- Ethylammonium nitrate (EAN)/Tf2O and EAN/TFAA: Ionic liquid based systems for aromatic nitration
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Acting as in situ sources of triflyl nitrate (TfONO2) and trifluoroacetyl nitrate (CF3COONO2), the EAN/Tf 2O and EAN/TFAA systems, generated via metathesis in the readily available ethylammonium nitrate (EAN) ionic liquid as solvent, are powerful electrophilic nitrating reagents for a wide variety of aromatic and heteroaromatic compounds. Comparative nitration experiments indicate that EAN/Tf2O is superior to EAN/TFAA for nitration of strongly deactivated systems. Both systems exhibit low substrate selectivity (K T/KB = 5-10) in (Figure presented) between values reported for covalent nitrates and preformed nitronium salts.
- Aridoss, Gopalakrishnan,Laali, Kenneth K.
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experimental part
p. 8088 - 8094
(2011/11/13)
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- Synthesis of pyrrolnitrin and related halogenated phenylpyrroles
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A general approach to halogenated arylpyrroles, including the antifungal natural product pyrrolnitrin, is described using newly synthesized halogenated pyrroles and 2,6-disubstituted nitrobenzenes or 2,6-disubstituted anilines.
- Morrison, Matthew D.,Hanthorn, Jason J.,Pratt, Derek A.
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supporting information; experimental part
p. 1051 - 1054
(2009/07/18)
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- Designing banana-shaped liquid crystals without Schiff's base units: m- Terphenyls, 2,6-diphenylpyridines and V-shaped tolane derivatives
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This paper reports attempts to obtain (anti)ferroelectric switchable achiral banana-shaped molecules without Schiff's base units. For this purpose we have synthesized novel V-shaped molecules consisting of rigid angular central units [1,3-disubstituted be
- Shen, Dong,Diele, Siegmar,Pelzl, Gerhard,Wirth, Ina,Tschierske, Carsten
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p. 661 - 672
(2007/10/03)
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- Syntheses and Physical Properties of Several Octiphenyls and a Septiphenyl
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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
- Ozasa, Shigeru,Fujioka, Yasuhiro,Fujiwara, Michiko,Ibuki, Eiichi
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p. 3210 - 3222
(2007/10/02)
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