A series of biaryls and biheteroaryls were synthesized by the Barbierreaction of aryl bromide with magnesium powder and 1,2‐dibromoethane in the presence of FeCl3 in THF under reflux reaction condition. The catalytic system differentiates itself from other homocouplingreactionscatalyzed by iron salts in that it requires neither the preliminary preparation of Grignard reagent nor the addition of
Tetrasubstituted Olefin Synthesis via Pd-Catalyzed Addition of Arylboronic Acids to Internal Alkynes Using O<sub>2</sub> as an Oxidant
作者:Chengxiang Zhou、Richard C. Larock
DOI:10.1021/jo060104d
日期:2006.4.1
alkynes provides a convenient route to a wide variety of tetrasubstituted olefins. The reaction is conducted in DMSO using molecular O2 as an oxidant in the absence of any base. The reaction involves the cis addition of two aryl groups from the arylboronic acid to opposite ends of the triple bond of the internal alkyne. The synthesis tolerates a wide variety of functional groups, including alcohol, aldehyde
Recyclable and reusable Pd(OAc)<sub>2</sub>/PPh<sub>3</sub>/PEG-2000 system for homocoupling reaction of arylboronic acids under air without base
作者:Jianhui Xia、Mingzhu Cheng、Qiurong Chen、Mingzhong Cai
DOI:10.1002/aoc.3254
日期:2015.2
A stable and efficient Pd(OAc)2/PPh3/PEG‐2000 catalytic system for homocoupling of arylboronicacids has been developed. In the presence of Pd(OAc)2 and PPh3, the homocouplingreaction of arylboronicacids was carried out smoothly in PEG‐2000 at 70 °C underairwithoutbase to afford a variety of symmetric biaryls in good to excellent yields. The isolation of the products was readily performed by extraction
A Copper-Catalyzed Reductive Defluorination of β-Trifluoromethylated Enones via Oxidative Homocoupling of Grignard Reagents
作者:Xiaoting Wu、Fang Xie、Ilya D. Gridnev、Wanbin Zhang
DOI:10.1021/acs.orglett.8b00379
日期:2018.3.16
An efficient copper-catalyzed reductive defluorination of β-trifluoromethylated enones via an oxidative homocoupling of Grignard reagents is reported. The reaction proceeded smoothly with a wide range of substrates, including the ones bearing aromatic heterocycles, such as furyl and thienyl ring systems in high yields (80–92%, except one example) under mild conditions. This provides a practical method