Pyrroles from ketoximes and acetylene. 29. Synthesis of alkylpyrroles from dialkylketoximes and dichloroethane by reaction with KOH-DMSO

Treatment of dialkylketoximes with dichloroethane and KOH-DMSO results in the formation of alkylpyrroles in 31–61% yields. In addition, the corresponding 1-vinylpyrroles are formed simultaneously in yields up to 18%. The corresponding 1,2-bis(alkylideneiminoxy)ethanes are obtained as side products in the reaction; they result from nucleophilic displacement of chlorine atoms by oximate anions.For Communication No. 28, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 59–62, January, 1985.     

Pyrroles from ketoximes and acetylene. 46. Pyrroles with sterically hindered substituents

The corresponding pyrroles and their N-vinyl derivatives were obtained by the catalyzed (by an MOH-DMSO superbase) reaction of acetylene and its crypto forms (vinyl chloride, 1,2-dichloroethane) with alkyl-2,4-, alkyl-2,5-, and alkyl-3,4-dimethylphenylketoximes. Reaction intermediates — O-vinylketoximes — were detected.For Communication 45 See [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1320–1323, October, 1991.     

Pyrroles from ketoximes and acetylene. 19. Regioselectivity of the reaction of alkyl benzyl ketoximes with acetylene

Alkyl benzyl ketoximes react with acetylene at 60–150 °C in MOH-dimethyl sulfoxide (M = Li, K) primarily by means of the methylene group of the benzyl grouping, which is primarily anti-oriented with respect to the hydroxy group, to give 2-alkyl-3-phenylpyrroles in greater than 70% yields. The specific participation of the antimethylene group in the construction of a pyrrole ring constitutes evidence against mechanisms that include a [3,3]-sigmatropic shift in O-vinyl oximes. It follows from the results obtained that the reaction proceeds through an anti-dianion of the benzyl type stabilized by conjugation with the aromatic ring.See [1] for communication 18.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 193–198, February, 1982.     

Pyrroles from ketoximes and acetylene 8. Synthesis of 4,5,6,7-tetrahydroindole and its 1-vinyl derivative

4,5,6,7-Tetrahydroindole or 1-vinyl-4,5,6,7-tetrahydroindole was obtained in 81 and 93% yields, respectively, by reaction of cyclohexanone oxime with acetylene at 90–140C in the presence of alkali metal hydroxides or alkoxides in dimethyl sulfoxide (DMSO) or mixtures of DMSO with low-polarity or nonpolar solvents. The reaction is effective both in an autoclave (initial pressure 8–16 gage atm) and at atmospheric pressure.See [1] for communication 7.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 197–199, February, 1979.     

Pyrroles from ketoximes and acetylene

2-(2-Furyl)pyrroles and 1-vinyl-2-(2-furyl)pyrroles were obtained in up to 80% yields in the reaction of ketoximes of the furan series with acetylene in MOH—dimethyl sulfoxide (M = Li, K) Superbase media.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1058–1061, August, 1981.     

Pyrroles from ketoximes and acetylene. 40. Reaction of alkyl hetaryl ketoximes with 1,2-dichloroethane in superbase media

2-(2-Furyl)- and 2-(2-thienyl)pyrroles and their N-vinyl derivatives were synthesized by the reaction of alkyl furyl (thienyl) ketoximes with 1,2-dichloroethane in superbase media. 2-Chloroethyl and vinyl ethers of alkyl hetaryl ketoximes are intermediates in the reaction.See [1] for Communication 39.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 901–906, July, 1989.     

Pyrroles from ketoximes and acetylene. 23. 2-(1-naphthyl)- and 2-(2-naphthyl)pyrroles and their 1-vinyl derivatives

2-(1-Naphthyl)- and 2-(2-naphthyl)pyrroles and their 1-vinyl derivatives were synthesized in 22–64% yields by the reaction of 1- and 2-acetylnaphthalene oximes with acetylene at both atmospheric pressure and elevated pressures in an alkali metal hydroxide-dimethyl sulfoxide system.See [1] for communication 22.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1351–1353, October, 1982.     

Pyrroles from ketoximes and acetylene

The reaction between ketoximes CH₃(RCH₂)C = NOH and acetylene in the presence of KOH and dimethyl sulfoxide at 120°C leads exclusively to 1-vinyl-2-methyl-3-R-pyrroles in 73–87% yields. The regiospecificity of the reaction is disrupted when the temperature is raised, and the fraction of a second isomer (1-vinyl-2-RCH₂-pyrrole) reaches 20–50% at 140°C. Regioselectivity is not observed for R¹CH₂(R²CH₂)C = NOH (R¹ and R² = n-alkyl). The relative shifts of the signals of the ring protons and the vinyl group for a number of 2-alkyl-1-vinyl- and 2,3-dialkyl-1-vinylpyrroles were measured. Alkyl substituents have a distinct effect on the chemical shifts of the protons of the 4–5 bonds. As the volume of the 2-alkyl substituent increases the protons of the N-vinyl group are deshielded by 0.10–0.13 ppm, and the 4-H ring proton is shielded by 0.05–0.16 ppm; this is explained by steric inhibition of the p- conjugation in the N-vinyl group during an s-trans(anti)-gauche conformational transition.This is actually communication XVI. The first publications (for example, see [1–3] and the literature cited in them) were not numbered.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 54–59, January, 1978.     

Pyrroles from ketoximes and acetylene

The respective 2-aryl- and N-vinyl-2-arylpyrroles were obtained by the reaction of the oximes of alkyl aryl ketones with acetylene in the superbasic medium MOH (M=Li, K)-DMSO. Their yields depended largely on the structure of the ketoximes and on the reaction conditions.For Communication 41, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 609–613, May, 1992.     

Reaction of 2-aminobenzimidazole with acetylene

The reaction of 2-aminobenzimidazole (1) with acetylene under pressure proceeds with the formation of vinyl monomers, corresponding to amine and imine forms, 1-vinyl-2-amino- and 1,3-divinyl-2-iminobenzimidazoles, depending on the reaction conditions. 1,3-Divinyl-2-benzimidazolone was also isolated in aqueous dioxane in addition to the monovinyl derivative of1. Cyclization of the divinyl derivative of1 with acetylene proceeds to give 9-vinyl-1,2-dimethylimidazo[1,2-a]-benzimidazole.Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 664033 Irkutsk. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 749–751, March, 1992.     

Oxidative addition of 1,3-dicarbonyl compounds to dienes in the presence of Mn(III) AND Cu(II) acetates

Conclusions The selective oxidative 1,2-addition of acetylacetone and other dicarbonyl compounds to conjugated dienes was realized in an acetic acid solution containing manganese(III) and copper(II) ions. A series of 5-(1-alkenyl)-substituted 4,5-dihydrofurans were synthesized by the reaction with yields of 30–97%.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2077–2084, September, 1981.     

Pyrroles from ketoximes and acetylene.

2-Aryl- and 1-viny1-2-pyrroles were synthesized by condensation of p-substituted acetophenone oximes with acetylene under pressure in superalkaline media (KOH/DMSO). The initially formed nitrogen-unsubstituted pyrroles can be vinylated in the presence of acetylene. Lithium hydroxide, which is completely inactive in the vinylation step, was found to be a selective catalyst for the construction of a pyrrole ring from oximes of aliphatic aromatic ketones. In the case of aliphatic and cycloaliphatic ketoximes (for example, cyclohexanone oxime) LiOH has virtually no catalytic effect on the reaction. The yields of 1-viny1-2-ary1-pyrroles depend substantially on the substituent in the phenyl ring. The structures of the synthesized compounds were confirmed by the IR, PMR, UV, and ¹³C NMR spectra.See [1] for communication II.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 489–491, April, 1978.     

Effect of Temperature on the Yields of Final Products in the γ-Radiolysis of Formaldehyde Solutions in C1–C3 Alkanols

The effect of temperature on the yields of 1,2-alkanediols in the -radiolysis of the methanol(or ethanol)–formaldehyde (0.9 M) systems and on the yields of 1,2-alkanediols, carbonyl compounds, methanol, and ethanol in the -radiolysis of the 1-propanol(or 2-propanol)–formaldehyde (1 M) systems was studied over the range 373–473 K. It was found that the temperature dependence of the yields of 1,2-butanediol and 2-methyl-1,2-propanediol exhibited maximums at 423 and 373 K, respectively.     

Nonempirical calculations of potential-energy surfaces for nucleophilic addition of H− and F− to an acetylene molecule

The minimal energy paths for the nucleophilic addition of a hydride ion (H^–) and a fluoride ion (F^–) to a molecule of acetylene (A) have been calculated with the use of 3–21++G and 3–21+G double basis sets in the framework of the Hartree-Fock-Roothaan method. The values of the total energies of the reactants, transition states, and products have been refined by means of calculations with more complete basis sets [6–31++G// 3–21++G and 6–31++G*//3–21++G for reaction (1); 6–31+G*//3–21+G and 6–31++G**//3–21+G for reaction (2)] and by taking into account the correlation energy for reaction (1) in the framework of the SCEP/6–31++*//3–21++G method. It has been established that the activation energy of reaction (2) is 15.94 kJ/mole lower than that for reaction (1), that reaction (1) is exothermic, and that the enthalpy change accompanying reaction (2) is close to zero. The character of the distribution of the electron density along the minimal energy paths of both reactions has been analyzed, and the differences appearing as a result of the replacement of the soft nucleophile H^– by the harder nucleophile F^– have been ascertained. The results of the calculations have been compared with the results available in the literature for reaction (1).Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 149–155, March–April, 1989.     

Reaction of trimethyliodosilane with monosubstituted acetylene derivatives

Conclusions The reaction of phenylacetylene and 1-hexyne with Me₃SiI in the presence of Mg at 170–180° gave the corresponding trimethyl(organylethynyl)silanes in 80–95% yield.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, p. 897, April, 1981.     

Research on imidazo[1,2-a]benzimidazole derivatives. 23. Syntheses based on 2-(2-hydroxyethylamino)benzimidazoles

The possibility of annelation of the imidazoline ring on the basis of 2(2-hydroxyethylamino)-benzimidazoles was studied. It was shown that the action of hydrobromic, sulfuric, nitrosylsulfuric, and polyphosphoric acids, acetic anhydride, and phosphorus oxychloride on them does not lead to 2,3-dihydroimidazo[1,2-a]-benzimidazoles. In the case of POCl₃ the products were 2-(2-chloroethylamino)benzimidazoles, treatment of which with alcoholic alkali led primarily to nucleophilic substitution of the chlorine atom by a methoxy group. Three-ring imidazolines are formed in 12–15% yields in this case. It was established that the reaction proceeds through the intermediate formation of aziridine derivatives.See [1] for communication 22.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 59–63, January, 1987.     

Pyrroles from ketoximes and acetylene. 45. A new route to 2,2-dipyrroles

The reaction of 1-methyl-2-acetylpyrrole oxime with acetylene at atmospheric and increased pressure can be catalyzed by KOH-DMSO superbase to give 1-methyl-2-(2-pyrrolyl)pyrrole, N-vinyl-2-[1-methyl(2-pyrrolyl)]pyrrole, and the reaction intermediate methyl-2-(1-methylpyrrolyl)-O-vinyloxime.See [1] for Communication 44.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 460–463, April, 1991.     

Interaction of acetylene with organic disulfides

Conclusions Dialkyl disulfides are added to acetylene, forming 1,2-bis(alkyithio)ethenes and vinylalkyl sulfides.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 454–456, February, 1967.     

1,2-Dimethyl-1,2-diphenyidisilane-1,2-diol and its K,Na, and FeII derivatives. Molecular structure of the all-trans-isomer, 2,3,5,6-tetra-methyl-2,3,5,6-tetraphenyl-1,4-dioxa-2,3,5,6-tetrasilacyclohexane

Hydrolysis of 1,2-dimethyl-1,2-diphenyl-1,2-dichlorodisilane yields 1,2-dimethyl-1,2diphenyldisilane-1,2-diol, which undergoes dimerization into stereoisomeric 2,3,5,6-tetramethyl-2,3,5,6-tetraphenyl-1,4-dioxa-2,3,5,6-tetrasilacyclohexanes under the action of H₂SO₄. Pure all-trans-isomer has been isolated and characterized by¹H NMR and IR spectroscopy and X-ray analysis. The reaction of sodium disilanediolate with FeBr₂ results in the formation of 1,2-dimethyl-1,2-diphenyl-4-ferra(ii)-3,5-dioxa-1,2-disilacyclopentane.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2550–2556, October, 1996.     

Pyrroles from ketoximes and acetylene

A series of previously unknown trifluoroacetyl derivatives of pyrroles were obtained with high yields by the reaction of pyrroles, including N-vinyl-substituted pyrroles, with trifluoroacetic anhydride in the presence of pyridine at room temperature. The solvent and the substituents at the and positions of the pyrrole ring do not affect the direction of electrophilic substitution.For Communication 37, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 48–52, January, 1989.