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Syntéza modifikovaných fluorescenčních nukleosidů
Riedl, Jan ; Hocek, Michal
A series of modified nucleosides bearing the fluorescent substituted biaryl labels attached to nucleobase was prepared and their luminescent properties were evaluated. The modified nucleosides show strong fluorescence at ca. 400 nm when excited at 310 nm in water depending on substitution pattern.
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Syntéza (purin-6-yl)acetátů a jejich transformace
Hasník, Zbyněk ; Hocek, Michal
A novel approach to the synthesis of (purin-6-yl)acetates was developed based on Pd-catalysed cross-coupling reactions of 6-chloropurines with the Reformatsky agent. These intermediates were converted into various products by functional group transformations. Amides were prepared by amidation of ester group with amines, 6-(hydroxyethyl)purines by reduction by NaBH4, and beta-substituted 6-ethylpurines by mesylation of 6-(hydroxyethyl)purines and subsequent nucleophilic substitution.
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Přímá C-H arylace purinů a purinových nukleosidů
Čerňa, Igor ; Hocek, Michal
Direct C–H arylation of purines to position 8 by diverse aryl halides was achieved using Pd catalysis in the presence of CuI and Cs2CO3. The methodology was applied in consecutive regioselective synthesis of 2,6,8-trisubstituted purines bearing three different C-substituents in combination with two cross-coupling reaction. In addition, direct arylation of unprotected purine nucleosides with aryl iodides at position 8 was developed to allow straightforward single-step introduction of diverse aryl groups.
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Modulární syntéza 5-substituovaných thiofen-2-yl C-2'-deoxyribonukleosidů
Bárta, Jan ; Hocek, Michal
A new modular methodology for the preparation of 5-substituted thiophen-2-yl C-nucleosides was developed. A Friedel–Crafts-type of C-glycosidation of 2-bromothiophene with bis-toluoyl protected methylglycoside gave the desired bis-toluoyl protected 1-beta-(5-bromothiophen-2-yl)-1,2-dideoxyribofuranose in 60%. Deprotection of the protected product gave free bromothiophene C-nucleoside, which was reprotected to bis-TBDMS protected C-nucleoside. The key intermediates were then subjected to a series of palladium catalyzed cross-coupling reactions to afford, after suitable deprotection, a series of free C-nucleosides. Alternatively, other types of C-nucleosides were prepared directly by aqueous-phase Suzuki cross-coupling reactions of free C-nucleosides with boronic acids.
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Příprava modifikovaných nukleosidů, nukleotidů a oligonukleotidů nesoucích komplexy kovů
Vrábel, Milan ; Hocek, Michal
Series of modified nucleosides and oligonucleotides bearing metal complexes were synthetized. Palladium catalyzed aqueous-phase cross-coupling reactions were used as key step in the synthesis of modified metallo-labeled nucleosides, nucleotides and oligonucleotides. The corresponding Fc modified dNTPs were good sustrates for DNA polymerases and were efficiently incorporated to DNA by primer extension (PEX). The modified nucleic acids are applicable as tools in bioanalysis.
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Modulární metodiky pro přípravu různých aryl C-2'-deoxyribonukleosidů
Joubert, Nicolas ; Bárta, Jan ; Urban, Milan ; Hocek, Michal
A modular methodology for the syntheses of various substituted aryl C-2´-deoxyribonucleosides has been developed. In each series, a larger scale synthesis of a versatile halogenated C-nucleoside intermediate has been accomplished, followed by its use for a generation of diverse derivatives by displacement of the halogen for alkyl, aryl or amino substituents by cross-coupling or amination reactions. Subsequent deprotection gave the final desired C-2´-deoxyribonucleosides. This methodology has been applied for the development of modular syntheses of 4- or 3-substituted benzene C-nucleosides, 6-substituted pyridin-2-yl C-nucleosides, 6-substituted pyridin-3-yl C-nucleosides and 5-substituted thiophen-2-yl C-nucleosides.
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