Thermally induced non-catalytic assembling of salicylaldehydes and dimedone in water or ethanol affords 9-(2-hydroxy-4,4-dimethyl-6-oxo-1-cyclohexen-1-yl)-3,3-dimethyl-2,3,4,9-tetrahydro-1H-xanthen-1-ones in 85–95% yields as a sequence of Knoevenagel and Michael reactions.

Electrohydrodimerization of 4,4-dimethyl-2-cyclohexen-1-one in dimethylformamide with 0.1 M tetrabutylammonium perchlorate as supporting electrolyte has been studied by polarography, cyclic voltammetry and controlled-potential electrolysis. A one-electron reduction process is found, which leads ...

Reaction of [(η4-COD)Ir(μ2-Cl)]2 (1) with tin CH2CRCHCRCH2SnR′3 (R = H, Me; R' = Me, n-Bu) or lithium pentadienide reagents gives the corresponding acyclic pentadienyl sandwich compounds [(η4-COD)Ir(η5-CH2CMeCHCMeCH2) (2) and [(η4-COD)Ir(η5-CH2CHCHCHCH2) (3). Treatment of 1 with diff...

The theoretical infrared spectra of 1,3-cis-cis-cyclooctadiene (1,3-COD) and 1,5-cis-cis-cyclooctadiene (1,5-COD), were obtained by ab initio MO calculations at Hartree–Fock level. The results were compared with the available IR experimental spectra of 1,3- and 1,5-COD. The apparent agreement b...

The molecular structure of [Rh(SnCl3)(norbornadiene)(dppb)] (1) and [Rh(SnCl3)(1,5-cyclooctadiene)(dppb)] (2) (dppb = 1,4-bis(diphenylphosphino)butane) has been determined by single-crystal X-ray techniques. In both compounds the structure is best described as distorted square pyramidal with the...

The reactions of cis,cis-1,3-, cis,trans-1,3- and 1,4-cyclooctadienes with platinum(II) and palladium(II) in various solvent systems have been investigated. The occurence of rearrangement of the coordinated dienes depends on the nature of the solvent. However, in RhI, IrI, RuII and Mo0 systems, ...

The isomerization of 1,5-cyclooctadiene to 1,3-cyclooctadiene and 1,4-cyclooctadiene catalyzed by silica-supported Ir4(CO)12 was investigated by means of statistical methods, and the yield in 1,4-cyclooctadiene was optimized. A complete factorial design was developed in order to evaluate the eff...

1,4-Cydooctadiene can isolated by careful rectification of reaction mixtures resulting from the isomerization of 1,5-cyclooctadiene with the catalyst system Ti(OBu)4/AlEt3. Its polymerization with metathesis catalysts yields a polybutadiene-like rubber with the structure of an alternating copoly...

The hydroboration of isoprene with N-azolylboranes in THF [az-BH2-THF: az = N-pyrrolyl (1a), N-2,5-dimethylpyrrolyl (1b), N-indolyl (1c), N-carbazolyl (1d)] affords the boracyclopentane derivatives 2a–d. In the case of 2b,c, the reduced species 3b,c with a 2,5-dimethylpyrrolidinyl and a 2,3-dih...

In the present paper, data are given for the infrared and Raman spectra; the ultra-violet vapour spectrum of bromofluorobenzene and the normal vibration frequencies are assigned on the basis of these data and of those published in earlier papers [1–3].

A new electrochemical procedure for the electrocatalytic carboxylation of 2-amino-5-bromopyridine with CO2 in ionic liquid, 1-butyl-3-methyllimidazolium tetrafluoborate (BMIMBF4), to 6-aminonicotinic acid was investigated for the first time. The experiments were carried out in three electrodes u...

The molecular structure of 2-(tert-butoxycarbonyl (Boc) -amino)-5-bromopyridine (BABP) was optimized by the DFT/B3LYP method with 6-311G (d,p), 6-311++G (d,p) and cc-pVTZ basis sets using the Gaussian 09 program. The most stable optimized structure of the molecule was predicted by the DFT/B3LYP ...

The FTIR and laser Raman spectra of 2-amino-5-bromopyridine have been recorded. The observed frequencies were assigned to various modes of vibrations on the basis of normal coordinate calculations, assuming Cs point group symmetry. The potential energy distribution associated with normal modes i...

Saturated cyclic ethers are being proposed as next-generation bio-derived fuels. However, their pyrolysis and combustion chemistry has not been well established. In this work, the pyrolysis and combustion chemistry of 2-methyl-tetrahydrofuran (MTHF) was investigated through experiments and detai...

The microwave spectrum of tetracyclanone has been analyzed, resulting in a dipole moment of 3.65 ± 0.02 D. This rather large dipole moment is explained as another manifestation of interactions between the Walsh orbitals of cyclopropyl groups and π-orbitals on substituent groups. We have develo...

Several thiourea and urea derivatives were prepared by the reaction of 4-aminopyrazoles with substituted isothiocyanates or isocyanates. The novel compounds were tested anticonvulsant activity using by pentylenetetrazole-induced seizure (PTZ) and maximal electroshock seizure (MES) tests. Among t...

The standard (p∘=0.1MPa) molar enthalpies of formation, at T=298.15K, in the condensed phases of two alkylpyrazoles, viz. 3-methylpyrazole and 1,3,5-trimethylpyrazole, were determined by static bomb calorimetry. Calvet microcalorimetry was used to measure the standard molar enthalpy of vaporisa...

For the first time 5,7-di-tert-butyl-1,3-dimethyl-3a,9a-diphenyl-3,3a-dihydro-1H-benzo[5,6][1,4]dioxino[2,3-d]imidazol-2(9aH)-one 13 and complex 9 of 4,6-di-tert-butyl-3-nitrobenzene-1,2-diol with 1,3-dimethyl-4,5-diphenyl-1H-imidazol-2(3H)-one 10a were prepared by the reactions of 3-alkylthio-5...

Ab initio theory and density functional theory (B3LYP) have been used to calculate the geometry optimized structures, configurational isomer energy differences (ΔE), and the configurational enthalpies (ΔH0), entropies (ΔS0), and free energies (ΔG0) of 4-alkyl equatorial tetrahydro-2H-thiopyr...

A new class of Pyrrolo[1,4]benzodiazepines (PBDs) analogs featuring a pyrazolo[4,3-e]pyrrolo[1,2-a][1,4]diazepinone ring system has been designed and synthesized. In these compounds the A-benzene ring, characteristic of PBDs, has been replaced by a dimethylpyrazole ring, a modification suggested...