116611-58-6Relevant articles and documents
Bioproduction of l-2-Aminobutyric Acid by a Newly-Isolated Strain of Aspergillus tamarii ZJUT ZQ013
An, Zhengfang,Gu, Xiaoxu,Liu, Yue,Ge, Jingyan,Zhu, Qing
, p. 837 - 844 (2017/03/24)
Abstract: l-2-Aminobutyric acid (l-ABA), an unnatural amino acid, is a key intermediate of several important drugs. Although some methods have been developed to prepare pure chiral l-ABA, there are still many drawbacks, including low catalytic efficiency, cumbersome steps and high cost due to the addition of some expensive catalysts or coenzymes. Herein, with chemical and biological approaches together, we discovered a newly isolated Aspergillus tamarii ZJUT ZQ013 strain containing a microbial lipase which could be employed to resolve racemic methyl N-Boc-2-aminobutyrate to produce l-ABA with high enantioselectivity (e.e.s?>?99.9%, E = 257). Moreover, the subsequent gram scale experiment confrimed that A. tamarii ZJUT ZQ013 could be an attractive biocatalyst for the efficient preparation of optically pure acid. Graphical Abstract: [Figure not available: see fulltext.]
Benzoxaborole Antimalarial Agents. Part 5. Lead Optimization of Novel Amide Pyrazinyloxy Benzoxaboroles and Identification of a Preclinical Candidate
Zhang, Yong-Kang,Plattner, Jacob J.,Easom, Eric E.,Jacobs, Robert T.,Guo, Denghui,Freund, Yvonne R.,Berry, Pamela,Ciaravino, Vic,Erve, John C. L.,Rosenthal, Philip J.,Campo, Brice,Gamo, Francisco-Javier,Sanz, Laura M.,Cao, Jianxin
, p. 5889 - 5908 (2017/07/22)
Carboxamide pyrazinyloxy benzoxaboroles were investigated with the goal to identify a molecule with satisfactory antimalarial activity, physicochemical properties, pharmacokinetic profile, in vivo efficacy, and safety profile. This optimization effort discovered 46, which met our target candidate profile. Compound 46 had excellent activity against cultured Plasmodium falciparum, and in vivo against P. falciparum and P. berghei in infected mice. It exhibited good PK properties in mice, rats, and dogs. It was highly active against the other 11 P. falciparum strains, which are mostly resistant to chloroquine and pyrimethamine. The rapid parasite in vitro reduction and in vivo parasite clearance profile of 46 were similar to those of artemisinin and chloroquine, two rapid-acting antimalarials. It was nongenotoxic in an Ames assay, an in vitro micronucleus assay, and an in vivo rat micronucleus assay when dosed orally up to 2000 mg/kg. The combined properties of this novel benzoxaborole support its progression to preclinical development.
Synthesis of enantioenriched aza-proline derivatives through gold(I)-catalyzed cyclization of chiral α-hydrazino esters
Bouvet, Sebastien,Moreau, Xavier,Coeffard, Vincent,Greck, Christine
, p. 427 - 437 (2013/04/10)
A selective gold(I)-catalyzed synthesis of chiral aza-proline derivatives has been developed by ring closure of enantioenriched α-hydrazino esters bearing an alkyne group. These are easily prepared through a synthetic strategy involving two key steps: org
Modular P-OP ligands in rhodium-mediated asymmetric hydrogenation: A comparative catalysis study
Nunez-Rico, Jose L.,Etayo, Pablo,Fernandez-Perez, Hector,Vidal-Ferran, Anton
supporting information, p. 3025 - 3035 (2013/01/15)
Highly efficient and enantioselective hydrogenation reactions for α-(acylamino)acrylates, itaconic acid derivatives and analogues, α-substituted enol ester derivatives, and α-arylenamides (25 substrates) catalyzed by chiral cationic rhodium complexes of a set of P-OP ligands have been developed. The catalytic systems derived from these P-OP ligands provided a straightforward access to enantiomerically enriched α-amino acid, carboxylic acid, amine, and alcohol derivatives that are valuable chiral building blocks. Excellent efficiencies (full conversion in all cases) and extremely high enantiomeric excesses (94-99% ee) were achieved for a wide range of α-substituted enol ester derivatives, regardless of the substitution pattern. The R-oxy group of the ligand (methoxy or triphenylmethoxy) strongly influences the enantioselectivity and catalytic activity. Greater steric bulk around the metal centre correlated to greater (or similar) enantioselectivity, but also to slower hydrogenation. Furthermore, the hydrogenation rates observed with the four model substrates follow the same trend, independently of the R-oxy group of the ligand: methyl 2-acetamidoacrylate>dimethyl itaconate>1-phenylvinyl acetate>N-(1- phenylvinyl)acetamide. A substrate-to-catalyst ratio (S/C) of up to 10,000:1 was sufficient for total hydrogenation of a model substrate of intermediate reactivity (dimethyl itaconate), and did not imply any loss in conversion or enantioselectivity. Copyright
The total synthesis of pamamycin-607. Part 2: Synthesis of the C6-C18 domain
Fraser, Benjamin H.,Mulder, Roger J.,Perlmutter, Patrick
, p. 2857 - 2867 (2007/10/03)
Synthesis of the C6-C18 domain of pamamycin-607 was achieved in ten steps and 7% overall yield from commercially available d-norvaline. The key asymmetric transformations included a Paterson anti aldol addition, an anti selective reduction of the resultan
Enzymatic approach to both enantiomers of N-Boc hydrophobic amino acids
Agosta, Eleonora,Caligiuri, Antonio,D'Arrigo, Paola,Servi, Stefano,Tessaro, Davide,Canevotti, Renato
, p. 1995 - 1999 (2007/10/03)
Protease catalysed hydrolysis of N-Boc-amino acid esters allows us to obtain N-Boc l-acids and d-esters of amino butanoic acid, nor-leucine, nor-valine, leucine and t-leucine in excellent ee. The reaction occurs in short reaction times and high concentrations. When a biphasic system (buffer-MTBE) is employed, a strong solvent effect is observed. This method could be of significance for the preparation of d-t-leucine, for which a practical method is currently unavailable.
Synthesis of optically active β,γ-alkynylglycine derivatives
Meffre, Patrick,Gauzy, Laurence,Branquet, Eric,Durand, Philippe,Le Goffic, Francois
, p. 11215 - 11238 (2007/10/03)
Full results on the first synthesis of optically active β,γ-alkynylglycine derivatives from naturally occurring L-serine are described. The methodology uses L-serinal as a key intermediate and allows great versatility in the introduction of N-protective groups and of alkyne substitution. The N-Boc protected β,γ-alkynylglycine derivatives described have ee greater than 90%.
ORGANOCUPRATES MEDIATED CARBON-CARBON BOND FORMATION IN γ POSITION OF α-AMINO ESTERS WITHOUT RACEMISATION
Bajgrowicz, J. A.,Hallaoui El, A.,Jacquier, R.,Pigiere, Ch.,Viallefont, Ph.
, p. 2231 - 2234 (2007/10/02)
A new general method of synthesis of optically pure α-amino esters by action of organocuprates on t-butyloxycarbonyl-L-α-amino-γ-bromobutyric acid methyl ester is described.
