Facile [3,3]-sigmatropic rearrangement in the reaction of α-chloroperfluorostyrene with allyl alcohol

The reaction of -chloroperfluorostyrene (1) with allyl alcohol in the presence of KOH at 45–50°C leads to a mixture of the allyl 2-pentafluorophenyl-2-chloro-4-pentenoate (2) and the product of the addition of the starting reagents (3). Ester2 is formed as the result of a mild [3,3]-sigmatropic rearrangement of the reaction intermediate.A. N. Nesmeyanov Institute of Organometallic Compounds, Russian Academy of Sciences, 117813 Moscow. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1925–1926, August, 1992.     

Effect of pressure on the free radical reactions of 2-alkoxytetrahydropyrans

In free radical transformations of 2-methoxy- and 2-ethoxytetrahydropyran initiated bytert-butoxy radicals at 130°C, the relative rate of formation of -valerolactone and valeric acid ester was found to change periodically with increase in the extent of transformation, expressed astert-butyl alcohol (TBA) concentration. The ratio of lactone: ether concentration is determined not by the pressure (up to 1000 MPa) as suggested earlier, but by the amplitudes and phase displacement of the oscillations of the rates of formation of lactone and ester. These results are explained by changes in the physical structure of the solution in proportion to the buildup of reaction products as a result of which the reactivity of the 2-alkoxytetrahydropyranyl radical changes in respect of rupture of the endocyclic and exocyclic C-O bonds.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 822–828, April, 1992.     

A new strategy for the synthesis of aryl- and heteroaryl-substituted exocyclic olefins from allyl alcohols using PBr3

Treatment of aryl and heteroaryl substituted allyl alcohols 7-14 with phosphorus tribromide at 0 °C furnished a new series of substituted exocyclic olefins 15-22 in good yields. The +I inductive effect of substituents on the aryl group is described.     

Alkylation of P-containing zwitter-ions based on 2-cyanoacrylates

The interaction of P-containing zwitter-ions based on ethyl 2-cyanoacrylate with methyl iodide, allyl bromide, -bromoacetophenone, and 1,3-dichloroacetone has been studied. Alkylation occurs at the central carbon atom of the pentade anion.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1641–1643, September, 1994.     

Acylation of phenols with γ-chlorobutyroyl chloride and transformations of the reaction products

Alkylphenols afford only O-acyl derivatives on treatment with -chlorobutyroyl chloride in the presence of both Et₃N and AIC1₃ at 20–60 °C. They cyclize under the action of K₂CO₃ in DMSO into the respective cyclopropanes and undergo Fries rearrangement on heating with AICl₃ at 120 °C into C-acyl derivatives.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 1023–1025, April, 1996.     

Chlorinating properties of the trimethylchlorosilane-potassium bromate-DMF system

-Dicarbonyl compounds such as ethyl acetoacetate, dimedone, and Meldrum's acid derivatives undergo monochlorination by the action of a mixture of C1SiMe₃ and KBrO₃ in DMF at 20°C.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 448–450, February, 1992.     

Cyclization of O-benzoyl-β-piperidinopropionamidoximes to form 5-phenyl-3-(β-piperidino)ethyl-1,2,4-oxadiazoles

The reactions of -piperidinopropionamidoxime with substituted benzoyl chlorides afforded O-benzoylation products, which underwent cyclization to form 5-phenyl-3-(-piperidino)ethyl-1,2,4-oxadiazoles upon heating in dimethylformamide in the presence of molecular sieves at 60 °C for 1—2.5 h. Heating of O-benzoyl--piperidinopropionamidoxime in dimethylformamide in the presence of K₂CO₃ at 85 °C for 4 h afforded a mixture of 5-phenyl-3-(-piperidino)ethyl-1,2,4-oxadiazole, benzoic acid, and N-(-piperidino)ethylurea.     

Reaction of the dimethoxyaminyl radical with tertiary nitrosoalkanes as a method for the preparation of N-alkyl-N′-methoxydiazene N-oxides

The reaction of the dimethoxyaminyl radical with functionally substituted nitrosoalkanes (2) in a 2:1 ratio at 20°C gives the corresponding N-alkyl-N-methoxydiazene N-oxides (3) as a single isomer in preparative yields.N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 10, pp. 2443–2445, October, 1992.     

Indoles

It has been found that arylhydrazones of carbonyl compounds smoothly undergo rearrangement into the corresponding indoles under the action of strong alkylating agents such as benzyl chloride, allyl bromide, and dimethyl sulfate in boiling methanol. The use of arylhydrazines substituted at the α-nitrogen atom leads to the formation of N-subsituted indoles; However, where a hydrazine of the type of ArNHNH₂ is used, a mixture of the corresponding indole and of the indole substituted on the nitrogen atom by the radical of the alkylating compound is formed.     

Stereochemical characteristics of the ammonia reaction with perfluoro-2-methyl-2-pentenethiocyanate-3: The defining role of the steric factor determined by geometric modeling

Geometric modeling has been used to analyze the stereochemical characteristics of the ammonia reaction with perfluoro-2-methyl-2-pentenethiocyanate-3. This reaction is stereospecific because it results in only one E stereoisomer of 2-aminoperfluoro-4,4-dimethyl-4,5-dihydro-5-ethylidene-1,3-thiazole (3). It is shown that such stereospecificity is determined by a lower steric hindrance in the anion from which the E isomer is formed as compared to that in the anion from which a Z isomer would be formed. Strong steric hindrances associated with the amino group attached to a double bond exclude the heat-dependent cyclization of E-2,4-diaminoperfluoro-4-methyl-2-pentenethiocyanate-3 (4), which would result in the formation of a thiazole ring. The substitution of the fluorine atom at the double exocyclic bond in thiazoline E-3 by an amino group does not occur because of the electron destabilization of the transition state resulting from the repulsion of the unshared electron pairs of the carbanion and the sulphur atom .A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 343–349, February, 1992.     

Ion mobilities in DMF-water mixtures at 25°C

Densities and viscosities of mixtures of N,N-dimethylformamide (DMF) with water at 25°C have been determined. Limiting equivalent conductances of cesium chloride, potassium chloride, potassium bromide and potassium thiocyanate in these solvent mixtures at 25°C are presented together with corresponding values of ion association constants and distance of closest approach parameters. The transference number of the potassium ion has been determined in solvent mixtures ranging from 0 to 0.75 mol fraction in DMF in water at 25°C. The conductimetric Hittorf method has been used for both potassium bromide and potassium chloride in solutions of up to 0.496 mole fraction of DMF. For solutions of potassium thiocyanate in 0.5 and 0.75 mole fraction in DMF the cationic transference number has been determined using the moving boundary method. Stokes radii have been evaluated. Transport properties are examined in relation to-solvent properties such as composition, dielectric constant, excess volume of mixing and free volume.To whom correspondence should be addressed.     

Conformational aspects of the solvation of polyhydroxy compounds in binary mixtures of N,N-dimethylformamide and water

Enthalpies of solution of -D-fructose and sucrose in binary solvent mixtures of water and N,N-dimethylformamide (DMF) at 25°C over the whole mole fraction region are reported and compared to those of -D-glucose. Because in these solvent systems the mutarotation of -D-fructose is fast and accompanied by large enthalpy changes, the measured enthalpies of solution of this compound had to be corrected for this effect. The dependences of the enthalpies of solution on the composition of the solvent mixtures are considered to result from preferential hydrogen-bonding of the hydroxyl groups and hydrophobic hydration of the apolar parts of the surface of the solute molecule. Distinctions between the enthalpy of transfer curves are discussed in terms of conformational differences and additivity aspects in the solvation behavior of the compounds. The predominance of furanose forms of fructose in DMF and that of pyranose forms of the same solute in water are related to differences in solvation.     

Formation of organopalladium complexes on SiO2 and Al2O3 as a result of the reaction of allyl alcohol with supported PdCl2; thermal decomposition of these complexes

It was established by electronic spectroscopy in the UV and visible regions and mass spectrometry that when allyl alcohol reacts from the gas phase with palladium chloride supported on SiO₂ and Al₂O₃ a complex similar in characteristics to a bis--allylpalladium chloride complex that is fixed on the surface of the support is formed. Decomposition of this complex in vacuo occurs at 135°C with the formation of allyl chloride and zero-valence supported palladium.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1536–1539, July, 1992.     

InBr3-catalyzed stereoselective synthesis of 3,4-disubstituted hexahydro-1H-furo[3,4-c]pyran derivatives

An ?,δ-unsaturated alcohol tethered with a hydroxyl group, that is, (E)-2-styrylbutane-1,4-diol (1) undergoes a smooth bicyclization with various aldehydes in the presence of 10 mol % InBr₃ and at 0 °C to afford a novel series of hexahydro-1H-furo[3,4-c]pyran derivatives in good yields with high diastereoselectivity.     

Preparation of alumina by sol-gel process,its structures and properties

Alumina monolithic gel has been prepared by ammonia method from anhydrous aluminium chloride and n-butanol using formamide as the solvent. The gel has been made by hydrochloric acid catalysis and using large quantity of water for hydrolysis (molar ratio of water to aluminium-n-butoxide, R>99). Transparent alumina xerogel of size 37.5×20×5 mm approximately has been prepared. The alumina gel has been dried and sintered at 400°C, 1000°C and 1200°C respectively and the powders formed thereby have been examined by XRD, FTIR spectroscopy, SEM and particle size analysis. These studies have confirmed the formation of -alumina at 1200°C having particle size as low as 0.2 m or less along with agglomerates. The density of the powder has increased gradually, where as its particle size has decreased, with the increase of the sintering temperature.     

Heterogeneous catalytic transformation of isobutyl benzoate by the inverse Tishchenko reaction

Using the catalytic transformation of isobutyl benzoate at 663 K in the presence of 12 % MnO₂/-Al₂O₃ in a He atmosphere as an example, it has been shown that the inverse Tishchenko reaction can take place at a temperature above 600 K. Isobutyl benzoate gives isobutanal and benzaldehyde as well as products of their transformation,i.e., benzyl isobutyrate, isobutanol, benzyl alcohol, and toluene.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1494–1496, August, 1994.     

Synthesis of new fused isoquinolines via reissert compounds

Reissert compounds 2 derived from isoquinoline, chloroformates and TMS‐cyanide were alkylated in position 1. The resulting alkylation products 3 as well as the precursors 2 reacted with Grignard reagents affording imidazoisoquinolines 4, 5, 7 and 8 by addition to the cyano group and Grignard reduction or by twofold addition to the cyano group, respectively. In both cases the alcohol of the 2‐alkoxycarbonyl moiety was eliminated by attack of the N‐atom at the carbonyl carbon atom. Under acid conditions, 1‐benzylated Reissert compound 3h cyclised by attack of the resulting N‐acyliminium C‐atom at the o‐position of the benzyl ring to form tetracyclic 1,3‐bridged tetrahydroisoquinolines 10 and 11. Bromocyclisation of 1‐allyl‐2‐menthyloxycarbonyl‐substituted Reissert compounds 3b, c led to tricyclic dibromo products 12, in which the menthol moiety was split off and addition to the enamine double bond occurred. A 2‐menthyloxycarbonyl group in Reissert compounds 2a and 3 failed to exert an asymmetric induction in all cases.     

脂质体的聚合反应（Ⅰ）：不饱和脂质体的单体合成

生物膜是由磷脂双分子层构成的基质和镶嵌或包埋在基质中的蛋白质所组成,脂质体与生物膜结构相似,但一般是热力学不稳定体系,为改善脂质体的稳定性,近年合成和制备了许多不饱和脂质体单体化合物和聚合脂质体。     

Reaction of sulfur with benzyl halides

Conclusions The main products of the reaction of benzyl chloride and benzyl bromide with sulfur at 230°C are tetraphenylthiophene, 2-phenylthianaphthene, E-stilbene, dibenzyl, and 2-phenyl-3-benzylthianaphthene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 653–654, March, 1989.     

Sulfonamidation of halogen-substituted electrophiles with <Emphasis Type="Italic">N</Emphasis>-(2,2,2-trichloroethyl)arenesulfonamides

Reactions of N-(2,2,2-trichloroethyl)arenesulfonamides with primary alkyl bromides and iodides, allyl bromide, chloroacetonitrile, and benzyl chloride in acetonitrile on heating in the presence of potassium carbonate gave the corresponding N-alkyl-N-(2,2,2-trichloroethyl)arenesulfonamides.