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General and Modular Synthesis of Isomeric 5-Substituted Pyridin-2-yl and 6-Substituted Pyridin-3-yl C-Ribonucleosides Bearing Diverse Alkyl, Aryl, Hetaryl, Amino, Carbamoyl, and Hydroxy Groups
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SYSNO ASEP 0364189 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title General and Modular Synthesis of Isomeric 5-Substituted Pyridin-2-yl and 6-Substituted Pyridin-3-yl C-Ribonucleosides Bearing Diverse Alkyl, Aryl, Hetaryl, Amino, Carbamoyl, and Hydroxy Groups Author(s) Štefko, Martin (UOCHB-X)
Slavětínská, Lenka (UOCHB-X) RID
Klepetářová, Blanka (UOCHB-X) RID, ORCID
Hocek, Michal (UOCHB-X) RID, ORCIDNumber of authors 4 Source Title Journal of Organic Chemistry. - : American Chemical Society - ISSN 0022-3263
Roč. 76, č. 16 (2011), s. 6619-6635Number of pages 17 s. Language eng - English Country US - United States Keywords nucleosides ; palladium-catalyzed amination ; C-2'-deoxyribonucleosides ; cytidine ; benzene Subject RIV CC - Organic Chemistry R&D Projects LC512 GA MŠMT - Ministry of Education, Youth and Sports (MEYS) IAA400550902 GA AV ČR - Academy of Sciences of the Czech Republic (AV ČR) CEZ AV0Z40550506 - UOCHB-X (2005-2011) UT WOS 000293759000016 DOI 10.1021/jo200949c Annotation A general modular and practical methodology for preparation of diverse 5-substituted pyridin-2-yl and 6-substituted pyridin-3-yl C-ribonucleosides was developed. Regioselective lithiation of 2,5-dibromopyridine proceeded at the position 5- or 2- depending on the solvent and the resulting bromopyridyl lithium species underwent additions to protected ribonolactone and further transformations to hemiketals that were diastereoselectively reduced to give either 5-bromopyridine-2-yl or 6-bromopyridine-3-yl silyl-protected C-ribonucleosides. These intermediates were then subjected to a series of cross-coupling reactions, aminations, aminocarbonylations and hydroxylations to give a series of protected 1beta-(5-alkyl-, 5-aryl-, 5-amino- 5-carbamoyl and 5-hydroxypyridin-2-yl)-C-ribonucleosides and beta-(6-alkyl-, 6-aryl-, 6-amino- 6-carbamoyl and 6-hydroxypyridin-3-yl)-C-ribonucleosides. Deprotection of silylated nucleosides by Et3N.3HF, TBAF or TFA gave a series of free C-nucleosides. Workplace Institute of Organic Chemistry and Biochemistry Contact asep@uochb.cas.cz ; Kateřina Šperková, Tel.: 232 002 584 ; Jana Procházková, Tel.: 220 183 418 Year of Publishing 2012
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