- Exploring the nitro group reduction in low-solubility oligo-phenylenevinylene systems: Rapid synthesis of amino derivatives
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A small series of amino oligo-phenylenevinylenes (OPVs) were successfully synthesized from their nitro-analogs in a rapid, simple, and highly efficient fashion employing a sodium sulfide/pyridine system as a reducing agent. In this research, classic and sustainable reduction methodologies including NH4HCO2/Zn and a choline chloride/tin (II) chloride deep eutectic solvent (DES) were also evaluated, showing degradation products, incomplete reactivity, and product isolation difficulties in all cases. The straightforward Na2S/pyridine synthetic protocol proved to maintain the E-E stereochemistry of the OPV backbone that has been previously assembled by the Mizoroki–Heck cross-coupling reaction. Also, the optoelectronic properties were determined and discussed, considering the amino group insertion in these conjugated systems as a contribution for future construction of novel materials with applications in supramolecular electronics, light harvesting, and photocatalysis.
- Acelas, Mauricio,Sierra, Andrés Felipe,Sierra, César A.
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supporting information
p. 1335 - 1352
(2020/03/04)
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- Method for preparing 3-nitro-4-(dimethylamino) benzaldehyde from nitrogen dioxide nitrated 4-(dimethylamino) benzaldehyde
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The invention discloses a method for preparing 3-nitro-4-(dimethylamino) benzaldehyde from nitrogen dioxide nitrated 4-(dimethylamino) benzaldehyde. According to the invention, 4-(dimethylamino) benzaldehyde and nitrogen dioxide are stirred and react in t
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Paragraph 0011; 0012; 0013; 0014
(2018/01/03)
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- 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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- Further naphthylcombretastatins. An investigation on the role of the naphthalene moiety
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By synthesis and biological studies of new naphthalene analogues of combretastatins, we have found that the naphthalene is a good surrogate for the isovanillin moiety (3-hydroxy-4-methoxyphenyl) of combretastatin A-4, always generating highly cytotoxic analogues when combined with the 3,4,5-trimethoxyphenyl or related systems. On the other hand, when the naphthalene replaces the 3,4,5-trimethoxyphenyl moiety, the cytotoxic activity is largely decreased. The most cytotoxic naphthalene analogues of combretastatins, which also produce inhibition of tubulin polymerization, exerted their antimitotic effects through microtubule network disruption and subsequent G2/M arrest of the cell cycle in human cancer cells.
- Maya, Ana B. S.,Pérez-Melero, Concepción,Mateo, Carmen,Alonso, Dulce,Fernández, José Luis,Gajate, Consuelo,Mollinedo, Faustino,Peláez, Rafael,Caballero, Esther,Medarde, Manuel
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p. 556 - 568
(2007/10/03)
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- ACTIVATING EFFECT OF THE IMINIUM GROUP IN AROMATIC NUCLEOPHILIC SUBSTITUTION OF AN ALKOXY GROUP AND HALOGEN ATOMS BY THE ACTION OF NITROGEN BASES
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The characteristics of aromatic nucleophilic substitution with activation by the iminium group in the iminium derivatives of p-alkoxy- and p-halogenobenzaldehydes were investigated.They are determined by the concurrent addition of the nucleophilic agents at the C=N multiple bond.The activating effect of the iminium group depends on the nature of the leaving group, the solvent, the substituent in the benzene ring, and the nature and concentration of the protonating agent.The action of heat on p-methoxybenzylidenemethylamine with a tenfold excess of methylamine hydrochloride in a 30percent alcohol solution of methylamine at 150 deg C for 40 h leads to substitutioon of the methoxymethylamino group with a yield of 90percent.
- Blokhin, A.V.,Bundel, Yu. G.,Terenin, V.I.,Kurtz, A.L.
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p. 2116 - 2123
(2007/10/02)
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- Light Absorption and Substituent Effects of Stilbene-4-diazonium Ions
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Substituent effects on νmax-values of 31 stilbene-4-diazonium ions are studied.With increasing donor strenth of a substituent in 4'-position the long wave absorption band of stilbene-4-diazonium ions shifts from the ultraviolet to the red regio
- Walkow, F.,Epperlein, J.,Mustroph, H.
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p. 799 - 807
(2007/10/02)
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- Electrophilic ipso-Substitutions. Part 3. Reactions of 3-Substituted Indoles, 4-Substituted N,N-Dimethylanilines, and 1- and 3-Substituted Indolizines with Nitrous Acid
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Reactions of 3-substituted indoles, N,N-dimethylanilines, and 1- and 3-substituted indolizines with nitrous acid yield products of ipso-substitutions, essentially the corresponding nitro-derivatives.An electron transfer process is proposed for the initial
- Colonna, Martino,Greci, Lucedio,Poloni, Marino
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p. 165 - 170
(2007/10/02)
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