Ruthenium-Catalyzed Oxidative Homo-Coupling of 2-Arylpyridines
作者:Xiangyu Guo、Guojun Deng、Chao-Jun Li
DOI:10.1002/adsc.200900375
日期:2009.9
A ruthenium-catalyzedoxidativehomo-coupling reaction of 2-arylpyridines via CH activation was developed. The reaction could tolerate various functional groups on both the aryl and the pyridyl rings to afford a series of dimerized products with iron(III) chloride (FeCl3) as a stoichiometric oxidant. A tentative mechanism was proposed for this oxidative CH/CH homo-coupling.
Tetraalkylammonium-based ionic liquids for a RuCl3 catalyzed C–H activated homocoupling
作者:Maren Muntzeck、Felix Pippert、René Wilhelm
DOI:10.1016/j.tet.2020.131314
日期:2020.7
[BuEt3N][NTf2] can be a superior ionic liquid in a RuCl3 catalyzed oxidative C-H activation reaction compared to standard imidazolium-based ionic liquids. The tetraalkylammonium-based ionic liquid resulted in higher yields. This could be due to the absence of a possible C-H activation on the tetraalkylammonium-based ionic liquid itself. This side reaction could occur with imidazolium-based ionic liquids. The ionic liquid could be recycled and different oxidation agents could be used in the reaction. The best results were obtained with FeCl3 center dot 6H(2)O and with a combination of LiCl under an oxygen atmosphere. Up to 83% yield were obtained in the homocoupling of 2-arylpyridines. (C) 2020 Elsevier Ltd. All rights reserved.