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Synthesis of novel helquats and their properties
Joshi, Vishwas ; Teplý, Filip (advisor) ; Šindelář, Vladimír (referee) ; Míšek, Jiří (referee)
The subject of this thesis comprises synthesis of novel helquats, exploration of their different properties, such as nonlinear optical properties, target-specific fluorescence light-up properties, molecular recognition properties (including chiral recognition of dsDNA using enantiopure helquat dyes) and their applicability based on these properties. Four novel helquats containing activated methyl groups were synthesized and one of the synthesized helquats has been successfully resolved in gram scale into two separate enantiomers for further applications. Synthesis of functionalized helquat derivatives employing Knoevenagel condensation reaction between helquats having activated methyl groups and various substituted aromatic and heteroaromatic aldehydes has been developed. This methodology opened an easy access to a structurally diverse library of more than 500 compounds via chromatography-free purifications in moderate to high yield. Members of this compound library have been explored in various directions: as novel nonlinear optical chromophores, target-specific fluorescence light-up probes for recognition of targets like heparin and dsDNA. Few helquat derivatives have shown fluorescence light-up in presence of AT-rich DNA sequences. This feature has been further studied in detail using various...
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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 of novel helquats and their properties
Joshi, Vishwas ; Teplý, Filip (advisor) ; Šindelář, Vladimír (referee) ; Míšek, Jiří (referee)
The subject of this thesis comprises synthesis of novel helquats, exploration of their different properties, such as nonlinear optical properties, target-specific fluorescence light-up properties, molecular recognition properties (including chiral recognition of dsDNA using enantiopure helquat dyes) and their applicability based on these properties. Four novel helquats containing activated methyl groups were synthesized and one of the synthesized helquats has been successfully resolved in gram scale into two separate enantiomers for further applications. Synthesis of functionalized helquat derivatives employing Knoevenagel condensation reaction between helquats having activated methyl groups and various substituted aromatic and heteroaromatic aldehydes has been developed. This methodology opened an easy access to a structurally diverse library of more than 500 compounds via chromatography-free purifications in moderate to high yield. Members of this compound library have been explored in various directions: as novel nonlinear optical chromophores, target-specific fluorescence light-up probes for recognition of targets like heparin and dsDNA. Few helquat derivatives have shown fluorescence light-up in presence of AT-rich DNA sequences. This feature has been further studied in detail using various...
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Synthesis of cyclodextrin derivatives for practical applications
Popr, Martin ; Jindřich, Jindřich (advisor) ; Kraus, Tomáš (referee) ; Šindelář, Vladimír (referee)
Synthesis of cyclodextrin derivatives for practical applications Abstract The first part of this PhD thesis is focused on the synthesis of a series of monosubstituted tetraalkylammonium cyclodextrin (CD) derivatives. The emphasis was placed on the possible applicability of the synthetic process to multigram or even industrial scale. Monotosylation of the native cyclodextrins (-, -, -) on the primary side of the macrocycle afforded the starting materials. Derivatives with one cationic group were prepared by the reaction with aqueous trimethylamine. The reaction of the mono-Ts-CD with neat N,N,N'-trimethylethane-1,2-diamine or N,N,N'-trimethylpropane-1,3-diamine and subsequent methylation led to derivatives with the substituent bearing two cationic groups (PEMEDA- and PEMPDA-β-CD). Analogs bearing a moiety with three tetraalkylammonium sites were synthesized by reaction of mono-Ts-CD with bis(3-aminopropyl)amine with subsequent methylation. 1,3-Dipolar cycloaddition of mono-6- azido--CD with diaminoacetylenes followed by methylation led to analogs with a avariable distance of the charged substituent from the CD core. Majority of the presented reactions are straightforward, relatively high-yielding and the workup does not require chromatographic steps. The second part of the work is dealing with the...
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