Heterocyclic Lithium Amides as Chiral Ligands for an Enantioselective Hydroxyalkylation with <i>n</i>-BuLi
作者:Nicolas Duguet、Sylvain M. Petit、Philippe Marchand、Anne Harrison-Marchand、Jacques Maddaluno
DOI:10.1021/jo8005396
日期:2008.7.1
Chiral heterocyclic structures based on 3-aminopyrrolidines (3APs), 3-aminotetrahydrothiophens (3ATTs), and 3-aminotetrahydrofurans (3ATFs) have been synthesized. The corresponding lithium amides have been evaluated as chiral ligands in the condensation of n-BuLi on o-tolualdehyde. The returned levels of induction were in the 46−80% ee range. The cheap and easily prepared 3ATFLi’s turned out to be
已经合成了基于3-氨基吡咯烷(3AP),3-氨基四氢噻吩(3ATT)和3-氨基四氢呋喃(3ATF)的手性杂环结构。在正丁基锂与邻甲苯甲醛的缩合反应中,相应的氨基酰胺锂已被评估为手性配体。返回的感应水平在46-80%ee范围内。事实证明,便宜且易于制备的3ATFLi也是最好的配体,可以在-78°C的THF中以相同的80%诱导水平获得预期的R或S醇。在所有情况下,感应的感觉都取决于C 8的绝对构型在3-氨基附肢上。提出了一个一般概念来合理化在有机锂物质存在下的诱导过程。