Palladium-Catalyzed Reductive Coupling Reaction of Terminal Alkynes with Aryl Iodides Utilizing Hafnocene Difluoride as a Hafnium Hydride Precursor Leading to <i>trans</i>
-Alkenes
作者:Keita Takahashi、Yohei Ogiwara、Norio Sakai
DOI:10.1002/asia.201701775
日期:2018.4.4
Herein, we describe a reductive cross‐coupling of alkynes and aryl iodides by using a novel catalytic system composed of a catalytic amount of palladium dichloride and a promoter precursor, hafnocene difluoride (Cp2HfF2, Cp=cyclopentadienyl anion), in the presence of a mild reducing reagent, a hydrosilane, leading to a one‐pot preparation of trans‐alkenes. In this process, a series of coupling reactions
在本文中,我们描述了通过使用新型催化体系(包括催化量的二氯化钯和助催化剂前体二茂fluor二氟化物(Cp 2 HfF 2,Cp =环戊二烯基阴离子)组成的炔烃和碘代芳烃的还原性交叉偶联。一种温和的还原剂,氢硅烷,可以一锅制备反式烯烃。在此过程中,一系列的偶联反应通过以下三个步骤有效地进行:(i)由二茂ha和氢硅烷初步形成initial氢化物,(ii)随后向炔烃加氢卤化,以及(iii)烯基ha物种变成钯络合物。该还原偶联可化学选择用于制备具有各种官能团(例如烷基,卤素,酯,硝基,杂环,硼酸酯和内部炔烃)的反式烯烃。