- Preparation method of 3-aminopropanol or 3-aminopropionic acid derivative
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The invention provides a preparation method of an optically active 3-aminopropanol or 3-aminopropionic acid derivative, and belongs to the technical field of organic synthesis. A compound having a structure as shown in a formula II and a formula III is used as a raw material, and the optically active 3-aminopropanol or 3-aminopropionic acid derivative is obtained through four basic steps, namely dehydration condensation, hydrogenation reduction, reduction and hydrolysis. The raw materials adopted in the preparation method are easy to obtain and low in cost; as a chiral phosphine-transitional metal catalyst is used in the hydrogenation reduction reaction, the optically active 3-aminopropanol or 3-aminopropionic acid derivative is efficient, high in selectivity, low in cost and suitable forlarge-scale production. Compared with existing chemical resolution and chiral introduction, the asymmetric hydrogenation synthesis method provided by the invention only produces one chiral product, ishigh in yield, and has relatively high advantages in economy and raw material utilization rate.
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Paragraph 0215; 0225; 0226
(2018/10/11)
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- Resolution of α/β-amino acids by enantioselective penicillin G acylase from Achromobacter sp.
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Penicillin G acylases (PGAs) are enantioselective enzymes catalyzing a hydrolysis of stable amide bond in a broad spectrum of substrates. Among them, derivatives of α- and β-amino acids represent a class of compounds with high application potential. PGAEc from Escherichia coli and PGAA from Achromobacter sp. CCM 4824 were used to catalyze enantioselective hydrolyses of seven selected N-phenylacetylated α/β-amino acid racemates. The PGAA showed higher stereoselectivity for enantiomers of N-PhAc-β-homoleucine, N-PhAc-α-tert-leucine and N-PhAc-β-leucine. To study the mechanism of enantiodiscrimination on molecular level, we have constructed a homology model of PGAA that was used in molecular docking experiments with the same substrates. In-silico experiments successfully reproduced the data from experimental enzymatic resolutions confirming validity of employed modeling protocol. We employed this protocol to evaluate enantiopreference of PGAA towards seven new substrates with application potential. For five of them, high enantioselectivity of PGAA was predicted.
- Grulich, Michal,Brezovsky, Jan,?těpánek, Václav,Palyzová, Andrea,Kyslíková, Eva,Kyslík, Pavel
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p. 240 - 247
(2015/10/28)
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- METHOD FOR OBTAINING OPTICALLY PURE AMINO ACIDS
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This invention relates to a method for obtaining optically pure amino acids, including optical resolution and optical conversion. This method significantly shortens the time taken for optical transformation, and enables the repeated use of an organic solution containing a enantioselective receptor, to thereby obtain optically pure amino acids in a simple and remarkably efficient manner, and to enable the very economical mass production of optically pure amino acids.
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Page/Page column 7
(2012/02/01)
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- METHOD FOR OBTAINING OPTICALLY PURE AMINO ACIDS
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This invention relates to a method for obtaining optically pure amino acids, including optical resolution and optical conversion. This method significantly shortens the time taken for optical transformation, and enables the repeated use of an organic solution containing a enantioselective receptor, to thereby obtain optically pure amino acids in a simple and remarkably efficient manner, and to enable the very economical mass production of optically pure amino acids.
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Page/Page column 10-11
(2012/02/14)
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- Thermal cleavage of the Fmoc protection group
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The Fmoc protection group is among the most commonly used protection groups for the amino function. A fast method for the thermal deavage of this protection group under base-free conditions without the need for dibenzofulvene scavengers is presented. The advantages of this method include straightforward testability by means of a simple high-temperature NMR experiment, usually high yields, and good selectivity towards the BOC protection group and t-butyl ethers.
- Hoeck, Stefan,Marti, Roger,Riedl, Rainer,Simeunovic, Marina
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experimental part
p. 200 - 202
(2011/08/05)
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- Parallel synthesis of homochiral β-amino acids
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The parallel asymmetric synthesis of an array of 30 β-amino acids of high enantiomeric purity using the conjugate addition of homochiral lithium N-benzyl-N-(α-methylbenzyl)amide as the key step is accomplished. The experimental simplicity and highly practical nature of the protocol is demonstrated by the efficient parallel conversion of 15 α,β-unsaturated esters to both enantiomeric series of the corresponding β-amino acids in high overall yields and selectivities with minimal purification involved in each step of the reaction protocol.
- Davies, Stephen G.,Mulvaney, Andrew W.,Russell, Angela J.,Smith, Andrew D.
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p. 1554 - 1566
(2008/02/09)
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- beta-peptides as catalysts: poly-beta-leucine as a catalyst for the Julia-Colonna asymmetric epoxidation of enones.
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Poly-beta-leucines have been evaluated as catalysts for the Julia-Colonna asymmetric epoxidation of enones; the beta 3-isomer was found to be an effective catalyst for the epoxidation of chalcone (70% ee) and some analogues.
- Coffey,Drauz,Roberts,Skidmore,Smith
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p. 2330 - 2331
(2007/10/03)
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- Chemoenzymatic synthesis of 4-amino-2-hydroxy acids: A comparison of mutant and wild-type oxidoreductases
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We describe a new chemoenzymatic synthesis of enantiopure 4-amino-2-hydroxy acids using two biotransformations in a single-pot process in aqueous medium. These compounds are valuable as γ-turn mimics for investigations into the secondary structure of peptides. The enzyme substrates are a series of carbobenzyloxy (CBZ)-protected 4-amino-2-keto esters, prepared efficiently from the L-amino acids, alanine, leucine, phenylalanine, and valine. First, the α-amino acids were converted to the corresponding β-amino acids in a simple five-step procedure. A further one-carbon homologation via ozonolysis of the corresponding β-keto cyanophosphoranes gave the required α-keto esters in good yield. The enzyme catalyzed hydrolyses of all the α-keto esters to the corresponding α-keto acids proceeded smoothly with the lipase from Candida rugosa. Using the same reaction pot, it was found that wild-type lactate dehydrogenases from either Bacillus stearothermophilus CBS-LDH) or Staphylococcus epidermidis (SE-LDH) could be used to specifically reduce the ketone of the alanine-derived α-keto acid 2, giving the (S)- and CR)-2-hydroxy acids, respectively, in good yields. However, the more bulky α-keto acids 3, 4, and 5 (derived from valine, leucine, and phenylalanine) were not substrates for these enzymes. In contrast, the genetically engineered H205Q mutant of D-hydroxyisocaproate dehydrogenase proved to be an ideal catalyst for the reduction of all the α-keto acids 2-5, giving excellent yields of the CBZ-protected (2R,4S)-4-amino2-hydroxy acids as single diastereomers. This genetically engineered oxidoreductase has great potential value in synthesis due to its broad substrate specificity and high catalytic activity. For example, reduction of 1 mmol of N-protected (S)-4-amino-2-oxopentanoic acid 2 took just 4 h with the H205Q mutant giving, after esterification, the CR)-2-alcohol 25 in 85% yield, whereas with SE-LDH the reaction required 4 days to give a 67% yield of 25.
- Sutherland, Andrew,Willis, Christine L.
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p. 7764 - 7769
(2007/10/03)
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- Enantioselektive Synthese von β-Aminosaeuren - TMS-SAMP als chirales Ammoniak-Aequivalent in der azaanalogen Michael-Addition an α,β-ungesaettigte Ester
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Stichworte: Aminosaeuren * Asymmetrische Synthesen * Chirale Hilfsstoffe * Michael-Additionen
- Enders, Dieter,Wahl, Heiner,Bettray, Wolfgang
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p. 527 - 529
(2007/10/02)
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- Synthesis of enantiomerically pure β- and γ-amino acids from aspartic and glutamic acid derivatives
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An efficient synthesis of enantiomerically pure β- and γ-amino acids starting from commercially available aspartic and glutamic acid derivatives is described. The acid function, α to the amino group, is first transformed to a good leaving group and the pr
- El Marini,Roumestant,Viallefont,Razafindramboa,Bonato,Follet
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p. 1104 - 1108
(2007/10/02)
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- Enantioselective synthesis of β-amino acids based on BINAP-ruthenium(II) catalyzed hydrogenation
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BINAP-Ru(II) catalyzed hydrogenation of β-substituted (E)-β-(acylamino)acrylic acids allows efficient enantioselective synthesis of β-amino acids. The Z double bond isomers which possess an intramolecular hydrogen bond between amide and ester groups are more reactive but are hydrogenated with poor enantioselectivity. BINAP-Rh(I) complexes afford only moderate stereoselectivity with the opposite sense of enantioselection.
- Lubell,Kitamura,Noyori
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p. 543 - 554
(2007/10/02)
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