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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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Pyrazine Carbonyl Compounds - Building Blocks in Dynamic Combinatorial Systems
Coufal, Radek ; Drahoňovský, Dušan (advisor) ; Jindřich, Jindřich (referee)
This bachelor thesis deals with the synthesis of bifunctional carbonyl derivatives of pyrazine, which are further examined for their potential to form dynamic hemiacetals with monofunctional alcohols. Newly prepared, in the literature not yet described bifunctional trifluormethyl derivatives exhibit considerable ability to form hemiacetals in a dynamic system. The obtained results show that these substances may find application as building blocks of dynamic combinatorial systems.
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Dynamers based on the reversible formation of hemiacetals
Nosek, Vladimír ; Drahoňovský, Dušan (advisor) ; Míšek, Jiří (referee)
This work deals with the design and synthesis of building blocks, usable for creating dynamic polymers based on the reversible formation of hemiacetals bond. Next part is focused on the study of the formation of hemiacetal between polyfunctional alcohols and trifluoromethylketones via NMR spectroscopy. Key words: constitutional dynamic chemistry, hemiacetals, trifluoromethylketones, diols and polyols
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Regiospecific cyclam derivatives for radiomedical and MRI utilizations
Blahut, Jan ; Kotek, Jan (advisor) ; Drahoňovský, Dušan (referee)
Cyclam (1,4,8,11-tetraazacyclotetradecane) derivatives are widely used for various purposes. In a medicine they are applied as ligands for radiometals applied as diagnostic or therapeutic agents against tumours, hypoxic brain tissues etc. In this thesis a new method for asymmetric cyclam derivati- ves preparation was developed. New cyclam derivatives with trifluoroethyl groups were prepared too. Paramagnetic metal complexes with these fluori- nated ligands can be used as contrast agents for 19 F-MRI. Keywords: Cyclam; Non-symmetric protection; Contrast agents; Trifluoroethylamines; Paramagnetic relaxation; 19 F-MRI.
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Transition metal catalyzed cross-coupling reactions of onium salts
Hidasová, Denisa ; Šrogl, Jiří (advisor) ; Drahoňovský, Dušan (referee)
The research of this thesis is focused on developing Suzuki cross-coupling reactions of various onium salts using the catalytic system Ni complex/trans-N,N'-dimethyl-1,2- cyklohexanediamine. As an expansion in the catalysis of nickel compounds, we have established that the catalytic system Ni(cod)2/trans-N,N'-dimethyl-1,2-cyklohexanediamine can affect Suzuki reactions of tetramethylenesulfonium salts with boronic acid, which leads to cleavage of C-S and formation of new C-C bonds under relatively mild reaction conditions. This explains the unique reactivity and biomimetic behavior of a nickel catalyst to activate the C-S bond. Key words: onium salts, Suzuki coupling, nickel complexes
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Reversible interactions of pyrazines and photoluminescent dihydropyrazines
Coufal, Radek ; Drahoňovský, Dušan (advisor) ; Roithová, Jana (referee)
This thesis deals with two independent topics. The first is focused on the study of reversible covalent interactions of a carbonyl group with alcohols and water forming hemiacetals (respectively hydrate) derived from pyrazine trifluormethylketone. The main research method in this part is the NMR spectroscopy and experimental results are also supported by quantum chemical calculations. The second topic aims to the preparation and the study of photochemical properties of three dihydropyrazines which exhibit fluorescence both in solution and solid phase. The fluorescence can be influenced by means of complexation by various metal ions. Prepared dihydropyrazines also show interesting values of the Stokes shift. The structure of these new compounds was confirmed by X-ray analysis.
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Preparation and characterization of building blocks of supramolecular polymers
Šichová, Kristýna ; Svoboda, Jan (advisor) ; Drahoňovský, Dušan (referee)
Aim of this thesis was to synthetize 5,5''-bis(terpyridine-4'-yl)-3ʹ-(6-bromohexyl)- 2,2ʹ:5ʹ,2ʺ-terthiophene. This substance consists of terthiophene chain, which is substituted with bromohexyl group in position 3' and capped by two terpyridine groups. The synthesis was approached in two different ways, with use of various initial compounds, using mainly the Suzuki reaction. Strategies were recorded, and their process and outcome evaluated. Prepared substances were characterized, and structurally identified using 1 H, 13 C and 11 B NMR spectroscopy. For the prepared oligomeric product 5,5ʺ-bis(terpyridine-4'-yl)-3ʹ-(6-bromohexyl)- 2,2ʹ:5ʹ,2ʺ-terthiophene, spectroscopic and oxidation-reduction properties were determined, by UV-VIS spectroscopy, emission fluorescence and cyclic voltammetry. Furthermore, the fluorescence quantum yield was also determined. Further in the thesis, the abillity of the prepared oligomer to form complexes with zinc ions was studied. Complexation was carried out in tetrahydrofuran solution, and studied using UV-VIS and fluorescence spectroscopy, measured in solution for samples of produced concentration range.
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Preparation and properties of bis(terpyridyl)oligofluorenes
Hrma, Martin ; Svoboda, Jan (advisor) ; Drahoňovský, Dušan (referee)
This bachelors thesis deals with the synthesis of bis(terpyridyl)oligofluorenes, that are suitable for the preparation of supramolecular polymers. The main aim was synthesis and characterisation of 7,7'-bis(terpyrid-4'-yl)-9,9,9',9'-tetrakis(6'-bromohexyl)-2,2'-bifluorene. As a starting substance was used commercially available 2-bromofluorene made by Sigma- Aldrich. In the preparation of the final ligand was used three reaction schemes, during the several steps used in the Suzuki coupling, or variations thereof.
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