Department of Chemistry, University of California, Berkeley, California 94720, USA.
J Am Chem Soc. 2012 Sep 19;134(37):15249-52. doi: 10.1021/ja306850b. Epub 2012 Sep 11.
We report the regio- and enantioselective allylation of an ester enolate, trimethylsiloxyfuran. This enolate reacts at the 3-position with linear aromatic allylic carbonates or aliphatic allylic benzoates to form the branched substitution products in the presence of a metallacyclic iridium catalyst. This process provides access to synthetically important 3-substituted butenolides in enantioenriched form. Stoichiometric reactions of the allyliridium intermediate suggest that the trimethylsiloxyfuran is activated by the carboxylate leaving group.
我们报告了酯烯醇化物三甲基硅氧基呋喃的区域和对映选择性烯丙基化反应。在金属环铱催化剂的存在下，这种烯醇化物与线性芳香族烯丙基碳酸酯或脂肪族烯丙基苯甲酸酯在 3 位反应，形成支链取代产物。该过程提供了以手性富集形式合成重要的 3-取代丁烯内酯的途径。烯丙基铱中间体的化学计量反应表明，三甲基硅氧基呋喃被羧酸盐离去基团激活。
