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Showing 1 to 20 of 101 for “"enantiopure"”.
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Chemoenzymatic routes to enantiopure hydroxytetrahydrofurans: muscarine and its analogues
Muscarine was identified as an active principle of the poisonous mushroom Amanita muscaria over 170 years ago and has been identified as an agonist of acetylcholine. The synthesis of all stereoisomers of muscarine have been accomplished at this stage by chemical methods and the biological activity …
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Self-Assembly of Enantiopure Subcomponents into Functional Metal–Organic Cages
… among other applications. However, the use of enantiopure metal–organic cages for enantioselective applications has been limited both due the difficulty in construction of enantiopure cages and subsequent utilisation of their largely pseudo-spherical cavities. To expand the use of metal–organic …
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Asymmetric Synthesis of 1,3-Amino Alcohols and Tropinone Derivatives From Enantiopure Sulfinimines
Heterocycles that contain nitrogen, such as piperidine, pyrrolidine and tropane, are widespread as natural product alkaloids and serve as templates for many bioactive drugs and drug candidates. The intent of this research is to the develop asymmetric syntheses of piperidine-containing syn and anti …
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Novel Enantiopure ß-Amino Alcohols and ß-Amino Thiols in Asymmetric Catalysis
… was shown in its utility to synthesize various enantiopure amino alcohols having a cyclohexyl core and bearing either a cis- or a trans-configuration at the stereogenic centres. The amino alcohols were tested for their efficacy in the catalytic asymmetric desymmetrization of meso anhydrides. The …
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Asymmetric Synthesis of Nitrogen Containing Bioactive Compounds via the Utilization of Enantiopure p-Toluenesulfinimines
… amine derivatives using p-toluenesulfinimines. Enantiopure sulfinimines are versatile chiral building blocks for the asymmetric synthesis of alkaloids. Sulfinimines were prepared by the condensation of (S)- or (R)-p-toluenesulfinamide with aldehydes and ketones in good to excellent yields, which …
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Producing Enantiopure Secondary Alcohols via a Silylation based Kinetic Resolution and a One-Pot Polishing Sequence
… our efforts to develop new methods of producing enantiopure compounds through a sequential one-pot polishing procedure and through kinetic resolutions via silylation and desilylation. Chapter 2 highlights how we have combined a moderately selective asymmetric reaction (either a reduction or …
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Asymmetric Synthesis of Homotropinone and Tropane Alkaloids using Enantiopure Sulfinimines and the Synthesis and Applications of Methanoprolines
… of homotropinone and tropane alkaloids using enantiopure sulfinimines [RS(O)N=CR1R²] is the primary objective of this thesis. In one study a four-step intramolecular Mannich cyclization cascade reaction was devised for the asymmetric synthesis of substituted homotropinone alkaloids from …
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A New Synthesis of enantiopure C-3-substituted Glutamates by Utilization of Ortho Ester protected (S)-Pyroglutamic acid
… of the present thesis were to generate various enantiopure C-3-substituted pyroglutamates as well as C-3-substituted glutamates, and furthermore to ameliorate the serious drawback of the bad atom-economy in the reaction sequence of previously published silylether-mediated procedures. To meet …
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Optimization of Enantiopure tetrahydro-β-carbolines as Potent Antimalarials and Exploration of salicylic acid analogs for combating multidrug-resistant Neisseria gonorrhoeae
The emergence of drug resistance towards existing drugs is a constant challenge in the fight against many diseases including Malaria and gonorrhoeae. To evade resistance, new targets must be engaged, and to do that, new structural classes of anti-infective must be prepared and evaluated. During the …
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Design and use of novel metal catalysts in organic synthesis
… Two describes the design and synthesis of novel, enantiopure dirhodium carboxylate complexes, drawing inspiration from the rhodium (S)-mandelate skeleton. Initially, two enantiopure rhodium carboxylates were synthesised, incorporating carboxylic acid ligands bearing a fenchyl chiral auxiliary. …
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Synthesis of nitrogen-containing heterocycles using nitro compounds as building blocks: Part I: Synthesis of 3-substituted azepanes. Part II: Synthesis of 1-azoniapropellanes as phase transfer catalysts
… in good yield. Efficient synthesis of chiral, enantiopure 1-azoniapropellanes as phase transfer catalysts has been developed. In the first method, the tandem [4+2]/[3+2] cycloaddition of nitroalkene was applied as the key step, wherein a chiral, enantiopure vinyl ether, a nitroalkene and a …
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The chemistry of thujone : new enantioselective syntheses of Ambrox[Registered trade mark] and Epi-Ambrox
… (2) and epi-Ambrox (3) using thujone (1) as an enantiopure building block. Thujone (1), a readily available starting material obtained from Western red cedar, can be efficiently converted to D-cyperone (144), which can be chemically elaborated to obtain the key intermediate, enone 143. As a …
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Synthesis of new substituted organosulfur donors for the preparation of conductive and multifunctional materials
… bridged dimeric BEDT-TTF donors (chapter 2), ii) enantiopure substituted EDT-TTF donors with hydrogen bonding functionalities (chapter 3) and iii) BEDT-TTF substituted ligands and their ability to form multifunctional materials (chapter 4). In chapter 2 the preparation of novel BEDT-TTF donors …
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Synthesis of Chiral Vanadium Phosphonates and Their Catalytic Activity
… cage molecules synthesized with racemic and enantiopure phosphonate starting materials. In addition, treatment of V2O 5 with (HO)2P(O)R in ethanol, where R = Ph and CHMePh- S, afforded (VO)(O3PR)·yEtOH·xH2O. (VO)(O3PCHMePh-S)·H2O is the first layered vanadium phosphonate …
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The Synthesis and Application of a Chiral Sulfonated Phosphine Ligand to Asymmetric Transition-Metal Catalysis
… sulfonated phosphine ligand, sSPhos, in its enantiopure form and its subsequent application in asymmetric transition-metal catalysis. sSPhos is a dialkylbiaryl phosphine ligand bearing a sulfonate group. This sulfonate group can engage in non-covalent interactions, allowing sSPhos to …
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Asymmetrischer katalytischer Phenyltransfer zur Synthese von Diarylmethanolen und Diarylmethylaminen
Enantiopure diarylmethanols and diarylmethylamines are important intermediates in the synthesis of biologically active compounds, since their derivatives have e. g. antihistaminic properties. For example, the (S)-enantiomer of the commercially important non-sedating antihistamine agent Cetirizine …
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Design and Synthesis of Novel Benzodiazepines
… anticancer agents. More recently enantiopure (S)-proline-derived 1,4-benzodiazepin-2,5-diones have been recognized as selective α5 GABAA receptor ligands. Despite the impressive diversity of 1,4-benzodiazepine-2,5-diones prepared to date, enantiopure examples possessing a …
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Mechanistic Studies on Memory of Chirality Alkylations of 1,4-Benzodiazepin-2-ones & Structure-based Design of Insecticidal AChE Inhibitors for Malaria Mosquito, Anopheles gambiae
… of the sole stereogenic center of the enantiopure starting material is "memorized" by a chiral non-racemic conformation in the intermediate; trapping then captures the stereochemical information, and generates a new stereogenic center with high fidelity. We experimentally and …
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1,3-Aminoalkohole als Bausteine in der asymmetrischen Synthese von Azetidinen, Azetidincarbonsäuren und Piperidin-3-olen
… with limited occurrence in nature. Nevertheless enantiopure azetidines and in particular derivatives of the azetidine-2-carboxylic acid are used in medicine, crop protection and asymmetric catalysis. Despite these promising developments in azetidine chemistry, the lack of general enantioselective …
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Metal based asymmetric catalysis in Baeyer-Villiger oxidations
… was based on a mediating species formed by enantiopure 2,2'-dihydroxy-1,1'-binaphthyl (BINOL) and Me2AlCl and utilized a hydroperoxide as oxidant. A first attempt towards an optimized version relied upon the modification of the substitution pattern of the binaphthyl ligand. The introduction …
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