Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
Science. 2020 Jan 31;367(6477):559-564. doi: 10.1126/science.aaz3855.
Stereochemical control in the construction of carbon-carbon bonds between an alkyl electrophile and an alkyl nucleophile is a persistent challenge in organic synthesis. Classical substitution reactions via S1 and S2 pathways are limited in their ability to generate carbon-carbon bonds (inadequate scope, due to side reactions such as rearrangements and eliminations) and to control stereochemistry when beginning with readily available racemic starting materials (racemic products). Here, we report a chiral nickel catalyst that couples racemic electrophiles (propargylic halides) with racemic nucleophiles (β-zincated amides) to form carbon-carbon bonds in doubly stereoconvergent processes, affording a single stereoisomer of the product from two stereochemical mixtures of reactants.
在有机合成中，构建烷基亲电试剂和烷基亲核试剂之间的碳-碳键时的立体化学控制是一个持久的挑战。通过 S1 和 S2 途径的经典取代反应在生成碳-碳键（由于重排和消除等副反应，范围不足）和控制立体化学方面的能力有限，尤其是从易得的外消旋起始原料开始时（得到外消旋产物）。在这里，我们报告了一种手性镍催化剂，它将外消旋亲电试剂（炔丙基卤化物）与外消旋亲核试剂（β-锌化酰胺）偶联，在双重立体协同过程中形成碳-碳键，从两个反应物的立体化学混合物中得到产物的单一立体异构体。
