- Synthesis and characterization of amino-functional, blue light-emitting copolymers and their composites with CdTe nanocrystals
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Random side-chain functionalized copolymers were synthesized, utilizing a facile Yamamoto protocol by applying 2,7-dibromo-9,9-bis(6-bromohexyl)-9H-fluorene, (E)-1,2-bis(4-bromophenyl)ethene, 2,7-dibromo-9,9-dioctyl-9H-fluorene as comonomers. The precurso
- Kanelidis, Ioannis,Elsner, Victoria,B?tzer, Monique,Butz, Maren,Lesnyak, Vladimir,Eychmüller, Alexander,Holder, Elisabeth
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Read Online
- Photochemical Modification of Carbene-Based Metallacycles: A Facile Route to Polycarbene Complexes and Their Derivatives
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The modification of dinuclear silver metallcycles via photochemical [2 + 2] cycloaddition is described. Reaction of benzimidazole with trans-4,4′-dibromostilbene gives trans-4,4′-bis(1H-benzo[d]imidazolyl)stilbene (L), which after subsequent dialkylation
- Wang, Chun-Xiang,Gao, Yang,Deng, Yu-Xin,Lin, Yue-Jian,Han, Ying-Feng,Jin, Guo-Xin
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Read Online
- 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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Read Online
- A mixed-valence bis(diarylamino)stilbene: Crystal structure and comparison of electronic coupling with biphenyl and tolane analogues
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The E-4,4′-bis[di(p-anisyl)amino]stilbene cation is a class-III mixed-valence species with electronic coupling comparable to that in its biphenyl-bridged analogue, whereas its tolane-bridged analogue belongs to class II. The Royal Society of Chemistry 200
- Barlow, Stephen,Risko, Chad,Coropceanu, Veaceslav,Tucker, Neil M.,Jones, Simon C.,Levi, Zerubba,Khrustalev, Viktor N.,Antipin, Mikhail Yu.,Kinnibrugh, Tiffany L.,Timofeeva, Tatiana,Marder, Seth R.,Bredas, Jean-Luc
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Read Online
- One-Pot Dual Catalysis of a Photoactive Coordination Polymer and Palladium Acetate for the Highly Efficient Cross-Coupling Reaction via Interfacial Electron Transfer
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We report herein an exploration of the straightforward one-pot dual-catalysis strategy, i.e., direct combination of a photoactive coordination polymer (CP) with another metal catalyst, for carrying out the desirable photoinduced organic transformation. Th
- Guo, Zhifen,Liu, Xin,Che, Yan,Chen, Dashu,Xing, Hongzhu
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supporting information
p. 2695 - 2705
(2022/02/14)
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- N-Methylphenothiazine S-Oxide Enabled Oxidative C(sp2)–C(sp2) Coupling of Boronic Acids with Organolithiums via Phenothiaziniums
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Herein, we report the development of a transition-metal-free oxidative C(sp2)–C(sp2) coupling of readily available boronic acids and organolithiums via phenothiazinium ions. Various biaryl, styrene, and diene derivatives were obtained using this reaction system. The key to this process is N-methylphenothiazine S-oxide (PTZSO), which allows efficient conversion of boronic acids to phenothiazinium ions. The mechanism of phenothiazinium formation using PTZSO was investigated using theoretical calculations and experiments, which provided insight into the unique reactivity of PTZSO.
- Yoshida, Tatsuki,Honda, Yuki,Morofuji, Tatsuya,Kano, Naokazu
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p. 9664 - 9668
(2021/12/17)
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- Exploring the Photocyclization Pathways of Styrylthiophenes in the Synthesis of Thiahelicenes: When the Theory and Experiment Meet
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The introduction of thiophene rings to the helical structure of carbohelicenes has electronic effects that may be used advantageously in organic electronics. The performance of these devices is highly dependent on the sulfur atom topology, so a precise knowledge of the synthetic routes that may afford isomeric structures is necessary. We have studied the photocyclization pathway of both 2- and 3-styrylthiophenes on their way to thiahelicenes by experiment and theory. To begin with, the synthesis of stereochemically well-defined 2- and 3-styrylthiophenes allowed us to register first, and simulate later, the UV-vis electronic spectra of these precursors. This information gave us access through time-dependent density functional theory calculations to the very nature of the excited states involved in the photocyclization step and from there to the regio- and stereochemical outcome of the reaction. For the widely known case of a 2-styrylthiophene derivative, the expected naphtho[2,1-b]thiophene type of ring fusion was predicted and experimentally observed by synthesis. On the contrary, 3-styrylthiophene derivatives have been seldom used in synthetic photocyclizations. Among the two possible structural outcomes, only the naphtho[1,2-b]thiophene type of ring fusion was found to be mechanistically sound, and this was actually the only compound observed by synthesis.
- Baciu, Bianca C.,Vergés, José Antonio,Guijarro, Albert
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p. 5668 - 5679
(2021/05/05)
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- Photophysical Properties of Silyl-Substituted Stilbene Derivatives
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The effects of silyl groups on the structural, absorption, fluorescence, and photoisomerization properties of stilbenes were investigated. In comparison to that of the parent stilbene (1), fluorescence quantum yields (Φf) of Me3Si-substituted stilbenes 2–4 and 6 in solution were higher. Derivative 5, in which Me3Si groups are present at all ortho positions of the arene moieties, did not fluoresce at room temperature. The absorption and fluorescence wavelength maxima of Me3SiMe2Si-substituted stilbene 7 occurred at longer wavelengths compared to those of the Me3Si analog 2. The results of theoretical calculations showed that this difference is a consequence of an increase in the HOMO energy of 7 caused by orbital interaction between π-system and the σ(Si–Si) orbital. Stilbene 14, with two Me3Si-C≡C groups at both para positions, had a high Φf (0.95). The calculated transition dipole moment (μ) was well correlated with Φf. Derivative 21, which contains Ph2N and Me3SiC≡C groups exhibited solvatofluorochromism because it possesses a twisted intramolecular charge transfer (TICT) excited state in which the Ph2N group and the aromatic ring are orthogonal.
- Maeda, Hajime,Horikoshi, Ryo,Yamaji, Minoru,Furuyama, Taniyuki,Segi, Masahito
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supporting information
p. 3410 - 3422
(2020/06/17)
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- E, Z -Selectivity in the reductive cross-coupling of two benzaldehydes to stilbenes under substrate control
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Unsymmetrical E- and Z-stilbenes can be synthesized from two differently substituted benzaldehydes in a MesP(TMS)Li-promoted reductive coupling sequence. Depending on the order of addition of the two coupling partners, the same olefin can be produced in either E- or Z-enriched form under identical reaction conditions. A systematic study of the correlation between the stereochemical outcome of the reaction and the substitution pattern at the two aldehydes is presented. The results can be used as guidelines to predict the product stereochemistry. This journal is
- Arkhypchuk, Anna I.,D'Imperio, Nicolas,Ott, Sascha
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p. 6171 - 6179
(2020/10/21)
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- Simpler and Cleaner Synthesis of Variously Capped Cobalt Nanocrystals Applied in the Semihydrogenation of Alkynes
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Unlike the classical organometallic approach, we report here a synthetic pathway requiring no reducing sources or heating to produce homogeneous hexagonal-close-packed cobalt nanocrystals (Co NCs). Involving a disproportionation process, this simple and fast (6 min) synthesis is performed at room temperature in the presence of ecofriendly fatty alcohols to passivate Co NCs. Through a recycling step, the yield of Co NCs is improved and the waste generation is limited, making this synthetic route cleaner. After an easy exchange of the capping ligands, we applied them as unsupported catalysts in the stereoselective semihydrogenation of alkynes.
- Moisset, A.,Petit, C.,Petit, M.,Salzemann, C.,Sodreau, A.,Vivien, A.
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supporting information
p. 13972 - 13978
(2020/10/09)
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- A Bidentate Ru(II)-NC Complex as a Catalyst for Semihydrogenation of Alkynes to (E)-Alkenes with Ethanol
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Four Ru(II)-NC complexes were tested as catalysts for semihydrogenation of internal alkynes to (E)-alkenes with ethanol, and the complex {(C5H4N)(C6H4)}RuCl(CO)(PPh3)2 (1a) showed the highest activity. The reactions proceeded well with 1 mol % catalyst loading and 0.1 equiv of t-BuONa at 110 °C for 1 h, and 32 alkenes were synthesized with excellent E:Z selectivity. This is the first ruthenium-catalyzed semihydrogenation of internal alkynes to (E)-alkenes using ethanol as the hydrogen donor.
- Chen, Dafa,Gong, Dawei,Hu, Bowen,Kong, Degong,Xia, Haiping,Yang, Weiwei
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- Tuning the Selectivity of Palladium Catalysts for Hydroformylation and Semihydrogenation of Alkynes: Experimental and Mechanistic Studies
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Here, we describe a selective palladium catalyst system for chemodivergent functionalization of alkynes with syngas. In the presence of an advanced ligand L2 bearing 2-pyridyl substituent as a built-in base, either hydroformylation or semihydrogenation of diverse alkynes occurs with high chemo- and stereoselectivity under comparable conditions. Mechanistic studies, including density functional theory (DFT) calculations, kinetic analysis, and control experiments, revealed that the strength and concentration of acidic cocatalysts play a decisive role in controlling the chemoselectivity. DFT studies disclosed that ligand L2 not only promotes heterolytic activation of hydrogen similar to frustrated Lewis pair (FLP) systems in the hydrogenolysis step for hydroformylation but also suppresses CO coordination to promote semihydrogenation under strong acid conditions. This switchable selectivity provides a strategy to design new catalysts for desired products.
- Beller, Matthias,Ge, Yao,Jackstell, Ralf,Jiao, Haijun,Liu, Jiawang,Wei, Duo,Wei, Zhihong,Yang, Ji
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p. 12167 - 12181
(2020/11/27)
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- Ligand-controlled iridium-catalyzed semihydrogenation of alkynes with ethanol: highly stereoselective synthesis of E- and Z-alkenes
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A ligand-controlled iridium-catalyzed semihydrogenation of alkynes to E- and Z-alkenes with ethanol was developed. Effective selectivity control was achieved by ligand regulation. The use of 1,2-bis(diphenylphosphino)ethane (DPPE) and 1,5-cyclooctadiene (COD) was critical for the stereoselective semihydrogenation of alkynes. The general applicability of this procedure was highlighted by the synthesis of more than 40 alkenes, with good stereoselectivities. The value of our approach in practical applications was investigated by studying the effects of pinosylvin and 4,4′-dihydroxystilbene (DHS) on zebrafish as a vertebrate model.
- Yang., Jinfei,Wang, Chengniu,Sun, Yufeng,Man, Xuyan,Li, Jinxia,Sun, Fei
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supporting information
p. 1903 - 1906
(2019/05/02)
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- Realizing n-Type Field-Effect Performance via Introducing Trifluoromethyl Groups into the Donor-Acceptor Copolymer Backbone
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Developing a new strategy to obtain n-type organic semiconductors is crucial for the advance of organic electronics. We herein report the synthesis and investigation of a series of donor-acceptor-type diazaisoindigo-based copolymers, named PAIID-TFBVB-C1,
- Wei, Congyuan,Zhang, Weifeng,Huang, Jianyao,Li, Hao,Zhou, Yankai,Yu, Gui
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p. 2911 - 2921
(2019/04/17)
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- NEW COMPOUNDS SUITABLE AS CATALYSTS FOR POLYMERIZATION REACTIONS
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The invention relates to a compound of formula (I) and a process for synthesizing said compound. The invention further relates to the use of said compound as a catalyst, preferably for polymerization, such as, olefin polymerization. The invention also relates to the polymers produced using said catalyst and articles comprising said polymers.
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Page/Page column 54; 63-64
(2019/04/10)
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- Porous organic polymer supported rhodium as a heterogeneous catalyst for hydroformylation of alkynes to α,β-unsaturated aldehydes
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A new porous organic polymer supported rhodium catalyst (Rh/POL-BINAPa&PPh3) has been developed for the hydroformylation of various alkynes to afford the corresponding α,β-unsaturated aldehydes with high chem- and stereoselectivity, excellent catalytic activity and good reusability (10 cycles). The heterogeneous catalyst exhibited more catalytic activity than the comparable homogeneous Rh/BINAPa/PPh3 system.
- Liang, Zuyu,Chen, Jianbin,Chen, Xin,Zhang, Kai,Lv, Jinhe,Zhao, Haowen,Zhang, Guoying,Xie, Congxia,Zong, Lingbo,Jia, Xiaofei
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supporting information
p. 13721 - 13724
(2019/11/19)
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- The role of electron-transporting Benzo[f]quinoline unit as an electron acceptor of new bipolar hosts for green PHOLEDs
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We prepared three new compounds [3,6-di(9H-carbazol-9-yl)phenanthrene (3,6-DCP), 2,9-di(9H-carbazol-9-yl)benzo[f]quinoline (2,9-DCBQ), and 3,9-di(9H-carbazol-9-yl)benzo[f]-quinoline (3,9-DCBQ)] containing phenanthrene or benzo[f]quinoline as an electron-withdrawing moiety and a carbazole as electron-donating moiety, respectively, as bipolar hosts for green phosphorescent organic light emitting diodes (PHOLEDs). We intentionally substituted nitrogen atom to the C-3 position of phenanthrene moiety to prepare benzo[f]quinolinegroup. And, we found that it allowed better electron transporting behavior than the phenanthrene moiety. Meanwhile, the benzo[f]quinoline/phenanthrene core moieties significantly improved the thermal stability of those host materials, which exhibited glass transition and decomposition temperatures of 132–139 and 395–427 °C, respectively. The green PHOLEDs which were fabricated with those host materials showed the lowest operating voltage of 4.7 V at 1000 cd/m2 when we used 3,9-DCBQ. Very interestingly, it has an asymmetric structure with completely separated HOMO and LUMO in space. In contrast, 3,6-DCP having phenanthrene and carbazole moieties showed much higher operating voltage of 6.1 V which imply that replacing nitrogen at the C-3 position of phenanthrene improves carrier transport, that is, electron transporting behavior. As a result, the 3,9-DCBQ-based PHOLED showed the best overall performance, exhibiting current and power efficiencies of 48.5 cd/A and 20.6 lm/W, respectively.
- Seo, Junseok,Park, So-Ra,Kim, Mina,Suh, Min Chul,Lee, Jihoon
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p. 959 - 966
(2018/11/26)
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- Effect of substituents on TiO2 photocatalytic oxidation of trans-stilbenes
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Photocatalytic reaction of trans-stilbene on TiO2 particles produces benzaldehyde with high selectivity in acetonitrile-water mixed solvent. Introduction of electron-donating substituents to the benzene rings accelerated the reaction. On the other hand, the rate was decelerated by electron-withdrawing substituents. These results suggest that the reaction proceeds by hydroperoxo or hydroperoxy, which were formed on TiO2 surface by UV irradiation, rather than free OH radicals.
- Miyake, Teruyuki,Hashimoto, Yuichiro,Jinnai, Seihou,Oketani, Ryusei,Higashida, Suguru
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- Well-Defined Rhodium-Gallium Catalytic Sites in a Metal-Organic Framework: Promoter-Controlled Selectivity in Alkyne Semihydrogenation to E-Alkenes
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Promoters are ubiquitous in industrial heterogeneous catalysts. The wider roles of promoters in accelerating catalysis and/or controlling selectivity are, however, not well understood. A model system has been developed where a heterobimetallic active site comprising an active metal (Rh) and a promoter ion (Ga) is preassembled and delivered onto a metal-organic framework (MOF) support, NU-1000. The Rh-Ga sites in NU-1000 selectively catalyze the hydrogenation of acyclic alkynes to E-alkenes. The overall stereoselectivity is complementary to the well-known Lindlar's catalyst, which generates Z-alkenes. The role of the Ga in promoting this unusual selectivity is evidenced by the lack of semihydrogenation selectivity when Ga is absent and only Rh is present in the active site.
- Desai, Sai Puneet,Ye, Jingyun,Zheng, Jian,Ferrandon, Magali S.,Webber, Thomas E.,Platero-Prats, Ana E.,Duan, Jiaxin,Garcia-Holley, Paula,Camaioni, Donald M.,Chapman, Karena W.,Delferro, Massimiliano,Farha, Omar K.,Fulton, John L.,Gagliardi, Laura,Lercher, Johannes A.,Penn, R. Lee,Stein, Andreas,Lu, Connie C.
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supporting information
p. 15309 - 15318
(2018/11/30)
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- Direct Conversion of Alcohols into Alkenes by Dehydrogenative Coupling with Hydrazine/Hydrazone Catalyzed by Manganese
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We have developed unprecedented methods for the direct transformation of primary alcohols to alkenes in the presence of hydrazine, and for the synthesis of mixed alkenes by the reaction of alcohols with hydrazones. The reactions are catalyzed by a manganese pincer complex and proceed in absence of added base or hydrogen acceptors, liberating dihydrogen, dinitrogen, and water as the only byproducts. The proposed mechanism, based on preparation of proposed intermediates and control experiments, suggests that the transformation occurs through metal–ligand cooperative N?H activation of a hydrazone intermediate.
- Das, Uttam Kumar,Chakraborty, Subrata,Diskin-Posner, Yael,Milstein, David
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supporting information
p. 13444 - 13448
(2018/09/14)
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- One-Pot Intermolecular Reductive Cross-Coupling of Deactivated Aldehydes to Unsymmetrically 1,2-Disubstituted Alkenes
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The phospha-Peterson reaction between a lithiated secondary phosphane, MesP(Li)TMS, and an aldehyde affords Mes-phosphaalkenes which, upon methanol addition and P-oxidation, react with a second carbonyl compound site specifically to produce unsymmetric alkenes. The E/Z selectivity of the one-pot cross coupling is largely determined by the electronic nature of the aryl substituent of the first aldehyde, with electron-donating groups giving rise to increased amounts of Z-alkenes.
- Arkhypchuk, Anna I.,D'Imperio, Nicolas,Ott, Sascha
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supporting information
p. 5086 - 5089
(2018/09/13)
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- SYNTHESIS OF ALKENES FROM PHOSPHAALKENES AND CARBONYL COMPOUNDS
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The present invention is a method for the reductive coupling of carbonyl compounds to selectively prepare unsymmetrical alkene(s). In a first step of the method according to the invention, a phosphorus reagent, such as a phosphanylphosphonate, a phosphoranylidenephosphane, or a silylphosphane, is used to convert the first carbonyl compound to a λ3 σ2 phosphaalkene intermediate. This phosphaalkene intermediate is activated by the addition of a base such as hydroxide or alkoxide, potentially under oxidizing conditions, and then reacted with a second carbonyl compound to form the alkene. The first and the second carbonyl compounds may be different from each other, substituted and selected from the group consisting of aldehydes, such as aromatic or aliphatic aldehyde, or ketones, such as aromatic or aliphatic ketones. In such a case, an unsymmetrical alkene is selectively formed. The invention also embraces any alkene compound prepared as taught by the present application. Another aspect of the invention is a kit of parts for the reductive coupling of a first and a second (substituted) carbonyl compound to selectively prepare unsymmetrically substituted alkene(s).
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Page/Page column 14; 15; 17
(2018/05/24)
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- Oxidative Dephosphorylation of Benzylic Phosphonates with Dioxygen Generating Symmetrical trans-Stilbenes
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Under a dioxygen atmosphere, benzylphosphonates and related phosphoryl compounds can readily produce the corresponding trans-stilbenes in high yields with high selectivity upon treatment with bases. Various functional groups were tolerable under the reaction conditions.
- Huang, Tianzeng,Chen, Tieqiao,Han, Li-Biao
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p. 2959 - 2965
(2018/03/09)
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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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- Unsymmetrical E-Alkenes from the Stereoselective Reductive Coupling of Two Aldehydes
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The unprecedented formation of unsymmetrical alkenes from the intermolecular reductive coupling of two different aldehydes is described. In contrast to the McMurry reaction which affords statistical product mixtures, selectivity in the reported procedure is achieved by a sequential ionic mechanism in which a first aldehyde is reacted with a phosphanylphosphonate to afford a phosphaalkene intermediate which, upon activation by hydroxide, reacts with a second aldehyde to the unsymmetrical E-alkenes. The described reaction is free of transition metals and proceeds under ambient temperature within minutes in good to excellent overall yields. It is a new methodology to use feedstock aldehydes for the direct production of C C double bond-containing products and may impact how chemists think of multistep synthetic sequences in the future.
- Esfandiarfard, Keyhan,Mai, Juri,Ott, Sascha
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supporting information
p. 2940 - 2943
(2017/03/11)
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- Synthesis and characterization of phenanthrene derivatives with anticancer property against human colon and epithelial cancer cell lines
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A variety of polycyclic aromatic hydrocarbons have been synthesized and structurally characterized in our laboratory. Phenanthrene derivatives were efficiently prepared in excellent yields and high purity via a two-step sequence. Heck coupling yielded the corresponding diarylethenes, followed by classical oxidative photocyclization to achieve the expected phenanthrenes. First, we envisioned to synthesize a variety of substituted phenanthrenequinones. Second, we investigated the possibility of a dibenz[a,c]phenazine formation by addition of o-phenylenediamine after completion of the oxidation process. Moreover, because phenanthrenequinones are available so simply, it is likely that other uses will be found for these compounds. For example, 9,10-phenanthrenequinone can be sequentially reduced, alkylated, acetylated, and sulfonated. All the synthesized derivatives were evaluated for cytotoxic activity in vitro against the human epidermoid carcinoma epithelial cells Hep-2 and human colon carcinoma cells Caco-2 using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. From the structure–activity point of view, position and nature of the electron donating and electron withdrawing functional groups attached to the phenanthrene skeleton may contribute to the anticancer action. Interestingly, the analysis of the IC50 values suggests that most compounds exerted cytotoxic effects with selectivity against both cancer cells. Among them, methyl 8-methyl-9,10-phenanthrenequinone-3-carboxylate 11d showed the highest potency with IC50 values of 2.81 and 0.97 μg/mL.
- Guédouar, Habiba,Aloui, Faouzi,Beltifa, Asma,Ben Mansour, Hedi,Ben Hassine, Béchir
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p. 841 - 849
(2017/06/20)
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- A highly stereoselective and efficient catalytic approach for the synthesis of trans-stilbene–arenes as π-conjugated materials
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The potential expansion of the variety of catalytic methods for carbon–carbon bond formation is explored in many research centers all over the world. In this work, we describe very precise and controlled catalytic transformations as useful tools for the synthesis of new trans-π-conjugated molecular organic compounds. The combination of Suzuki–Miyaura coupling and cross-metathesis reactions is established as a simple and efficient method for the design of new (E)-stilbenes in the presence of well-defined transition-metal catalysts at 0.0001–1 % loadings. All of the desired products are isolated in good-to-excellent yields (up to 96 % isolated yield) with high purity.
- Majchrzak, Mariusz,Wilkowski, Grzegorz,Kubicki, Maciej
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supporting information
p. 4291 - 4299
(2018/10/05)
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- Palladium-Catalysed Desulfitative Heck Reaction Tolerant to Aryl Carbon-Halogen Bonds for Access to (Poly)halo-Substituted Stilbene or Cinnamate Derivatives
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The palladium-catalysed desulfitative Heck type reaction of (poly)halo-substituted benzenesulfonyl chlorides with alkenes was investigated. Styrene or acrylates in the presence of bromo- or iodobenzenesulfonyl chlorides and a phosphine-free palladium catalyst were found to afford the expected β-arylated Heck type products with complete regio- and stereoselectivities. The reaction tolerates a variety of substituents on the halobenzenesulfonyl chloride. Moreover, no cleavage of the C-Br and C-I bonds was observed in the course of these reactions, allowing further transformations. Using 4-bromobenzenesulfonyl chloride as the central unit, consecutive desulfitative Heck type reaction followed by palladium-catalysed direct arylation allowed to prepare heteroarylated stilbene derivatives in only two steps.
- Skhiri, Aymen,Salem, Ridha Ben,Soulé, Jean-Francois,Doucet, Henri
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p. 3097 - 3106
(2016/09/09)
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- Tert-butyl phenyl sulfoxide: A traceless sulfenate anion precatalyst
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tert-Butyl phenyl sulfoxide is employed as a traceless precatalyst for the generation of sulfenate anions under basic conditions and has been used to catalyze the coupling of benzyl halides to trans-stilbenes. The advantage of this precatalyst over previous precatalysts is that the byproduct generated on catalyst formation is a gas, facilitating product isolation in high purity. Using this second generation catalyst, a variety of trans-stilbenes were generated in 39-98% isolated yield.
- Zhang, Mengnan,Jia, Tiezheng,Sagamanova, Irina K.,Pericás, Miquel A.,Walsh, Patrick J.
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supporting information
p. 1164 - 1167
(2015/03/14)
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- Encapsulation of Hoveyda-Grubbs2nd Catalyst within Yolk-Shell Structured Silica for Olefin Metathesis
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Through postreducing the pore size of a mesoporous shell, Hoveyda-Grubbs2nd catalyst was successfully encapsulated within yolk-shell structured silica, leading to a heterogeneous catalyst for olefin metathesis. Such a catalyst exhibits much higher activity than the reported encapsulated catalysts in olefin ring-closing metathesis and cross metathesis. This excellent activity can be attributed to the combination of a hollow structure in the interior and permeable mesopores in the shells. This catalyst shows good recyclability, highlighted by eight cycles of reaction. This work not only supplies an excellent heterogeneous olefin metathesis catalyst but also demonstrates that yolk-shell structured silica materials can be used as an innovative scaffold to encapsulate homogeneous catalysts.
- Li, Qibiao,Zhou, Ting,Yang, Hengquan
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p. 2225 - 2231
(2015/04/14)
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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 0045; 0046; 0047; 0048
(2013/03/26)
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- Synthesis and characterization of a novel ambipolar polymer semiconductor based on a fumaronitrile core as an electron-withdrawing group
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Two conjugated polymers containing stilbene and fumaronitrile moieties were synthesized to investigate their electronic properties by the existence of electron-withdrawing cyano groups on a vinylene backbone. The cyclic voltammetry investigation and time-dependent density functional theory calculations indicated that the cyano substituents lowered the lowest unoccupied molecular orbital (LUMO) energy level by about 0.65 and 0.63 eV, respectively. The lowering of the LUMO energy levels due to the electron-withdrawing properties of the cyano substituents could enhance electron injection capability. Furthermore, bithiophene-fumaronitrile (donor-acceptor) intermolecular interaction facilitates the self-assembly of the polymer chains. Organic field-effect transistors (OFETs) based on PBTSB without the electron-withdrawing group only exhibit hole transport, while OFETs based on PBTFN with cyano substituents exhibit ambipolar characteristics. The growth of PBTFN crystalline fibrils was observed with increasing annealing temperature, which enhanced hole and electron mobility. A complementary-like inverter using PBTFN with ambipolar properties exhibited good symmetry with an inverting voltage nearly half that of the power supply with a gain of 9 at VDD = 100 V. 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013. Copyright
- Jeong, Hyung-Gu,Khim, Dongyoon,Jung, Eunhwan,Yun, Jin-Mun,Kim, Juhwan,Ku, Jamin,Jang, Yun Hee,Kim, Dong-Yu
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p. 1029 - 1039
(2013/08/24)
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- Synthesis of combretastatin A-4 O-alkyl derivatives and evaluation of their cytotoxic, antiangiogenic and antitelomerase activity Dedicated to Professor G. Asensio, University of Valencia, on the occasion of his 65th birthday
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We here report the synthesis and biological evaluation of several combretastatin A-4 derivatives alkylated at the phenol hydroxyl group. Some of these derivatives contain an (E)-arylalkene fragment reminiscent of that present in some natural stilbenes like resveratrol. The cytotoxicities towards one human healthy kidney embryonic and two tumoral cell lines were determined. In addition, the ability of these compounds to inhibit the production of the vascular endothelial growth factor (VEGF) was measured. Finally, the expression of genes controlling the production of telomerase was measured. Some of the compounds were found to have an activity comparable or higher than that of combretastatin A-4 in at least one of the aforementioned biological properties. The compounds with the (E)-arylalkene fragment were in general terms more active than the simple O-alkyl derivatives. However, no clear structure/activity correlations were perceived when comparing the observed compound activities across the three biological properties. This points out the existence of marked differences between the mechanisms responsible for their cytotoxicity.
- Torijano-Gutiérrez, Sandra,Díaz-Oltra, Santiago,Falomir, Eva,Murga, Juan,Carda, Miguel,Marco, J. Alberto
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p. 7267 - 7274
(2013/11/19)
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- Encapsulation of an olefin metathesis catalyst in the nanocages of SBA-1: Facile preparation, high encapsulation efficiency, and high activity
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By postreducing the window size through silylation, 2nd generation Hoveyda-Grubbs catalyst was encapsulated in the nanocages of a mesoporous material SBA-1. The encapsulation efficiency of SBA-1 was up to 70%, much higher than that of other mesoporous materials such as SBA-16, FDU-12, and MCM-41 (0-43%). The successful encapsulation was confirmed by N2 sorption analysis and FTIR and diffusion reflectance UV/Vis spectroscopy. Such a SBA-1-encapsulated catalyst showed good activity in both olefin ring-closing metathesis and cross metathesis. A wide range of olefins could be transformed to the desired products with conversions of 27-100%. The encapsulated catalyst showed more sensitive temperature effects than the homogeneous counterpart, reflecting the unique properties of the encapsulated catalyst. At reaction temperatures of 40-60°C, the activity of the encapsulated catalyst was sufficiently comparable to that of the homogeneous catalyst for the cross metathesis of styrene-type substrates, probably because of the confinement effects of the nanocages. The solid catalyst could be recycled seven times. This study not only supplies a new solid catalyst for olefin metathesis but also demonstrates our improvement in immobilizing metal complex catalyst toward a green and effective level.
- Yang, Hengquan,Ma, Zhancheng,Zhou, Ting,Zhang, Wenjuan,Chao, Jianbin,Qin, Yong
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p. 2278 - 2287
(2013/08/23)
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- Synthesis and photovoltaic properties of two-dimensional conjugated polythiophene derivatives presenting conjugated triphenylamine/thiophene moieties
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In this study we synthesized three two-dimensional (2-D) polythiophene derivatives (PTs), namely PTBPTPA, PTStTPA, and PTCNStTPA, featuring three different conjugated units - biphenyl (BP), stilbene (St), and cyanostilbene (CNSt), respectively - in the po
- Wang, Hsing-Ju,Chen, Yuan-Peng,Chen, Yung-Chung,Chen, Chih-Ping,Lee, Rong-Ho,Chan, Li-Hsin,Jeng, Ru-Jong
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p. 4091 - 4103
(2012/11/13)
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- Ruthenium stilbenyl and diruthenium distyrylethene complexes: Aspects of electron delocalization and electrocatalyzed isomerization of the Z-isomer
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Regio- and stereoselective insertion of the terminal ethynyl functions of 4-ethynylstilbene, the E and Z isomers of 4,4′-bis(ethynylphenyl)ethene and a backbone-rigidified cyclohexenyl derivative of the Z isomer into the Ru-H bond of the complex RuClH(CO)(PiPr3)2 provides the corresponding vinyl ruthenium complexes, which have been characterized spectroscopically and by X-ray crystallography. Large red shifts of the UV/vis absorption bands evidence efficient incorporation of the vinyl metal subunit(s) into the conjugated π-system. All complexes oxidize at low potentials. The various oxidized forms of all complexes were generated and characterized by UV/vis/NIR, IR and EPR spectroscopies. These studies indicated electrocatalytic Z→E isomerization of the oxidized Z-distyrylethene complex Ru-Z2, which is prevented in its backbone-rigidified derivative Ru-Z2fix. The radical cations of the E and the configurationally stable cyclohexene-bridged Z-derivatives are spin-delocalized on the EPR time scale but charge-localized on the faster IR time scale. The degree of ground-state charge delocalization in the mixed-valent state has been quantified by the incremental shifts of the Ru-CO bands upon stepwise oxidation to the radical cations and the dications and was found to be remarkably large (19% and 9%) considering redox splittings ΔE 1/2 of just 49 or 74 mV. Quantum chemical studies with various levels of sophistication reproduce our experimental results including the electronic spectra of the neutral complexes and the intrinsically localized nature of the radical cations of the dinuclear complexes.
- Linseis, Michael,Zalis, Stanislav,Zabel, Manfred,Winter, Rainer F.
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supporting information
p. 16671 - 16692
(2013/01/15)
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- Sodium sulfinate-mediated trans-stilbene formation from benzylic halides
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A convenient and efficient method for the synthesis of various symmetrical and non-symmetrical trans-stilbene derivatives from benzylic halides in the absence of any transition metals is described. Sodium sulfinates played an important role in this transformation. Various functional groups were well tolerated under the optimized reaction conditions. Copyright
- Zhao, Feng,Luo, Jiaying,Tan, Qi,Liao, Yunfeng,Peng, Shengming,Deng, Guo-Jun
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supporting information; experimental part
p. 1914 - 1918
(2012/09/22)
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- Synthesis of stilbene analogues by one-pot oxidation-Wittig and oxidation-Wittig-Heck reaction
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Synthesis of symmetrical (and unsymmetrical) stilbene derivatives is achieved by a combination of one-pot steps of Kornblum type oxidation of benzyl halide, its simultaneous in situ formation of phosphonium salt, and subsequently their Wittig reaction. In other variant it is oxidized to aldehyde, treated with ylide generated from phosphonium salt (CH3PPh3X) to give styrene, and subjected to Pd catalyzed Heck reaction with arylhalide to give stilbenes as the three-step one-pot sequence.
- Saiyed, Akeel S.,Patel, Krupa N.,Kamath, Bola V.,Bedekar, Ashutosh V.
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supporting information; experimental part
p. 4692 - 4696
(2012/09/10)
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- Rh catalyzed c-h activation and oxidative olefination without chelate assistance: On the reactivity of bromoarenes
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A Rh catalyzed, no-chelate-assisted C-H activation/oxidative olefination reaction of bromoarenes has been discovered, in which the latter ones seem to act as a substrate, terminal oxidant, and catalyst modifier.
- Patureau, Frederic W.,Nimphius, Corinna,Glorius, Frank
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supporting information; experimental part
p. 6346 - 6349
(2012/01/15)
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- Convenient and stereoselective synthesis of symmetrical (E)-stilbenes via homocoupling of 1,3-dibenzylbenzotriazolium bromides
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Using NaH as the base and DMSO as the solvent, a series of symmetric (E)-stilbenes were prepared in good yields via the -homocoupling of 1,3-dibenzylbenzotriazolium bromides at room temperature. Georg Thieme Verlag Stuttgart · New York.
- Xiao, Xiaohui,Lin, Daqin,Tong, Shuitian,Luo, Hong,He, Yinfeng,Mo, Hailan
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supporting information; experimental part
p. 1731 - 1734
(2011/09/16)
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- Expeditious synthesis of helicenes using an improved protocol of photocyclodehydrogenation of stilbenes
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An improved procedure has been developed for photodehydrocyclization of stilbenes for the synthesis of phenanthrenes and helicenes. This procedure involves the use of THF as a scavenger of hydriodic acid produced during iodine mediated photodehydrocyclization. The use of THF is advantageous due to its higher boiling point, lower cost and easy availability as compared to propylene oxide. The method is applied to synthesize a number of phenanthrenes and helicenes. ARKAT-USA, Inc.
- Talele, Harish R.,Chaudhary, Anju R.,Patel, Parthiv R.,Bedekar, Ashutosh V.
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experimental part
p. 15 - 37
(2011/06/19)
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- Stilbene derivative, light emitting element, light emitting device, and electronic appliance
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An object is to provide a novel substance which exhibits blue light emission with excellent color purity, and to provide a light emitting element and a light emitting device using the novel substance. A stilbene derivative represented by the general formula (G1) is provided. Note that in the general formula (G1), each of A1 and B1 represents any one of structures represented by the following general formulae (G1-1) to (G1-4). In addition, in each of the general formulae (G1-1) to (G1-4), each of R1 to R24 represents any one of hydrogen and an alkyl group having 1 to 4 carbon atoms. Such a stilbene derivative can exhibit blue light emission with excellent color purity.
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Page/Page column 77
(2010/08/04)
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- Transformable periodic mesoporous organosilica materials
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The synthesis of novel periodic mesoporous organosilica (PMO) materials incorporating a mixture of functional monomers (cis- and trans-stilbene-based) and structural monomers has been accomplished. EDX analysis of these materials in combination with HAADF
- Dickson, Steven E.,Crudden, Cathleen M.
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supporting information; scheme or table
p. 2100 - 2102
(2010/08/22)
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- The catalytic Z to E isomerization of stilbenes in a photosensitizing porous coordination network
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(Figure Presented) One way only: The Z → E photoisomerization of stilbene under visible light occurs within a porous coordination network (see picture). The reaction proceeds through the photoexcitation of a chargetransfer complex between the highly elec-tron-deficient ligand and the stilbene in the pore. The in situ formed E isomer rapidly exchanges with unreacted Z isomer in solution, hence a catalytic amount of the network is sufficient to promote the reaction.
- Ohara, Kazuaki,Inokuma, Yasuhide,Fujita, Makoto
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supporting information; experimental part
p. 5507 - 5509
(2010/10/03)
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- Stilbene Derivative, Light-Emitting Element, Display Apparatus, and Electronic Appliance
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An object of the present invention is to provide a novel material having heat resistance which provides blue light emission, and a light-emitting element, a display apparatus, and an electronic appliance using the material. Aspects of the invention are a stilbene derivative represented by the following general formula (1), the light-emitting element in which a layer containing a light-emitting material interposed between two electrodes is included and the stilbene derivative is contained in the layer containing a light-emitting material, the display apparatus including the light-emitting element, and the electronic appliance including the display apparatus.
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Page/Page column 34-35
(2010/11/30)
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- Stilbene Derivative, Light Emitting Element, Light Emitting Device, and Electronic Appliance
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An object is to provide a novel substance which exhibits blue light emission with excellent color purity, and to provide a light emitting element and a light emitting device using the novel substance. A stilbene derivative represented by the general formula (G1) is provided. Note that in the general formula (G1), each of A1 and B1 represents any one of structures represented by the following general formulae (G1-1) to (G1-4). In addition, in each of the general formulae (G1-1) to (G1-4), each of R1 to R24 represents any one of hydrogen and an alkyl group having 1 to 4 carbon atoms. Such a stilbene derivative can exhibit blue light emission with excellent color purity.
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- AROMATIC AMINE DERIVATIVE AND ORGANIC ELECTROLUMINESCENCE DEVICE USING THE SAME
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To attain an organic electroluminescence device having a long lifetime and high luminous efficiency, and is capable of emitting blue light having a high color purity, and an aromatic amine derivative for realizing the device, the present invention provide
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Page/Page column 62
(2008/06/13)
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- Simple ruthenium precatalyst for the synthesis of stilbene derivatives and ring-closing metathesis in the presence of styrene initiators
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The ruthenium complex RuCl2(p-cymene)(IMes) was found to be an efficient precatalyst, with styrene as an initiating species, for the alkene metathesis of various styrenes into symmetrical and unsymmetrical stilbene derivatives and for the ring-closing metathesis reaction of a sterically hindered olefin leading to a tetrasubstituted cycloolefin.
- Lo, Cheikh,Cariou, Renan,Fischmeister, Cedric,Dixneuf, Pierre H.
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p. 546 - 550
(2008/02/08)
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- SiCl4-Zn induced reductive coupling of carbonyl compounds: novel and efficient routes for one-pot syntheses of 1,2,3-triaryl-2-propen-1-ones and pinacolones at room temperature
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An unprecedented one-pot reductive trimerization of aromatic aldehydes to 1,2,3-triaryl-2-propen-1-ones as well as tandem reductive coupling-rearrangements of aryl ketones to pinacolone analogues was efficiently achieved using tetrachlorosilane-zinc at room temperature.
- Salama, Tarek A.,Elmorsy, Saad S.,Khalil, Abdel-Galel M.
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p. 4395 - 4398
(2008/02/03)
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- Stilbene derivatives, light-emitting element and light-emitting device
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The present invention provides a novel substance having an excellent color purity of blue, a light-emitting element and a light-emitting device using the novel substance. A stilbene derivative has a structure shown by the general formula (1). In the general formula (1), R1 is hydrogen, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 25 carbon atoms. R2 is an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 25 carbon atoms. Each of R3 to R5 is hydrogen or an alkyl group having 1 to 4 carbon atoms. Ar1 is an aryl group having 6 to 25 carbon atoms.
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Page/Page column 65-66
(2008/06/13)
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- Stilbene derivative, light emitting element material, light emitting element, light emitting device and electronic appliance
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An object of the present invention to provide a novel stilbene derivative having a large energy gap. In addition, it is another object of the present invention to provide a novel light emitting element material having a large energy gap which is suitable for a host material in a light emitting layer. Further in addition, it is another object of the present invention to provide a novel light emitting element material having a large energy gap and an electron transporting property. The present invention provides a stilbene derivative represented by a following general formula (3) and a light emitting element material including the stilbene derivative represented thereby: wherein, n is an integer of 0 or more and 2 or less and m is an integer of 1 or more and 2 or less.
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Page/Page column 15
(2008/06/13)
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- Lanthanitin: A chiral nanoball encapsulating 18 lanthanum ions by ferritin-like assembly
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(Figure Presented) A chiral supramolecule, obtained by self-assembly of 24 chiral ditopic carboxylate ligands, 18 La ions, and two carbonate anions, has been dubbed lanthanitin because of its structural resemblance to ferritin. The picture shows the molec
- Jeong, Kyung Seok,Kim, Young Shin,Kim, Yun Ju,Lee, Eunsung,Yoon, Ji Hye,Park, Won Hwa,Park, Young Woo,Jeon, Seung-Joon,Kim, Zee Hwan,Kim, Jaheon,Jeong, Nakcheol
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p. 8134 - 8138
(2008/02/12)
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