Regioselective Tandem C-H Alkylation/Coupling Reaction of ortho-Iodophenylethylenes via C,C-Pallada(II)cycles was written by Zhu, Bin-Bin;Ye, Wen-Bo;He, Zhi-Tao;Zhang, Shu-Sheng;Feng, Chen-Guo;Lin, Guo-Qiang. And the article was included in ACS Catalysis in 2021.Application of 823-61-0 This article mentions the following:
Five-membered C,C-pallada(II)cycles are a unique class of diorganopalladium species with favorable stability and an electron-rich nature, leading to efficient sequential reactions with diverse electrophiles and nucleophiles. Specifically, the development of aryl-alkenyl-palladacycle-based transformations could provide an attractive approach with regio- and stereocontrol for the construction of multifunctionalized arylethylenes. However, currently, the C,C-pallada(II)cycle formation relies on a rigid skeleton or steric congestion in the backbone to promote cyclopalladation, and the formation of aryl-alkenyl-palladacycle without an α-substituent has not been achieved. Furthermore, reactions that could discriminate between the two sp2 carbon centers of such C(sp2),C(sp2)-palladacycle remain elusive. Herein, a regioselective three-component tandem alkylation/coupling reaction applicable for a variety of non-, α-, or β-substituted and α,β-disubstituted ortho-iodophenylethylenes is reported. Electron-rich 2-pyridone ligands are employed to enable the cyclopalladation process leading to aryl-alkenyl-palladacycle intermediates, of which the two C-Pd bonds are discriminated toward alkylation by their inherent steric and electronic differences. Good linear free-energy relationships between regio-/chemoselectivities and Hammett σ values are observed In the experiment, the researchers used many compounds, for example, 3,6-Dimethyl-2-pyridinamine (cas: 823-61-0Application of 823-61-0).
3,6-Dimethyl-2-pyridinamine (cas: 823-61-0) belongs to pyridine derivatives. Pyridine has a conjugated system of six π electrons that are delocalized over the ring. The molecule is planar and, thus, follows the Hückel criteria for aromatic systems. Many analogues of pyridine are known where N is replaced by other heteroatoms . Substitution of one C–H in pyridine with a second N gives rise to the diazine heterocycles (C4H4N2), with the names pyridazine, pyrimidine, and pyrazine.Application of 823-61-0