Pd-Catalyzed Homo Cross-Dehydrogenative Coupling of 2-Arylpyridines by Using I2 as the Sole Oxidant
作者:Chao-Jun Li、Wenbo Liu、Youquan Zhu
DOI:10.1055/s-0035-1561399
日期:——
rationalize this homo CDC reaction. A palladium-catalyzed homo cross-dehydrogenative coupling (CDC) of 2-arylpyridines via C–Hactivation is described. This reaction employs I2 as the sole oxidant without any other additives, which complements the hypervalent iodine chemistry, such as of phenyliodonium diacetate (PIDA) or IOAc, in C–Hactivation research field. A tentative mechanism involving a Pd(II)–Pd(IV)
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.
Ruthenium-Catalyzed Reductive Cleavage of Unstrained Aryl–Aryl Bonds: Reaction Development and Mechanistic Study
Cleavage of carbon-carbon bonds has been found in some important industrial processes, e.g. petroleum cracking, and has inspired development of numerous synthetic methods. However, non-polar unstrained C(aryl)-C(aryl) bonds remain one of the toughest bonds to be activated. As a detailed study of a fundamental reaction mode, here a full story is described about our development of a Ru-catalyzed reductive
AbstractA method for the synthesis of 2‐aryl‐N‐heterocyclic dimers via a cross‐dehydrogenative homocoupling (homo‐CDC) has been developed using commercially available Ruthenium on charcoal as catalyst and iron trichloride as oxidant. A large variety of heterocyclic scaffolds and functional groups are tolerated and a complete regioselectivity resulting from the activation of the less sterically hindered C−H bonds was observed for meta‐substituted substrates. Starting from several homocoupling products obtained, a series of pyridine‐borane complexes was synthesized and the impact of the dimerization on their photophysical properties was studied and rationalized using theoretical calculations.