Peng, Qingrui published the artcileEffects of different ligand modifications on catalytic transfer hydrogenation of Lewis acid catalysts: Quantum chemical studies on the case of ZrCl2-Sal(ph)en, Computed Properties of 539-88-8, the main research area is electronic ligand modification catalytic transfer hydrogenation Lewis acid catalyst.
The systematic description of the steric and electronic ligand effects on the reactivity of the catalysts is one of the main goals in homogeneous catalysis. The experiments and mol. modeling calculations were performed to establish the structure-reactivity relationship with various ligand substituents of ZrCl2-Sal(ph)en-X (X = H, CH3, OCH3, Br, NO2, Cl). A clear linear free-energy relationship (LFER, r2=0.97/0.93) was found between Hammett σp value of the phenoxyl side group substituent X and the rate KX or reaction barrier of the hydrogenation of Et levulinate. Lewis acid sites are stronger in catalysts with an electron-withdrawing group close to the Zr site. In addition, the auxiliary ligands at two axial sites connected to the Zr site have a more significant impact on the catalyst activity. Among the three axial ligands (Cl, OH and OiPr), the -OH ligand with a smaller size endows addnl. basicity of catalyst, which is beneficial to the activation and dissociation of the hydroxyl group in the 2-propanol at the Lewis acidic sites (Zr4+) and basic sites(O2-), thus increasing the reaction rate of the Meerwein-Ponndorf-Verley (MPV)reaction of Et levulinate.
Journal of the Taiwan Institute of Chemical Engineers published new progress about Basicity, Lewis. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Computed Properties of 539-88-8.
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics