Formation of nitrone in the reaction ofpara-nitroso-N,N-dimethylaniline with tetracyanoethylene

para-Nitroso-N,N-dimethylaniline reacts with tetracyanoethylene to give [4-(dimethyl-amino)phenylimino]malononitrileN-oxide 1 (65%) in addition to [4-(dimethyl-amino)phenylimino]malononitrile 2 (17%). The structures of the products are confirmed by spectral data and chemical transformations. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 617–619, March, 1997.     

Study on the 1,3-dipolar cycloaddition reaction of 4-ethoxy-1,1,1-trifluoro-3-buten-2-one with nitrile oxides

1,3-Dipolar cycloaddition (1,3-DC) reaction of 4-ethoxy-1,1,1-trifluoro-3-buten-2-one 1 with nitrile oxides was studied. It was found that besides its CC participating in the formation of isoxazole rings, trifluoromethyl activated CO also underwent 1,3-DC reaction with nitrile oxides to afford 1,4,2-dioxazole rings. Single crystal diffraction analysis also evidenced the diheterocyclic configuration.     

Reaction of 2-Isobutyl-4,5-dimethyl-1,3,2-dioxaborinane with Anhydrous Aluminum Bromide

Russian Journal of General Chemistry -     

Caged phosphorane with P-C bond based on chloral and 4,5-dimethyl-2-(2-oxo-1,2-diphenylethoxy)-1,3,2-dioxaphospholane

The key methods of caged phosphoranes synthesis are analyzed. Reaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenylethoxy)-1,3,2-dioxaphospholane (prepared from the meso-form of 2,3-butanediol) with chloral has yielded the caged phosphorane containing a phosphorus-carbon bond: 1,1-(1,2-dimethylethylenedioxy)-3,4-diphenyl-6-trichloromethyl-2,5,7,1-trioxaphosphabicyclo[2.2.1^1,4]heptane; spatial structure of the product has been elucidated with X-ray diffraction analysis.

     

Stereochemistry of the formation of 2-alkyl-4,5-dimethyl-1,3,2-dioxaborinanes

It is demonstrated with the help of¹H and¹³C NMR spectroscopy and GLC that the formation of the stereoisomers of 2-alkyl-4,5-dimethyl-1,3,2-dioxaborinanes from 2-methyl-1,3-butanediol and acyclic boric acid esters occurs stereospecifically. This conclusion was confirmed by calculations of the optimal geometries and relative energies of the molecules of thecis-andtrans-isomers of model 4,5-dimethyl-1,3,2-dioxaborinanes and the proposed intermediate with a tetravalent boron atom using the method of molecular mechanics.A. V. Bogatskii Physicochemical Institute, National Academy of Sciences of Ukraine, Odessa 270080, Ukraine. Institute of Organic Chemistry, Ufa Science Center, Russian Academy of Science, Ufa 450054, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 400–404, March, 1998.     

Molecular structure of 6,6-dimethyl-2-dimethylamino-2-oxo-4,5; 7,8-dibenzo-1,3,6,2-dioxasilaphosphocin and 2-methyl-2,6-dioxo-4,5; 7,8-dibenzo-1,3,2-dioxaphosphocin

An x-ray structural investigation of the synthesized title compounds (1) and (2) has been performed. The heterocycle of 1 has a boat-chair conformation with the P²=O² bond in the axial position. The heterocycle of 2 has a distorted-boat conformation with the C⁶=O carbonyl in the plane of one of the fused benzene rings. The P²=O² bond is in a pseudoequatorial position.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences, 420083 Kazan'. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 329–334, February, 1992.     

Reactions of some 2-oxo-1,3,2-oxathiaphospholanes and 2-oxo-1,3,2-phosphorinanes with phosphorus pentachloride

2-Phenoxy- and 2-dialkylamino-2-oxa-1,3,2-oxathiaphospholanes react with PCl₅ with ring opening and formation of the corresponding acid chlorides of thiophosphoric acid. Under analogous conditions, 2-phenoxy-2-oxo-1,3,2-oxathiaphosphorinanes do not react with PCl₅, while acid chlorides of thiophosphoric acid are formed in low yield along with other products in the reaction of 2-dialkylamino-2-oxo-1,3,2-oxthiaphosphorinanes with PCl₅.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Science Center, Russian Academy of Sciences, 420083 Kazan. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2676–2678, November, 1992.     

Intermolecular [2+2] photocycloaddition of chalcones with 2,3-dimethyl-1,3-butadiene under neat reaction conditions

The intermolecular [2 + 2] photocycloaddition of chalcones with 2,3-dimethyl-1,3-butadiene under visible-light irradiation for the synthesis of cyclobutane derivatives has been developed. Without using any photosensitizer, metallic catalyst and solvent, the reaction proceeded with high regioselectivity and moderate to high stereoselectivity. Mild reaction conditions and no additives make the reaction easy to operate. Control experiments and density functional theory (DFT) computations demonstrated that the reaction takes place via visible-light activation of chalcones, which is different from the previously reported [2 + 2] cycloaddition of chalcones.     

反式-2-取代硫代氨基脲基-4-芳基-5,5-二甲基-2-氧-1,3,2-二氧磷杂环己烷的立体选择性合成及立体化学研究

首先合成了重要的磷酰异硫氰酸酯中间体3, 然后便捷、高产率且立体选择性地合成了反式-2-取代硫代氨基脲基取代的新型六元磷杂环, 其立体化学通过2D NOESY NMR确证. 所有合成的化合物均进行了元素分析和光谱表征, 其中目标产物的13C NMR表征为1,3,2-二氧磷杂环己烷衍生物的碳骨架表征提供了难得的依据. 在溶剂DMSO-d6中, 所有产物均异构化, 生成磷原子的差向异构体. 这一研究结果证明了C4—H 以及31P NMR谱图与立体结构的相关性.     

4,5-Dioxo-and 4-oxo-2,3-diaryl-5-diazo-6,6-dimethyl-4,5,6,7-tetrahydroindazoles

The oxidation of 2,3-diphenyl-, 3-(4-chlorophenyl)-2-phenyl-, 3-(4-dimethylaminophenyl)-2-phenyl-, 3-(4-methoxyphenyl)-2-phenyl-, 2-phenyl-3-(3-pyridyl)-, 3-phenyl-2-(2-pyridyl)-, and 3-(4-dimethylaminophenyl)-6,6-dimethyl-4-oxo-2-(2-pyridyl)-4,5,6,7-tetrahydroindazoles using H₂SeO₃ in acetic acid in the presence of sulfuric acid gave the corresponding 4,5-dioxo derivatives. Reaction of these with tosylhydrazine gave 4-oxo-5-tosylhydrazino derivatives which were decomposed by alkali to give the corresponding 2,3-diaryl-5-diazo-6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazoles. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1829–1833, December, 2005     

Synthesis and reaction of N-butyl-N-isobutenyl-aminotrimethylsilane with 4,5-benzo-2-chloro-1,3,2-dioxaphospholane

The reaction of N-butylisobutyraldimine with trimethyliodosilane obtained in situ proceeds to give N-butyl-N-isobutenylaminotrimethylsilane, which reacts with 4,5-benzo-2-chloro-1,3,2-dioxaphospholane to yield 2-(N-butyl-N-isobutenylamino)-4,5-benzo-1,3,2-dioxaphospholane.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Science Center, Russian Academy of Sciences, 420083 Kazan. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1923–1924, August, 1992.     

The model of 1,3-dipolar cycloaddition reaction of 4,5-dihydro-1H-imidazole 3-oxide derivatives with alkynes

The influence of solvents and different structural factors on the rate of 1,3-dipolar cycloaddition reaction of the 4,5-dihydro-1H-imidazole 3-oxide derivatives with alkynes have been studied. Nitrones and alkynes have been ranged by their relative activity in this reaction. Using the DFT calculation with the triple zets basis set, the energy profile of the reaction has been plotted, and the structures and energy characteristics of the transition states have been determined. The mechanism of this reaction has been shown to be concerted and asynchronous. The validity of the used computational approach for the detailed investigation of 1,3-dipolar cycloaddition of nitrones has been demonstrated.