1166-19-4Relevant academic research and scientific papers
Acid-catalyzed rearrangements in arenes: Interconversions in the quaterphenyl series
Skraba-Joiner, Sarah L.,Holt, Carter J.,Johnson, Richard P.
, p. 2655 - 2663 (2019/12/11)
Arenes undergo rearrangement of phenyl, alkyl, halogen and other groups through the intermediacy of ipso arenium ions in which a proton is attached at the same carbon as the migrating substituent. Interconversions among the six quaterphenyl isomers have b
Role of the base and control of selectivity in the suzuki-miyaura cross-coupling reaction
Lima, Carlos F. R. A. C.,Rodrigues, Ana S. M. C.,Silva, Vera L. M.,Silva, Artur M. S.,Santos, Luis M. N. B. F.
, p. 1291 - 1302 (2014/05/20)
The outcome of the Suzuki-Miyaura cross-coupling for the direct competition reaction between two boronic acids was evaluated under routine synthesis conditions. The reaction selectivity was found to depend on the amount of the base used, with fewer bases
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
Syntheses and Physical Properties of Several Octiphenyls and a Septiphenyl
Ozasa, Shigeru,Fujioka, Yasuhiro,Fujiwara, Michiko,Ibuki, Eiichi
, p. 3210 - 3222 (2007/10/02)
Six symmetrical linear octiphenyls were synthesized by the Ullmann homo-coupling reaction of iodoquaterphenyl.Another satisfactory method for synthesizing octiphenyls is also described, i.e., a Kharash-type Grignard cross-coupling of biphenylylmagnesium bromide and diiodoquaterphenyl in the presence of bis(acetylacetonato)nickel(II).Moreover, m-septiphenyl was succesfully synthesized by deamination of the corresponding amino compound.Infrared studies of the polyphenyls indicated that the fine-structure bands in the regions of 770-810 and 870-915 cm-1 may be considered as indicators of the presence of consecutive m-phenylene rings, regardless of the existence of o- or p-phenylene rings.The ultraviolet spectra of the octiphenyls, which contain two kinds of linkages, showed absorption curves closely related to those of quaterphenyls corresponding to the structural units of the former compounds.The nuclear magnetic resonance spectra of the polyphenyls without an o-phenylene ring showed multiplet peaks due to the resonances of an isolated m-phenylene proton at the lowest field within a narrow region (δ 7.81-7.95).Hueckel molecular orbital calculations of the longest wavelength absorption bands of ten polyphenyls were carried out.The calculated and observed wavelengths were in rather good agreement except for the cases of three compounds.Keywords - Ullmann reaction; Ni-complex-catalyzed cross-coupling; octiphenyls; septiphenyls; IR; UV; NMR; MO; quaterphenyl derivatives; polyphenyls
