β- and γ-Disubstituted Olefins: Substrates for Copper-Catalyzed Asymmetric Allylic Substitution
作者:Caroline A. Falciola、Karine Tissot-Croset、Hugo Reyneri、Alexandre Alexakis
DOI:10.1002/adsc.200800086
日期:2008.5.5
The copper-catalyzed asymmetric allylic alkylation has shown through many examples that it is a powerful means to generate stereogenic centers with mono β- and γ-substituted olefinic substrates. However, little has been reported about more substituted olefinic patterns, such as β-disubstituted allylic electrophiles. In this paper, we show that a simple procedure using easily accessible Grignard reagents
铜催化的不对称烯丙基烷基化通过许多实例表明,它是用单β-和γ-取代的烯烃底物生成立体异构中心的有效手段。然而,关于更多取代的烯烃图案,例如β-二取代的烯丙基亲电试剂,几乎没有报道。在本文中,我们表明,使用容易获得的格氏试剂和低至3 mol%的铜/配体的简单程序可以促进高至近乎完美的对映选择性(高达> 99%ee),并且在很宽的范围内具有很好的γ选择性一组脂族或芳族β-二取代底物。