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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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I. Synthesis and Application of N-Silyloxy Enamines II. Helquats: Synthesis and Properties
Sonawane, Manoj Rambhau ; Teplý, Filip (advisor) ; Dvořák, Dalimil (referee) ; Veselý, Jan (referee)
1. Abstract The work reported in this thesis is divided into two parts. In the first part, the chemistry of N-silyloxy enamine is discussed. The introductory section contains a brief overview of enamines, N,N-bis(silyloxy)enamines and N-silyloxy enamines, including their preparation, reactivity as well as comparison of their nucleophilicity with enolates and silyl enol ethers. Enamines in aldol reactions and synthetic challenges of asymmetric cross-aldol reactions are briefly discussed. The results and discussion section describes the synthesis of N-silyloxy enamines derived from aldehydes and use of N-(trimethylsilyloxy)enamines as new aldehyde enolate synthons for general, efficient and diastereoselective aldol-type reaction with dimethyl acetals and ketals. Also the syn-diastereoselectivity in β-methoxy nitrone products and their conversion to respective β-methoxy aldehydes is mentioned. Furthermore, synthesis of N-methyl-N-(trimethylsilyloxy)enamines from ketones is reported. In the second part, synthesis of new symmetric and non-symmetric helquats is reported. In the introductory section a brief overview of N-heteroaromatic cations including their natural occurrence and synthetic aspects as well as their applications in organocatalysis, molecular biology is discussed. Helicenes, viologens,...
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Enantioseparation and estimation of racemization barriers of selected helquats and their derivatives by capillary electrophoresis using sulfated cyclodextrins as chiral selectors
Sázelová, Petra ; Koval, Dušan ; Severa, Lukáš ; Reyes Gutierrez, Paul Eduardo ; Jirásek, Michael ; Teplý, Filip ; Kašička, Václav
Anionic highly sulfated β- and γ-cyclodextrins (S-CDs) and single-isomer heptakis-(2,3-diacetyl-6-sulfato)-β-CD (14Ac-7S-β-CD) were used for chiral separation of [5], [6] and [7]-ring helquats and helquat styryl dyes by capillary electrophoresis (CE) in the background electrolyte composed of 22 mM NaOH/35 mM H3PO4, pH 2.4. The CE method was applied for monitoring of racemization of eight helquats and helical dyes. Rate constant k of conversion, half-life T1/2 of racemization, and activation Gibbs free energy ΔGǂ of interconversion of one enantiomer into the other were calculated from the dependence of natural logarithm of enantiomeric excess (ee) on time using linear regression analysis.
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Affinity capillary electrophoresis applied to chiral separations of diquats and to determination of the stability constants of their complexes with sulfated cyclodextrins
Kašička, Václav ; Bílek, Jan ; Koval, Dušan ; Sázelová, Petra ; Talele, Harish Ramesh ; Severa, Lukáš ; Reyes Gutierrez, Paul Eduardo ; Teplý, Filip
Affinity capillary electrophoresis (ACE) using an aqueous 22/35 mM sodium/phosphate buffer, pH 2.5, as the background electrolyte (BGE), and 6 mM randomly highly sulfated alpha-, beta- and gamma-cyclodextrins (CDs) as chiral selectors has been successfully applied for separation of (P)- and (M)-enantiomers of a series of eleven new diquats (DQs) and for estimation of the strength of their complexes with the above CDs. The apparent stability constants of the DQs-CDs complexes were determined from the simultaneous ACE measurements of the dependence of effective electrophoretic mobilities of (P)- and (M)-enantiomers of DQs on the concentrations of CDs in the BGE by nonlinear regression analysis. The DQs enantiomers formed strong complexes with all three types of CDs with the apparent stability constants in the range (7.80 547.4) × 103 L/mol.
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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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I. Synthesis and Application of N-Silyloxy Enamines II. Helquats: Synthesis and Properties
Sonawane, Manoj Rambhau ; Teplý, Filip (advisor) ; Dvořák, Dalimil (referee) ; Veselý, Jan (referee)
1. Abstract The work reported in this thesis is divided into two parts. In the first part, the chemistry of N-silyloxy enamine is discussed. The introductory section contains a brief overview of enamines, N,N-bis(silyloxy)enamines and N-silyloxy enamines, including their preparation, reactivity as well as comparison of their nucleophilicity with enolates and silyl enol ethers. Enamines in aldol reactions and synthetic challenges of asymmetric cross-aldol reactions are briefly discussed. The results and discussion section describes the synthesis of N-silyloxy enamines derived from aldehydes and use of N-(trimethylsilyloxy)enamines as new aldehyde enolate synthons for general, efficient and diastereoselective aldol-type reaction with dimethyl acetals and ketals. Also the syn-diastereoselectivity in β-methoxy nitrone products and their conversion to respective β-methoxy aldehydes is mentioned. Furthermore, synthesis of N-methyl-N-(trimethylsilyloxy)enamines from ketones is reported. In the second part, synthesis of new symmetric and non-symmetric helquats is reported. In the introductory section a brief overview of N-heteroaromatic cations including their natural occurrence and synthetic aspects as well as their applications in organocatalysis, molecular biology is discussed. Helicenes, viologens,...
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Modular synthesis of N-heteroaromatic cations by (2+2+2) cycloaddition
Čížková, Martina ; Teplý, Filip (advisor) ; Kotora, Martin (referee) ; Potáček, Milan (referee)
5 Abstract N-Heteroaromatic cations represent a family of compounds with diverse application potentials including natural products, DNA probes, fluorescence dyes, herbicides, ionic liquids, organocatalysts, etc. The preparation of these species proceeds mainly through N-alkylation which is used mostly as a last step of the synthetic sequence. Only limited diversity of cationic substrates can be achieved with this manner, hence, searching for other methods leading to novel Nheteroaromatic cations is of great interest. Some examples of transition metal-catalyzed transformations on organic cations have appeared over the last two decades including Suzuki- Miyaura reaction, Sonogashira and Stille coupling, oxidative homocoupling, ring-closing metathesis, etc. Here, the successful construction of new N-heteroaromatic cations by [2+2+2] cycloaddition is presented. A methodology for the synthesis of novel pyridine-type organic monocations was developed using gaseous acetylene as a reaction partner in the cyclization step. Subsequently, the double [2+2+2] cycloaddition was utilized for the preparation of oligo-p-phenylenes with two to seven para connected phenylene units. Furthermore, the intramolecular version of the cyclization step led to two helical and four linear dications which can be considered as extended...
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Helquats - modular synthesis and properties of new helical dications.
Vávra, Jan ; Teplý, Filip (advisor) ; Jindřich, Jindřich (referee) ; Kvíčala, Jan (referee)
Charles University Faculty of Science Department of Organic and Nuclear Chemistry Mgr. Jan Vávra Helquats - Modular synthesis and properties of novel helical dications PhD. Thesis Synopsis Supervisor: Mgr. Filip Teplý, PhD. Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i. Prague 2010 Obsah / Contents 1. ÚVOD.............................................................................................................4 2. INTRODUCTION..................................................................................................7 3. CÍL DIZERTAČNÍ PRÁCE....................................................................................... 10 4. THE AIM OF THE WORK ....................................................................................... 11 5. VÝSLEDKY A DISKUZE......................................................................................... 12 6. RESULTS AND DISCUSSION .................................................................................. 15 7. ZÁVĚR.......................................................................................................... 18 8. CONCLUSION .................................................................................................. 19 9. SEZNAM PUBLIKACÍ A KONFERENČNÍCH PŘÍSPĚVKŮ / LIST OF...
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