Yulia B. Dudkina

Electrochemical properties of diphosphonate-bridged palladacycles and their reactivity in arene phosphonation

A series of diphosphonate-bridged dipalladacycles [(phpy)Pd(EtO)2P(O)]2, [(bhq)Pd(EtO)2P(O)]2, [(phpz)Pd(EtO)2P(O)]2 (phpy=2-phenylpyridine, bhq=benzo[h]quinoline, phpz=1-phenylpyrazole), which are known to be involved in catalytic C–H phosphonation reactions, was prepared and characterized by NMR spectroscopy and cyclic voltammetry in acetonitrile solutions and in carbon paste electrode. Diphosphonate dipalladacycles are oxidized irreversibly at more positive potentials as distinguished from related acetate palladacycles. Electrochemical preparative oxidations carried out under mild conditions without any specially added oxidants quantitatively afforded corresponding arylphosphonates. For complete conversion of dipalladacycles into arylphosphonates, four electrons per each palladium atom are required, that probably indicates a mechanism involving Pd(IV)/Pd(II) redox couple.

Redox trends in cyclometalated palladium( ii ) complexes

A series of diverse binuclear and mononuclear cyclometalated palladium(ii) complexes of different structure was investigated by electrochemical techniques combined with density functional theory (DFT) calculations. The studies including cyclic and differential pulse voltammetry, X-ray structure analysis and quantum chemical calculations revealed a regularity of the complexes oxidation potential on the metal-metal distance in the complexes: the larger Pd-Pd distance, the higher oxidation potentials. The reduction potentials feature unusually high negative values while no correlation depending on the structure could be observed. These results are in a good agreement with the electron density distribution in the complexes. Additionally, ESR data obtained for the complexes upon oxidation is reported.

Eco-efficient electrocatalytic C–P bond formation

Abstract The development of practical, efficient and atom-economical methods of formation of carbon-phosphorus bonds remains a topic of considerable interest for the current synthetic organic chemistry and electrochemistry. This review summarizes selected topics from the recent publications with particular emphasis on phosphine and phosphine oxides formation from white phosphorus, chlorophosphines in electrocatalytic processes using aryl, hetaryl or perfluoroalkyl halides as reagents. This review includes selected highlights concerning recent progress in modification of catalytic systems for aromatic C–H bonds phosphonation involving metal-catalyzed ligand directed or metal-induced oxidative processes. Furthermore, a part of this review is devoted to phosphorylation of olefins with white phosphorus under reductive conditions in water-organic media. Finally, we have also documented recent advances in ferrocene C–H activation and phosphorylation.

Synthesis and Reactivity of New Aminophenolate Complexes of Nickel

New well-defined, paramagnetic nickel complexes have been prepared and characterized by X-ray crystallography. The complexes were found to be active for the cross-coupling of alkyl electrophiles (especially ethyl 2-bromobutyrate) with alkyl Grignard reagents. The ligand architecture in these new complexes could potentially be rendered chiral, opening up future possibilities for performing asymmetric cross-coupling reactions.