- Activation of Aptamers with Gain of Function by Small-Molecule-Clipping of Intramolecular Motifs
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Click reactions have the advantages of high reactivity, excellent orthogonality, and synthetic accessibility. Inspired by click reactions, we propose the concept of “clipped aptamers”, whose binding affinity is regulated by the “clip”-like specific intera
- Huang, Mengjiao,Li, Tingyu,Xu, Yuanfeng,Wei, Xinyu,Song, Jia,Lin, Bingqian,Zhu, Zhi,Song, Yanling,Yang, Chaoyong
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p. 6021 - 6028
(2021/01/29)
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- Syntheses, Spectroscopic Properties, and Computational Study of (E, Z)-Ethenyl and Ethynyl-Linked BODIPYs
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A series of (E,Z)-ethenyl- and ethynyl-linked boron dipyrromethene (BODIPY) dimers were synthesized in 23-34% yields by condensation of pyrroles with the corresponding bis-benzaldehydes, followed by oxidation and boron complexation. The BODIPY dimers were characterized by 1H, 13C, and 11B NMR spectroscopy, high-resolution mass spectrometry, and, in the cases of 1b, 2, and 3, by X-ray crystallography. The spectroscopic properties for this series of dimers were investigated in tetrahydrofuran solutions, and very similar absorption and emission profiles were observed for all dimers. Density functional theory calculations show minimal conjugation between the two BODIPY units in the dimers, as a result of the large dihedral angle between the BODIPYs and the linker. The (E)-ethenyl-linked dimer 1a showed the highest fluorescence quantum yield of all dimers investigated in this study.
- Zhang, Guanyu,Zhao, Ning,Bobadova-Parvanova, Petia,Wang, Maodie,Fronczek, Frank R.,Smith, Kevin M.,Vicente, M. Gra?a H.
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p. 6256 - 6265
(2018/07/15)
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- DERIVATIVES HAVING VINYL GROUP AND ITS USE IN ELECTROLUMINESCENT ELEMENT
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The present invention relates to imidazole derivatives having vinyl group represented by general formula (I) which possess electron transporting character, have a high glass transition temperature (Tg), and high decomposition temperature (Td): wherein all symbols are defined as recited in the specification. The present invention also relates to a use of the imidazole derivatives having vinyl group as a guest emitter or electron transporter in luminescent elements.
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Paragraph 0049; 0050; 0051; 0052
(2013/03/26)
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- Novel branched alpha-cyanostilbene fluorophores
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A branched α-cyanostilbene fluorescent materials with a new structure useful to the organic electroluminescence display (OELD), which includes the organic substance in the state of powder, liquid and film with the stilbene core structure and the terminal branched phenyl structure. The fluorescent materials of the invention exhibits the high luminescent efficiency and is capable of tuning the fluorescent colors of red, green and blue according to the core structure in the molecular, i.e., the structure of stilbene radical, particularly it exhibits the higher luminescent efficiency in the state of solid more than solution.
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Page/Page column 4
(2008/06/13)
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- Precipiton reagents: Precipiton phosphines for solution-phase reductions
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(Equation Presented) Several Precipiton phosphines were prepared and employed in the Staudinger reaction and in the reduction of secondary ozonides. Both amines and aldehdyes were obtained in good to excellent yields and purities. After use of the phosphine, isomerization and precipitation of the spent phosphorus reagent were induced by exposure to visible light in the presence of erythrosin B, a triplet sensitizer. Products were isolated by simple filtration. The use of the triplet sensitizer has the added advantage of eliminating [2 + 2] cycloaddition reactions between trans-Precipitons.
- Bosanac, Todd,Wilcox, Craig S.
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p. 2321 - 2324
(2007/10/03)
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- The synthesis of dicationic extended bis-benzimidazoles
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The synthesis of extended dicationic bis-benzimidazoles starting from trans-1,2-bis(4-cyanophenyl)ethene and trans-1,2-bis(4-cyanophenyl)cyclopropane is reported. The target diamidines show significant in vitro activity against B. subtilis.
- Kang, Zhijan,Dykstra, Christine C.,Boykin, David W.
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p. 158 - 163
(2007/10/03)
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- Preparation, properties and coordination of new conjugated ferrocenyl-based ligands with an end-capped nitrile
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New ferrocenyl-nitrile conjugated ligands have been obtained by several routes in which we combined Wittig and Horner-Emmons-Wadsworth (HEW) reactions, being the latter the one that shows better results both in yield and selectivity for the E isomers. The coordination capabilities of these new ligands have been proved using different metal carbonyls and the electronic spectra of the compounds have been studied, showing a clear dependence on the length of the conjugated chain and in the nature of the coordinated metal carbonyl fragment.
- Mata, José A.,Falomir, Eva,Llusar, Rosa,Peris, Eduardo
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- Synthesis and Intramolecular Electron- and Energy-Transfer Reactions of Polyyne- or Polyene-Bridged Diporphyrins
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A series of geometrically restricted polyyne- or polyene-bridged diporphyrins 1-7 has been prepared by a convenient, one-pot, double porphyrin cyclization reaction in acceptable yields from the corresponding dialdehydes 1-7CHO.Polyene-bridged diporphyrins 8 and 9 were prepared by a double Horner-Emmons-Wadsworth reaction of formyl-substituted zinc-porphyrin monomer 12 with bis-phosphonate esters 13 and 14, respectively.The diporphyrins 1-9 were transformed into zinc-free-base and zinc-ferric hybrid diporphyrins.Photoinduced intramolecular electron transfer in the zinc-ferric hybrid diporphyrins as well as intramolecular excitation energy transfer in the zinc-free-base hybrid diporphyrins have been studied by picosecond time-resolved fluorescence spectroscopy.Rate constants through the polyene-bridges are larger than those through the polyyne-bridges in both reactions.The distance dependence of the electron-transfer rate was found to be quite small: the attenuation factors were determined to be 0.08 and 0.1 Angstroem-1 for the polyene- and polyyne-bridged diporphyrins, respectively.The distance dependence of the energy-transfer rate was quite similar to that of the electron transfer and was explained better by the Dexter mechanism rather than by the Foerster mechanism.These results clearly demonstarate that the linear ?-conjugated polyyne and polyene spacers enhance through-bond electronic coupling between the donor and acceptor.
- Osuka, Atsuhiro,Tanabe, Nobuhiro,Kawabata, Shigeki,Yamazaki, Iwao,Nishimura, Yoshinobu
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p. 7177 - 7185
(2007/10/03)
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- Process for the Pd-catalyzed arylation of olefins with aryl halides
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Compounds of the formula I STR1 in which A is C2-12 -alkenyl, C4-8 -cycloalkenyl or a grouping--C(R)=C(R')--Y and Y, R, R', R1, R2, R3 and R3 ' are as defined in patent claim 1, can be prepared in high yields in a simple and economical manner by reacting corresponding bromobenzenes or iodobenzenes with a compound HA in the presence of an alkali metal salt or alkaline earth metal salt of an aliphatic monocarboxylic acid having 1-12 C atoms or benzoic acid, of a cyclic or N,N-disubstituted amide as the solvent, particularly N,N-dimethylformamide, and of a palladium compound which can, if desired, contain arsenic or phosphorus, as the catalyst.
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- Process for the preparation of styrene derivatives and/or stilbene derivatives
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Compounds of the formulae in which Z represents unsubstituted or substituted phenyl or naphthyl, Z1 represents hydrogen or has the same meaning as Z and Z2 represents unsubstituted or substituted phenylene, naphthylene or p-biphenylene or an unsubstituted or substituted stilbene radical, can be obtained in a simple and economical manner in accordance with a novel process by reacting ethylene, under a pressure of 0.1 to 20 bar, in the presence of a base and with the addition of specific palladium catalysts, such as palladium acetate, with appropriate acid halides. The compounds of the formulae Ia and Ib are valuable intermediates, in particular for the preparation of fluorescent brighteners or scintillators.
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- 6>Paracyclophanes - Large Ring Compounds with Extended ?-Systems
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Two 6>paracyclophanes with unsaturated bridges, containing perimeters with 36 ?-electrons, have been prepared by fourfold Wittig reactions.Attempts to prepare cyclophanes with even larger ?-systems are reported.The reversible two-electron red
- Raston, Ilona,Wennerstroem, Olof
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p. 655 - 660
(2007/10/02)
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