Carboxyethenylation of polychlorobiphenyls

For the first time 2-carboxyethenylation was performed with butyl acrylate in the presence of palladium catalysts of bromine derivatives of polychlorobiphenyls obtained by bromination of polychlorobiphenyls. The haloderivatives of the butyl phenylcinnamate are readily hydrolyzed and hydrodehalogenized affording a mixture of phenylhydrocinnamic acids.     

Novel methods for synthesis and sorption properties of N,O-(2,3-dihydroxy)propylchitosan

The direct addition of glycidol to chitosan in a gel medium under exposure to ultrasound afforded the chelating aminopolymer N,O-(2,3-dihydroxy)propylchitosan with a degree of substitution up to 2.3. The sorption characteristics of the crosslinked aminopolymers with respect to boron-containing ions were estimated.     

First example of the planar rectangular 18-nuclear nickel(II) hydroxo complex with n-(2-pyridylmethyl)iminodipropionic acid

A planar rectangular cluster Ni₁₈ (I) was obtained from N-(2-pyridylmethyl)iminodipropionic acid (II). The crystal structure of complex I was determined by X-ray diffraction. Complex I is built from the octanuclear planar framework (III) of the nickel(II) hydroxo complex (Ni...Ni 2.976–3.092 Å), four nickel chelates with the corresponding acid (IV), which are coplanar with the framework and are on both its sides (Ni...Ni, 2.938–3.188 Å), four hydroxo complexes, and two mixed chloro chelates V), which are not coplanar with the framework (Ni...Ni, 3.141 and 3.181 Å). In the chelate parts of complex I, the organic ligand is hexadentate because of bridging bonds; the coordination polyhedroLn of the metal center is a distorted square bipyramid (4 + 2).     

Reaction of 2,3-Epoxypropyl Ethers with 1-Butanol

Nucleophilic opening of the oxirane ring in 2,3-epoxypropyl ethers with alcohols in the presence of titanium alkoxides and other catalysts was studied. The mechanism of catalysis by titanium alkoxides was discussed on the basis of comparison with acid–base catalysts.     

Synthesis and sorption properties of new hybrid chelating sorbents with β-alanine functional groups

A series of -aminopropylsilylated sorbents was obtained from different oxide supports (silica gels, silica fillers, macroporous glasses, alumina) and by the direct synthesis (hydrolytic polycondensation of tetraalkoxysilanes with -aminopropyltriethoxysilane). The highest degree of immobilization was achieved for silicas, while the most convenient solvent was methanol. Sorbents with -alanine functional groups were obtained by the subsequent reaction with acrylic acid. The degree of -carboxyethylation was 1.3–1.9, and the highest content of functional groups (v_COOH = 3.23 mmol g^–1) was achieved for carboxyethylated xero gel synthesized by the copolycondensation of tetraethoxysilane with -aminopropyltriethoxysilane. The sorbents containing -alanine possess a higher selectivity of Cu²⁺ ion sorption than the initial -aminopropylsilylated sorbents.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2620–2625, December, 2004.     

Synthesis,properties, and mass-spectrometric fragmentation of 2-thio derivatives of 3-arylquinazolin-4-ones

We have studied the reactions of alkylation, oxidation, and hydrolysis of 3-aryl-2-thioxoquinazolin-4-ones. Alkylation in an alkaline medium occurs exclusively at the sulfur atom. Oxidation by hydrogen peroxide leads to formation of 3-arylquinazoline-2,4-diones. The latter are also obtained in base or acid hydrolysis of the synthesized S-alkyl derivatives. When 3-aryl-2-thioxoquinazolin-4-ones are reacted with iodine, we obtain the disulfides, while the reaction with chlorine in hydrochloric acid leads to 2-chloroquinazolin-4-ones. Studying the mass spectrometric behavior of the compounds obtained made it possible to observe in the gas phase ring-chain isomerization of the heterocyclic ring, and also S-N migration of the propargyl radical in molecular ions of the S-propargyl derivatives. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 440–446, March, 2007.     

The first cubane-like complex of copper based on <Emphasis Type="Italic">N</Emphasis>-carboxyethyl-tris(hydroxymethyl)aminomethane: Synthesis and crystal structure

The interaction of acrylic acid with tris(hydroxymethyl)aminomethane (I) was studied. A simple method was suggested for preparing N-carboxyethyl-tris(hydroxymethyl)aminomethane (homotricin) (II). On the basis of compound II, the 1:1 Cu complex, [Cu(OCH₂C(CH₂OH)₂NHCH₂CH₂COO)]₄·nH₂O (n = 4–11.25) (III), which is alkoxycarboxylate, was synthesized. The crystal structure of III was found to correspond to a cubane-like tetranuclear cluster (an automated Bruker X8Apex diffractometer with CCD detector (MoK _α radiation, graphite monochromator, ? = 1.11°?27.5°), 8016 reflections, space group P \(\overline 1 \), a = 12.5573(3), b = 19.1012(4), c = 21.2903(5) Å, α = 80.7770(10)°, β = 75.7430(10)°, γ = 75.2260(10)°, V = 4761.62(19) ų, ρ(calcd.) = 1.704 g/cm³, Z = 4). The crystals are unstable due to the large number of water molecules.     

N-2-(2-pyridyl)ethyl chitosan: Synthesis in gel and sorption properties

A procedure was developed for preparing a new heterocyclically substituted chelating aminopolymer, N-2-(2-pyridyl)ethyl chitosan, by direct addition of 2-vinylpyridine to chitosan under the conditions of synthesis in gel. The resulting polymer has the degree of substitution of up to 1. The ability of the samples obtained to sorb transition and noble metal ions was evaluated.