- Modular and Selective Arylation of Aryl Germanes (C?GeEt3) over C?Bpin, C?SiR3 and Halogens Enabled by Light-Activated Gold Catalysis
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Selective C (Formula presented.) –C (Formula presented.) couplings are powerful strategies for the rapid and programmable construction of bi- or multiaryls. To this end, the next frontier of synthetic modularity will likely arise from harnessing the coupling space that is orthogonal to the powerful Pd-catalyzed coupling regime. This report details the realization of this concept and presents the fully selective arylation of aryl germanes (which are inert under Pd0/PdII catalysis) in the presence of the valuable functionalities C?BPin, C?SiMe3, C?I, C?Br, C?Cl, which in turn offer versatile opportunities for diversification. The protocol makes use of visible light activation combined with gold catalysis, which facilitates the selective coupling of C?Ge with aryl diazonium salts. Contrary to previous light-/gold-catalyzed couplings of Ar–N2+, which were specialized in Ar–N2+ scope, we present conditions to efficiently couple electron-rich, electron-poor, heterocyclic and sterically hindered aryl diazonium salts. Our computational data suggest that while electron-poor Ar–N2+ salts are readily activated by gold under blue-light irradiation, there is a competing dissociative deactivation pathway for excited electron-rich Ar–N2+, which requires an alternative photo-redox approach to enable productive couplings.
- Dahiya, Amit,Fricke, Christoph,Funes-Ardoiz, Ignacio,Gevondian, Avetik G.,Schoenebeck, Franziska,Sherborne, Grant J.
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supporting information
p. 15543 - 15548
(2020/06/22)
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- ONE STEP DIRECT ARYLATION OF COMMODITY CHEMICALS TO SPECIALTY CHEMICALS BY TANDEM CATALYTIC PLATFORM
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The present invention relates to a continuous direct arylation process based on a tandem catalyst for synthesizing specialty chemicals. A method for synthesizing an aryl-aryl structure from a substrate selected from the group consisting of benzyl alcohol, benzyl amine and toluene which are low value added compounds is developed using a silver ion-containing tandem catalyst. The method is applied for synthesizing hexaphenyl arylene and can be applied for synthesizing high value added compounds (not only natural substances and chemical compounds but pharmaceutical and agricultural pesticide relative fields) directly from primary raw materials through the reaction.COPYRIGHT KIPO 2017
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Paragraph 0038; 0039; 0041; 0042; 0106
(2018/02/28)
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- Efficient synthesis of N-alkyl-2,7-dihalocarbazoles by simultaneous carbazole ring closure and N-alkylation
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The N-alkyl-2,7-dihalocarbazole as the main product was formed by the reaction of 4,4′-dihalo-2-nitrobiphenyl with aromatic nitro compound and trialkyl phosphite. The presence and crucial role of aromatic nitro compound causes simultaneous carbazole ring closure and N-alkylation unlike the Cadogan ring closure where non-alkylated carbazole is formed as a main product. In addition, the mixture of aromatic nitro compound and trialkyl phosphite was found to be a possible N-alkylating agent for heterocycles, such as carbazole or indole.
- Vyprachticky, Drahomír,Kmínek, Ivan,Pokorná, Veronika,Cimrová, Věra
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scheme or table
p. 5075 - 5080
(2012/07/28)
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- A novel three-step synthesis of N-(2-ethylhexyl)-2,7-diiodocarbazole
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A new short and reasonably efficient synthesis of N-(2-ethylhexyl)-2,7- diiodocarbazole is presented. 4,4-Diiodobiphenyl was nitrated and the resulting 4,4-diiodo-2-nitrobiphenyl was converted via Freeman's modification of the Cadogan ring closure into 2,7-diiodocarbazole, which was then alkylated in the final step. The synthesis represents a significant simplification of the reported five-step procedure.
- Vyprachticky, Drahomir,Kminek, Ivan,Pavlakova, Petra,Cimrova, Vera
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experimental part
p. 1472 - 1476
(2011/06/20)
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- Synthesis of functionalized triazatriangulenes for application in photo- Switchable self-assembled monolayers
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Various triazatriangulenes are synthesized by nucleophilic attack at the central C atom of triazatriangulenium ions. The molecular functions, especially azobenzenes, are fixed via an ethynyl linker by in situ deprotection of trimethylsilylalkynes. The structure of two of these molecules is further investigated by X-ray crystallography. The photo-inducedtrans/cis-isomerization of the azobenzene substituted derivatives is analyzed in solution and shows great promise for the preparation of switchable functionalized monolayers, as the triazatriangulenes are known for their self-assembly on gold surfaces. [1].
- Kubitschke, Jens,Naether, Christian,Herges, Rainer
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scheme or table
p. 5041 - 5055
(2010/11/05)
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- Fluorescent bis(oligophenylylamino)terephthalates
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The reaction of succinyl succinates with aniline, iodoaniline and iodobiphenylamine yielded 2,5-bis(arylamino)-terephthalates. Suzuki cross-coupling reactions of the iodofunctionalized compounds with phenyl- and biphenylylboronic acids gave 2,5-diaminoter
- Zhang, Yawei,Starynowicz, Przemyslaw,Christoffers, Jens
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experimental part
p. 3488 - 3495
(2009/04/14)
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- Synthesis of symmetrically and unsymmetrically para-functionalized p-quaterphenylenes
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Oligo-p-phenylenes have proven to be versatile building blocks for the generation of self-assembled nanoaggregates with interesting optical properties via vapor deposition on solid supports. Preliminary studies have shown that both the properties and the morphologies of these aggregates can be influenced by the introduction of functional groups. To this end, we have developed general approaches to the synthesis of symmetrically and unsymmetrically 1,4?-substituted p-quaterphenylenes through the application of a reliable Suzuki cross-coupling strategy. Georg Thieme Verlag Stuttgart.
- Schiek, Manuela,Al-Shamery, Katharina,Luetzen, Arne
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p. 613 - 621
(2008/01/04)
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- Single and double Suzuki-Miyaura couplings with symmetric dihalobenzenes
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(Chemical Equation Presented) m- or p-diiodobenzene undergoes selective double coupling reactions with arylboronic acids and esters. Selectivity for double coupling over single coupling is remarkably strong: even with a diiodobenzene:monoboronic acid ratio of 10:1, the products of double coupling are formed in good yields. Steric hindrance and electronic influences of the boronic acid or ester, and reaction conditions do not appear to impact significantly upon the outcome of the reaction. In contrast, m- and p-dibromobenzenes undergo single couplings with aryl boronic acids with high selectivity.
- Sinclair, David J.,Sherburn, Michael S.
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p. 3730 - 3733
(2007/10/03)
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- Organic electroluminescence device and phenylenediamine derivative
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The invention is to provide an organic EL device having a long life time that can reduce the driving voltage of the organic EL device, and to provide a material having a small ionization potential and exhibiting a large hole mobility by using as a layer or a zone. The organic electroluminescence device comprises a pair of electrodes and an organic light emitting layer sandwiched in the electrodes, characterized in that a hole transporting zone provided between the electrodes comprises the phenylenediamine derivative represented by the specific structural formulae, and the phenylenediamine derivative has a hole mobility of 10?4cm2/V·s or more upon using as a layer or a zone, with the organic light emitting layer containing a charge injection auxiliary.
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- Liquid crystal compounds, liquid crystal medium and liquid crystal display
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The instant invention relates to liquid crystal media comprising a strongly dielectrically positive component A, preferably comprising isothiocyanate compounds, most preferably compounds of formula I, as given in the text, and a further dielectrically positive component B, preferably comprising terminally polar substituted bi- or terphenyl compounds, most preferably comprising compounds of formula II, as given in the text, further to novel isothiocyanato compounds as well as to liquid crystal displays comprising these media, in particular to PDLC display and most particular to holographic PDLC displays. The instant invention further relates to compounds of formula I wherein the parameters are as as specified in the text.
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- Substituent effects on the in vitro and in vivo genotoxicity of 4-aminobiphenyl and 4-aminostilbene derivatives
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4-Amino-4'-substituted biphenyls and 4-aminostilbenes substituted in the 3' or 4' position were studied for their in vitro and in vivo genotoxicity. The in vitro mutagenicity of the biphenyls with and without S9 activation was established with Salmonella strains TA98 and TA100 and that of the stilbenes with the same strains plus TA98/1,8-DNP6. The in vivo genotoxicity assay with both series of compounds was for chromosomal aberrations in the bone-marrow cells of mice following intraperitoneal administration of the chemicals. Hammett values of substituents, partition coefficients and frontier orbital energies (E(LUMO) and E(HOMO) of the compounds were used for correlations with mutagenicity. The Salmonella mutagenicity in TA98 and TA98/1,8-DNP6 with S9 was correlated to Hammett σ+ values for the 4-aminostilbene substituents, showing a strong trend of increasing mutagenicity with an increase in the electron-withdrawing capability of the substituent. Hydrophobicity of the stilbenes, however, had little effect on their relative mutagenicity. The 4-aminobiphenyls showed a correlation between their mutagenicity and Hammett σ+ values of their 4'-substituents in stain TA98 with S9, although the trend was not as strong as for the stilbenes. But unlike the stilbenes, TA98 mutagenicity of the biphenyls could also be correlated to hydrophobicity, and structure-activity correlations for the biphenyls was substantially improved when both σ+ and hydrophobicity data were included. For strain TA100 with S9, little correlation was found between mutagenicity of the stilbenes and any of the parameters. However, a limited orrelation did exist between the mutagenicity of the biphenyls and their hydrophobicity. There was also limited correlations of the mutagenicity for the stilbenes in TA98 and TA98/1,8-DNP6 with S9 to E(LUMO) or E(HOMO). The in vivo genotoxicity results for the biphenyls and stilbenes could not be correlated to electronic effects as for the in vivo results, nor could they be explained by hydrophobicity. However, it is interesting to note that 3'-substituted 4-aminostilbenes were all substantially more genotoxic in vivo than their corresponding 4'-substituted counterparts. The most genotoxic compound in vivo in either series was 4-aminostilbene which would not have been predicted from the in vitro results.
- You,Brezzell,Das,Hooberman,Sinsheimer
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