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β-Cyclodextrin conjugates with selectively methylated rims
Lebedinskiy, Konstantin ; Jindřich, Jindřich (advisor) ; Lhoták, Pavel (referee) ; Kraus, Tomáš (referee)
β-Cyclodextrin conjugates with selectively methylated rims The current doctoral thesis focuses on studying cyclodextrin conjugates with selectively methylated rims and testing their potential applicability for solubility enhancement and guest- specific complexation. This work's principal aim is to develop new synthetic methods for the preparation of monofunctionalized β-cyclodextrin derivatives with selectively methylated rims and their further transformations into operating conjugates. The thesis is divided into four sections - preparation of monoazido-β-cyclodextrin derivatives with selectively methylated rims and some conjugates from them; direct transformation of the prepared azides into corresponding monoamines and monohalides that enables the synthesis of other types of conjugates; testing the potential of the prepared conjugates for tetracene solubility increase in different media and selective binding of one component from a mixture of steroid substances; finally, the work explores the complexation of some noradamantane molecules with natural cyclodextrins and the phenomenon of guest's signals splitting in their 13 C-NMR spectra. Keywords: cyclodextrin conjugates, bisCDs, selective methylation, selective binding, solubility enhancement
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Synthesis of cyclodextrin derivatives suitable for binding to solid supports
Kasal, Petr ; Jindřich, Jindřich (advisor) ; Kraus, Tomáš (referee) ; Lhoták, Pavel (referee)
Synthesis of cyclodextrin derivatives suitable for binding to solid supports This presented doctoral thesis studies the preparation of new cyclodextrin (CD) derivatives suitable for binding to solid supports. This work aims to develop synthetic protocols for monosubstituted and selectively persubstituted CD derivatives possessing permanent positive charges. These compounds have the potential to be electrostatically bound to negatively charged supports, including silica gel, alumina, Nafion® , cation exchange resins, etc. Compared to the covalent bond, the advantages of this electrostatic binding are mainly the easiness of modification and maintenance. Dipping solid support for a defined time into a solution of charged CD derivatives should ensure the bond between positively and negatively charged partners. Thus, this thesis is divided into several parts. The first part covers the preparation of neopentyl skeleton compounds (anchors) bearing positive charges suitable for ionic bonding with negatively charged solid supports, and a reactive functional group suitable for a reaction with CD derivatives. The first partially successful synthetic tries are described, together with various leaving groups kinetic studies performed by NMR spectroscopy. The final synthesis of anchors developed with potential...
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Selectively substituted cyclodextrins for analytical and pharmaceutical applications
Benkovics, Gábor ; Jindřich, Jindřich (advisor) ; Lhoták, Pavel (referee) ; Šindelář, Vladimír (referee)
3 Selectively substituted cyclodextrins for analytical and pharmaceutical applications Abstract This thesis is focused on the selective modification of cyclodextrins, and its primary aim is the preparation and characterization of mono- and persubstituted derivatives of cyclodextrins in a regioselective and straightforward manner. The work is divided into two main parts describing synthetic strategies and applications of modified cyclodextrins with one or several substituents, respectively. The first section deals with the introduction of a single chromophoric moiety on the cyclodextrin scaffold such as cinnamyl, rhodaminyl, fluoresceinyl and eosinyl groups. The complete set of monocinnamyl-α-cyclodextrin regioisomers has been prepared by direct alkylation, and the self-assembling properties of the corresponding regioisomers were thoroughly investigated by dynamic light scattering and NMR experiments. These investigations revealed that the different isomers (mono-6-O-, mono-2-O- and mono-3-O- cinnamyl-α-cyclodextrin) form distinct supramolecular species through intermolecular association. A fast method for the unambiguous identification of the pure regioisomers has also been developed based on a series of 2D NMR measurements. Xanthene-modified β-cyclodextrins, other representatives of monosubstituted...
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Synthesis of cyclodextrin derivatives for organocatalysis
Chena Tichá, Iveta ; Jindřich, Jindřich (advisor) ; Lhoták, Pavel (referee) ; Šindelář, Vladimír (referee)
Synthesis of cyclodextrin derivatives for organocatalysis This doctoral thesis examines the preparation of new cyclodextrin (CD) derivatives suitable for organocatalysis. The aim of this work is to prepare monosubstituted and disubstituted CD derivatives as organocatalysts for different types of enantioselective reactions potentially performed in water. In addition, disubstituted CD derivatives require considering the potential mixture of regioisomers and pseudoenantiomers. Thus, this thesis is divided into several sections - preparation of CD precursors and derivatives for organocatalysis, preparation of pure regioisomers and pseudoenantiomers of disubstituted CDs and final application of CD derivatives in enantioselective reactions. Furthermore, this thesis also focuses on the molecular modeling of the prepared CD derivatives and on their catalytic activity in silico. The first section covers the preparation of new disubstituted CD precursors as pure regioisomers for organocatalysts, specifically to develop a new method for the preparation of heterodisubstituted AC regioisomers on the primary rim of α-CD. This section also includes the determination of the regioisomer ratios of common α-CD intermediates disubstituted on the primary rim to evaluate their potential as precursors in organocatalysis....
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Selectively substituted cyclodextrins for analytical and pharmaceutical applications
Benkovics, Gábor ; Jindřich, Jindřich (advisor) ; Lhoták, Pavel (referee) ; Šindelář, Vladimír (referee)
3 Selectively substituted cyclodextrins for analytical and pharmaceutical applications Abstract This thesis is focused on the selective modification of cyclodextrins, and its primary aim is the preparation and characterization of mono- and persubstituted derivatives of cyclodextrins in a regioselective and straightforward manner. The work is divided into two main parts describing synthetic strategies and applications of modified cyclodextrins with one or several substituents, respectively. The first section deals with the introduction of a single chromophoric moiety on the cyclodextrin scaffold such as cinnamyl, rhodaminyl, fluoresceinyl and eosinyl groups. The complete set of monocinnamyl-α-cyclodextrin regioisomers has been prepared by direct alkylation, and the self-assembling properties of the corresponding regioisomers were thoroughly investigated by dynamic light scattering and NMR experiments. These investigations revealed that the different isomers (mono-6-O-, mono-2-O- and mono-3-O- cinnamyl-α-cyclodextrin) form distinct supramolecular species through intermolecular association. A fast method for the unambiguous identification of the pure regioisomers has also been developed based on a series of 2D NMR measurements. Xanthene-modified β-cyclodextrins, other representatives of monosubstituted...
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Synthesis and properties of monosubstituted derivatives of cyclodextrins
Řezanka, Michal ; Jindřich, Jindřich (advisor) ; Kraus, Tomáš (referee) ; Lhoták, Pavel (referee)
This Ph.D. thesis deals with synthesis of monosubstituted cyclodextrin derivatives and investigating their properties. Alkylation of -cyclodextrin with allyl or cinnamyl bromide followed by peracetylation of remaining hydroxyl groups and separation of isomers resulted in the set of peracetylated 2I - O-, 3I -O- and 6I -O-alkylated cyclodextrins in up to 27% yields. Oxidative cleaveage of peracetylated allyl or cinnamyl derivatives resulted in a complete set of peracetylated 2I -O-, 3I -O- and 6I -O- formylmethyl or carboxymethyl derivatives which are useful precursors for preparation of regioselectively monosubstituted derivatives of -cyclodextrin. Moreover, a quick method to recognize single 2I -O-, 3I -O- and 6I -O- monosubstituted peracetylated cyclodextrins from each other using only 1 H NMR spectrum has been proposed. Ru-carbene complex catalyzed cross-metathesis of monoallyl -, -, and -cyclodextrins with perfluoroalkylpropenes resulted in the formation of the corresponding perfluoroalkylated cyclodextrins. The reactions proceeded under standard reaction conditions and the desired compounds were obtained in reasonable yields. Dynamic light scattering measurements proved the ability of the prepared compounds to aggregate in water solution forming nanoparticles in the range of tens and...
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