Electric Literature of 52522-40-4, Catalysts function by providing an alternate reaction mechanism that has a lower activation energy than would be found in the absence of the catalyst. In some cases, the catalyzed mechanism may include additional steps.In a article, 52522-40-4, molcular formula is C52H43Cl3O3Pd2, introducing its new discovery.
Atom economy. Palladium-catalyzed formation of coumarins by addition of phenols and alkynoates via a net C-H insertion
A strategy to achieve ortho substitution of phenols initiated by an ortho-palladation to create coumarins was examined. Indeed, treatment of alkynoates with electron-rich phenols in the presence of a palladium catalyst and an acid does generate coumarins. The scope of the reaction with respect to the phenol and the alkynoates is defined. With unsymmetrical aromatic substrates, generally good regioselectivity that reflects the HOMO coefficients can be observed. In the course of these studies, numerous important naturally occurring coumarins have been synthesized, including fraxinol methyl ether, ayapin, herniarin, xanthoxyletin, and alloxanthoxyletin. The fact that a Pd(0) is the precatalyst rather than a Pd(+2) species and that an acid that reduces Pd(+2) salts, formic acid, functions better than other carboxylic acids raises doubts about the initial working hypothesis. A novel mechanism involving a palladium phenoxide formed from a hydridopalladium carboxylate and phenol is invoked to rationalize the results.
The proportionality constant is the rate constant for the particular unimolecular reaction. the reaction rate is directly proportional to the concentration of the reactant. I hope my blog about 52522-40-4 is helpful to your research. Electric Literature of 52522-40-4
Reference：
Chapter 1 An introduction to palladium catalysis,
Palladium/carbon catalyst regeneration and mechanical application method