Li, Weipeng; Yuan, Dandan; Wang, Guoqiang; Zhao, Yue; Xie, Jin; Li, Shuhua; Zhu, Chengjian published an article on February 20 ,2019. The article was titled 《Cooperative Au/Ag Dual-Catalyzed Cross-Dehydrogenative Biaryl Coupling: Reaction Development and Mechanistic Insight》, and you may find the article in Journal of the American Chemical Society.Quality Control of 1-Methylpyrazole The information in the text is summarized as follows:
In the presence of (Me2S)AuCl and AgOAc, pyrazoles such as 1-phenylpyrazole underwent chemoselective and regioselective oxidative dehydrogenative coupling reactions with fluorinated arenes and pyridines such as 2,3,5,6-tetrafluoropyridine mediated by PhI(OAc)2 in 1,4-dioxane to yield (fluoroaryl)pyrazoles such as I. The mechanism of the oxidative coupling reaction was studied by determination of the reaction kinetics, kinetic isotope effects, and deuterium exchange, by generation and preparation of gold and silver complexes as potential intermediates, and by DFT calculations of transition state structures and energies for arene metalation, transmetalation, and reductive elimination reactions. Silver acetate is determined to be is the actual catalyst for C-H activation of electron-poor arenes, rather than gold(I) complexes. A mechanism of gold/silver dual catalysis is proposed, in which silver is responsible for the activation of electron-poor fluoroarenes via a concerted metalation-deprotonation pathway, and gold is responsible for the activation of electron-rich pyrazoles via an electrophilic aromatic substitution process. Kinetic studies reveal that C-H activation of pyrazoles by fluoroarylgold complexes is most likely the rate-limiting step. The experimental part of the paper was very detailed, including the reaction process of 1-Methylpyrazole(cas: 930-36-9Quality Control of 1-Methylpyrazole)
1-Methylpyrazole(cas: 930-36-9) belongs to pyrazoles. Pyrazoles and their related multiring analogs are common elements of a wide variety of bioactive compounds. These ring structures are rare in nature. A consequence of this is that they have previously been thought to be poor moieties to include in potential new drugs. Quality Control of 1-Methylpyrazole
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics