铜(I)催化的不对称烯丙基还原可实现S N 2'形式的氢化物亲核试剂的区域和立体选择性转移到烯丙基溴上。这种转变代表了与碳亲核试剂进行烯丙基取代反应的概念上正交的方法。基于手性N-杂环卡宾(NHC)配体的铜(I)配合物可使立体选择性达到99%ee。不管起始材料的双键构型如何,该催化剂都能进行立体收敛反应。
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)。
Copper-Catalyzed Asymmetric Allylic Substitution of Allyl Phosphates with Aryl- and Alkenylboronates
The asymmetricallylicsubstitution of allylphosphates with aryl‐ and alkenylboronates catalyzed by a copper/N‐heterocyclic carbene complex was developed and the γ‐substitution products were obtained with high enantioselectivity (see scheme). To account for the observed influence of the reaction parameters a possible catalytic cycle for this process was proposed.
作者:Damien Polet、Xavier Rathgeb、Caroline A. Falciola、Jean-Baptiste Langlois、Samir El Hajjaji、Alexandre Alexakis
DOI:10.1002/chem.200801879
日期:2009.1.19
We describe herein the development of the first iridium‐catalyzed allylic substitution using arylzinc nucleophiles. High enantioselectivities were obtained from the reactions, which used commercially available Grignardreagents as the starting materials. This methodology was also shown to be compatible with halogen/metal exchange reactions. Its synthetic potential is demonstrated by its application
Iridium-Catalyzed Asymmetric Allylic Substitution with Aryl Zinc Reagents
作者:Alexandre Alexakis、Samir El Hajjaji、Damien Polet、Xavier Rathgeb
DOI:10.1021/ol0713842
日期:2007.8.1
Thanks to iridium catalysis, arylzinc reagents undergo regioselective allylic substitution with very high enantioselectivity, when associated with phosphoramidite ligands.
Enantioselective Copper-Mediated Allylic Substitution with Grignard Reagents Employing a Chiral Reagent-Directing Leaving Group
作者:Bernhard Breit、Daniel Breuninger
DOI:10.1055/s-2004-831247
日期:——
Enantioselective copper-mediated allylic substitution with Grignard reagents was achieved employing the ortho-diphenylphosphanylferrocene carboxylate (o-DPPF) system as a planar chiral reagent-directing leaving group. Careful optimization of reaction parameters resulted in excellent regioselectivities and enantioselectivies of up to 95% ee.
利用邻二苯基膦酰二茂铁羧酸酯(邻DPPF)体系作为平面手性试剂导向离去基团,实现了铜介导的烯丙基取代格氏试剂的对映体选择性。通过对反应参数的精心优化,获得了极佳的区域选择性和高达 95% ee 的对映选择性。