Copper-Free Asymmetric Allylic Alkylation with Grignard Reagents
作者:Olivier Jackowski、Alexandre Alexakis
DOI:10.1002/anie.201000577
日期:2010.4.26
Open wide and say AAA: The copper‐free asymmetric allylicalkylation reaction of Grignardreagents, catalyzed by N‐heterocyclic carbenes, is reported for allyl bromide derivatives. This reaction offers good enantioselectivity and good to excellent γ regioselectivity, particularly for the formation of quaternary chiral centers (see scheme; Mes=mesityl).
张开嘴说AAA:据报道,N-杂环卡宾催化了格氏试剂的无铜不对称烯丙基烷基化反应,是烯丙基溴衍生物的反应。该反应提供了良好的对映选择性和良好的至优异的γ区域选择性,特别是对于形成四元手性中心(参见方案; Mes =甲磺酰基)。
Generation of Allylmagnesium Reagents by Hydromagnesiation of 2‐Aryl‐1,3‐dienes
Magnesium hydride, generated in situ by solvothermal treatment of sodium hydride and magnesium iodide in tetrahydrofuran, was found capable of inducing regio and stereocontrolled hydromagnesiation of 2-aryl-1,3-dienes to form allylmagnesium species. Downstream functionalization of the resulting allylmagnesium species with various electrophiles provided synthetically valuable synthons such as homoallylic