A new reaction of phosphorylated N-sulfonylimines with hydrophosphoryl agents involving C → N transfer of phosphoryl groups

Hydrophosphoryl nucleophilic agents add to the CN bond of N-sulfonyltrichloroacetimidoylphosphonates to give unstable C,C-diphosphorylated adducts, which undergo competitive 1,2-C → N phosphorotropic rearrangement and dehydrochlorination with the formation of aza-Perkow reaction products, C,N-diphosphorylated dichlorovinylsulfonamides. This is the first reliably identified case of an aza-Perkow transformation for acid phosphites and their initial nucleophilic attack at the C atom of the azomethine bond in the aza-substrates.     

A new reaction of vicinal sulfonyliminocarboxylates with phosphites

The reaction of alkyl trifluoro(organylsulfonylimino)propionates with phosphites occurs with NC transfer of the RSO₂ group and leads to sulfonyl-substituted trifluoroalanine derivatives. The novel rearrangement is interpreted as cheletropic 1,4-cycloaddition of the phosphite and subsequent 1,2-shift of the sulfonyl group in the intermediate cyclic phosphorane.     

35Cl NQR spectra and molecular structure of cyclic chlorophosphoranes

The structure of chlorine-containing cyclic pentacoordinated phosphorus compounds has been studied by³⁵Cl NQR. The distortion of molecular geometry from trigonal bipyramid to tetragonal pyramid in going from monocyclic phosphoranes to spiro phosphoranes and the corresponding changes in the NQR spectrum are discussed.Perm State University. Institute of Organic Chemistry, Ukrainian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 34, No. 3, pp. 75–79, May–June 1993.Translated by L. Smolina     

Reactions of 1,2,2,2-tetrachloroethyl isocyanate with trialkyl and trimethylsilyl phosphites

The reaction of 1,2,2,2-tetrachloroethyl isocyanate with trialkyl phosphites is unselective. It involves chlorine substitution, addition by the isocyanate group, and dehydrochlorination and gives rise to a mixture of mono- and diphosphorylated compounds. Diethyl trimethylsilyl phosphite more selectively reacts with 1,2,2,2-tetrachloroethyl isocyanate. At a 1:1 molar reagent ratio, an -phosphorylated trichloroethyl isocyanate is formed, and at a 2 : 1 ratio, chlorine substitution and addition by the isocyanate group take place to give a related 1,3-diphosphonate.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 9, 2004, pp. 1456–1459.Original Russian Text Copyright © 2004 by Onysko, Maidanovich, Sinitsa.This revised version was published online in April 2005 with a corrected cover date.     

Synthesis and Reaction Peculiarities of Phosphorylated Trifluoroethane Imines

Abstract

Convenient methods for C,N - mono- and biphosphorylated trifluoroethane imines have been developed. These are reactive synthons allowing important derivatives of aminophosphonic acids, fluorine- and phosphorus-containing heterocycles, vinylamides, etc. A rare example of a Perkov-type reaction involving trifluoromethyl group has been discovered.     

An expert system for identification of lines in vibrational-rotational spectra

An expert system for automatic identification of the complex vibrational-rotational spectra of molecules has been developed. An iteration approach is implemented in this system, in which employment of the exact combination rule is combined with determination of the spectroscopic constants by solving of the inverse problems and comparison of the calculated parameters of spectral lines with the corresponding measured values. In order to calculate the energy levels and the frequencies and intensities of lines, the Watson Hamiltonian, the Padé-Borel approximants, and generating functions are used. The system is based on the application of pattern-recognition algorithms. Recognition training makes it possible to obtain the required flexibility of the system and to use different methods of identification based on the application of combination rules both for the analysis of strong bands and for the assignment of weak single lines. The system developed can be used to analyze the spectra of the C _s and C _2V molecules, as well as employ the calculated spectrum of a molecule of any type prepared in advance. This system was successfully used to identify the H ₂ ¹⁶ O, H ₂ ¹⁷ O, H ₂ ¹⁸ O, D₂O, HDO, H ₂ ³² S, H ₂ ³⁴ S, and H ₂ ³³ S and molecules.     

High-Order Resonances in the Water Molecule

The water-vapor spectra in the near-infrared and visible region were reanalyzed with the purpose of finding experimental evidences of unusual high-order resonance between "dark" high-bending and "bright" stretch vibration states. About 70 transitions to the (050), (060), (070), (080), (160), (061), (170), (071), and, even (0 10 0) bending states, and their resonating partners were assigned in the spectra that gives the experimental energy levels lying near or above the potential energy barrier to linearity. The assignments were confirmed by combination differences and simultaneous observation of both perturbed and perturbing levels. It was found that the high-order resonances with large changing of vibration quantum numbers are typical for the water molecule and they are caused by the strong centrifugal distortion near the linear configuration. These resonances destroy the usual polyad scheme originating from well-known Coriolis, Darling-Dennison, and Fermi resonances in H(2)O molecule. Copyright 2001 Academic Press.     

Synthesis of 3-fluoroimidazo[1,2-a]pyrimidines and 5-fluoroimidazo[2,1-b][1,3]thiazoles via heterocyclization of (N-heteroarylimino)trifluoropyruvates

Synthesis of 3-fluoroimidazo[1,2-a]pyrimidines and 5-fluoroimidazo[2,1-b][1,3]thiazoles was accomplished via triethyl phosphite-induced heterocyclization of the corresponding N-(heteroarylimino)trifluoropyruvates. This method provides a convenient approach to synthesize ring-fluorinated fused imidazoles of biological relevance.