E. E. Nifant’ev

Electron-donating ability of triarylphosphines and related compounds studied by 31P NMR spectroscopy

The influence of aryl, heterocyclic, amide, alkyl, alkoxyl, thioalkoxyl, and ferrocenyl substituents at the phosphorus atom on its electron-donating ability was studied by the measurement of direct 31P—77Se spin-spin coupling constants for the corresponding selenides. Series of diphenylorganylphosphines and their selenides were studied.

Palladium-catalyzed P-arylation of hydrophosphoryl derivatives of protected monosaccharides

Palladium-catalyzed arylation of hydrophosphorylated protected monosaccharides of the pyranose and furanose series gave the corresponding P-aryl derivatives.

New type of 2-alkyl-substituted 1,8-naphthyridine systems containing a phosphoryl group in the side chain

First organophosphorus derivatives of 2-alkyl-and 2,3-alkylene-substituted 1,8-naphthyridines were synthesized by the Friedländer reaction starting from 2-aminonicotinaldehyde and diphenylphosphoryl(cyclo)alkanones, respectively.

Extraction of f-elements from nitric acid solutions with phosphoryl ketones

The extraction ability and selectivity of a series of phosphoryl ketones Ph2P(O)CH2C(O)Me, and Ph2P(O)CRR’CH2C(O)Me (R = H, Me; R’ = H, Me, n-C5H11, Ph, 2-thienyl, 2-furyl) towards trivalent lanthanides (LaIII, NdIII, HoIII, YbIII) and actinides (UVI, ThIV) were studied. The efficiency and selectivity of the new ligands in the extraction of f-elements from nitric acid solutions into chloroform were compared to those of model phosphine oxide Ph2P(O)Bu and known extractants: tributyl phosphate (BuO)3P(O), trioctylphosphine oxide (C8H17)3P(O), and carbamoylmethyl phosphine oxide Ph2P(O)CH2C(O)NBu2.

Acetylation of α- and β-cyclodextrines

Applying acetyl chloride and versatile bases and solvents per- and regioacetylated derivatives of α- and β-cyclodextrines were prepared. Conditions were established for performing regiodirected acetylation of the primary hydroxy groups of α- and β-cyclodextrines in the presence of free secondary hydroxy groups.

β-Diphenylphosphorylated alkanones and related compounds: synthesis and structure

The reactions of diphenyl(diisopropyl)chlorophosphine with arylidene(heteroarylidene)-acetones and 3-benzylidenepentane-2,4-dione in the presence of acetic acid proceed at a high rate at room temperature to afford the corresponding β-diorganylphosphorylated alkanones and alkanediones in high yields. The reaction of diphenylchlorophosphine with 4-methoxybut-3-en-2-one and dibenzylideneacetone carried out under similar conditions at the equimolar reagent ratio can serve as a convenient method for the synthesis of unique β-diphenylphosphorylalkenones. The structures of compounds obtained were established by IR, Raman, and NMR spectroscopy and X-ray diffraction.

Acetylation of secondary hydroxy groups of α- and β-cyclodextrines silyl derivatives

The application of acetyl chloride in the combination with different solvents and bases permitted the preparation of silyl derivatives of α- and β-cyclodextrines containing a definite amount of acetyl substituents on the secondary hydroxy groups. It was found that by means of the 1H and 13C NMR spectroscopy it is possible to make an exact attribution of acetyl groups to C2 or C3 carbon atoms of carbohydrate fragments of α- and β-cyclodextrines. Desilylation with ammonium fluoride in methanol gives acetyl derivatives of cyclodextrines containing free primary hydroxy groups.

Sterically oriented synthesis and structure of new perphosphorylated resorcinarenes

Tetraarylresorcinarenes in a chair conformation of C2h symmetry were synthesized by sterically oriented condensation of aromatic aldehydes with resorcinol and 2-methylresorcinol. By further phosphorylation of resorcinarenes with phosphorous amides perphosphorylated derivatives were obtained with rctt configuration of substituents at internuclear methylidene bridges. Structure of these compounds was proved using NMR spectroscopy and X-ray diffraction analysis.

β-cyclodextrin and its silyl derivative inclusion complexes and conjugates with medicine preparation “Ibuprofen” and its synthetic precursors

A possibility of formation of various inclusion complexes and conjugates of β-cyclodextrin and its silyl derivatives with the medicine preparation “Ibuprofen” and its synthetic precursors in dependence of nature of solvent and size of cyclodextrin cavity is demonstrated.

Dismutation of arylene phosphorodiamidites : Specific features and aspects of preparative use

The dismutation of arylene phosphorodiamidites derived from the simplest phenols and naphthols and of their dibasic analogs was studied. The main regular trends of this process and the limits of its synthetic applicability were determined.