3375-31-3Relevant articles and documents
The Mechanism and Kinetic Models of the Catalytic Oxidation of Ethylene by p-Benzoquinone in Aqueous–Acetonitrile Solutions of Pd(II) Cationic Complexes
Martynov,Efremov,Bovyrina,Katsman,Temkin
, p. 436 - 443 (2018)
A kinetic study of ethylene oxidation to acetaldehyde by p-benzoquinone in the Pd(OAc)2–HClO4?LiClO4–CH3CN–H2O system has been carried out under conditions when palladium(II) cationic complexes exist at a molar fraction of water of 0.67 and 30°С. For a reaction that mostly lead to the formation ofPd(CH3CN)(H2O)32+ two-route mechanism and a kinetic model have been proposed that describe adequately the experimental dependence of the reaction initial rate on the concentration of p-benzoquinone, HClO4, and palladium. The model takes into account previous findings on the H2O/D2O and C2H4/C2D4 kinetic isotope effects and the important role of Pd(0) quinone complexes.
Oxidation of adamantane by palladium acetate systems
Beattie, James K.,MacLeman, Susan,Masters, Anthony F.
, p. 99 - 102 (1999)
Only low yields have been found for the oxidative substitution of adamantane catalysed by diacetatopalladium(II) in trifluoroacetic acid. Addition of copper(II) acetate produced a significant increase in conversion, exclusively to 1-adamantanol. The addition of potassium persulfate gave even higher yields, but at the expense of selectivity, with some 2-adamantanol product.
[Pd(CH3COO)2]n from X-ray powder diffraction data
Kirik, Sergei D.,Mulagaleev, Ruslan F.,Blokhin, Alexander L
, p. m449-m450 (2004)
The synthesis and crystal structure of [Pd(C2H3O 2)2]n was analyzed. X-ray powder diffraction technique was used to determine the crystal structure of the compound. It was found that palladium acetate complexes were connected into a polymeric in which two Pd atoms were bridged by two acetate groups. It was observed that Pd atom occupied the special position (0,1/2,1/2) and formed rows with a Pd....Pd distance of 2.9192(I)A.
Can Donor Ligands Make Pd(OAc)2a Stronger Oxidant? Access to Elusive Palladium(II) Reduction Potentials and Effects of Ancillary Ligands via Palladium(II)/Hydroquinone Redox Equilibria
Bruns, David L.,Musaev, Djamaladdin G.,Stahl, Shannon S.
supporting information, p. 19678 - 19688 (2020/12/18)
Palladium(II)-catalyzed oxidation reactions represent an important class of methods for selective modification and functionalization of organic molecules. This field has benefitted greatly from the discovery of ancillary ligands that expand the scope, reactivity, and selectivity in these reactions; however, ancillary ligands also commonly poison these reactions. The different influences of ligands in these reactions remain poorly understood. For example, over the 60-year history of this field, the PdII/0 redox potentials for catalytically relevant Pd complexes have never been determined. Here, we report the unexpected discovery of (L)PdII(OAc)2-mediated oxidation of hydroquinones, the microscopic reverse of quinone-mediated oxidation of Pd0 commonly employed in PdII-catalyzed oxidation reactions. Analysis of redox equilibria arising from the reaction of (L)Pd(OAc)2 and hydroquinones (L = bathocuproine, 4,5-diazafluoren-9-one), generating reduced (L)Pd species and benzoquinones, provides the basis for determination of (L)PdII(OAc)2 reduction potentials. Experimental results are complemented by density functional theory calculations to show how a series of nitrogen-based ligands modulate the (L)PdII(OAc)2 reduction potential, thereby tuning the ability of PdII to serve as an effective oxidant of organic molecules in catalytic reactions.
Detection of Palladium(I) in Aerobic Oxidation Catalysis
Jaworski, Jonathan N.,McCann, Scott D.,Guzei, Ilia A.,Stahl, Shannon S.
supporting information, p. 3605 - 3610 (2017/03/21)
Palladium(II)-catalyzed oxidation reactions exhibit broad utility in organic synthesis; however, they often feature high catalyst loading and low turnover numbers relative to non-oxidative cross-coupling reactions. Insights into the fate of the Pd catalyst during turnover could help to address this limitation. Herein, we report the identification and characterization of a dimeric PdI species in two prototypical Pd-catalyzed aerobic oxidation reactions: allylic C?H acetoxylation of terminal alkenes and intramolecular aza-Wacker cyclization. Both reactions employ 4,5-diazafluoren-9-one (DAF) as an ancillary ligand. The dimeric PdI complex, [PdI(μ-DAF)(OAc)]2, which features two bridging DAF ligands and two terminal acetate ligands, has been characterized by several spectroscopic methods, as well as single-crystal X-ray crystallography. The origin of this PdI complex and its implications for catalytic reactivity are discussed.