2566-35-0Relevant academic research and scientific papers
Catalytic enantioselective synthesis of N,Cα,Cα-trisubstituted α-amino acid derivatives using 1H-imidazol-4(5H)-ones as key templates
Etxabe, Julen,Izquierdo, Joseba,Landa, Aitor,Oiarbide, Mikel,Palomo, Claudio
, p. 6883 - 6886 (2015)
Abstract 1H-Imidazol-4(5H)-ones are introduced as novel nucleophilic α-amino acid equivalents in asymmetric synthesis. These compounds not only allow highly efficient construction of tetrasubstituted stereogenic centers, but unlike hitherto known templates, provide direct access to N-substituted (alkyl, allyl, aryl) α-amino acid derivatives. A BB method: 1H-imidazol-4(5H)-ones serve as effective and easily available α-amino acid surrogates for the catalytic and highly diastereo- and enantioselective direct construction of N-substituted quaternary α-amino acid derivatives. The reaction is catalyzed by a Br?nsted base (BB) and proceeds with different Michael acceptors. EWG=electron-withdrawing group.
Biocatalytic Synthesis of Chiral N-Functionalized Amino Acids
Hyslop, Julia F.,Lovelock, Sarah L.,Sutton, Peter W.,Brown, Kristin K.,Watson, Allan J. B.,Roiban, Gheorghe-Doru
supporting information, p. 13821 - 13824 (2018/09/27)
N-Functionalized amino acids are important building blocks for the preparation of diverse bioactive molecules, including peptides. The development of sustainable manufacturing routes to chiral N-alkylated amino acids remains a significant challenge in the pharmaceutical and fine-chemical industries. Herein we report the discovery of a structurally diverse panel of biocatalysts which catalyze the asymmetric synthesis of N-alkyl amino acids through the reductive coupling of ketones and amines. Reactions have been performed on a gram scale to yield optically pure N-alkyl-functionalized products in high yields.
Dudawalamides A-D, Antiparasitic Cyclic Depsipeptides from the Marine Cyanobacterium Moorea producens
Almaliti, Jehad,Malloy, Karla L.,Glukhov, Evgenia,Spadafora, Carmenza,Gutiérrez, Marcelino,Gerwick, William H.
, p. 1827 - 1836 (2017/06/28)
A family of 2,2-dimethyl-3-hydroxy-7-octynoic acid (Dhoya)-containing cyclic depsipeptides, named dudawalamides A-D (1-4), was isolated from a Papua New Guinean field collection of the cyanobacterium Moorea producens using bioassay-guided and spectroscopic approaches. The planar structures of dudawalamides A-D were determined by a combination of 1D and 2D NMR experiments and MS analysis, whereas the absolute configurations were determined by X-ray crystallography, modified Marfey's analysis, chiral-phase GCMS, and chiral-phase HPLC. Dudawalamides A-D possess a broad spectrum of antiparasitic activity with minimal mammalian cell cytotoxicity. Comparative analysis of the Dhoya-containing class of lipopeptides reveals intriguing structure-activity relationship features of these NRPS-PKS-derived metabolites and their derivatives.
Resolution of racemic N-benzyl α-amino acids by liquid-liquid extraction: A practical method using a lipophilic chiral cobalt(III) salen complex and mechanistic studies
Dzygiel, Pawel,Reeve, Toby B.,Piarulli, Umberto,Krupicka, Martin,Tvaroska, Igor,Gennari, Cesare
supporting information; experimental part, p. 1253 - 1264 (2009/04/07)
The efficient resolution of racemic N-benzyl α-amino acids (N-Bn-AA) has been achieved by a liquid-liquid extraction process using the lipophilic chiral salen-cobalt(III) complex [CoIII(3)(OAc)]. As a result of the resolution by extraction, one enantiomer (S) of the N-benzyl α-amino acid predominated in the aqueous phase, while the other enantiomer (R) was driven into the organic phase by complexation to cobalt. The complexed amino acid (R) was then quantitatively released by a reductive (CoIII→Co II) counter-extraction with aqueous sodium dithionite or L-ascorbic acid in methanol. The reductive cleavage allowed to recover the [Co II(3)] complex in good yield, which could be easily re-oxidized to [CoIII(3)(OAc)] with air/AcOH and reused with essentially no loss of reactivity and selectivity. Investigation on the nitrogen substitution indicates that the presence of a single benzyl group on the amino acid nitrogen is important to obtain high enantioselectivity in the extraction process. The kinetic vs. thermodynamic nature of the resolution process was also investigated with an enantiomeric exchange experiment, which shows that the liquid-liquid extraction with [CoIII(3)-(OAc)] is an equilibrium process operating under thermodynamic control. In the absence of a suitable crystal structure of the [CoIII(3)(N-Bn-AA)] complexes, computational and spectroscopic studies were used to investigate how the N-benzyl α-amino acids are accommodated in the "binding pocket" of the chiral cobalt complex. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Primordial reductive amination revisited
Huber, Claudia,W?chtersh?user, Günter
, p. 1695 - 1697 (2007/10/03)
Amino acids are formed efficiently by reductive amination of α-keto acids under aqueous, conditions with freshly precipitated FeS or Fe(OH)2 and with NH3, CH3NH2 or (CH3)2NH at pH values near their pKa.
Method of producing optically active N-methylamino acids
-
, (2008/06/13)
A method of producing an optically active N-methylamino acid of the general formula (2): wherein R represents a hydrogen atom or an alkyl, alkenyl, alkynyl, cycloalkyl, aryl or heterocycle residue group, which may optionally have one or more substituents, which comprises reacting an α-keto acid compound of the general formula (1): wherein R is as defined above, with methylamine using a microorganism cell and/or processed matter thereof, said microorganism being able to convert the carbonyl group of said α-keto acid compound stereoselectively to a methylamino group.
Substituted quinoxaline-2-ones as glutamate receptor antagonists
-
, (2008/06/13)
A novel series of substituted quinoxaline 2-ones useful as neuroprotective agents are taught. Novel intermediates, processes of preparation, and pharmaceutical compositions containing the compounds are also taught. The compounds are glutamate receptor antagonists and are useful in the treatment of stroke, cerebral ischemia, or cerebral infarction resulting from thromboembolic or hemorrhagic stroke, cerebral vasospasms, hypoglycemia, cardiac arrest, status epilepticus, perinatal asphyxia, anoxia, seizure disorders, pain, Alzheimer's, Parkinson's, and Huntington's Diseases.
Synthesis and utilization of a novel glycine derived chiral precursor, based on a recyclable L-prolinol auxiliary, for the enantioselective preparation of α-amino acids and their N-methyl derivatives
Pandey,Reddy,Das
, p. 3175 - 3178 (2007/10/03)
α-Amino acids and their N-methyl derivatives are synthesized in fairly high optical purity employing a new glycine derived template based on a recyclable L-prolinol chiral auxiliary.
The Determination of Chirality of N-Methyl- and N,N-Dimethyl-phenylalanine by G.L.C.
Arbain, Dayar,Langley, Janette,Picker, Kelvin,Taylor, Walter C.
, p. 887 - 890 (2007/10/02)
The chirality of N-methylphenylalanine enantiomers can be determined on a micro scale by g.l.c. of N-pentafluoropropionyl amino acid isopropyl esters on a Chirasil-L-Val capillary column.N,N-Dimethylphenylalanine enantiomers cannot be similarly derivatize
Nummularine-O, a cyclopeptide alkaloid from Zizyphus nummularia
Pandey,Dwivedi,Shah,Eckhardt
, p. 2690 - 2691 (2007/10/02)
In addition to the known peptide alkaloid jubanine-B, a new peptide alkaloid, nummularine-O, has been isolated from the stem bark of Zizyphus nummularia and their structures have been elucidated by chemical and spectroscopic methods.
