- Efficient indium-mediated dehalogenation of aromatics in ionic liquid media
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An efficient indium-mediated dehalogenation reaction of haloaromatics and haloheteroaromatics in ionic liquids has been studied. This method is simple and effective in the presence of [bmim]Br. Furthermore, this methodology is environmentally friendly compared with conventional ones.
- Canete, Alvaro F.,Salas, Cristian O.,Zacconi, Flavia C.
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p. 398 - 407
(2013/03/13)
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- Syntheses and Absolute Stereochemistry of Chiral 9,10-Dihydro-9,10-ethanoanthracenes and their Tricarbonylchromium Complexes
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Several chiral mono- and disubstituted 9,10-dihydro-9,10-ethanoanthracenes have been prepared from the corresponding anthracenes.Most of them were separated into enantiomers by chromatography on cellulose triacetate (CTA) and their absolute chiralities established by chiroptical comparison (via their CD spectra) with key compounds of known configuration.From the laevorotatory 1,5-dibromo derivative 16 the dextrorotatory dideuterio hydrocarbon (+)(9S,10S)-20 was obtained.Complexation of 2,6-dimethyl 9,10-dihydro-9,10-ethanoanthracene (+)-25, obtained by enantioselective chromatography on CTA , with Cr(CO)6 afforded two mono tricarbonylchromium complexes as well as the bis-exo,endo-complex (+)-28.Configurational assignments (exo,endo) are based on the absorption patterns of the bridge protons in the 1H NMR spectra. Keywords: (+)-1,5-Dideuterio-9,10-dihydro-9,10-ethanoanthracene; Enantioselective chromatography on CTA; Circular dichroism; Configurational correlation; Tricarbonylchromium complexes.
- Li, Z.,Werner, A.,Schloegl, K.
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p. 441 - 452
(2007/10/02)
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- Benzannulated Isobenzofurans
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A number of arynes, generated by treatment of haloarenes with sodium or potassium amide in tetrahydrofuran, were trapped with furan.The resulting dihydro epoxy arenes were converted into the following annulated isobenzofuran derivatives by using reverse Diels-Alder methodology: naphthofuran, phenanthrofuran, pyrenofuran, pyrenofuran, anthrafuran, phenanthrofuran and phenathrofuran.Bimolecular rate constants for the addition of maleic anhydride to these furans were measured, and were correlated with the Herndon structure count.Addition of arynes to selected members of this furan series yielded adducts which were deoxygenated to afford polycyclic aromatic hydrocarbons.
- Moursounidis, John,Wege, Dieter
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p. 235 - 249
(2007/10/02)
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- Sulfonation of aromatic compounds in the presence of solvents
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A process for the sulfonation of aromatic compounds wherein an aromatic substance consisting of one or more aromatic compounds susceptible to the action of sulfur trioxide is formed into a reactant by admixture with one or more organic liquids, substantially inert to sulfur trioxide under the conditions of the process, which reactant is brought to boiling at a temperature not greater than 100° C under a pressure of from 0.1 mm Hg to atmospheric pressure, gaseous sulfur trioxide is introduced thereinto thereby causing it to continue to boil, the component or components of the reactant thus volatilized is or are reconverted to liquid in a heat-exchanger and recycled to the reaction chamber, and the pressure in the reaction chamber and the rate at which the gaseous sulfur trioxide is introduced into the reactant are controlled so as to ensure that there is always present in the reaction chamber an amount of volatilizable matter exceeding that amount volatilizable by the heat of reaction of the aromatic substance present in the reaction chamber with the gaseous sulfur trioxide in contact with said aromatic substance and that the temperature of the reaction mixture is a temperature of 100° C or below.
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