Condensation of aryl bromides with styrenes,catalyzed by nickel complexes in the presence of zinc

Conclusions Condensation of aryl bromides with styrenes in acetonitrile in the presence of nickel organometallic complex catalysts and metallic zinc occurs regio- and stereoselectively to give E-stilbenes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2508–2511, November, 1987.     

1H and 13C NMR study of the enol–enolic tautomerism of some cyclic β-ketoaldehydes

Aldehyde (δCH) and enolic (δOH) proton chemical shifts, the corresponding spin–spin coupling constants (JCH,OH) and the ¹³C chemical shifts (δC) have been measured for three cyclic β-ketoaldehydes as a function of temperature. A tautomeric equilibrium has been shown to exist between the aldo–enol ( A ) and hydroxymethylene ketone ( B ) forms. The chemical shifts δCH δOH and δC for the two pure tautomeric forms A and B have been calculated. The enthalpy changes ΔH in the tautomeric process A ? B and the percentages of the tautomeric forms have been determined.     

Analysis of the Products from the Reaction of L-Cysteine with Fe(III) Compounds in Acidic Medium

Journal of Applied Spectroscopy - The reaction of L-cysteine solution with the iron(III) compounds FeCl3, Fe2(SO4)3, and Fe(NO3)3 in an acidic medium (pH 2) was studied. The reaction was complete...     

The selective coupling of aryl and styryl halides with butylzinc chloride in the presence of a homogeneous nickel catalyst

Conclusions The use of (Ph₃P)₂NiCl₂ as catalyst permits the cross-coupling of unsubstituted aryl and styryl halides, including bromides and chlorides, with aliphatic compounds such as BuZnCl with high selectivity.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 679–681, March, 1986.     

13C NMR study of the enol forms of β-diketones

Carbon-13 NMR spectra of a series of β-diketones in the enol form with various β-substituents have been studied. An additive influence of the β-substituents on the chemical shifts of the carbon atoms in the hydrogen bonded chelate ring has been found. It is shown that the α- and β-carbon chemical shifts can be calculated by means of a set of increments for arbitrary combinations of the X and Y substituents. Analysis of the experimental data enables the conclusions to be drawn that enol–enolic tautomerism with different populations of the forms (A) and (B) is absent in β-diketones and that the carbon chemical shift changes are caused by electron density redistribution in the hydrogen bonded chelate ring (C).     

Synthesis and structures of 10-hydroxy- and 10-acetoxy-6(5H)phenanthridinones

Treatment of 2,4,8,10-tetranitro-6(5H)-phenanthridinone with hexamethylphosphoric triamide leads to intermolecular nucleophilic substitution of the nitro group by a hydroxy group, the source of which is the water contained in the solvent, to give 10-hydroxy-2,4,8-trinitro-6(5H)-phenanthridinone. An intramolecular interaction with the participation of a proton of the aromatic ring and an oxygen atom of the hydroxy or acetoxy group of the 10-hydroxy- or 10-acetoxy-2,4,8,-trinitro-6(5H)-phenanthridinone, the properties of which are characteristic for an intramolecular hydrogen bond, was detected by x-ray diffraction analysis and PMR spectroscopy.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 314–319, March, 1987.     

Synthesis and structure of nitro-substituted 6(5H)-phenanthridinones

Methods for the preparation of nitro-substituted 6(5h)-phenanthridinones were examined. The nitration of 6(5H)-phenanthridinone, 5-methyl-6-(5H)- phenanthridinone, and 2-bromo-6(5H)-phenanthridinone was studied, and 2-, 3-, 4-nitro-, 2,4-, 2,8-, 4,8-dinitro-, 2,4,8-trinitro-, and 2,4,8,10-tetranitro-6(5H)-phenanthridinones, 2,4,8-trinitro- and 2,4,8,10-tetranitro-6-(5H)-phenanthridinones, and 2-bromo-4,8-dinitro- and 2-bromo-4,8,10-trinitro-6-(5H)-phenanthridinones were obtained. Proton magnetic resonance spectroscopy was used to identify the structure and predict the orientation of substitution in the nitration of 6(5H)-phenanthridinone and its nitro-substituted derivatives. The distribution of the electron density in these compounds was evaluated from an analysis of the chemical shifts of the protons.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1106–1113, August, 1985.