Homologation of Carbonyl Compounds: Conversion of Carbonyl Compounds to α-Hydroxy Acids, Esters, and Amides and α,α'-Dihydroxy Ketones
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One-carbon homologation of carbonyl compounds to α-hydroxy acids, esters, and amides by the use of 1-chloroalkyl p-tolyl sulfoxide as a hydroxycarbonyl anion equivalent is reported.Oxidation of the vinyl chlorides, the intermediates of the above-mentioned
- Satoh, Tsuyoshi,Onda, Ken-ichi,Yamakawa, Koji
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p. 4129 - 4134
(2007/10/02)
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- Potent Prostacyclin Analogues Based on the Bicyclooctane Ring System
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The novel and biologically active prostacyclin mimetics 2 and 29 were prepared in a sequence based on the regioselective opening of epoxide 7 with a lithium acetylide in the presence of boron trifluoride etherate.The regioselectivity of epoxide opening wa
- Kluge, Arthur F.,Kertesz, Denis J.,O-Yang, Counde,Wu, Helen Y.
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p. 2860 - 2868
(2007/10/02)
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