Vol 122, No 2 (2024): THEMED SECTION: FUNDAMENTAL PRINCIPLES OF ORGANIC ELECTROCHEMISTRY, CREATION OF NEW FUNCTIONAL MATERIALS AND MATERIALS FOR MEDICINE

The possibility of electrooxidative C—H functionalization of azopyrazoles was demonstrated for the first time on the example of their mono- and dithiocyanation under mild conditions with a yield of 47–52%. The main patterns of the process were studied and the antifungal activity of the resulting products was revealed, comparable to or superior to the antifungal drug fluconazole.

A novel strategy for the stereoselective synthesis of cysteine derivatives containing a malonate fragment in the β-position has been proposed, based on a series of consecutive transformations in the Ni(II) Schiff-base coordination environment. Electrochemical Corey–Chaykovsky cyclopropanation of the dehydroalanine complexes followed by reductive ring opening and subsequent Michael addition of S-nucleophiles to thus formed unsaturated amino acids derivatives open a route to novel cysteine derivatives. New protocol for isolation of the substituted aryl cysteines with strong CH acidity via disassembling of the Schiff-base template has been elaborated.

It is proposed to use complexes of antimony (V), tin (IV) with a tridentate O,N,O'-donor ligand as electromediators for the oxidation of C4, C6 alkanethiols to disulfides and in reactions with 1-hexene, bromocyclopentane aimed at producing sulfides at room temperature. In the presence of Sb (V), Sn (IV) complexes, alkanethiols were subjected to oxidative or reductive activation in solution, which made it possible to reduce the overvoltage of electrode processes compared to heterogeneous electron transfer. The [(p-FC6H5)3Sb(Cat-N-Cat)] complex showed high activity in the electrocatalytic transformations of alkanethiols into disulfides. This complex also turned out to be effective in the synthesis of sulfides based on alkanethiols of various structures and 1-hexene. The interaction of alkanethiols with bromocyclopentane with the participation of the mediator [Ph2Sn(Cat-N-SQ)] leads to the formation of unsymmetrical sulfides along with disulfides of symmetrical structure. The involvement of Sb(V), Sn(IV) complexes with a redox-active ligand in mediator electrosynthesis turned out to be appropriate due to its energy efficiency and environmental safety in comparison with direct electrochemical methods for the production of mono- and disulfides.

This study is focused on the development of highly efficient and environmentally friendly methods for production of new catalysts based on complexes of group VIII 3d-metals (cobalt and nickel) bearing α-diphenylphosphinoglycines in the coordination sphere for the processes of homogeneous ethylene oligomerization and polymerization. Novel α-diphenylphosphinoglycines were synthesized by the threecomponent condensation reaction using diphenylphosphine, the primary amine, and glyoxylic acid monohydrate and characterized by various physicochemical methods. Their electrochemical properties and reactivity have been studied in the presence of neutral and doubly charged complexes of group VIII 3d metals (cobalt and nickel). Quantum-chemical calculations have been performed to rationalize the influence of the substituents at amino group in N-derivatives of α-diphenylphosphinoglycines on the molecular weight distribution of the formed α-olefin products. It was established that the difference in catalytic performance of L/Ni systems, where L – N-aryl-diphenylphosphinoglycines, is mainly due to the steric effects influencing the relative thermodynamic stability of various conformations of the catalyst as well as the thermodynamic and kinetic parameters of various competing catalytic transformations. The obtained results can serve as the basis for the future rational design of new catalytically active systems with desired properties.