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Ultrasonic and Densitometric Characterization of Hyaluronan and its Interaction with Surfactant
Hurčíková, Andrea ; Hrdina, Radim (referee) ; Mráček,, Aleš (referee) ; Pekař, Miloslav (advisor)
This disertation thesis is focused on the study of physico-chemical interactions of hyaluronan (with molecular weights from 10 to 1750 kDa) with cationic surfactants measured using uncommon technique named high resolution ultrasonic spectroscopy. Densitometer was also used for the study of these interactions, in measuring of density and ultrasonic velocity of hyaluronan with different molecular weight in dependence on elevated temperature (25 50 °C). The aim is the determination of critical micelle concentration (CMC) and critical aggregation concentration (CAC) of the suractants in the absence and in the presence of hyaluronan with various molecular weights. Interactions in this system are important for the design of the systems for the targeted delivery, especially for the drugs. The experiments were made in water and sodium chloride solution. The significant breakpoint in the ultrasonic velocity showed changes in the system hyaluronan-surfactant.
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Synthesis of tricyclic hydrocarbon derivatives
Tuzova, Uliana ; Hrdina, Radim (advisor) ; Rýček, Lukáš (referee)
This bachelor thesis deals with the preparation of enantiopure Binol-derived phosphoric acids with different substituents at the 3,3'-position, which are typically used as Brønsted acids in enantioselective non-covalent organocatalysis. The prepared 3,3'-adamantane substituted Binol-derived phosphoric acids are planned to be used as organocatalysts. Bulky alkyl substituents at the 3,3' position have been introduced in order to compare their properties with those of phenyl substituents at the 3,3' position. The different dispersion forces between substrate and catalyst are expected when aryl and alkyl substituents are incorporated into the catalyst structure. Keywords Organocatalysis, asymmetric synthesis, Brønsted acids.
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Synthesis of Adamantane Derivatives
Todd, Matthew Zagorey ; Hrdina, Radim (advisor) ; Rýček, Lukáš (referee)
Undirected functionalization of adamantane by electrophilic oxidation proceeds mainly at the tertiary positions, owing to the higher reactivity of its C-H bonds and stability of electron deficient species, relative to the secondary positions. Ring contraction and expansion methods have been shown as a powerful tool to prepare such derivatives avoiding the reactivity constraints of undirected electrophilic oxidation reactions. Previous ring contraction methods proceeded under harsh conditions limiting their scope to simple alkyl substituents. In this work a new ring contraction method for the preparation of noradamantane derivatives from adamantane under mild conditions has been developed, enabling the presence of additional functional groups during the process. The new method utilizes the commercially available Burgess reagent for mild dehydration conditions of the starting material leading to 1,3- and 3,7-disubstituted (3-noradamantyl)methylene aldehydes, that were previously hard to obtain, if not unobtainable, and post functionalized to their corresponding protected amino-alcohols and diols. The method was also applied for the synthesis of protoadaman-4-one that is mainly synthesized through the deamination of 2-aminoadamantan-1-ol. The deamination method was also optimized for the preparation...
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Molecular Machines in Medicine
Dědek, Matěj ; Kaleta, Jiří (advisor) ; Hrdina, Radim (referee)
This bachelor thesis is focused on synthesis of light-driven molecular motors and switches, their physical properties and potential utilisation in medicinal chemistry. It is expected, that these molecular machines might possibly in the future serve as mechanical weapons against various cellular pathogens, modulate ion transport and other cellular processes. Within the framework of this thesis were studied preparations of rotors of the molecular machines based on cyclopenta-[a]-naphtalen-1-ones from comercially affordable chemicals and substitution of these rotors on aromatic core was examined. The main effort was put on verification and optimalisation of previously published synthetic processes and on isolation and characterisation of side products of the reactions. Another aim of this work was synthesizing building blocks of a molecular motor model, imitating a light-driven bacterial flagellum.
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Synthesis of chemical constituents from the Selaginellaceae family
Mulenga, Mutale Jane ; Rýček, Lukáš (advisor) ; Hrdina, Radim (referee)
The genus Selaginella belongs to the family Selaginellaceae. There have been about 30 selaginellins reported with possession of biological activities such as antimicrobial, cytotoxic, antioxidant, and phosphodiesterase-4 (PDE4) inhibitory properties. This master's thesis will focus on the synthesis of the natural product selaginellin T, containing the isobenzofuran- 1(3H)-one core in its structure. The first attempts to create the core were attempted via partially intramolecular [2+2+2] cyclotrimerization from the corresponding diyne connected by an ester linker and external alkyne. This strategy failed, as the formation of the stating ester was not feasible. The alternative strategy relying on [4+2] cycloaddition was evaluated, however, without any success. Finally, the isobenzofuran-1(3H)-one core was formed via [2+2+2] cyclotrimerization of the corresponding diyne connected by ether linker, leading to the corresponding 1,3-dihydroisobenzofuran, which was further oxidized to the desired lactone. The difficulties with the removal of the protecting groups were encountered at the later stage of the synthesis, and therefore, the use of alternative protecting groups is proposed. Key words: Selaginellaceae, selaginella, cyclotrimerization, metal catalysis.
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Synthesis of helical aromatics for applications in enantioselective catalysis and nanoscience
Klívar, Jiří ; Stará, Irena (advisor) ; Hrdina, Radim (referee) ; Církva, Vladimír (referee)
The aim of this work was to explore the scope and limitations of [2+2+2] co- cyclotrimerization of cyanodiynes in the preparation of conformationally stable and optionally optically pure azahelicenes, helically chiral bipyridines and helicenes laterally extended by a pyridine unit. As a key reaction for the construction of a helical skeleton, crucial [2+2+2] (co-)cyclotrimerization mediated by various transition metal complexes was chosen for the preparation of racemic azahelicenes. Oligoynes as key intermediates were prepared by a sequence of Sonogashira and Suzuki-Miyaura coupling. For optically pure azahelicenes and bispyridohelicenes, a sequence of Sonogashira and Suzuki-Miyaura coupling and Mitsunobu reaction was used. Importantly, the Mitsunobu reaction was used for its extraordinary ability to transfer chirality from the starting chiral alcohol to the early helicene precursor without configurational scrambling. It is worth noting that optical purity of the key oligoynes have crucial role in the chirality transfer to final azahelicenes or bispyridohelicenes. An in situ generated Ni(0) catalyst was used for bispyridohelicenes with a connection in the 2,2'-position, which enabled both [2+2+2] cyclotrimerization and Ullmann-type coupling. The conformationally stable racemic aza[6]- and...
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Development of New Syntheses of Azaaromatic Compounds with Extended π-System
Ulč, Jan ; Kotora, Martin (advisor) ; Hrdina, Radim (referee) ; Tobrman, Tomáš (referee)
Azapolyaromatic compound are a class of heterocyclic compounds, which contains at least one nitrogen atom. A subclass of these compounds are quinolizinium salts, which contains nitrogen atom in bridgehead position. These salts usually have interesting photophysical properties. Naphthoquinolizinium salts are a group of quinolizinium salts, but their synthesis as well as their photophysical properties haven't been studied in detail yet. This work is about development of a new modular method for preparation of naphthoquinoliziniu salts. This method is based on catalytic C-C and C-H bond activations by transition metal catalysts. 1-Azabiphenylene was used as a starting material, which reacted in catalytic C-C bond cleavage followed by insertion of various alkyne to form benzo[h]quinolines. These benzo[h]quinolines then reacted in catalytic C-H bond activation reaction followed by insertion of another alkyne to form final tetrasubstituted naphthoquinolizinium salts. Photophysical properties of the prepared salts was studied. The developed method was used on a more complex starting material such as linear 1- 1-aza-[3]triphenylene, which was converted to phenanthroquinolines and eventually to the corresponding azonia salts. Key words: azapolyaromatic compounds, catalysis by transition metal complexes, C-C...
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Preparation of chiral amides and their use as organocatalysts
Brandejsová, Aneta ; Veselý, Jan (advisor) ; Hrdina, Radim (referee)
This bachelor thesis is focused on preparation of C-9 amino derivatives of Cinchona alkaloids and derived bifunctional squaramide catalysts, which are used as organocatalysts in a wide variety of chemical transformations leading to enantiomerically pure compounds. The first part deals with choosing the most efficient method for the preparation of C-9 amino derivates of Cinchona alkaloids and the synthesis of four selected examples. In the second part, the prepared derivates are used for the synthesis of bifunctional squaramide catalysts, which are further tested in newly designed cyclization reactions.
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Synthesis of annelated ferrocene compounds by C-H activation
Varmužová, Věra ; Štěpnička, Petr (advisor) ; Hrdina, Radim (referee)
Title: Synthesis of annelated ferrocene compounds by C-H activation Author: Věra Varmužová Department: Department of Inorganic chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: This diploma thesis disrcibes the synthesis of two annelated ferrocenes, ferroceno[c]isoquinoline (9) and benzo[f]ferroceno[c]isoquinoline (13). Starting compound used for their synthesis, [(methylsulfonyl)amino]ferrocene, was prepared from aminoferrocene. During the synthesis of compound 9, the reaction sequence was optimized, which includes the nucleophilic substitution, C-H activation and aromatization. Compound 13 was prepared similarly using the optimized reaction conditions An intermediate prepared during the synthesis of compound 9, 1,2-dihydro-2-(methylsulfonyl)ferroceno[c]isoquinoline (7), was additionally used to prepare cationic ruthenium complex 14, wherein it links as a η6 -ligand via its benzene ring. For compounds 7, 9 and 14 UV-VIS absorption spectra were recorded and compared. Key words: ferrocene, annelated ferrocenes, C-H activation, organometallic chemistry
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