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Synthesis of Alkaloid-like Compounds with Quaternary Carbon Centers
Jansa, Petr ; Matoušová, Eliška (advisor) ; Baszczyňski, Ondřej (referee) ; Nováková, Veronika (referee)
Synthesis inspired by natural products has a long tradition in drug development. Because the structure of bioactive natural compounds is often very complex, preparation of their derivatives requires the development of specific synthetic procedures. This thesis focuses on derivatives of certain alkaloids from the Amaryllidaceae plant family as examples of such compounds. The thesis explores the possibilities of preparing polycyclic compounds that contain the structural motif present in tazettine, crinine, or mesembrine-type alkaloids. This motif includes a quaternary all-carbon center, for which a method involving a tandem cyclization/Suzuki coupling reaction and a halocarbocyclization was developed and optimized in this work. The scope of these reactions was studied, and variously substituted products containing oxygen and nitrogen cycles were prepared. Furthermore, methods for the synthesis of N-alkylated derivatives, dehydrohalogenation to form a double bond, or various mainly oxidative modifications of the cycle adjacent to the aromatic ring were developed. After developing a method for the preparation of enantiomerically enriched starting material, an asymmetric version of the entire synthesis was successfully performed. Finally, biological properties of selected compounds were studied. Some...
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Synthesis of analogues of natural alkaloids containing quaternary carbon centres
Sádková, Michaela ; Matoušová, Eliška (advisor) ; Baszczyňski, Ondřej (referee)
This bachelor thesis is concerned with organic synthesis of polycyclic compounds containing quarternary carbon centres, which are structurally similar to Amaryllidaceae and Sceletium alkaloids. The aim of this work was to prepare compounds suitable for biological activity screening. To obtain the quarternary carbon centre, two key steps were used - tandem cyclisation/Suzuki cross-coupling and halocarbocyclisation. The first part of this work is focused on the synthesis of starting materials with two types of silyl groups. The second part deals with the preparation of quarternary carbon centre using tandem cyclisation/Suzuki cross-coupling and halocarbocyclisation. In the last part, experiments to form a double bond are described, together with its derivatisation to synthesise compounds with a potential biological activity. Key words: synthesis, alkaloids, Amaryllidaceae, Sceletium, polycyclic compounds, quarternary carbon centres
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Using Heck reaction for aromatic ring formation in the synthesis of polycyclic compounds
Bažíková, Ema ; Matoušová, Eliška (advisor) ; Míšek, Jiří (referee)
This bachelor's thesis focuses on the synthesis of a polycarbocyclic compound with naphthalene core and the following oxidation to the corresponding ortho-naphthoquinone. The naphthalene and naphthoquinone skeleton can be found in many natural products with interesting biological properties. This thesis extends the scope of a method developed by our group for the synthesis of naturally occurring ortho-naphthoquinones. The key step of the synthesis was to form an aromatic ring using the Heck reaction. Keywords: synthesis, polycyclic compounds, naphthalenes, catalysis, Heck reaction
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Using levoglucosenone in the synthesis of naphthoquinone containing compounds
Neumannová, Johana ; Matoušová, Eliška (advisor) ; Baszczyňski, Ondřej (referee)
This bachelor thesis is focused on using levoglucosenone in the synthesis of the naphthoquinone containing compounds. Levoglucosenone is a versatile and easily available substance which can be prepared by pyrolysis of renewable cellulose-containing materials. The synthesis of the target compound begins with the preparation of the substrate for the tandem reaction (propargyl ether) in three steps. The following key steps of the synthesis include palladium-catalyzed tandem cyclization/Suzuki cross coupling and subsequent Heck reaction. Oxidation of the prepared methoxy-substituted naphthalene yields the o-naphthoquinone, which has a similar structure as some naturally occurring substances with naphthoquinone skeleton, e.g. mansonone D and populene C. Key words: Synthesis, naphthalenes, naphthoquinones, levoglucosenone, catalysis, polycyclic compounds
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Synthesis of five-membered ring analogues of Amaryllidaceae alkaloids
Kvapilová, Pavlína ; Matoušová, Eliška (advisor) ; Jindřich, Jindřich (referee)
This bachelor Thesis deals with the synthesis of polycyclic compounds containing all-carbon quaternary centres. Quaternary centres with a similar substitution as our target compounds can be found in some natural products. In particular, nitrogen-containing compounds, structurally related to Amaryllidaceae alkaloids, have been prepared in this work. For the construction of the all-carbon quaternary centre we used tandem cyclization/Suzuki cross-coupling and halocarbocyclisation reaction sequence. The first part of the Thesis is dedicated to compounds that have a nitrogen atom protected by a p-methoxybenzenesulfonyl group. In the second part we deal with the preparation of N-methyl derivatives of these compounds. The third part is dedicated to the synthesis of a protected amine from 2-oxazolidinone, which we have unsuccessfully used for the preparation of polycyclic compounds with a hydroxyethyl group on the nitrogen atom. Key words: Synthesis, Amaryllidaceae alkaloids, polycyclic compounds, biological activity
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Synthesis of polycyclic compounds containing quaternary carbon centers
Vašíček, Tomáš ; Matoušová, Eliška (advisor) ; Míšek, Jiří (referee)
In this diploma Thesis, a method for the preparation of polycarbocyclic compounds containing all-carbon quaternary centers embedded in triquinane skeleton was prepared. The key reaction sequence leading towards the preparation of these carbocycles was Pd-catalyzed tandem cyclization/Suzuki cross-coupling reaction followed by halocarbocyclization. In the first part of synthetic project, a model oxygen-containing polycyclic derivative was prepared. In the second part, 3 novel polycarbocyclic compounds containing all-carbon quaternary centers were successfully prepared. Synthetic procedure for the starting material required for the key reaction sequence was developed. This approach represents another pathway for the synthesis of polycarbocyclic natural products. Keywords: synthesis, polycyclic compounds, quaternary centers, catalysis
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