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Amino Acid Derivatives (amino + acid_derivative)
Selected Abstracts"Tail,Tail Dimerization" of Ferrocene Amino Acid DerivativesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 25 2010Daniel Siebler Abstract Acid anhydrides of N-protected 1,-aminoferrocene-1-carboxylic acid (Fca) have been prepared and spectroscopically characterized (protection group Boc, Fmoc, Ac; 4a,4c). The structure of the Boc-derivative 4a has been determined by single-crystal X-ray crystallography. An intramolecular N,H···O hydrogen bond involving the carbamate units results in a ring structure containing the two ferrocene units, the anhydride moiety, and the hydrogen bond. In the crystal, the individual molecules are connected by intermolecular N,H···O hydrogen bonds of the carbamate unit. Experimental and theoretical studies suggest that the ring motif is also a dominant species in solution. Electronic communication across the anhydride moiety is found to be very weak as judged from electrochemical, spectroscopic, and theoretical experiments. [source] Straightforward Synthesis of Non-Natural Selenium Containing Amino Acid Derivatives and PeptidesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 20 2005Antonio L. Braga Abstract A series of non-natural selenium-containing amino acid derivatives and peptides have been synthesized, in a flexible and modular strategy. The peptide coupling reaction between N -protected amino acids and chiral ,-seleno amines afforded the desired products in high yields. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Asymmetric Synthesis of ,-Fluorinated ,-Amino Acid DerivativesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 4 2005Deepak M. Shendage Abstract Asymmetric alkylation of (S)-Boc-BMI (1a, BMI = 2- tert -butyl-3-methylimidazolidin-4-one) and its ,-methyl derivative 1b with 2-fluoroallyl tosylate, subsequent mild acidic deprotection of the products 2a and 2b, and basic hydrolysis of the thus formed N -methylamides 4a and 4b gave (S)-2-amino-4-fluoropent-4-enoic acid (5a) and (S)-2-amino-4-fluoro-2-methylpent-4-enoic acid (5b). Basic hydrolysis of compound 4a was accompanied by partial racemization, which was overcome by applying a new stereoconservative deamidation procedure. The alkylated cis -configured product 2a formed under kinetic control epimerized on refluxing with 2 n NaOH to give the thermodynamically more stable trans isomer 9. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Preparation of ,2 -Amino Acid Derivatives (,2hThr, ,2hTrp, ,2hMet, ,2hPro, ,2hLys, Pyrrolidine-3-carboxylic Acid) by Using DIOZ as Chiral Auxiliary,HELVETICA CHIMICA ACTA, Issue 8 2005Francois Gessier The title compounds were prepared from valine-derived N -acylated oxazolidin-2-ones, 1,3, 7, 9, by highly diastereoselective (,,90%) Mannich reaction (,,4,6; Scheme,1) or aldol addition (,,8 and 10; Scheme,2) of the corresponding Ti- or B-enolates as the key step. The superiority of the ,5,5-diphenyl-4-isopropyl-1,3-oxazolidin-2-one' (DIOZ) was demonstrated, once more, in these reactions and in subsequent transformations leading to various t -Bu-, Boc-, Fmoc-, and Cbz-protected ,2 -homoamino acid derivatives 11,23 (Schemes,3,6). The use of , -bromo-acyl-oxazolidinones 1,3 as starting materials turned out to open access to a variety of enantiomerically pure trifunctional and cyclic carboxylic-acid derivatives. [source] Amphiphilic Homochiral Oligopeptides Generated via Phase Separation of Nonracemic , -Amino Acid Derivatives and Lattice-Controlled Polycondensation in a Phospholipid EnvironmentHELVETICA CHIMICA ACTA, Issue 11 2003Irina Rubinstein Racemic S -ethyl thioesters of N, -stearoyllysine (=,S -ethyl (R,S)-2-amino-6-(stearoylamino)hexanethioate) and S -ethyl thioesters of , -stearyl glutamic acid (=stearyl (R,S)-4-amino-5-(ethylsulfanyl)-5-oxopentanoate) self-assemble as separated two-dimensional crystalline monolayers within an achiral phospholipid environment of racemic 1,2-dipalmitoylglycerol (DPG) and 1,2-dipalmitoylglycero-3-phosphoethanolamine (DPPE), as demonstrated by grazing-incidence X-ray-diffraction (GIXD) measurements performed on the surface of H2O. Lattice-controlled polycondensation within these crystallites with deuterium-enantiolabeled monomers was initiated by injecting aqueous solutions of Ag+ or I2/KI beneath the monolayers, which yielded mixtures of diastereoisomeric oligopeptides containing up to six to eight repeating units, as analyzed by MALDI-TOF mass spectrometry. Analysis of the diastereoisomeric distribution showed an enhanced relative abundance of the oligopeptides with homochiral sequences containing three or more repeating units. Within the DPPE monolayers, the nucleophilic amino group of the phospholipid operates as an initiator of polymerization at the periphery of the monomer two-dimensional crystallites. Enhanced relative abundance of enantiomerically enriched homochiral oligopeptides was obtained by the polycondensation of nonracemic monomers. This enhancement indicated a phase separation into racemic and enantiomorphous monomer crystallites within the phospholipid environment, although this separation could not be observed directly by GIXD. A possible role that might have been played by crystalline assemblies for the abiotic generation and amplification of oligopeptides with homochiral sequences is discussed. [source] A General Approach to the Synthesis of ,2 -Amino Acid Derivatives via Highly Efficient Catalytic Asymmetric Hydrogenation of ,-AminomethylacrylatesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2010Yujuan Guo Abstract A new strategy was developed for the synthesis of a valuable class of ,-aminomethylacrylates via the Baylis,Hillman reaction of different aldehydes with methyl acrylate followed by acetylation of the resulting allylic alcohols and SN2,-type amination of the allylic acetates. Asymmetric hydrogenation of these diverse olefinic precursors using rhodium(Et-Duphos) catalysts provided the corresponding ,2 -amino acid derivatives with excellent enantioselectivities and exceedingly high reactivities (up to >99.5% ee and S/C=10,000). The first hydrogenation of (Z)-configurated substrates was studied for the synthesis of ,2 -amino acid derivatives. The high influence of the substrate geometry and steric hindrance on the reactivity and enantioselectivity was also disclosed for this reaction. This protocol provides a highly practical, facile and scalable method for the preparation of optically pure ,2 -amino acids and their derivatives under mild reaction conditions. [source] Copper(I)-Catalyzed Asymmetric Addition of Terminal Alkynes to ,-Imino Esters: An Efficient and Direct Method in the Synthesis of Chiral ,3 -Alkynyl ,2,2 -Dimethyl Amino Acid DerivativesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2009Jun Wang Abstract The first catalytic asymmetric addition of terminal alkynes to ,-imino esters was carried out using chiral copper(I) complexes as catalysts under mild reaction conditions, providing an efficient and direct synthetic approach to ,3 -alkynyl ,2,2 -dimethyl amino esters with yields of 73,97% and 48,90% ee. The rich chemistry of the alkynyl functionality makes the present method a powerful and versatile approach to a wide range of optically active ,2,2 -dimethyl amino acid derivatives. [source] Amino Acid Derivatives, Part 4: Synthesis and Anti-HIV Activity of New Naphthalene DerivativesARCHIV DER PHARMAZIE, Issue 7 2010Nawar S. Hamad Abstract A new series of 2-(naphthalen-2-yloxy)- N -[(aryl-5-thioxo-4,5-dihydro-1H -1,2,4-triazol-3-yl)methyl] acetamides 5a,f was synthesized from naphthalene-derived glycine derivative 2 via the hydrazinoacetamide analogs 4a,f. Alternatively, treatment of 4a with H2SO4 afforded 2-(naphthalen-2-yloxy)- N -((5-(phenylamino)-1,3,4-thiadiazol-2-yl)methyl) acetamide 6a. Alkylation or sulphonylation of 5a afforded the S-alkylated derivatives 7 and 8, respectively. Interestingly, treatment of 3 with methoxide ion gave the triazine derivative 9. The synthesized compounds have been screened for their inhibitory activity against HIV-1 and HIV-2 in MT-4 cells. However, 7 was found to be the potent inhibitor in vitro for the replication of HIV-1 (EC50 = 0.20 ,g/mL), suggesting a new lead in the development of an antiviral agent. [source] ChemInform Abstract: Addition of Lithiated Methoxyallene to Aziridines , A Novel Access to Enantiopure Piperidine and ,-Amino Acid Derivatives.CHEMINFORM, Issue 6 2010Vladimir Prisyazhnyuk Abstract ChemInform 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. [source] ChemInform Abstract: Reactions of Morita,Baylis,Hillman Acetates with Huisgen Zwitterions: A Novel Strategy for the Synthesis of ,-Amino Acid Derivatives.CHEMINFORM, Issue 42 2009Anu Jose Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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. [source] ChemInform Abstract: Facile Approach to Natural or Non-Natural Amino Acid Derivatives: Me3SiCl-Promoted Coupling Reaction of Organozinc Compounds with N,O-Acetals.CHEMINFORM, Issue 25 2009Norio Sakai Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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. [source] ChemInform Abstract: Preparation of ,,,-Disubstituted ,-Amino Acid Derivatives via Alkyl Addition to ,-Oxime Esters with Organozinc Species.CHEMINFORM, Issue 27 2008Michiharu Mitani Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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. [source] ChemInform Abstract: A Versatile Synthesis of ,-Amino Acid Derivatives via the Ugi Four-Component Condensation with a Novel Convertible Isonitrile.CHEMINFORM, Issue 18 2008Kentaro Rikimaru Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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. [source] ChemInform Abstract: Synthesis of Unnatural ,-Amino Acid Derivatives via a Three-Component Coupling Method Utilizing an Allylpalladium Umpolung.CHEMINFORM, Issue 13 2008Chad D. Hopkins Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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. [source] Chiral Calcium Complexes as Broensted Base Catalysts for Asymmetric Addition of ,-Amino Acid Derivatives to ,,,-Unsaturated Carbonyl Compounds.CHEMINFORM, Issue 37 2007Susumu Saito Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis of ,-Amino Acid Derivatives by Nickel(0)-Mediated Sequential Addition of Carbon Dioxide and Dibenzoyldiazene onto Unsaturated Hydrocarbons.CHEMINFORM, Issue 32 2007Masahiro Murakami Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] 1-(2,4,6-Triisopropylphenyl)ethylamine: A New Chiral Auxiliary for the Asymmetric Synthesis of ,-Amino Acid Derivatives.CHEMINFORM, Issue 21 2007Pascale Cividino Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Catalytic, Asymmetric Synthesis of 1,4-Benzoxazinones: A Remarkably Enantioselective Route to ,-Amino Acid Derivatives from o-Benzoquinone Imides.CHEMINFORM, Issue 13 2007Jamison Wolfer Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Kinetic Resolution of Protected ,-Amino Acid Derivatives by a Chiral O-Nucleophilic Acyl Transfer Catalyst.CHEMINFORM, Issue 31 2006Gregory T. Notte Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Conformationally Constrained ,-Amino Acid Derivatives by Intramolecular [2 + 2]-Photocycloaddition of a Tetronic Acid Amide and Subsequent Lactone Ring Opening.CHEMINFORM, Issue 14 2006Birte Basler Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] The Catalytic Mannich Reaction of 1,1-Difluoro-2-trialkyl(aryl)silyl-2-trimethylsilyloxyethenes: Preparation of ,-Amino Acid Derivatives.CHEMINFORM, Issue 5 2006Woo Jin Chung Abstract For Abstract see ChemInform Abstract in Full Text. [source] Catalytic Enantio- and Diastereoselective Aldol Reactions of Glycine-Derived Silicon Enolate with Aldehydes: An Efficient Approach to the Asymmetric Synthesis of anti-,-Hydroxy-,-Amino Acid Derivatives.CHEMINFORM, Issue 47 2004Jun Kobayashi No abstract is available for this article. [source] Diels,Alder Cycloadditions of 3-Phenylamino-5-bromo-2-pyrone for the Synthesis of Constrained ,-Amino Acid Derivatives.CHEMINFORM, Issue 21 2004Won-Suk Kim Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis of 4-Substituted Indolizidin-9-one Amino Acid Derivatives.CHEMINFORM, Issue 39 2003Christelle Lamazzi Abstract For Abstract see ChemInform Abstract in Full Text. [source] Asymmetric Protonation of Lithium Enolates of ,-Amino Acid Derivatives with ,-Amino Acid-Based Chiral Broensted Acids.CHEMINFORM, Issue 25 2003Kentaro Futatsugi Abstract For Abstract see ChemInform Abstract in Full Text. [source] Tetrachlorosilane,Sodium Azide System in the Synthesis of Tetrazole-Containing Amino Acid Derivatives.CHEMINFORM, Issue 16 2003K. A. Esikov Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Synthesis of Unsaturated ,-Amino Acid Derivatives from Carbamates of the Baylis,Hillman Products.CHEMINFORM, Issue 27 2002Marco Ciclosi Abstract ChemInform 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. [source] ChemInform Abstract: Pd-Catalyzed Asymmetric Hydrogenation of ,-Fluorinated Iminoesters in Fluorinated Alcohol: A New and Catalytic Enantioselective Synthesis of Fluoro ,-Amino Acid Derivatives.CHEMINFORM, Issue 20 2001Hajime Abe Abstract ChemInform 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. [source] ChemInform Abstract: Efficient Chemoenzymatic Synthesis of Enantiomerically Pure ,-Heterocyclic Amino Acid Derivatives.CHEMINFORM, Issue 20 2001Valerie Rolland-Fulcrand Abstract ChemInform 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. [source] ChemInform Abstract: A Two-Step, One-Pot Synthesis of Diverse N-Pyruvoyl Amino Acid Derivatives Using the Ugi Reaction.CHEMINFORM, Issue 12 2001Masayuki Nakamura Abstract ChemInform 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. 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