Дисертації з теми "Amino-carboxylic"
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Dobson, Allison J. "X-ray diffraction investigations of quinoline and amino carboxylic acids /." The Ohio State University, 1998. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487949836206992.
Повний текст джерелаBadiani, Kamal. "Synthesis and evaluation of enzyme inhibitors based on amino- and cyclopropane carboxylic acids." Thesis, University of St Andrews, 1997. http://hdl.handle.net/10023/14052.
Повний текст джерелаMarsh, Paul Robert. "3-Azido-tetrahydrofuran carboxylates as scaffolds for oligomers of β-amino-THF carboxylic acids". Thesis, University of Oxford, 2002. https://ora.ox.ac.uk/objects/uuid:749edfc8-8e18-4811-9247-8e29a3f54c7b.
Повний текст джерелаChampion, Susan M. "Asymmetric synthesis of 2-amino carboxylic acids and the synthesis of novel phosphono-compounds." Thesis, University of Bristol, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260485.
Повний текст джерелаLundberg, Helena. "Group (IV) Metal-Catalyzed Direct Amidation : Synthesis and Mechanistic Considerations." Doctoral thesis, Stockholms universitet, Institutionen för organisk kemi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-116955.
Повний текст джерелаAmidbindningen är en kemisk enhet som utgör ryggraden i proteiner, och som även återfinns i en stor mängd läkemedelsmolekyler, polymera material som nylon och Kevlar, samt i tillsatser i livsmedelsindustrin, exempelvis aspartam. Amider produceras i enorma mängder varje år, och det är av stor vikt att utveckla miljövänliga och selektiva metoder för deras framställning. Denna avhandling behandlar direkt amidering av icke-aktiverade karboxylsyror och aminer med hjälp av katalytiska mängder metallkomplex, baserade på titan, zirkonium och hafnium. Den enda biprodukten från denna amideringsreaktion är vatten. Jämfört med de metoder som generellt används idag för amidsyntes, så är de presenterade metoderna avsevärt mer miljövänliga med avseende på toxicitet hos reagensen såväl som på mängden avfall som genereras. Dessutom redovisas här en katalytisk metod för syntes av primära och tertiära amider genom att använda olika karbamat som källa till gasformiga aminer, vilka annars kan vara praktiskt svåra att arbeta med. Preliminära resultat från en pågående mekanistisk studie av de zirkonium- och hafnium-katalyserade processerna är också inkluderade.
At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 2: Accepted.
Navin, V. "One-Pot Synthesis Of Chiral Disulfides & Diselenides From α-Amino Acids Mediated By Ammonium Tetrathiomolybdate In Water". Thesis, Indian Institute of Science, 2001. http://hdl.handle.net/2005/268.
Повний текст джерелаHu, Zilun. "CONSTRAINED β–PROLINES: I. METHANOPYRROLIDINE β-AMINO ACIDS: SYNTHESIS AND CHARACTERIZATION OF NOVEL C6- SUBSTITUTED ANALOGUES AND PEPTIDE OLIGOMERS II. SYNTHESIS OF 2,2-DISUBSTITUTED PYRROLIDINE-3-CARBOXYLIC ACIDS". Diss., Temple University Libraries, 2015. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/339315.
Повний текст джерелаPh.D.
In the study of structurally restricted cyclic β-amino acids and peptides, methanopyrrolidine-5-carboxylic acids (MetPyr-5-acids), or 5-syn-carboxy-2-azabicyclo[2.1.1] hexanes, and derivatives were investigated. MetPyr-5-acids are a series of highly conformationally constrained β-proline derivatives, which belong to a novel category of β-amino acids utilized as building blocks for the synthesis of β-peptides. These β-peptides lack the backbone hydrogen bonds necessary for folding in the usual manner. Substituents and functional groups in this ring system were envisioned to impact the folding properties and functionalities of the corresponding β-peptides. In the present study, the analogues of MetPyr-5-acids with C6- substitutions were prepared, and the folding properties of their peptides were explored. To introduce different functionalities at C6 in MetPyr-5-acids, 6-syn-hydroxymethyl substituted derivatives were synthesized and were used as key intermediates. In the synthesis of this core structure, the major steps in their preparation included the Michael addition of benzyloxymethyl allyl amine to 3-butynone, followed by UV light irradiation of the diene to afford 5-acetyl-6-benzyloxymethyl-2-azabicyclo[2.1.1]hexane. Haloform (Br2/NaOH) oxidation of the acetyl group leads to the 6-substituted MetPyr-5-acid. Resolution of the racemate was achieved either by resolving (±)-6-syn-benzyloxymethyl-MetPyr-5-acid via a classical crystallization resolution method using (S)-(-)-α-methylbenzylamine, or by chiral preparative HPLC separation of (±)-6-syn-benzyloxymethyl-MetPyr-5-acid methyl ester. The absolute stereochemistry was confirmed by X-ray crystallography of a derivative. Novel analogs with a range of functionalities incorporated at the C6 position in MetPyr-5-acid were synthesized from 6-syn-hydroxymethyl-MetPyr-5-acid methyl ester, and include hydrophilic groups such as hydroxyl, amino, methyl ether, and hydrophobic groups, such as substituted phenyl groups and triazole. From the protected C6-substituted analogs of MetPyr-5-acids, peptide oligomers of C6-benzyloxymethyl-2,4-methanopyrrolidine-b-amino acid were prepared up to the length of octomer in high yields. This series of oligomers were characterized by circular dichroism (CD) and indicated enhanced order of folding uniformity for the tetramer and up, with increasing ordered folding for longer oligomers. The octomer exhibited minimal solvent effects, and was stable with increasing temperature up to 80 °C. Analysis by NMR of the iso-butyric amide capped monomer indicated a mixture of cis/trans conformation favoring the cis conformation. This was slightly different from the C6 unsubstituted iso-butyric amide derivative, which favored the trans conformation. For the dipeptide, the C6-benzyloxymethyl substitution increased the percentage of cis conformation of the dipeptide amide bond, but the major peptide had the trans conformation. This demonstrated that C6 substitutions could shift the cis/trans equilibrium towards the cis conformation. Longer oligomers showed ordered secondary folding structure as demonstrated by the increase in ellipticity per amino acid unit, but was too complicated to be determined by NMR analysis. Both the CD patterns and molecular model calculation predicted that the longer oligomers (tetramer and above) favor the trans conformation. This preference was driven by the backbone dipole effect. II. SYNTHESIS OF 2,2-DISUBSTITUTED PYRROLIDINE-3-CARBOXYLIC ACIDS Due to the perceived steric influence of 2,2-disubstitution in the pyrrolidine-3-carboxylic acid, it is believed that the adjacent amide/peptide bonds should result in a trans amide bond conformation. Because of the difficulty in introducing disubstitution at the hindered C2 position, the synthesis of such derivatives has not been successful. For this reason a new method was introduced to prepare novel derivatives, at the N- and C- termini of protected 2,2-dimethyl pyrrolidine-3-carboxylic acid, i.e., benzyloxycarbonyl protected 2,2-dimethylpyrrolidine-3-carboxylate. This procedure included the Michael addition of 2-nitropropane to dimethyl fumarate, followed by ring closure of the amino ester derived from reduction of the nitro ester providing the pyrrolidinone. Reduction of the pyrrolidinone to the pyrrolidine with borane finished 2,2-dimethylpyrrolidine-3-carboxylate in moderate overall yield. A preliminary set of two amides, iso-butyric amide and 3,5-dichlorobenzamide of this 2,2-dimethylpyrrolidine-3-carboxylate, were also prepared. NMR analysis of this pyrrolidine derivative suggested the amide bonds adopted the trans conformation. It was concluded that steric bulk of the 2,2-disubstitution favorably influenced the trans amide conformation. This demonstrated that trans amide conformation control of a β-proline amide was possible.
Temple University--Theses
Olszewski, Tomasz Krzysztof. "Original syntheses of new biomolecules : from imidazole and thiazole derivatives of α-aminophosphonic acids and γ-amino-α, β-dihydroxy carboxylic acid derivatives to disaccharide mimics". Montpellier 2, 2006. http://www.theses.fr/2006MON20017.
Повний текст джерелаRocha, Sandra Carla. "Avaliação das perspectivas terapêuticas do ácido L-tiazolidina-4-carboxílico, um análogo de prolina, na infecção de camundongos pelo Trypanosoma cruzi." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/42/42135/tde-16082011-160411/.
Повний текст джерелаTrypanosoma cruzi is dependent on proline for a variety of processes such as energy metabolism, host cell invasion, differentiation and resistance to osmotic, metabolic and oxidative stress. L-thiazolidine-4-carboxylic acid (T4C), a proline structural analogue, inhibits the proline uptake and interacts with several stress factors that the parasite undergoes throughout its life cycle. Herein, we evaluated the T4C effects on mice infection by T. cruzi. It was observed a reduction of 49% of the parasitemia peak in infected mice that were treated with a unique dose of T4C (100 mg/Kg). Histological and quantitative PCR analysis of several tissues revealed a significant reduction of parasite load in the intestine (100 or 150 mg/kg). In the other hand, the unique dose of 200 mg/Kg reduced the body weight and survival of non-infected mice. A T4C prolonged treatment (10 mg/Kg day), did not diminish the parasitemia, but increased survival and reduced the parasite load in the intestine. T4C did not affect the gene expression of g-IFN and IL-10 in any of the organs analyzed (heart, spleen, intestine). In conclusion, T4C-treatment contributes to reduce the virulence of T. cruzi infection, but it was toxic in doses over 150 mg/kg.
Bianco, Angelica. "Formation photoinduite du radical hydroxyle dans la phase aqueuse du nuage : impact sur les acides carboxyliques et les acides aminés." Thesis, Clermont-Ferrand 2, 2016. http://www.theses.fr/2016CLF22746/document.
Повний текст джерелаClouds represent a multiphase complex and reactive medium in which gases, liquid particles and aerosols are in continuous interaction. A large fraction of atmospheric chemical compounds present in the particulate and gaseous phases can be transferred to the cloud droplets where can undergo chemical, photochemical and microbiological transformations. Cloud waters were sampled at the puy de Dôme station. The first part of my PhD work is focused on the photoreactivity of cloud water. Formation of a reactive species such as hydroxyl radical, by direct photolysis of inorganic sources was investigated, as well as the correlation between the concentration of sources and the hydroxyl radical formation rate. The spectroscopic proprieties and fate of tartronic acid, were investigated under cloud water conditions. Moreover, photochemical experiments were performed using continuous irradiation (direct and hydroxyl radical mediated photolysis) and nanosecond flash photolysis in order to assess the reactivity of this compound in cloud aqueous phase. The second part of my work is centered on the characterization of organic matter in clouds. Two studies are presented: i) Detection and quantification of tryptophan by fluorescence spectroscopy and the assessment of its reactivity; ii) detection and quantification of amino acids. Amino acids are detected for the first time in cloud water using a derivatization method and this work show that they represent the 9% of the dissolved organic matter in cloud. Their reactivity with hydroxyl radical was compared to the reactivity of carboxylic acids and dissolved organic matter. These results clearly demonstrate that amino acids represent a major sink of hydroxyl radicals in cloud water
Roberts, Sarah Elizabeth. "Synthesis of 2,4,5-Triaminocyclohexane Carboxylic Acid as a Novel 2-Deoxystreptamine Mimetic." Diss., CLICK HERE for online access, 2009. http://contentdm.lib.byu.edu/ETD/image/etd2890.pdf.
Повний текст джерелаLian, Dai Jen, and 連黛禎. "Chiral Vanadyl Complexs Derived from N-Salicylidene Alpha-amino Carboxylic Acids and Tetrazoles in Asymmetric Reduction and Aldol Reaction." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/47442298763004226914.
Повний текст джерела國立清華大學
化學系
102
A series of chiral oxidovanadium (V) methoxides were derived from 3,5-disubstituted-N-salicylidene α-amino carboxylic acids and tetrazoles. These complexes serve as enantioselective catalysts for asymmetric reduction and aldol reaction. We are the first group that used chiral vanadyl (V) complexes to study the asymmetric reduction. In this study, α-keto amides served as the best substrate class and methanol-modified pinacolborane served as the best reducing agent among five different reducing agents examined. With catalysts 1a (C3 = tBu, C5 = Br) and 1a’ (C3 = tBu, C5 = Br), up to 62% yield and 85% ee (R form) of the α-hydroxyamides were afforded at -20 oC in toluene. In the past five years, we have already found that chiral vanadyl (V) complexes derived from N-salicylidene α-amino carboxylic acids 1a and tetrazoles 11a (C3 = 2,5-dimethoxyphenyl, C5 = NO2) could achieve complementary asymmetric catalytic aldol processes in addition of silyl ketene acetals (SKA) to isatins at -40 oC in dichloromethane. Herein we further optimized these reactions in the case of 5-nitro-isatin by adding trichloroethanol to facilitate turnover, leading to the corresponding aldol product in moderate yield (61%) and good enantioselectivity (88% ee, S form) with catalyst 1a. Without any additives, using catalyst 11a could furnish a series of R form isatin adducts with up to 97% yield and 90% ee in a complementary manner. Molecular simulations of the adducts between these two catalysts and N-benzylisatin indicated that the preferred coordination mode involve in a facile π-π interaction between the N-benzyl moiety and N-salicylidene template of catalyst 1a to avoid concomitantly the steric hindrance of the C3 tert-butyl. On the other hand, another π-π interaction between the C3 2,5-dimethoxylphenyl group of catalyst 11a and the N-benzyl group of the isatin to avoid concomitantly the el-el repulsion with the tetrazole moiety is involved, leading to a complementary, enantiofacial exposure of the carbonyl moiety in the N-benzylisatin.
黃中彥. "Asymmetric Aldol Reactions Catalyzed by Chiral Vanadyl Complexes Derived from N-Salicylidene α-Amino Carboxylic Acids and N-Salicylidene Tetrazoles". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/9cs6wr.
Повний текст джерелаYang, Zhen Xing, and 楊振興. "Chiral Vanadyl Complexs Derived from N-Salicylidene and N-Salicylidane Alpha-Amino Carboxylic Acids in Asymmetric Reduction of Alpha-Hydroxyamides." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/73535271045916603046.
Повний текст джерела國立清華大學
化學系
104
We have developed a catalytic protocol for complementary enantioselective reduction of α-ketobenzylamide with pinacolborane and catecholborane catalyzed by chiral oxidovanadium (V) methoxides complexes derived from 3,5-disubstituted-N-salicylidene α-tert-leucinate. The catalysts 1a and its reduce form 1a' (C3 = t-Bu, C5 = Br) with pinacholborane afforded upto 62% yield and 84% (R-form) enantioselectivity, at −20 °C in toluene under Argon. However, asymmetric reduction with catecholborane provides complementary enantioselectivity upto 64% (S-form) and 99% yield. A series of α-ketobenzylamide substrates were examined, the substrates with small and planar α-keto functional groups can get better enantioselectivity. With pinacolborane, α-cinnamyl substituted system shows better enantioselectivity 93% (R-form) and 45% yield. While in the case of catecholborane, 2-thiophenyl case show better enantioselectivity 76% (S-form) and 89% yield. The complementary enantioselectivity can be explained by a plausible mechanism, in which the step is the chelation of carbonyl group of amide with vanadyl(V) center axially anti to vanadyl oxygen . In the next step, the methoxide chelates with bulky pinacholborane lead to a s-trans conformation of the α-ketoamide and directs the hydride transfer from Si-face. This results in the formation of R-isomer. Conversely, the π-π interaction between the catecholborane and substrate coordinates in an s-cis conformation instigate the hydride transfer from Re-face. This results in the formation of S-isomer.
Lai, Chien-Fu, and 賴建福. "Chiral Oxidovanadyl Complexes Derived from N-Salicylidene Alpha-Amino Carboxylic Acids in Asymmetric Reduction of Beta-Keto-Amides and -Phosphonates." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/cq5r7v.
Повний текст джерелаLin, Ce-Hsuan, та 林世軒. "Enantioseparation of N-protected amino acids and carboxylic acids by high-performance liquid chromatography with π-acid derived quinidine as chiral stationary phase". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/22960169773696111614.
Повний текст джерела朝陽科技大學
應用化學系碩士班
91
Abstract Due to dissimilarity of steric structure, the optically active medicines often result in the significant difference of pharmacology. This situation is gradually changing as number of companies have now stared to move towards producing enatiomerically pure forms. This proposal plans to develop one type of quinidine-derived chiral stationary phases (3,5-dinitrobenzoyl quinidine thiopropylsilanized silica ) which simultaneously possess the functions of aromatic π acid, aromatic π base and anion-exchanger. With this type of CSP, we plan to do enantioseparations of non-steroidal anti-inflammatory drugs and N-derivatized amino acids by high performance liquid chromatography. This CSP is used in HPLC with normal-phase mode and reversed-phase mode. In normal-phase mode, DNB-, DNP-derivatized amino acids and ascorbic acid are well separated. An example of 3,5-dintrobenzoyl leucine, the mobile phase was 100% methanol at a flow-rate of 1 ml/min and 240 nm wavelength of detection. The resolution(Rs) is 1.3. In reversed-phase mode, DNB-, DNP-derivatized amino acids and non-steroidal anti- inflammatory drugs are well separated. An example of 3,5-dintrobenzoyl leucine, the mobile phase is consisted of 2% 10 mM ammonium acetate (the mixture is adjusted with trifluoracetic acid to the pH = 4.5) and 98% methanol at a flow-rate of 1 ml/min and 240 nm wavelength of detection. This resolution is 2.5. This chiral column can enantioseparate several kinds of compound induding aromatic π acid, aromatic π base and ascorbic acid.
Karri, Phaneendrasai. "Mechanistic And Synthetic Investigations On Carboxylic Anhydrides And Their Analogs." Thesis, 2008. http://hdl.handle.net/2005/1058.
Повний текст джерелаMohammadpourmir, Fatemeh. "Synthesis of Aza- and α,α-disubstituted Glycinyl peptides and application of their electronic and steric interactions for controlling peptide folding, and for biomedical applications". Thèse, 2019. http://hdl.handle.net/1866/21698.
Повний текст джерела