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Enantioselective synthesis of spirooxindoles
Vopálenská, Andrea ; Veselý, Jan (advisor) ; Rýček, Lukáš (referee)
This diploma thesis is focused on the enantioselective synthesis of spiro[cyclopentane- oxindoles] from 3-alkylideneoxindoles and 1-bromo-3-nitropropane catalyzed by chiral bifunctional organocatalysts. The first part of this work is devoted to the preparation of the proposed starting 3-alkylideneoxindoles and 1-bromo-3-nitropropane. In the second part, the reaction conditions of the enantioselective synthesis of chiral spirooxindoles were optimized, and then the scope of the method's use on selected substrates was studied under the optimized conditions.
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Derivatives of N-acetylglucosamine-1-phosphate as potential inhibitors of UDP-GlcNAc pyrophosphorylase
Černá, Lucie ; Baszczyňski, Ondřej (advisor) ; Veselý, Jan (referee)
This bachelor thesis deals with the preparation of phosphonate derivatives of N-acetyl- ᴅ-glucosamine-1-phosphate (GlcNAc-1-P), the substrate for UDP-GlcNAc pyrophospho- rylase (UAP1) enzyme, which is responsible for the chitin synthesis in fungal cell walls. Structural analogs of GlcNAc-1-P could potentially inhibit UAP1 and; therefore, their synthesis may enable the development of new antifungal drugs. This work is mainly focused on the synthesis of diethyl (2-acetamido-1,2-dideoxy-β-ᴅ-glucopyranosyl)phosphonate which was selected as a key model compound. The goal was to find the most suitable synthetic route leading to the synthesis of phosphonate and phosphinate GlcNAc-1-P analogues. Two synthetic methods were studied: 1) Michael addition of H-phosphonates to 2-nitroglucals; and 2) nucleophilic substitution of activated GlcNAc substrates (trichloroacetimidate and bromide) by phosphorus nucleophiles. Keywords: GlcNAc-1-P, UDP-GlcNAc pyrophosphorylase, antifungal, inhibitor
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Design, Synthesis, and Application of Novel Bifunctional (Thio)urea Organocatalysts Derived from Saccharides & Catalytic Asymmetric C−H Arylation of (η6-Arene)Chromium Complexes
Gergelitsová, Ivana ; Veselý, Jan (advisor) ; Sedlák, Miloš (referee) ; Urban, Milan (referee)
The first part of the thesis is focused on the design, synthesis, evaluation, and application of novel bifunctional (thio)urea organocatalysts derived from saccharides. Combination of H-bonding donor (thio)urea moiety with Lewis base active site in a single chiral scaffold (e.g., 1,2-trans-cyclohexyl, cinchona alkaloids, 1,1'-binaphthyl) is a popular motif in catalyst design. Only limited attention has been paid to the synthesis of bifunctional (thio)ureas using saccharides as a chiral scaffold. Saccharides bring the advantage of the availability of various diastereomeric forms. Moreover, they offer modification of steric, electronic, and solubility properties via O-substitution. Three types of novel organocatalysts were designed: C2-symmetrical thiourea/tertiary amines entirely derived from 2-amino-2-deoxy saccharides, thiourea/primary amines based on pentopyranose and a cyclohexane skeleton, and (thio)urea/tertiary phosphines containing both saccharide and α-amino acid unit. Both functional groups of organocatalysts of the first type are located on the saccharide unit, and it is the only element which fully determines stereoselectivity. This is an exceptional approach as the majority of saccharide-based organocatalysts use saccharide as a bulky electron- withdrawing substituent. However, the...
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Synthesis of chiral secondary amines useful as organocatalysts
Urban, Michal ; Veselý, Jan (advisor) ; Drahoňovský, Dušan (referee)
This bachelor thesis deals with the preparation of chiral secondary amines, which are used as catalysts in many chemical transformations leading to enantimerically pure compounds. The emphasis of this work is placed on the comparison of the effectiveness of published syntheses those organocatalysts. The first part focuses on the comparison of efficiency and optimization of two methods of preparation Jørgensen's catalyst, the first approach is based on the Z-protected (S)-proline, and in the second approach as starting material was used. The second part deals with the preparation of other Jørgensen's and Hayashi's types of catalysts, via introduction of various silyl functional groups.
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Catalytic testing of polar amidophosphines
Šrámková, Helena ; Štěpnička, Petr (advisor) ; Veselý, Jan (referee)
Catalytic testing of polar amidophosphines: abstract A series of new nine arylruthenium complexes [(aryl)RuCl2(L)] was studied in isomerisations of allylic alcohols to carbonyl compounds. The best reaction conditions were found. The best solvent and reaction temperature were chosen. The best amount of catalyst and the best base and its amount were chosen too. In these conditions, the catalysts were tested for four substituted allylic alcohols. It was proven that these catalysts isomerise readily simple allylic alcohols, but not substrates that is highly substituted.
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Withdrawal from a contract in business relations (preconditions and consequences)
Veselý, Jan ; Čech, Petr (advisor) ; Plíva, Stanislav (referee)
62 Grounds for termination of a commercial contract: summary and keywords The thesis you are about to read deals with the concept of termination of a contract (sometimes referred to as withdrawal from a contract, "odstoupení od smlouvy" in Czech) under the general provisions of the Czech Commercial Code concerning commercial contractual obligations. This concept is generally perceived as a unilateral remedy designated to resolve the situations of fundamental non-performance of the contract and as such it presents an exception from the principle of preservation of the contract. The thesis focuses namely on general and particular grounds for termination. The purpose of the thesis is to compare the scope in which this remedy is available to the aggrieved party under the general provisions of the Czech Commercial Code as interpreted by relevant doctrine and case law with the standard scope under various international legal documents. The thesis consists of four chapters. The first chapter characterizes the concept of termination in general and outlines its' role within the contract law. The main functions of termination (protection of the aggrieved party, motivation and penalty of the other party, possible way of escape from the contract) are described. A brief introduction of the compared international legal...
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Synthesis and Utilization of Selected Nitrogen Heterocycles
Mikušek, Jiří ; Pour, Milan (advisor) ; Veselý, Jan (referee) ; Bureš, Filip (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Inorganic and Organic Chemistry Candidate: Mgr. Jiří Mikušek Supervisor: prof. RNDr. Milan Pour, PhD. Title of Doctoral Thesis: Synthesis and Utilization of Selected Nitrogen Heterocycles The thesis is divided into two parts, both dealing with the synthesis of pyridine and pyrimidine derivatives. The first one is focused on the cyclization of enynes with gold(I) catalysts. Main attention is paid to the synthesis of various acyclic precursors starting from propargylamines, their addition to propiolates and Sonogashira cross-coupling. The mechanism of the cyclization with (TFP)AuCl is then discussed in detail. Prepared dihydropyridines were converted to pyridines or tetrahydropyridines. A precursor of the antidepressant drug paroxetine was prepared. The second part deals with quinazoline alkaloids with pyrimidine moiety and their structural variations towards potential organocatalysts and biologically active compounds. Therein new types of organocatalysts based on the structure of vasicine were prepared and screened on model aldolization and addition reactions. Prepared compounds were tested for bronchodilator activity.
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