Asymmetric Synthesis Of Amino Acids Research Articles

8-Isopropyl-7,10-dimethoxy-3-phenyl-1-oxa-2,6,9-triazaspiro[4.5]deca-2,6,9-triene

The title compound, C 17 H 21 N 3 O 3 , is an intermediate in an asymmetric synthesis of amino acids. It has an essentially planar central bis-lactim ether ring, with both methoxy groups lying in the plane of the heterocycle. The isopropyl group adopts the same conformation as found in similar structures. The phenyl substituent is nearly coplanar with the isoxazoline ring.

1H, 13C and 15N NMR Spectra of Ni(II) Complex of Schiff Base from (S)-2-(N-Benzylprolyl)amino-5-methylbenzophenone and Glycine

Nickel(II) complex of Schiff base derived from (S)-2-(N-benzylprolyl)amino-5-methylbenzophenone and glycine (I) was prepared. It was characterized by mass, 1H, 13C and 15N NMR spectra. The NMR signals were assigned and the data thus obtained can serve for study of products in the asymmetric synthesis of amino acids, starting from this complex.

Synthesis of both D- and L-Fmoc-Abu[PO(OCH 2CHCH 2) 2]-OH for solid phase phosphonopeptide synthesis

The Schöllkopf bislactim ether asymmetric amino acid synthesis was coupled with a subsequent enzyme mediated ester hydrolysis to generate a practical synthesis of both D and L enantiomers of Fmoc-Abu[PO(OCH 2CHCH 2) 2]-OH ( 6). With this building block phosphonopeptide isosteres of serine phosphopeptides are accessible by Fmoc-solid phase peptide synthesis.

Chemo-enzymatic asymmetric synthesis of amino acids. Enantioselective hydrolyses of 2-phenyl-oxazolin-5-ones.

Porcine pancreatic lipase and the lipase of Aspergillus niger catalyze the enantioselective hydrolysis of a series of 4-substituted-2-phenyl-oxazolin-5-ones to yield optically active ( S )-and ( R )-N-benzoyl amino acids respectively.

Efficient asymmetric synthesis of amino acids through hydrogenation of the didehydroamino acid residue in cyclic imino-ester derivatives

The trisubstituted olefinic bond of chiral cyclic α,β-didehydroamino acid derivatives was hydrogenated in the presence of Pd/C with >95% diastereoface discrimination to give, after hydrolysis, the corresponding S-amino acids. The reduction of the double bond with L-selectride® does not change the orientation of diastereoface discrimination and the diastereoselectivity is still high.

Chiral complexes of Ni(II) Cu(II), and Cu(I) as reagents, catalysts and receptors for asymmetric synthesis and chiral recognition of amino acids

Abstract

ChemInform Abstract: Asymmetric Synthesis of Amino Acids by the Catalytic Reduction of Azlactones of Substituted Acylaminoacrylic Acids. Part 26. Aminolysis of 2‐Methyl‐4‐benzyl‐5‐oxazolinone Under the Action of (S)‐ Phenylalanine Derivatives.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Asymmetric synthesis of amino acids via the catalytic reduction of substituted acylaminoacrylic acid azlactone derivatives

We have studied the reaction of Δ2-oxazolin-5-ones with R-phenylglycine methyl ester in the presence of PdCl2; the reaction gives phenylalanine or valine dipeptide derivatives with the RS-configuration. The presence of triethylamine during the reductive aminolysis of oxazolinones in dimethoxyethane solvent significantly increases the stereoselectivity of the reaction process. The stepwise mechanism of the reaction has also been explored.

Asymmetric synthesis of amino acids via the catalytic reduction of substituted acylaminoacrylic acid azlactones

The kinetics of aminolysis and racemization of 2-methyl-4-benzyloxazolin-5-one upon reaction with S-phenylalanine methyl ester have been studied in dimethoxyethane solvent. The rates of aminolysis and racemization are comparable. Addition of an achiral component, namely Et3N, to the reaction mixture, however, dramatically increases the rate of racemization. The presence of Et3N also increases the ratio of rate constants for the formation of RS- and SS-diastereomers, which determines the reaction stereoselectivity.

Asymmetric synthesis of amino acids via the catalytic reduction of acylaminoacrylic acid azlactone derivatives

Asymmetric synthesis of amino acids via the catalytic reduction of acylaminoacrylic acid azlactone derivatives

ChemInform Abstract: Asymmetric Synthesis of Amino Acids by Addition of Cyanide to the Schiff Bases in the Presence of Cyanide‐Modified Hemin‐Copolymer.

ChemInformVolume 21, Issue 13 Natural Products ChemInform Abstract: Asymmetric Synthesis of Amino Acids by Addition of Cyanide to the Schiff Bases in the Presence of Cyanide-Modified Hemin-Copolymer. K. SAITO, K. SAITO Dep. Chem., Univ. Tsukuba, Tsukuba, Ibaraki 305, JapanSearch for more papers by this authorK. HARADA, K. HARADA Dep. Chem., Univ. Tsukuba, Tsukuba, Ibaraki 305, JapanSearch for more papers by this author K. SAITO, K. SAITO Dep. Chem., Univ. Tsukuba, Tsukuba, Ibaraki 305, JapanSearch for more papers by this authorK. HARADA, K. HARADA Dep. Chem., Univ. Tsukuba, Tsukuba, Ibaraki 305, JapanSearch for more papers by this author First published: March 27, 1990 https://doi.org/10.1002/chin.199013299AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume21, Issue13March 27, 1990 RelatedInformation

ChemInform Abstract: Asymmetric Synthesis of Amino Acids by Catalytic Reduction of Azlactones of Substituted Acylaminoacrylic Acids. Part 23. Reductive Aminolysis of 2‐Methyl‐4‐benzylidene‐δ2‐oxazolin‐5‐one (I) with the Chiral Catalytic System Pd/(S)‐Amino Alcohol, e.g. PdCl2/(S)‐(II).

ChemInform Abstract: Asymmetric Synthesis of Amino Acids by Catalytic Reduction of Azlactones of Substituted Acylaminoacrylic Acids. Part 23. Reductive Aminolysis of 2‐Methyl‐4‐benzylidene‐δ2‐oxazolin‐5‐one (I) with the Chiral Catalytic System Pd/(S)‐Amino Alcohol, e.g. PdCl2/(S)‐(II).

ChemInform Abstract: Asymmetric Synthesis of Amino Acids by Catalytic Reduction of Substituted Acylaminoacrylic Acid Azlactones. Part 21. Catalytic Asymmetric Synthesis of N‐Acyl‐p‐difluoromethoxyphenylalanine Phenylethylamides.

AbstractCatalytic reduction of the azlactones (I) in the presence of (S)‐(‐)‐α‐phenylethylamine (S)‐(‐)‐(II) predominantly gives the phenylalanine amides (III) with a diastereomeric excess of the (SS) diastereomers up to 47% depending on the solvent.

ChemInform Abstract: Asymmetric Synthesis of Amino Acids by Enantio‐ and Diastereodifferentiating Reactions

ChemInform Abstract: Asymmetric Synthesis of Amino Acids by Enantio‐ and Diastereodifferentiating Reactions

ChemInform Abstract: Asymmetric Amino Acid Synthesis: Preparation of the β Anion Derived from Aspartic Acid.

ChemInformVolume 20, Issue 29 Natural Products ChemInform Abstract: Asymmetric Amino Acid Synthesis: Preparation of the β Anion Derived from Aspartic Acid. J. E. BALDWIN, Dyson Perrins Lab., Oxford Cent. Mol. Sci., Oxford Univ., Oxford OX1 3QY, UKSearch for more papers by this authorM. G. MOLONEY, Dyson Perrins Lab., Oxford Cent. Mol. Sci., Oxford Univ., Oxford OX1 3QY, UKSearch for more papers by this authorM. NORTH, Dyson Perrins Lab., Oxford Cent. Mol. Sci., Oxford Univ., Oxford OX1 3QY, UKSearch for more papers by this author J. E. BALDWIN, Dyson Perrins Lab., Oxford Cent. Mol. Sci., Oxford Univ., Oxford OX1 3QY, UKSearch for more papers by this authorM. G. MOLONEY, Dyson Perrins Lab., Oxford Cent. Mol. Sci., Oxford Univ., Oxford OX1 3QY, UKSearch for more papers by this authorM. NORTH, Dyson Perrins Lab., Oxford Cent. Mol. Sci., Oxford Univ., Oxford OX1 3QY, UKSearch for more papers by this author First published: July 18, 1989 https://doi.org/10.1002/chin.198929264Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume20, Issue29July 18, 1989 RelatedInformation

ChemInform Abstract: Synthesis of Nonproteinogenic Amino Acids. Part 2. Preparation of a Synthetic Equivalent of the γ‐Anion Synthon for Asymmetric Amino Acid Synthesis.

Abstract The synthesis of α- t -butyl γ-methyl N -trityl-(S)-glutamate (12) from (S)-glutamic acid (6) is described. Diester (12), on treatment with lithium Isopropylcyclohexylamide followed by the addition of carbonyl compounds, reacts to give the γ-substituted glutamic acid derivatives (13a-i) with retention of optical purity at the α centre.

Asymmetric synthesis of amino acids by catalytic reduction of azlactones of substituted acylaminoacrylic acids. 23. Study of the reductive aminolysis of 2-methyl-4-benzyllidene-?2-oxazolin-5-one with the chiral catalytic system pd-s-aminoalcohol

1. Reductive aminolysis of 2-methyl-4-benzylidene-Δ2-oxazolin-5-one in the chiral catalytic system PdCl2-S-phenylglycinol results in the formation of phenylalanine amides with an excess of the SS-diastereomer. 2. Reductive aminolysis in the catalytic system PdCl2-S-phenylalaninol mainly gives phenylalanine amides with an excess of the RS-diasteromer.

Asymmetric synthesis of amino acids by catalytic reduction of azlactones of substituted acylaminoacrylic acids

Asymmetric synthesis of amino acids by catalytic reduction of azlactones of substituted acylaminoacrylic acids

Asymmetric synthesis of amino acids via catalytic reduction of azalactone-substituted acylaminoacrylic acids. 21. Catalytic asymmetric synthesis of the phenylethylamide of N-acyl-p-difluoromethoxyphenylalanine

1. Catalytic reductive aminolysis of the azalactones of N-acyl-p-difluoromethoxy-α-aminocinnamic acid in dimethoxyethane, isopropanol, and tert-butanol proceeds stereoselectively, leading to the α-phenylethylamides of N-acyl-p-difluoromethoxyphenylalanine with a 3–55% excess of the S,S-diastereomer. 2. Replacement of dimethoxyethane by isopropanol or tert-butanol leads to an increase in the stereoselectivity of the process. 3. Hydrogenation of the S-(+)-α-phenylethylamide of N-acyl-p-difluoromethoxy-α-aminocinnamic acid proceeds stereoselectively, and leads to production of the α-phenylethylamide of N-acyl-p-difluoromethoxyphenylalanine with a 9–18% excess of the R,S-diastereomer.

Asymmetric syntheses of amino acids by addition of cyanide to the schiff bases in the presence of cyanide-modified hemin-copolymer

Sterically controlled addition reactions of CN group to the Schiff bases by using CN-modified hemin-copolymer were carried out, and the optical yields (80–95 e.e.) of the resulting amino acids were much higher than that obtained without hemin-copolymer.