Catalytic Asymmetric Synthesis of Secondary Nitriles via Stereoconvergent Negishi Arylations and Alkenylations of Racemic α-Bromonitriles
作者:Junwon Choi、Gregory C. Fu
DOI:10.1021/ja303442q
日期:2012.6.6
α-alkyl substituents; the first examples of the use of alkenylzinc reagents in stereoconvergent Negishi reactions of alkyl electrophiles; demonstration of the utility of a new family of ligands for asymmetric Negishi cross-couplings (a bidentate bis(oxazoline), rather than a tridentate pybox); in the case of arylzinc reagents, carbon-carbon bond formation at a remarkably low temperature (-78 °C), the lowest
描述了外消旋 α-卤腈的立体会聚交叉偶联的第一种方法,特别是镍催化的 Negishi 芳基化和烯基化,它们分别提供了一系列对映体富集的 α-芳基腈和烯丙腈。该研究的显着特点包括:具有二级α-烷基取代基的α-烷基-α-芳基腈的高度对映选择性合成;烯基锌试剂在烷基亲电试剂的立体聚合根岸反应中使用的第一个例子;展示新配体家族对不对称 Negishi 交叉偶联(双齿双(恶唑啉),而不是三齿 pybox)的效用;对于芳基锌试剂,在极低的温度(-78°C)下形成碳-碳键,迄今为止报道的最低的烷基亲电子试剂的对映选择性交叉偶联;未活化与活化仲烷基溴的 Negishi 反应之间的机械二分法。