- Solid-state Suzuki-Miyaura cross-coupling reactions: Olefin-accelerated C-C coupling using mechanochemistry
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The Suzuki-Miyaura cross-coupling reaction is one of the most reliable methods for the construction of carbon-carbon bonds in solution. However, examples for the corresponding solid-state cross-coupling reactions remain scarce. Herein, we report the first broadly applicable mechanochemical protocol for a solid-state palladium-catalyzed organoboron cross-coupling reaction using an olefin additive. Compared to previous studies, the newly developed protocol shows a substantially broadened substrate scope. Our mechanistic data suggest that olefin additives might act as dispersants for the palladium-based catalyst to suppress higher aggregation of the nanoparticles, and also as stabilizer for the active monomeric Pd(0) species, thus facilitating these challenging solid-state C-C bond forming cross-coupling reactions.
- Seo, Tamae,Ishiyama, Tatsuo,Kubota, Koji,Ito, Hajime
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p. 8202 - 8210
(2019/09/19)
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- Artificial light-harvesting supramolecular polymeric nanoparticles formed by pillar[5]arene-based host-guest interaction
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Artificial light-harvesting nanoparticles were prepared from supramolecular polymers comprised of pillar[5]arene with anthracene-derived donors and acceptors through host-guest interactions. The resulting water-dispersible nanoparticles displayed efficient energy transfer and excellent light harvesting ability in part because the steric bulk of pillar[5]arene suppressed the self-quenching of the chromophores.
- Sun, Cai-Li,Peng, Hui-Qing,Niu, Li-Ya,Chen, Yu-Zhe,Wu, Li-Zhu,Tung, Chen-Ho,Yang, Qing-Zheng
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supporting information
p. 1117 - 1120
(2018/02/07)
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- Novel methoxy spirobifluorene and alkyl substituted diphenylacene based organic blue light emitting polymers for application in organic electronics
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We report on the synthesis and characterisation of a series of blue light emitting alkoxy substituted poly(spirobifluorenes) based on acene moiety. The obtained polymers had been fully characterised by FTIR, NMR, TGA, GPC techniques. The obtained polymers showed good photoluminescence and electroluminescence properties with blue fluorescence, obtained by supressing the excimer formation as a result of intermolecular interactions. The optical band gaps of all polymers were estimated to be in the range of 2.64–2.71 eV with good fluorescent quantum yield. The introduction of a spiro-structure in polymer backbone leads to its high thermal stability and good solubility in common organic solvents such as CH2Cl2, CH3Cl, toluene, tetrahydrofuran etc.
- Chalke, Rhushirajeshwari M.,Patil, Vishwanath R.
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p. 355 - 365
(2017/07/25)
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- Water-soluble fluorescent polymers that respond to singlet oxygen
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Although acenes with more than three fused rings can both fluoresce efficiently and react with singlet oxygen (1O2) rapidly, their hydrophobic nature presents a challenge to their use in aqueous environments. Herein we report a series of fluorescent, water-soluble random copolymers that each comprise (oligoethylene glycol) methacrylate (OEGMA) and one of several diarylacene methacrylates, including a tetracene methacrylate and a tetraceneothiophene methacrylate. Exposure to 1O2 in water oxidizes the pendant acenes, resulting in diminution of their fluorescence intensities. The observed rate of oxidation of the tetracene-containing polymers compares favorably with a commercial 1O2-sensitive dye. Polymers that also include energy-donating coumarin side chains show ratiometric fluorescence changes in response to 1O2.
- Altinok, Esra,Frausto, Fanny,Thomas, Samuel W.
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p. 2526 - 2535
(2016/07/14)
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- A new organic two-electron oxidant: 9,10-diaryl-9,10-dihydroanthracene-9, 10-bis(ylium)
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Strong as an Ox: A dicationic compound with a 9,10-dihydroanthracene skeleton has been produced from the corresponding 9,10-dialkoxy-9,10- dihydroanthracene, which was readily prepared from anthraquinone. The dication functions as a powerful two-electron oxidant, comparable to aminium cation radicals, and has been employed in oxidative processes such as the self-coupling of anilines and naphthols, and oxidative deprotection of p-methoxybenzyl (PMB) ethers. Copyright
- Ichikawa, Junji,Tanabe, Hiroyuki,Yoshida, Suguru,Kawai, Takaharu,Shinjo, Masahiko,Fujita, Takeshi
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supporting information
p. 2588 - 2591
(2013/11/19)
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- Synthesis and properties of thermotropic liquid-crystalline polyesters containing 9,10-diphenylanthracene moiety in the main chain
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We synthesized thermotropic liquid-crystalline polyesters in which 9,10-diphenylanthracene moieties are incorporated into the main chain type of polyester forming the chiral smectic C (Sm C*). The polymers were prepared by the isopropyltitanate-catalyzed reaction of biphenyldicarboxylic acid and the corresponding diols, with different ratios of diol of 9,10- diphenylanthracene moiety to the alkane diols (1, 5, and 10 mol %) under nitrogen atmosphere. The polymers exhibited thermotropic liquid crystals despite the presence of a bulky diphenylanthracene moiety in the main chain. The circular dichroism spectra revealed that a Sm C*phase was formed in the polymer with 1 mol % of anthracene moiety, although only an Sm A phase was formed in the other polymers. This is the first example of a Sm C*polyester containing a diphenylanthracene moiety in the main chain. Furthermore, we measured the optical properties of the polymers and found that they exhibited very high fluorescent efficiency. The fluorescence spectra of the thin film differed from that of a CH2Cl2 solution.
- Uchimura, Makoto,Ishige, Ryohei,Shigeta, Masayuki,Arakawa, Yuki,Niko, Yosuke,Watanabe, Junji,Konishi, Gen-Ichi
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p. 403 - 414
(2013/02/25)
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- Synthesis of diarylated aromatic hydrocarbons by dehydroxylation of diols using the titanium(IV) chloride and triethylamine reagent system
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1,2-Diarylacenaphthylene, 9,10-diarylphenanthrene and 9,10-diarylanthracene derivatives were obtained in good yields (61-92%) in short reaction times (5-30 min) from the corresponding diols with the titanium(III) reagent prepared in situ using the TiCl4/Et3N reagent system in dichloromethane at 25 °C. Georg Thieme Verlag Stuttgart ? New York.
- Periasamy, Mariappan,Beesu, Mallesh,Shanmugaraja, Masilamani
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p. 2913 - 2918
(2013/10/22)
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- 9,10-Diarylanthracenes as stable electrochemiluminescent emitters in water
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Two hydrophilic diarylanthracenes, explicitly 9,10-bis(N-methylimidazolium- 3-propoxyphenyl)anthracene (DAA1) and 9,10-bis(N-methylimidazolium-3-propoxy-2, 6-dimethylphenyl)anthracene (DAA2), are synthesized and fully characterized. Both are found to be soluble in aqueous medium and to exhibit optical properties similar to those of the parent 9,10-diphenylanthracene, whose solubility is virtually negligible in water. The detailed analysis of their photochemical stability as well as electrochemical and electrochemiluminescent properties reveals that the sterically highly shielded anthracene DAA2 shows inertness toward reactions with singlet oxygen and OH- ions during photo- and electrochemical initiation and stable ECL emission in aqueous medium.
- Natarajan, Palani,Schmittel, Michael
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p. 8669 - 8677,9
(2020/09/15)
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- Remote substituent effects on the photooxygenation of 9,10- diarylanthracenes: Strong evidence for polar intermediates
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Two different reaction pathways in the photooxygenation of 9,10-diarylanthracenes are identified, with strong evidence for polar (forward, singlet oxygen addition) and radical (backward, thermolysis) intermediates. The Royal Society of Chemistry.
- Fudickar, Werner,Linker, Torsten
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p. 1771 - 1773
(2008/12/22)
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- Synthesis of symmetrical and unsymmetrical 9,10-diarylanthracene derivatives via bis-Suzuki-Miyaura cross-coupling reaction
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Synthesis of various 9,10-diarylanthracene derivatives via bis-Suzuki-Miyaura cross-coupling reaction as a key step is described. Availability of the 9,10-dithienylanthracenes derivatives where the thiophene unit is present in the molecule (e. g. 11, 12, 14) may provide an easy access to novel polymer and/or dendrimer preparation. In addition, we have synthesized unsymmetrical 9,10-diarylanthracene derivatives 20-25 by the Suzuki-Miyaura cross-coupling reaction, which are difficult to prepare by other transition metal-catalyzed cross-coupling reactions.
- Kotha, Sambasivarao,Ghosh, Arun Kumar,Deodhar, Kodand Dinkar
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p. 549 - 557
(2007/10/03)
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- Synthesis of 9,10-diarylanthracene derivatives via bis Suzuki-Miyaura crosscoupling reaction
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A convenient and one-step synthesis of 9,10-diarylanthracenes is described via a bis Suzuki-Miyaura (SM) cross-coupling reaction. In this regard, 9,10-dibromoanthracene was reacted with various aryl boronic acids in presence of palladium(O) catalyst to give 9,10-diarylanthracenes in good yield.
- Kotha, Sambasivarao,Ghosh, Arun Kumar
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p. 451 - 452
(2007/10/03)
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- A novel acid-catalyzed rearrangement of 9,10-diaryl-9,10- dihydroanthracene-9,10-diols affording 10,10'-diaryl-9-anthrones
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Usually, 9,10-diarylanthracenes can be obtained by reduction of the corresponding 9,10-diaryl-9,10-dihydroanthracene-9,10-diols with Kl/NaH2PO2 in acetic acid. In contrast, we found that in case of heteroaromatic aryl substituents and when peri substituents are present on the anthracene residue, high amounts of anthrones are formed. These anthrones can be considered to result from a vinylogous pinacol rearrangement of the initial diol. To the best of our knowledge, this type of rearrangement is rarely observed, and the 10,10'-diaryl-9-anthrones obtained in this way, are difficult to prepare otherwise. We prepared a number of such compounds and studied the mechanism of the transformation involved. The results are in agreement with a bridged transition state 10.
- Smet, Mario,Van Dijk, Joachim,Dehaen, Wim
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p. 7859 - 7874
(2007/10/03)
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- Remote substituent effects on the reactivity of 9-aryl- and 9,10-diarylanthracene radical cations with anions and amines
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Radical cations of 9-aryl- and 9,10-diarylanthracenes with substituents on the 4 position of the aryl rings (PA-X?+ and DPA-X?+, respectively) have been generated by photoionization in acetonitrile. Their reactivity with n-butylamine (n-BuNH2) and 1,4-diazabicyclo[2.2.2]octane (DABCO) and a number of anions (CH3CO2-, Br-, CN-, N3-) has been studied using nanosecond laser flash photolysis. Reactions proceed by electron transfer and/or nucleophilic addition. Using PA-X and DPA-X as chemical probes, simple criteria are established that allow one mechanistic pathway to be distinguished from another. When electron transfer is thermodynamically feasible, this pathway dominates (e.g., DABCO and azide). For endothermic electron transfer, addition is not necessarily the preferred ultimate reaction pathway and an inner sphere process (addition/ homolysis) can compete. In these cases other, criteria including steric factors and the strength of the incipient bond become important. Simple kinetic criteria and an approach to estimate the thermochemistry of the addition process are developed. It is clear from these studies that reactivity trends in the radical cation chemistry cannot be generalized as easily as those in carbocation chemistry. This has some implications concerning the development and utility of "clock" reactions in radical cation chemistry.
- Workentin, Mark S.,Parker, Vernon D.,Morkin, Tracy L.,Wayner, Danial D. M.
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p. 6503 - 6512
(2007/10/03)
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- Ferrocene derivatives containing anthracene linked by spacers
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Several ferrocene derivatives linked by a non-conjugated spacer to a 9,10-diphenylanthracene unit have been prepared, among them an amphiphilic isoquinolinium salt. By X-ray structure analysis of the intermediate 9,10-bis(4-hydroxyphenyl)anthracene, an almost perpendicular arrangement of the phenyl groups with respect to the anthracene was found. The properties of the compounds were studied by NMR and cyclovoltammetry, which suggest that the isoquinolinium salt forms inverse micelles in organic solvents. No indication for intramolecular aggregation of ferrocene and isoquinolinium moieties by folding of the flexible alkyl spacers could be detected. The compound forms a monolayer when spread on water which can be transferred to a quartz surface. Repeated transfer leads to a non-centrosymmetric Z-type array of layers in the Langmuir-Blodgett film.
- Wagner, Gabriele,Herrmann, Rudolf,Scherer, Wolfgang
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p. 225 - 233
(2007/10/03)
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