88335-89-1Relevant articles and documents
A new structural motif for bifunctional bronsted acid/base organocatalysis
Wakchaure, Vijay N.,List, Benjamin
supporting information; experimental part, p. 4136 - 4139 (2010/08/07)
"Chemical equation presented" Naturally synthetic: Acid/base catalyst (S)-I can be used in highly enantioselective alcoholytic desymmetrizations of meso anhydrides. For example, the methanolysis of cyclobutane anhydride deriva-tive 2 gave hemiester 3 in 99:1 e.r. (see scheme). Ester 3 was used in a short enantioselective synthesis of (+ )-grandisol.
INHIBITORS OF DIACYLGLYCEROL O-ACYLTRANSFERASE TYPE 1 ENZYME
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Page/Page column 89, (2010/11/29)
The present invention relates to compounds of formula (I) wherein R1, R3, X, Q, Z, A, D, m, and n are defined herein. Pharmaceutical compositions and methods for treating DGAT-1 related diseases or conditions are also disclosed.
Synthesis of the constrained glutamate analogues (2S,1′R,2′R)- and (2S,1′S,2′S)-2-(2′-carboxycyclobutyl)glycines L-CBG-II and L-CBG-I by enzymatic transamination
Gu, Xin,Xian, Mo,Roy-Faure, Sophie,Bolte, Jean,Aitken, David J.,Gefflaut, Thierry
, p. 193 - 196 (2007/10/03)
Optically pure trans-cyclobutane analogues of glutamic acid are prepared by highly selective enzymatic transamination of a single racemic trans-cyclobutane α-ketoglutaric acid derivative 5, which is synthesized in five steps from maleic anhydride. (2S,1′R,2′R)- and (2S,1′S,2′S)-2- (2′-carboxycyclobutyl)glycines L-CBG-II and L-CBG-I are obtained using aspartate aminotransferase (AAT) and branched chain aminotransferase (BCAT), respectively.
Stereoselective chemoenzymatic synthesis of the four stereoisomers of L-2-(2-carboxycyclobutyl)glycine and pharmacological characterization at human excitatory amino acid transporter subtypes 1, 2, and 3
Faure, Sophie,Jensen, Anders A.,Maurat, Vincent,Gu, Xin,Sagot, Emmanuelle,Aitken, David J.,Bolte, Jean,Gefflaut, Thierry,Bunch, Lennart
, p. 6532 - 6538 (2007/10/03)
The four stereoisomers of L-2-(2-carboxycyclobutyl)glycine, L-CBG-I, L-CBG-II, L-CBG-III, and L-CBG-IV, were synthesized in good yield and high enantiomeric excess, from the corresponding cis and trans-2- oxalylcyclobutanecarboxylic acids 5 and 6 using the enzymes aspartate aminotransferase (AAT) and branched chain aminotransferase (BCAT) from Escherichia coli. The four stereoisomeric compounds were evaluated as potential ligands for the human excitatory amino acid transporters, subtypes 1, 2, and 3 (EAAT1, EAAT2, and EAAT3) in the FLIPR membrane potential assay. While the one trans-stereoisomer, L-CBG-I, displayed weak substrate activity at all three transporters, EAAT1-3, we found a particular pharmacological profile for the other trans-stereoisomer, L-CBG-II, which displayed EAAT1 substrate activity and inhibitory activity at EAAT2 and EAAT3. Whereas L-CBG-III was found to be a weak inhibitor at all three EAAT subtypes, the other cis-stereoisomer L-CBG-IV was a moderately potent inhibitor with 20-30-fold preference for EAAT2/3 over EAAT1.
Enantioselective synthetic approaches to cyclopropane and cyclobutane β-amino acids: Synthesis and structural study of a conformationally constrained β-dipeptide
Martin-Vila, Marta,Muray, Elena,Aguado, Gemma P.,Alvarez-Larena, Angel,Branchadell, Vicenc,Minguillon, Cristina,Giralt, Ernest,Ortuo, Rosa M.
, p. 3569 - 3584 (2007/10/03)
Synthetic approaches to carbocyclic compounds, namely cyclopropane and cyclobutane β-amino acids, are presented. One of them is based on enzymatic desymmetrization of meso diesters, leading to the enantioselective production of cis-hemiesters, which afforded β-amino acids through Curtius rearrangements. The enantiomeric excess for the cyclobutane derivatives was 91% whereas the cyclopropanes were obtained in 63% ee. According to another strategy, an enantiomerically pure cyclopropane trans-β-amino acid, bearing a quaternary center, has been synthesized from a homochiral precursor easily available from D-glyceraldehyde. The preparation and structural investigation of the first synthesized cyclobutane containing dipeptide is also described. A hairpin-like conformation of this molecule in the solid state has been demonstrated by X-ray structural analysis, showing crystal packing induced by the presence of the rigid cyclobutane moiety and the formation of intermolecular hydrogen bonds. NMR experiments confirmed that these molecules also tend to produce aggregates in solution. On the contrary, theoretical calculations suggest that intramolecular interactions are important in the gas phase, as expected. Copyright (C) 2000 Elsevier Science Ltd.
Practical and Highly Enantioselective Ring Opening of Cyclic Meso-Anhydrides Mediated by Cinchona Alkaloids
Bolm, Carsten,Schiffers, Ingo,Dinter, Christian L.,Gerlach, Arne
, p. 6984 - 6991 (2007/10/03)
The cinchona alkaloid-mediated opening of prochiral cyclic anhydrides in the presence of methanol leading to optically active hemiesters is described. Very structurally diverse anhydrides are converted into their corresponding methyl monoesters, and either enantiomer can be obtained with up to 99% ee by using quinine or quinidine as directing additive. After the reaction, the alkaloids can be recovered almost quantitatively and reused without loss of enantioselectivity. Additionally, a catalytic protocol which permits the substoichiometric use of quinidine in the presence of easily accessible pentamethylpiperidine (pempidine) is presented.
Stereoselective synthesis of (-)-(1R,2S)-2-aminocyclobutane-1-carboxylic acid, a conformationally constrained β-amino acid
Martin-Vila, Marta,Minguillon, Cristina,Ortuno, Rosa M.
, p. 4291 - 4294 (2007/10/03)
The title compound as well as some derivatives have been synthesized for the first time in optically active form by means of a chemoenzymatic transformation used to induce asymmetry in achiral precursors. The enantio- and diastereomeric purity has been determined by HPLC and NMR techniques.