Four new bidentate phosphine ligands have been synthesized, characterized and evaluated in Ni-catalyzed C-P coupling reaction. The readily available and inexpensive highly active sulfonate Ni(cod)(2)-L8catalyzes the reaction leading to the desired aryl phosphonates accumulated with moderate to excellent yields. This method is characterized by good functional groups tolerance, wide substrate scope, and easy scaling up.
The bulky and electron-rich MOP-type ligand was efficient for the Pd-catalyzed amination of aryl tosylates. The in situ generated Pd(0) was a more efficient catalyst precursor than Pd(dba)2. In the presence of Pd(OAc)2, PhB(OH)2, and a hindered and electron-rich MOP-type ligand, a variety of primary aryl amines reacted with various aryl tosylates to form the corresponding secondary aryl amines in high yields with high selectivity. Furthermore, the catalyst system was also efficient for the arylation of indoles and hydrazones with aryl tosylates.
Visible‐Light Photoredox‐Catalyzed and Copper‐Promoted Trifluoromethoxylation of Arenediazonium Tetrafluoroborates
作者:Shaoqiang Yang、Miao Chen、Pingping Tang
DOI:10.1002/anie.201901447
日期:2019.6.3
We report the development of photoredox‐catalyzed and copper‐promoted trifluoromethoxylation of arenediazonium tetrafluoroborates, with trifluoromethyl arylsulfonate (TFMS) as the trifluoromethoxylation reagent. This new method takes advantage of visible‐light photoredoxcatalysis to generate the aryl radical under mild conditions, combined with copper‐promoted selective trifluoromethoxylation. The
Four new bidentate phosphine ligands have been synthesized, characterized and evaluated in Ni-catalyzed C-P coupling reaction. The readily available and inexpensive highly active sulfonate Ni(cod)(2)-L8catalyzes the reaction leading to the desired aryl phosphonates accumulated with moderate to excellent yields. This method is characterized by good functional groups tolerance, wide substrate scope, and easy scaling up.