Cyclization by Intramolecular Carbolithiation of Alkyl- and Vinyllithiums Prepared by Reductive Lithiation: Surprising Stereochemistry in the Lithium Oxyanion Accelerated Cyclization
作者:Kai Deng、Ahlem Bensari、Theodore Cohen
DOI:10.1021/ja027988c
日期:2002.10.1
yield cyclopentylmethyllithiums by unconjugated organolithiums is greatly increased (1) by generating the organolithiums by reductive lithiation of phenyl thioethers with aromatic radical anions and (2) by using allylic or homoallylic alcohol groups on the receiving alkene. This type of reductive lithiation allows virtually any kind of organolithium to be generated, usually in a connective manner.
简单烯烃的分子内碳锂化以通过未共轭有机锂产生环戊基甲基锂的多功能性大大增加(1)通过苯基硫醚与芳香基阴离子的还原锂化产生有机锂和(2)通过在接收烯烃上使用烯丙醇或高烯丙醇基团。这种类型的还原锂化几乎可以生成任何种类的有机锂,通常以连接方式生成。此外,烯烃上的烯丙基或均烯丙基锂氧阴离子基团极大地加速了反应并在大多数情况下导致在 -78 度下完全立体选择性环化。最重要的是,反式立体选择性与有机金属为烯丙基时观察到的相反。通过这种方法也生成了四元环。