Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 2, CZ-16610 Prague 6, Czech Republic.
Molecules. 2020 Sep 19;25(18):4307. doi: 10.3390/molecules25184307.
An efficient route to acylated acyclic nucleosides containing a branched hemiaminal ether moiety is reported via three-component alkylation of -heterocycle (purine nucleobase) with acetal (cyclic or acyclic, variously branched) and anhydride (preferentially acetic anhydride). The procedure employs cheap and easily available acetals, acetic anhydride, and trimethylsilyl trifluoromethanesulfonate (TMSOTf). The multi-component reaction is carried out in acetonitrile at room temperature for 15 min and provides moderate to high yields (up to 88%) of diverse acyclonucleosides branched at the aliphatic side chain. The procedure exhibits a broad substrate scope of -heterocycles and acetals, and, in the case of purine derivatives, also excellent regioselectivity, giving almost exclusively -9 isomers.
通过 -杂环（嘌呤核苷碱基）与缩醛（环状或非环状，各种支化）和酸酐（优先使用乙酸酐）的三组分烷基化，报道了含有支化半缩醛醚部分的酰化非环状核苷的有效途径。该程序采用廉价且易于获得的缩醛、乙酸酐和三甲基甲硅烷基三氟甲磺酸酯（TMSOTf）。多组分反应在乙腈中于室温下进行 15 分钟，提供了具有中等至高收率（高达 88%）的各种在脂肪侧链支化的非环核苷。该程序显示了 -杂环和缩醛的广泛底物范围，并且对于嘌呤衍生物，还具有极好的区域选择性，几乎只得到 -9 异构体。
