4499-83-6Relevant academic research and scientific papers
Iodine-Promoted Metal-Free Aromatization: Synthesis of Biaryls, Oligo p-Phenylenes and A-Ring Modified Steroids
Domingo, Victoriano,Prieto, Consuelo,Castillo, Alexis,Silva, Lucia,Quílez Del Moral, José F.,Barrero, Alejandro F.
, p. 3359 - 3364 (2015/11/03)
We describe efficient procedures based on the use of iodine for the synthesis of biaryls from arylcyclohexenols or arylcyclohexanols using sub-stoichiometric/catalytic iodine and dimethyl sulfoxide (DMSO) as oxidant. Heteroarylcyclohexanols also produced the corresponding biaryl products. It was proven that biphenyl can also be efficiently obtained when the quantity of iodine was reduced to 0.05 equiv. The method is compatible with different functional groups in the aromatic ring (either electron-donating or electron-withdrawing groups). For substrate scope, apart from cyclohexanone and cyclohexenone, some substituted cyclohexanones were also used to synthesize the starting arylcyclohexanols. The process was applied to the synthesis of oligo p-phenylenes and A-ring aromatized steroids, where the combined use of I2/DMSO not only provoked the necessary migration of the methyl group at C-10, but also further extended the conjugation.
Calculated and experimental uv and ir spectra of oligo-para-phenylenes
Park, Kwangyong,Lee, Tae-Won,Yoon, Min-Ju,Choe, Jong-In
, p. 531 - 538 (2014/03/21)
The quantum mechanical properties of a series of oligo-para-phenylenes (2-11) were characterized using DFT B3LYP/6-311G(d,p) calculations. The global minimum among the various torsional conformers of an oligo-pphenylene is calculated to be a twist conformation. A less stable planar conformation, in which all the dihedral angles in oligo-p-phenylene are restricted to be planar, has also been calculated. The total electronic energies, normal vibrational modes, Gibbs free energies, and HOMOs and LUMOs of the two different conformations (twisted and planar) of the oligo-p-phenylenes were analyzed. The energy differences between the HOMOs and LUMOs of the substrates are in accord with the maximum absorption peaks of the experimental UV spectra of 2-6. The calculated normal vibrational modes of 2-6 were comparable with their experimental IR spectra.
Easy synthesis of phenyl oligomers using a Ni complex
Peres, Laura O.,Guillet, Francoise,Froyer, Gerard
, p. 452 - 454 (2007/10/03)
In this work are described the syntheses of p-sexiphenyl and p-octiphenyl starting from 4-bromo-p-terphenyl and 4-bromo-p-quaterphenyl, respectively, by using a nickel complex in the presence of bipyridine with DMF as solvent. This type of synthesis was shown to give an improved yield as well as easy preparation and purification of these phenylene oligomers.
Synthese et caracterisation d'oligomeres lineaires du phenylene
Faid, K.,Siove, A.,Chevrot, C.,Riou, M. T.,Froyer, G.
, p. 1305 - 1312 (2007/10/02)
Electrochemical reduction of monohalide aromatic compounds with catalytic amount of zero-valent nickel complex leads to corresponding linear dimeric oligophenylens in N,N dimethylacetamide.Effect of applied potential on a mercury pool on the yield of sublimated sexiphenyl under vacuum was studied.Oligophenylens were mainly characterized by infrared spectroscopy.Moreover, electrochemical behavior of parasexiphenyl and of 4 bromo-terphenyl were compared in acetonitrile medium.
One Pot Synthesis of p-Polyphenyls via the Intramolecular Cyclization of 3-Dimethylaminohex-5-en-1-ynes
Unroe, Marilyn R.,Reinhardt, Bruce A.
, p. 981 - 986 (2007/10/02)
Para linked polyphenyls of various molecular weights are conveniently synthesized from p-bis(3-dimethylamino-1-propynyl)arenes and 1-aryl-2-propenyl bromides in moderate yields using a three step, one-pot procedure.
Syntheses and Spectral Properties of Several Unsymmetrical Sexiphenyls
Ozasa, Shigeru,Fujioka, Yasuhiro,Ibuki, Eiichi
, p. 2698 - 2704 (2007/10/02)
Six sexiphenyls, including four new isomers, 2,3'-di(4-biphenylyl)biphenyl (2), 4-(2-biphenylyl)-o- (4), 4-(2-biphenylyl)-m-quaterphenyl (5), and 2-phenyl-p-quinquephenyl (6), were synthesized by the Ullmann cross-coupling of iodobiphenyl and diiodobiphenyl or of two kinds of iodoterphenyls.The characteristic bands of the infrared spectra (680-920 cm-1) and signals of the proton magnetic resonance spectra of the sexiphenyls were assigned tentatively and are discussed briefly.The remarkable high field shifts of the p-phenylene proton signals in 4 (1.23 and 0.89 ppm) as compared with that of p-terphenyl (δ 7.68) presumably reflect the ring current effects caused by the presence of adjacent o-phenylene rings.Ultraviolet spectral studies indicated that the absorption curves of the sexiphenyls were related closely to those of the polyphenyls corresponding to their partial structures.Keywords-Ullmann reaction; IR; UV; 1H-NMR; sexiphenyls; polyphenyls
Studies of Polyphenyls and Polyphenylenes. II. The Synthesis and Physical Properties of Polyphenyls Containing Para Linkage
Ozasa, Shigeru,Hatada, Noriko,Fujioka, Yasuhiro,Ibuki, Eiichi
, p. 2610 - 2617 (2007/10/02)
Twelwe linear polyphenyls, including quinque- to octiphenyl, were synthesized by the Ullmann cross-coupling reaction of iodobiphenyl with diiodobenzene or iodoterphenyl.Ultraviolet spectral studies of the polyphenyls indicated that the positions of the K-bands above ca.260 nm, regardless of the presence of o- or m-phenylene unit(s), may be considered to be an indication of the approximate number of consecutive p-phenylene units.Infrared studies also showed that the locations of strong or medium bands in the 815-850 cm-1 region may give the same information.The HMO calculations of the longest wavelength absorption bands of twenty-four polyphenyls were carried out.A comparison between the calculated and observed wavelengths gave rather good agreement, except in the cases of two compounds.The signals of the proton magnetic resonanse spectra of eighteen polyphenyls were assigned tentatively.The correlations between the arrangement of the benzene rings and the spectral patterns are discussed.
