Liu Haijuan, Laporte Adrien G, Tardieu Damien, Hazelard Damien, Compain Philippe
Laboratoire d'Innovation Moléculaire et Applications (LIMA), Univ. de Strasbourg | Univ. de Haute-Alsace | CNRS (UMR 7042), Equipe de Synthèse Organique et Molécules Bioactives (SYBIO), ECPM, 25 Rue Becquerel, 67000 Strasbourg, France.
J Org Chem. 2022 Oct 7;87(19):13178-13194. doi: 10.1021/acs.joc.2c01635. Epub 2022 Sep 12.
The intermolecular C-O coupling reaction of 1,4-quinones with -glycals under iron hydride hydrogen atom transfer (HAT) conditions is described. This method provides a direct and regioselective access to a wide range of phenolic -ketosides related to biologically relevant natural products in diastereomeric ratios up to >98:2 in the furanose and pyranose series. No trace of the corresponding -glycosylated products that might have resulted from the radical alkylation of 1,4-quinones was observed. The results of mechanistic experiments suggest that the key C-O bond-forming event proceeds through an oxidative radical-polar crossover process involving a single-electron transfer between the HAT-generated glycosyl radical and the electron-acceptor quinone.
描述了在氢化铁氢原子转移（HAT）条件下1,4-醌与-糖苷发生的分子间碳-氧偶联反应。该方法提供了一种直接且区域选择性地获得各种与具有生物学相关性的天然产物相关的酚类-酮糖苷的途径，在呋喃糖和吡喃糖系列中，非对映体比例高达>98:2。未观察到1,4-醌自由基烷基化可能产生的相应-糖基化产物的痕迹。机理实验结果表明，关键的碳-氧键形成过程是通过氧化自由基-极性交叉过程进行的，该过程涉及HAT产生的糖基自由基与电子受体醌之间的单电子转移。
