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The effect of substituents, structure of the reactant and type of active sites on the reaction rate and selectivity of cyclization reactions
Živný, Marek ; Veselý, Ondřej (advisor) ; Bulánek, Roman (referee)
Tetrahydropyrans (THPs) are valuable compounds in the synthesis of pharmaceuticals and fragrances. Currently, THPs are most commonly synthesized using the Prins cyclisation, hetero-Diels-Alder reaction and oxy-Michael reaction. These reactions are undesirable because they use catalysts based on heavy metals and strong acids, which are harmful to the environment. In this thesis, we investigated the synthesis of THPs with the aim of replacing toxic heavy metals and strong acids with more benign catalysts, such as zeolites. Zeolites are microporous crystalline metallosilicates, which are commonly used as catalysts due to their high acidity, selectivity and stability. Previous research has successfully shown that zeolites can catalyse THP synthesis through cyclisation of unsaturated alcohols and determined the effect of pore size on catalytic activity. In contrast, this work aimed to examine zeolites with different framework elements, which introduce diverse types of acid sites. Additionally, we aimed to investigate the impact of functional groups present in the structure of the reactants, specifically functional groups with either electron-donating (EDG) or electron-withdrawing (EWG) effects and with different aromatic cycle systems. We chose (E)5-phenyl-4-pentenol as the primary reactant for the cyclisation....
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Synthesis and Reactivity of Enynes with Terminal Double Bond
Grobař, Bartoloměj ; Matouš, Petr (advisor) ; Opálka, Lukáš (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of organic and bioorganic chemistry Candidate: Bartoloměj Grobař Supervisor: PharmDr. Petr Matouš, Ph.D. Title of thesis: Synthesis and reactivity of enyns with terminal double bond This work focuses on synthesis of structures containing terminal vinyl moiety and their subsequent reactivity. We tested various approaches that lead to formation of enynes, which are then cyclized using gold complex catalyst into tetrahydropyridines. Both utilize the addition of propargylamine protected by 4-methoxybenzenesulfonyl group to substituted butynone and methoxyphenyl propiolates. Tetrahydropyridine molecules that are successfully created, are further derivatized forming polycyclic structures.
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Synthesis of Ortho-Condensed Nitrogen Heterocycles Using Gold Complexes
Makaj, Petr ; Matouš, Petr (advisor) ; Kuneš, Jiří (referee)
5 ABSTRACT Charles University, Faculty of Pharmacy in Hradci Králové Department of Organic and Bioorganic Chemistry Candidate: Petr Makaj Supervisor: PharmDr. Petr Matouš, Ph.D Title of Thesis: Synthesis of Ortho-Condensed Nitrogen Heterocycles Using Gold Complexes This diploma thesis is focused on the preparation of pyridopyridine derivatives using gold-catalyzed cyclizations. The synthesis is based on MBS-protected propargylamine, which after substitution with aryl using Sonogashira coupling reacts with tert-butyl (3- oxopent-4-ynyl)carbamate to form substituted 1,5-enyne. The enyne thus prepared then undergoes cycloisomerization using tris(2- furanyl)phosphinegold(I)chloride as a catalyst to form pyridopyridine. Substances with this scaffold can be further used to synthesize potentially biologically active structures. Keywords: gold catalysis, cyclization, pyridopyridine derivatives, 1,8-naphthyridine derivatives
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Aplications of hydrogenation catalysts prepared by reductive demetalation of zeolites
Kurucová, Svetlana ; Přech, Jan (advisor) ; Vyskočilová, Eliška (referee)
Hydrogenation reactions belong to the most important reactions in the chemical industry. They are needed for crude oil processing, production of pharmaceutical, polymers, chemical specialties, etc. Supported noble metal catalysts are commonly used industrial catalysts due to their high activity and selectivity. However, the high cost of production and recovery of noble metal catalysts is one of the disadvantages of their use. The application of transition metal catalysts containing Cu, Fe or Zn presents a more environmentally friendly alternative to currently used catalysts. In this work, we studied the catalytic activity of metal@zeolite composite catalysts containing CuFe and CuZn bimetallic nanoparticles, prepared by reductive demetallation in hydrogenation of -NO2, -C≡C-, -C=C- and -C=O groups. Reductive demetallation is a novel method for the synthesis of bimetallic nanoparticles encapsulated inside zeolite pores. The catalytic activity of the metal@zeolite composites prepared by reductive demetallation was compared with analogues synthesised by impregnation and ion exchange in the hydrogenation of p-nitrotoluene, 3-ethynylanisole and cinnamaldehyde. Metal@zeolite catalysts synthesised by reductive demetallation were active in the hydrogenation of all the cited groups: -NO2, -C≡C-, -C=C- and...
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Utilization of modified polyethylenes as macroscopic ligands
Ráliš, Václav ; Pinkas, Jiří (advisor) ; Vojtíšek, Pavel (referee)
Charles University in Prague Faculty of Science Department of Inorganic Chemistry Author: Václav Ráliš Supervisor: Mgr. Jiří Pinkas, Ph.D.prof. Consultant: RNDr. Petr Štěpnička, Ph.D., DrSc. Title: Utilization of modified polyethylenes as macroscopic ligands Termination of growing polyethylene (PE) chain by silane HSiR1 R2 R3 leads to polymers bearing chain-end silyl group (SiPE). These materials can be further modified to form polymers terminated by silanol group (PE-SiOH). Using suitable default conditions, a modified PE with relatively low molecular weight (Mn ~1000 Da) and useful solubility profile can be obtained. Due to the presence of reactive silanol or hydrosilane groups, such materials can serve as a support for grafting a wide range of metals. The aim of the thesis is to verify the possibility of grafting metals by chemical bonding on a modified PE (which in this particular case can be seen as a "slightly larger" ligand. Prepared materials will be tested with regard on their possible use in catalysis. This research is interdisciplinary at the border between inorganic (coordination chemistry) and physical chemistry (polymers, catalysis). Keywords: supported complexes, modified polyethylene, catalysis
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Synthesis of Chromenopyridines with the New All-Carbon Quaternary Centre
Sedláček, Patrik ; Matouš, Petr (advisor) ; Krátký, Martin (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Candidate: Patrik Sedláček Supervisor: PharmDr. Petr Matouš, Ph.D. Title of thesis: Synthesis of Chromeno[3,4-c]pyridines with New All-Carbon Quaternary Centre This diploma thesis focuses on the synthesis of 3,4-disubstituted pyridine derivatives and their subsequent cyclization to form chromeno[3,4-c]pyridine derivatives with a new all-carbon quaternary center. Phenyl-propiolate reacts with an aryl-substituted propargyl amine protected with 4- methoxybenzenesulfonyl group to form a 1,5-enyne. Substituted 1,5-enyne undergoes intramolecular cyclization catalyzed by tri(2-furyl)phosphinogold(I)chloride [AuCl(TFP)] to form the corresponding dihydropyridine. In the presenece of concentrated H2SO4, dihydropyridine undergoes carbocyclization forming the corresponding chromenopyridine with a new all-carbon quaternary center. The compounds prepared and their derivatives could find application as potentially biologically active substances and intermediates in organic synthesis.
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Ferrocene acylphosphines
Vosáhlo, Petr ; Štěpnička, Petr (advisor) ; Čermák, Jan (referee) ; Horáček, Michal (referee)
6 Abstract The Thesis is aimed at the synthesis of novel ferrocene-based acylphosphines of the type FcC(O)PR2 and R1 2PfcC(O)PR2 2 (Fc = ferrocenyl, fc = 1,1'-ferrocendiyl), evaluation of their electron-donating capabilities and steric demands. The impact of these features was scrutinized by further coordination and catalytical studies. First, a series of monodentate acylphosphine ligands FcC(O)PR2 was synthesized (PR2 = diphenylphosphino [PPh2], dicyclohexylphosphino [PCy2], di(1-adamantyl)phosphino [PAd2] a 1,3,5,7-tetramethyl-2,4,6-trioxa-8- phosphaadamantyl [PCg]), which underwent oxidation by elemental selenium to give corresponding phosphine selenides used to probe their electron-donating capabilities via measuring 1 JPSe coupling constant. Then, chlorogold complexes were prepared from these ligands to evaluate their catalytic activity in gold-catalysed hydration of alkynes and cyclization of N-propargylbenzamide. Second, the model compound FcC(O)PPh2 was extensively studied as a ligand in palladium(II) complexes. The ligand was smoothly ortho-metallated by Na2[PdCl4] to form chloro-bridged palladium(II) dimer, which reacted with P-, N- and C-donors under cleavage to give monopalladium complexes. One of these complexes, containing trimethylphosphine auxiliary ligand, was alkylated with organometallic...
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Polar ferrocene phosphines with nitrogen-containing linkers
Navrátil, Michal ; Štěpnička, Petr (advisor) ; Dostál, Libor (referee) ; Horáček, Michal (referee)
Title: Polar Ferrocene Phosphines with Nitrogen-Containing Linkers Author: RNDr. Michal Navrátil Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: This Ph.D. thesis describes three series of bridged ferrocene phosphines derived from aminoferrocene. The first series is comprised of homoannular α- and β-aminophosphines 1-3. The α-aminobis(phosphine) 1 was synthesized from aminoferrocene and (diphenylphosphino)- methanol via phospha-Mannich reaction in a 87% yield. This product was formed regardless of the reaction stoichiometry. Later, ligand 1 was utilized as a ligand for group 10 and 11 metal ions. With group 10 metal precursors, the ligand afforded five different square-planar complexes [MX2(1-κP)] (M/X = Ni/Cl, Pd/Cl, Pd/Br, Pd/I, Pt/Cl). In contrast, the complexes of group 11 metals showed varied geometry around the metal centre, ranging from a linear arrangement in [Au2Cl2(1-κP)], cyclic structure in [Au2(1-κP)2][SbF6]2 and tetrahedral arrangement in [M(1-κP)2][X] (M/X = Cu/BF4; Ag/SbF6; Au/SbF6). The cyclic voltammetry measurements suggested that Fe(II) oxidation is the first oxidation process. The attribution was corroborated by DFT calculations of 1 and [PdCl2(1-κP)]. To obtain the analogous monophosphine 2, aminoferrocene was N-methylated prior to the phospha-Mannich reaction. Subsequent...
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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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Mechanistic Insights into Reactive Zeolite-Water Interactions
Benešová, Tereza ; Heard, Christopher James (advisor) ; Maldonado Dominguez, Carlos Mauricio (referee)
Title: Mechanistic Insights into Reactive Zeolite-Water Interactions Author: Tereza Benešová Department: Department of Physical and Macromolecular Chemistry Supervisor: Christopher Heard, PhD. Abstract: An in silico investigation of zeolite-water interactions was undertaken using a combined static and dynamic approach within density functional theory. Two periodic models of zeolite chabazite were used, purely siliceous and aluminosilicate in order to explain the different behaviour of water near Si-O-Si and Al-O-Si bridges. One or two water molecules per supercell of the model were used, corresponding to experimental conditions of steaming. Under such conditions, water can interact with zeolites by non-reactive adsorption but also by reactive interactions such as hydrolysis and oxygen exchange between water and the framework. The main goal of the study was to explain oxygen exchange at an atomistic level. The viable mechanisms of oxygen exchange were established. These mechanisms are different for Si-O-Si and Al-O-Si bridges but for both of them oxygen exchange is initiated by partial hydrolysis of the framework. After this hydrolysis, oxygen exchange heals the framework while incorporating into it the oxygen that originated from the water. Both established mechanisms are competitive with non-exchange...
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