ИСТИНА

The interest in the development of polymer ligands is caused by the environmental safety issues of existing synthesis methods and leads to the development of catalytic systems and reagents for organic synthesis based on them [1]. The cobalt(II) chloride complex with the polymer ligand poly-N-vinyl-3(5)-methylpyrazole (poly-N-VP) was obtained by polymerization of N-vinyl-3(5)-methylpyrazole in the presence of azobisisobutyronitrile (AIBN) with the addition of a complex of cobalt(II) chloride and N-vinyl-3(5)-methylpyrazole (N-VP). Kinetic patterns of polymerization of N-vinyl-3(5)-methylpyrazole were studied by rheometric methods. The structure of the resulting complex of cobalt (II) chloride and N-vinyl-3(5)-methylpyrazole was confirmed by X-ray diffraction analysis. The complex has a tetrahedral configuration, and it is interesting to note that the unit cell contains two structures that are enantiomers with respect to each other. The resulting complex structures with polymer ligands were characterized by IR spectroscopy. The shift of the imine bond signal -HC=N- compared with the initial N-vinyl-3(5)-methylpyrazole indicates the preservation of cobalt coordination over this nitrogen atom when interacting with poly-N-vinyl-3(5)-methylpyrazole and the reproduction of the tetrahedral configuration of the cobalt atom during complexation with poly-N-vinyl-3(5)-methylpyrazole. The synthesized complex compounds are applicable in the synthesis of tertiary phosphine oxides containing heterocyclic fragments as catalytically active centers. The cross-combination proceeds more efficiently than in comparison with the traditional system for this reaction based on palladium (II) acetate and 1,1'-bis(diphenylphosphino)ferrocene. Moreover, the yield of the target 2,6-diylbis(diethylphosphine oxide) in the case of using a complex with a polymer ligand (poly-N-vinyl-3(5)-methylpyrazole) is higher (76%) than when using N-vinyl-3(5)-methylpyrazole (70%). The product was characterized by 1H and 31P NMR spectroscopy.