Reference of 32005-36-0, Chemistry is the science of change. But why do chemical reactions take place? Why do chemicals react with each other? The answer is in thermodynamics and kinetics.In a document type is Article, and a compound is mentioned, 32005-36-0, Bis(dibenzylideneacetone)palladium, introducing its new discovery.
The Pd-catalyzed decarboxylative allylation of alpha-(diphenylmethylene) imino esters (1) or allyl diphenylglycinate imines (2) is an efficient method to construct new C(sp3)-C(sp3) bonds. The detailed mechanism of this reaction was studied by theoretical calculations [ONIOM(B3LYP/ LANL2DZ+p:PM6)] combined with experimental observations. The overall catalytic cycle was found to consist of three steps: oxidative addition, decarboxylation, and reductive allylation. The oxidative addition of 1 to [(dba)Pd(PPh 3)2] (dba=dibenzylideneacetone) produces an allylpalladium cation and a carboxylate anion with a low activation barrier of +9.1 kcal mol-1. The following rate-determining decarboxylation proceeds via a solvent-exposed alpha-imino carboxylate anion rather than an O-ligated allylpalladium carboxylate with an activation barrier of +22.7 kcal mol -1. The 2-azaallyl anion generated by this decarboxylation attacks the face of the allyl ligand opposite to the Pd center in an outer-sphere process to produce major product 3, with a lower activation barrier than that of the minor product 4. A positive linear Hammett correlation [rho=1.10 for the PPh3 ligand] with the observed regioselectivity (3 versus 4) supports an outer-sphere pathway for the allylation step. When Pd combined with the bis(diphenylphosphino)butane (dppb) ligand is employed as a catalyst, the decarboxylation still proceeds via the free carboxylate anion without direct assistance of the cationic Pd center. Consistent with experimental observations, electron-withdrawing substituents on 2 were calculated to have lower activation barriers for decarboxylation and, thus, accelerate the overall reaction rates. Copyright
Balanced chemical reaction does not necessarily reveal either the individual elementary reactions by which a reaction occurs or its rate law.Reference of 32005-36-0. In my other articles, you can also check out more blogs about 32005-36-0
Reference：
Chapter 1 An introduction to palladium catalysis,
Palladium/carbon catalyst regeneration and mechanical application method