Synthesis of phosphiranes

Russian Journal of General Chemistry - Phosphiranes, three-membered phosphorus-containing heterocycles, have been prepared via reaction of tertiary phosphines dilithium derivatives with carbon...     

Chiral fluorophosphonomethylbenzaldehydes

Russian Journal of General Chemistry -     

Convenient method for determination of optical purity of chiral alcohols and amines

Russian Journal of General Chemistry -     

Selective Recovery of Nonferrous Metal Cations from Wastewater with Weakly Basic Anion Exchangers

Selective recovery of transition metals (Ni^{2 +}, Cu^{2 +}, and Cr^{2 +}) with weakly basic anion exchangers from aqueous solutions simulating naturally mineralized water was studied. The exchange capacity of anion exchangers for these cations was determined. The technique for efficient resin regeneration was developed.     

Synthesis of Optically Active α-Hydroxyalkylphosphonates

Russian Journal of General Chemistry -     

Dual Stereochemical Control in Reaction of Di- and Trialkyl Phosphites with Aldimines

Stereochemistry of addition of di- and trialkyl phosphites to C=N compounds was investigated. Reactions of achiral dialkyl phosphites with chiral aldimines as well as that of chiral di-(1R,2S,5R)-menthyl phosphite with achiral aldimines result in low diastereomeric enrichment of the addition compound. Reaction stereoselectivity increased when supplementary chiral inductor was introduced to the reaction system. Reaction of di-(1R,2S, 5R)-menthyl phosphite with (S)-α-methylbenzylbenzaldimine proceeds as concerted asymmetric induction to form practically one diastereomer of N-substituted aminophosphonic acid. However, reaction of di-(1R,2S, 5R)-menthyl phosphite with (R)-α-methylbenzylbenzaldimine proceeded as not concerted asymmetric induction, and diastereomeric enrichment of the product was low. By chemical extrapolation, absolute configuration of compounds formed was established. Tri-(1R,2S,5R)-menthyl phosphite reacts with C=N compounds in the presence of boron trifluoride etherate to form aminophosphonic acid derivatives with the absolute configuration opposite to that appearing in the reaction of di-(1R,2S,5R)-menthyl phosphite with the same C=N compounds.     

Relative reactivities of the pyridine and benzimidazole systems in the chichibabin reaction

1- (or)-Pyridyl- and 1- (or)-pyridylethylbenzimidazoles were synthesized, and their behavior with respect to methyl iodide and sodium amide was studied. The results are discussed from the point of view of the basicities, magnitudes of the dipole moments, interaction of the heterorings, and the electron density distribution in them, calculated by the Hückel MO method or estimated on the basis of the relative position of the chemical shifts in the PMR spectra. It was established that the benzimidazole system undergoes the Chichibabin reaction considerably more readily than the pyridine system. On the basis of the PMR spectral data for the pyridine and benzimidazole bases and cations, it is assumed that this is due to the greater polarizability of the C = N bond of benzimidazole as compared with the C = N bond of pyridine during coordination with NaNH₂.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1252–1263, September, 1972.The authors sincerely thank L. E. Nivorozhkin and G. V. Gorshkova for their assistance in measuring the PMR spectra.