L. R. Yakupova

Diels-Alder Reactions of Alumina- and Magnesacyclopentadienes

Abstract[4π + 2π]-Cycloaddition of substituted alumina-and magnesacyclopenta-2,4-dienes with such dienophiles as maleic anhydride, N-methylmaleimide, 1,4-benzoquinone, and 1,4-naphthoquinone resulted in the formation of the corresponding fused alumina-and magnesanorbornenes whose hydrolysis gave isobenzofuran, isoindole, naphthalene, and anthracene derivatives in high yields.

Synthesis of 1,2,3,4-tetrasubstituted aluminacyclopent-2-enes using Cp2ZrCl2 as catalyst

Efficient procedures have been developed for the synthesis of 1,2,3,4-tetrasubstituted aluminacyclopent-2-enes via intermolecular cycloalumination of terminal olefins and acetylenes with EtAlCl2 or cycloalumination of acetylenes with higher trialkylalanes in the presence of Cp2ZrCl2 as catalyst.

Free-radical chain oxidation of 1,4-dioxane inhibited by 2-thio-6-aminouracil

The effect of 2-thio-6-aminouracil on the oxygen uptake kinetics has been studied in 1,4-dioxane free-radical chain oxidation as a model system. The presence of a thiocarbonyl group in the 2-position of the uracil ring makes 6-aminouracil highly reactive towards 1,4-dioxane peroxy radicals. The rate constant of the 1,4-dioxane peroxy radical interaction with 2-thio-6-aminouracil has been measured to be k7 = (3.0 ± 0.5) × 105 L mol–1 s–1 (333 K). The stoichiometric inhibition factor f = 1.1 ± 0.1 has been determined.

Kinetics of the radical-chain oxidation of methyl oleate inhibited by 5-amino-6-methyluracil and 5-amino-1,3,6-trimethyluracil

The effects of 5-amino-6-methyluracil (AMU) and 5-amino-1,3,6-trimethyluracil (ATMU) on the rate of oxygen uptake in methyl oleate (MO) radical-chain oxidation initiated by 2,2′-azobisisobutyronitrile as a model reaction have been investigated. The rate constant (k7) for the reactions of the peroxyl radical forming from MO with AMU and ATMU at 333 K in the medium of the substrate being oxidized has been measured. k7 is (1.7 ± 0.2) × 104 L mol−1 s−1 in the presence of AMU and (1.3 ± 0.2) × 104 L mol−1 s−1 in the presence of ATMU. k7 for MO oxidation in aqueous cetyltrimethylammonium bromide solution takes a much smaller value of (2.8 ± 0.8) × 103 L mol−1 s−1.

Effect of Metallocenes on Benzoyl Peroxide Decomposition

Benzoyl peroxide (BP) decomposition in the presence of the Cp2Fe, (C5Me5)2Fe, (C5Me5)2ZrCl2, (AcC5H4)(C5H4)Fe, Cp2ZrCl2, and Cp2TiCl2 metallocenes in ethylbenzene oxidation as a model reaction has been studied. It has been shown that the metallocenes have a catalytic effect on BP decomposition in accordance with their electrochemical potentials. The rate constant of the bimolecular BP decomposition reaction with the formation of radicals in the BP-ferrocene system (1.46 L mol−1 s−1) has been found.

Mechanism of 5-amino-6-methyluracil-inhibited oxidation of organic compounds

Based on experimental and theoretical data obtained in the mechanism study of the 5-amino-6-methyluracil-inhibited radical chain oxidation of 1,4-dioxane, a scheme for the process is proposed. A kinetic analysis of the scheme has been performed to obtain an equation describing the regularities of oxygen consumption that agree with the experimental data and provide evidence in favor of the chain consumption of the inhibitor under certain conditions. The composition of resulting products confirms the proposed mechanism.

Synthesis and transformations of metallacycles. 29. Direct alumination of olefins, conjugated dienes, and acetylenes with alkylhaloalanes catalyzed by Zr and Ti complexes

Catalytic methods were developed for the synthesis of acyclic 1,2- and 1,4-dialuminum compounds by the reactions of olefins, dienes, or acetylenes with R2AlCl (R = Et, Et2N, (cyclo-C6H11)2N, BunO, or n-C6H13O) in the presence of Ti- or Zr-containing complex catalysts and magnesium metal as an acceptor of chloride ions.