A series of novel sugar-modified derivatives of cytostatic 6-hetaryl-7-deazapurine ribonucleosides: 2′-C-methylribonucleosides, arabinonucleosides and 2′-deoxy-2′-fluoroarabinonucleosides bearing an alkyl, aryl and hetaryl group in position 6 were prepared by palladium catalyzed cross-coupling reactions of corresponding (protected) 6-chloro-(7-fluoro)-7-deazapurine nucleosides with (het)arylboronic, hetarylstannanes and trimethylaluminium eventually followed by deprotection. Key intermediate 6-chloro-7-deazapurine 2′-C-methyl-β-D-ribofuranoside was prepared via a stereoselective nucleobase anion glycosylation with toluoyl-protected 1,2-anhydro-2-C-methylribofuranose. The 1,2-anhydro sugar was synthesized in 3 steps starting from readily available 2-C-methylribonolactone. The 6-chloro-7-deazapurine arabinofuranoside intermediate was obtained by epimerization from 3′,5′-protected 6-chloro-7-deazapurine ribofuranoside via 2′-hydroxyl oxidation followed by reduction. None of the prepared compounds showed any considerable cytostatic or antiviral activity.
一系列新型糖基修饰的细胞毒性6-杂环-7-脱氮嘌呤核苷衍生物:2'-C-甲基核糖核苷、阿拉伯核苷和带有烷基、芳基和杂芳基团的位置6的2'-脱氧-2'-氟阿拉伯核苷,通过钯催化的相应(受保护的)6-氯(7-氟)-7-脱氮嘌呤核苷与(杂)芳基硼、杂芳基锡烷和三甲基铝的交叉偶联反应制备,最终通过去保护反应得到。关键中间体6-氯-7-脱氮嘌呤2'-C-甲基-β-D-核糖呋喃苷通过具有立体选择性的核碱基负离子糖基化与对甲苯基保护的1,2-脱氧-2'-C-甲基核糖呋喃糖制备而成。1,2-脱氧糖在3步合成,起始原料为易得的2-C-甲基核糖内酯。6-氯-7-脱氮嘌呤阿拉伯呋喃苷中间体通过从3′,5′-保护的6-氯-7-脱氮嘌呤核糖苷经2'-羟基氧化再还原而获得。所有制备的化合物均未显示出明显的细胞毒性或抗病毒活性。