- α,ω-Diphenylpolyenes cabable of exhibiting twisted intramolecular charge transfer fluorescence: A fluorescence and fluorescence probe study of nitro- and nitrocyano-substituted 1,4-diphenylbutadienes
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1,4-Diphenylbutadiene compounds, namely 1-p-cyanophenyl-4-phenylbuta-1E,3E-diene (2), 1-p-nitrophenyl-4-phenylbuta-1E,3E-diene (3), 1-cyano-1,4-diphenylbuta-1Z,3E-diene (4), 1-p-cyanophenyl-4-p-nitrophenylbuta-1E,3E-diene (5), 1-cyano-1-p-nitrophenyl-4-ph
- Singh, Anil K.,Darshi, Manjula,Kanvah, Sriram
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- Synthesis and anticancer activity of new azo compounds containing extended π-conjugated systems
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A series of novel azo compounds with extended π-conjugated systems were prepared by azo coupling reaction compounds trans-2-(4′-aminostyryl)-thiophene, 1-(4-aminophenyl)-4-phenyl-1,3-butadiene and 4-amino-4′-methoxystilbene with some phenols. The compounds were evaluated for their cytotoxicity against breast cancer adenocarcinoma (MCF-7), cervix adenocarcinoma (HeLa) and human embryonic kidney (HEK 293) cell lines using the MTT assay. The results showed all derivatives had more toxic effects than tamoxifen. Of all the compounds tested, the azo product obtained from coupling trans-2-(4′-Aminostyryl)-thiophene with 2-naphthol (compound 5b) exhibited the potent in vitro antiproliferative activity with IC50 27 ± 1 and 18 ± 0 μg/mL against MCF-7 and HeLa cell lines, respectively, while it was devoid of any cytotoxicity against normal HEK 293 cells even at 200 μg/mL.
- Rezaei-Seresht, Esmail,Mireskandari, Erfan,Kheirabadi, Mitra,Cheshomi, Hamid,Rezaei-Seresht, Hasan,Aldaghi, Leila Sadat
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- Synthesis and evaluation of a series of 1,4-diarylbutadienes for anticoccidial activity
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During the course of a collaborative screening program, a set of 1-phenyl-4-pyridyl-butadienes was found to exhibit in vitro activity against Eimeria tenella in a cell-based assay. Activity was dependent on the chain length and degree of unsaturation of t
- Gage, Jennifer L.,Kirst, Herbert A.,O'Neil, Deirdre,David, Bridget A.,Smith II, Charles K.,Naylor, Sharon A.
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- Pd-Catalyzed Cross-Coupling of Organostibines with Styrenes to Give Unsymmetric (E)-Stilbenes and (1 E,3 E)-1,4-Diarylbuta-1,3-dienes and Fluorescence Properties of the Products
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A general and effective palladium-catalyzed cross-coupling of organostibines with styrenes to give (E)-olefins was disclosed. By the use of an organostibine reagent, this method can produce unsymmetric (E)-1,2-diarylethylenes and (1E,3E)-1,4-diarylbuta-1,3-dienes in good yields with high E/Z selectivity and good functional group tolerance. Resveratrol and DMU-212 were synthesized in high yield. The protocol can be extended to the synthesis of (1E,3E,5E)-1,6-diphenylhexa-1,3,5-triene in 40% yield. Products 5e, 5f, and 7a showed good photoluminescence quantum yields ranging from 72 to 99%.
- Zhang, Zhao,Zhang, Dejiang,Zhu, Longzhi,Zeng, Dishu,Kambe, Nobuaki,Qiu, Renhua
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supporting information
p. 5317 - 5322
(2021/06/28)
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- Phosphorus-recycling wittig reaction: Design and facile synthesis of a fluorous phosphine and its reusable process in the wittig reaction
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This study shows that phosphorus sources can be recycled using the appropriate fluorous phosphine in the Wittig reaction. The designed fluorous phosphine, which has an ethylene spacer between its phosphorus atom and the perfluoroalkyl group, was synthesized from air-stable phosphine reagents. The synthesized phosphine can be used for the Wittig reaction process to obtain various alkenes in adequate yields and stereoselectivity. The concomitantly formed fluorous phosphine oxide was extracted from the reaction mixture using a fluorous biphasic system. The fluorous phosphine was regenerated by reducing the fluorous phosphine oxide with diisobutylaluminum hydride. Finally, a series of gram scale phosphorus recycling processes were performed, which included the Wittig reaction, separation, reduction, and reuse.
- Yamamoto, Yuki,Kawaguchi, Shin-Ichi,Nishimura, Misaki,Sato, Yuki,Shimada, Yoshihisa,Tabuchi, Akihiro,Nomoto, Akihiro,Ogawa, Akiya
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p. 14684 - 14696
(2020/11/30)
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- Photoisomerization of Trans Ortho-, Meta-, Para-Nitro Diarylbutadienes: A Case of Regioselectivity
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A series of ortho-, meta- and para-substituted trans-nitro aryl (phenyl and pyridyl) butadienes have been synthesized and characterized. The effect of substitution and positional selectivity on their fluorescence and photoisomerization were systematically investigated. Among all dienes, meta- and para-nitro phenyl-substituted derivatives exhibit remarkable solvatochromic emission shifts due to intramolecular charge transfer. On the other hand, ortho derivatives undergo regioselective isomerization upon photoexcitation in contrast to inefficient isomerization of para and meta nitro-substituted dienes. Single crystal X-ray analysis revealed existence of intramolecular hydrogen bonding between the nitro group and the hydrogen of the proximal double bond. This restricts the rotation of the proximal double bond thereby allowing regioselective isomerization. The observations were also supported by NMR spectroscopic studies.
- Agnihotri, Harsha,Paramasivam, Mahalingavelar,Palakollu, Veerabhadraiah,Kanvah, Sriram
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p. 1324 - 1331
(2015/11/10)
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- Selective photoisomerization of methyl substituted nitro diphenylbutadienes
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A series of p-nitro substituted trans-diphenylbutadienes is synthesized and their photophysical and photochemical properties are investigated. All the dienes have a very low quantum yield of fluorescence but exhibit remarkable solvatochromic emission shifts attributed to twisted intramolecular charge transfer. Photochemical irradiation of simple p-nitro substituted diphenylbutadienes reveals inefficient or no detectable photoisomerization. However, substituting a methyl group on the butadiene chain of p-nitro substituted diphenylbutadiene or replacing the nitro group with cyano group yields the corresponding trans-cis isomers. In the case of simple nitrodienes, strong intramolecular charge transfer character in the excited state aids dissipation of absorbed energy through non-photochemical and non-radiative channels. The steric effect caused by the presence of methyl group lowers the isomerization barrier in methyl substituted dienes leading to a regioselective isomerization.
- Agnihotri, Harsha,Palakollu, Veerabhadra,Kanvah, Sriram
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- Oxidative cross-coupling of vinylsilanes in water
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Palladium-promoted cross-dimerization reaction of alkenylsilanes is reported for the first time, which is also one of the very first studies on oxidative cross-coupling between vinylic organometallic reagents. The reaction occurs at room temperature in aqueous micelles and represents a convenient access to all-trans push-pull butadienes.
- Cicco, Stefania R.,Martinelli, Carmela,Pinto, Vita,Naso, Francesco,Farinola, Gianluca M.
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- Inhibition of monoamine oxidase by selected C5- and C6-substituted isatin analogues
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Previous studies have shown that (E)-5-styrylisatin and (E)-6-styrylisatin are reversible inhibitors of human monoamine oxidase (MAO) A and B. Both homologues are reported to exhibit selective binding to the MAO-B isoform with (E)-5-styrylisatin being the most potent inhibitor. To further investigate these structure-activity relationships (SAR), in the present study, additional C5- and C6-substituted isatin analogues were synthesized and evaluated as inhibitors of recombinant human MAO-A and MAO-B. With the exception of 5-phenylisatin, all of the analogues examined were selective MAO-B inhibitors. The C5-substituted isatins exhibited higher binding affinities to MAO-B than the corresponding C6-substituted homologues. The most potent MAO-B inhibitor, 5-(4-phenylbutyl) isatin, exhibited an IC50 value of 0.66 nM, approximately 13-fold more potent than (E)-5-styrylisatin and 18,500-fold more potent than isatin. The most potent MAO-A inhibitor was found to be 5-phenylisatin with an IC 50 value of 562 nM. The results document that substitution at C5 with a variety of substituents is a general strategy for enhancing the MAO-B inhibition potency of isatin. Possible binding orientations of selected isatin analogues within the active site cavities of MAO-A and MAO-B are proposed.
- Manley-King, Clarina I.,Bergh, Jacobus J.,Petzer, Jacobus P.
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experimental part
p. 261 - 274
(2011/02/26)
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- Catalysis by ionic liquids: Cyclopropyl carbinyl rearrangements catalyzed by [pmim]Br under organic solvent free conditions
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Aryl substituted cyclopropyl carbinol derivatives undergo stereoselective rearrangements catalyzed by the ionic liquid, 1-methyl-3-pentylimidazolium bromide, under sonication, without any organic solvent, to produce the substituted conjugated all-trans-butadienes.
- Ranu, Brindaban C.,Banerjee, Subhash,Das, Arijit
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p. 881 - 884
(2007/10/03)
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- Direct CC Triple Bond Formation from the C=C Double Bond and Direct Hydroxylation into the o-Position of a Nitro Group on the Benzene Nucleus with Potassium t-Butoxide in N,N-DImethylformamide in the Air
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A novel and facile method for direct CC acetylenic bond formation from the C=C double bond by treatment with potassium t-butoxide (t-BuOK) in N,N-dimethylformamide in the air has been found in a 9,10-bis(4-substituted styryl)anthracene series, in 4-substituted 4'-nitrostilbene series, and in 1-(p-nitrophenyl)-4-(p-substituted phenyl)-1,3-butadiene series; its scope and limitations have been examined.The ESR spectrum of the reaction against 4-diethylamino-4'-nitrostilbene was measured to identify an anion radical specied expected for explanation of the mechanism of the dehydrogention reaction.Further, cyclic voltammetric measurements of a series of stilbenes and diphenylacetylenes were carried out in connection with the abovw mechanism.In many cases, interestingly, the use of a large excess of t-BuOH brought about succeeding hydroxylation into the ortho-position of a nitro group on the benzene nucleus.The simple hydroxylation is useful for the synthesis of substituted 5-(arylethynyl)-2-nitrophenols, which are expected to function as non-linear optical materials with the corresponding non-hydroxy compounds.The ultraviolet-visible and fluorescence spectral properties were measured and discussed also with those of the related compounds.
- Akiyama, Shuzo,Tajima, Kunihiko,Nakatsuji, Shin'ichi,Nakashima, Kenichiro,Abiru, Kazuko,Watanabe, Miwa
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p. 2043 - 2052
(2007/10/03)
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- A novel and convenient synthesis of E,E-bis(styryl)sulfones and E,E-1,4-diaryl-1,3-butadienes
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The condensation of 2-phenylethanesulfonylacetic acid (4) with araldehydes (5) in presence of a base gave E-styryl-2-phenylethyl sulfones (6) which on dehydrogenation with DDQ (7) yielded E,E-bis-(styryl)sulfones (8). The 8 on treatment with dichlorotris(triphenyl-phosphine)ruthehium(II) catalyst resulted 1,4-diaryl-1,3-butadienes (9). The configurations of 6, 8 and 9 have been determined based on IR and 1H NMR spectral data.
- Ramana Reddy,Manjubhashini,Reddy,Ramana Reddy,Bhaskar Reddy
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p. 1589 - 1596
(2007/10/02)
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