- Photodimers of a soluble tetracene derivative. Excimer fluorescence from the head-to-head isomer
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Equation presented. Irradiation of 5,12-didecyloxytetracene (1) leads to photodimers P1 (planosymmetric) and P2 (centrosymmetric). P1 is characterized by naphthalene excimer fluorescence, whereas P2 emits naphthalene monomer fluorescence.
- Reichwagen, Jens,Hopf, Henning,Del Guerzo, Andre,Desvergne, Jean-Pierre,Bouas-Laurent, Henri
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- Synthesis of (±)-Idarubicinone via Global Functionalization of Tetracene
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Anthracyclines are archetypal representatives of the tetracyclic type II polyketide natural products that are widely used in cancer chemotherapy. Although the synthesis of this class of compounds has been a subject of several investigations, all known approaches are based on annulations, relying on the union of properly prefunctionalized building blocks. Herein, we describe a conceptually different approach using a polynuclear arene as a starting template, ideally requiring only functional decorations to reach the desired target molecule. Specifically, tetracene was converted to (±)-idarubicinone, the aglycone of the FDA approved anthracycline idarubicin, through the judicious orchestration of Co- and Ru-catalyzed arene oxidation and arenophile-mediated dearomative hydroboration. Such a global functionalization strategy, the combination of site-selective arene and dearomative functionalization, provided the key anthracycline framework in five operations and enabled rapid and controlled access to (±)-idarubicinone.
- Dennis, David G.,Okumura, Mikiko,Sarlah, David
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- Ortho-quinodimethane from anthracene epidioxide: Scope of the Diels-Alder reaction and mild preparation of naphthalene derivatives
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The thermal isomerisation of anthracene epidioxide 3 has been known to give phenylenedioxy-ortho-quinodimethane 5 as a reactive transient. We presented herein the scope of the Diels-Alder reaction of this transient 5 with some dienophiles. In addition, a mild synthesis of naphthalene derivatives has been developed via base-induced cleavage of the obtained Diels-Alder adducts.
- Siret, Bernard,Albrecht, Sébastien,Defoin, Albert
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- A Dynamic Tetracationic Macrocycle Exhibiting Photoswitchable Molecular Encapsulation
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Designing macrocycles with appropriate molecular recognition features that allow for the integration of suitable external stimuli to control host-guest processes is a challenging endeavor which enables molecular containers to solubilize, stabilize, and separate chemical entities in an externally controllable manner. Herein, we introduce photo- and thermal-responsive elements into a semi-rigid tetracationic cyclophane, OPVEx2Box4+, that is composed of oligo(p-phenylenevinylene) pyridinium units and the biphenylene-bridged 4,4-bipyridinium extended viologens and adopts a rectangle-like geometry. It transpires that when the photoactive oligo(p-phenylenevinylene) pyridinium unit is incorporated in a macrocyclic scaffold, its reversibility is dramatically improved, and the configurations of the cyclophane can go back and forth between (EE)- and (EZ)-isomers upon alternating blue light irradiation and heating. When the macrocycle is found in its (EE)-configuration, it is capable of binding various π-electron-rich guests - e.g., anthracene and perylene - as well as π-electron-deficient guests - e.g., 9,10-anthraquinone and 5,12-tetracenequinone - through charge-transfer and van der Waals interactions. When irradiated with blue light, the (EE)-isomer of the cyclophane can be transformed successfully to the (EZ)-isomer, resulting in the switching off of the binding affinity for guest molecules, which are bound once again upon heating. The use of light and heat as external stimuli to control host-guest interactions involving a multi-responsive host and various guests provides us with a new opportunity to design and construct more-advanced molecular switches and machines.
- Wu, Huang,Chen, Yong,Zhang, Long,Anamimoghadam, Ommid,Shen, Dengke,Liu, Zhichang,Cai, Kang,Pezzato, Cristian,Stern, Charlotte L.,Liu, Yu,Stoddart, J. Fraser
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- Tetracene Derivatives as Potential Red Emitters for Organic LEDs
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(Equation presented) As part of our program investigating the use of ethynylated acenes in organic electronics, we have prepared a series of functionalized tetracene derivatives in search of a material with red emission suitable for use in display technologies. A number of such compounds with functionalization on the alkyne and/or the acene ring were easily prepared in one or two steps from commercially available materials. Solution fluorescence quantum efficiencies were generally good for these derivatives, which possessed emission maxima spanning the range 540-637 nm. Simple light-emitting diodes fabricated from these compounds showed that one of the derivatives did exhibit red electroluminescence.
- Odom, Susan A.,Parkin, Sean R.,Anthony, John E.
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- Electron Acceptors Based on Cyclopentannulated Tetracenes
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New cyclopenta-fused polycyclic aromatic hydrocarbons (CP-PAHs) based on tetracene have been prepared by a palladium-catalyzed cyclopentannulation reaction. The new compounds have low-energy lowest unoccupied molecular orbitals (LUMOs) and relatively small band gaps. The photooxidative stability was intermediate to previously prepared CP-PAHs based on anthracene and pentacene as found in traditional acene stabilities. Scholl cyclodehydrogenation of pendant aryl groups led to materials that quickly formed endoperoxide products.
- Kulkarni, Gajanan C.,Morales-Cruz, Jean L.,Hussain, Waseem A.,Garvey, Ian J.,Plunkett, Kyle N.
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- Interplay between singlet and triplet excited states in a conformationally locked donor-acceptor dyad
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The synthesis and photophysical characterization of a palladium(ii) porphyrin - anthracene dyad bridged via short and conformationally rigid bicyclo[2.2.2]octadiene spacer were achieved. A spectroscopic investigation of the prepared molecule in solution has been undertaken to study electronic energy transfer in excited singlet and triplet states between the anthracene and porphyrin units. By using steady-state and time-resolved photoluminescence spectroscopy it was shown that excitation of the singlet excited state of the anthracene leads to energy transfer to the lower-lying singlet state of porphyrin. Alternatively, excitation of the porphyrin followed by intersystem crossing to the triplet state leads to very fast energy transfer to the triplet state of anthracene. The rate of this energy transfer has been determined by transient absorption spectroscopy. Comparative studies of the dynamics of triplet excited states of the dyad and reference palladium octaethylporphyrin (PdOEP) have been performed.
- Filatov, Mikhail A.,Etzold, Fabian,Gehrig, Dominik,Laquai, Frédéric,Busko, Dmitri,Landfester, Katharina,Baluschev, Stanislav
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- Effects of Substituents and Solvents on the Electronic Spectra of 9,10-Dihydro-9,10-o-benzenoanthracene-1,4-diones: Intramolecular Charge Transfer
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Electronic spectra of substituted 9,10-dihydro-9,10-o-benzenoanthracene-1,4-diones (triptycenequinones) in various solvents and that of benzo- and dibenzotriptycenequinones were investigated in this paper.Intramolecular charge-transfer (CT) bands were observed in triptycenequinone system as a result of intramolecular interaction between benzene ring and benzoquinone moiety.Substituents on the benzene rings strongly affected the CT bands.Electron-donating groups gave absorption maxima at long wavelength.Naphthalene ring gave similar but stronger CT bands than benzene ring.Hammett ?+ value of substituents gave good linear relationship with the energy of the CT bands.Calculations of reduced charge matrix of triptycenequinones by extended Hueckel theory showed the charge of aromatic ring(s) were transferred to benzoquinone moiety accompanying HOMO-LUMO excitation.Especially, absorption maxima of the methyl-substituted triptycenequinones gave good correlation with the amounts of charge transferred from benzene ring to benzoquinone moiety.These analysis confirmed clearly CT character of the absorption maxima of triptycenequinones.However, solvent effect of these CT bands maxima is not so clear as the substituent effect.
- Kitaguchi, Nobuya
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- Bis(methylthio)tetracenes: Synthesis, crystal-packing structures, and OFET properties
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5,12-Bis(methylthio)tetracene (2) and 5,11-bis(methylthio)tetracene (3) were synthesized. DFT calculations indicate that the HOMO and LUMO energy levels of 2 and 3 are lowered by 0.13-0.24 eV and their HOMO-LUMO energy gaps are reduced by 0.1 eV relative to those of tetracene. X-ray crystallographic data revealed that 2 is arranged as a result of a 1-D slipped-cofacial π-stacking with S-S and S-π interactions, similar to the packing arrangement of 6,13-bis(methylthio)pentacene (1), whereas 3 exhibits a herringbone packing arrangement without S-S interactions. The OFET devices fabricated using spin-coated films of soluble 1 and 2, with a bottom-contact device configuration, exhibited hole mobilities as high as 1.3 × 10-2 and 4.0 × 10-2 cm2 V-1 s-1 with current on/off ratios of over 105 and 104, respectively.
- Kimoto, Takakazu,Tanaka, Kenro,Kawahata, Masatoshi,Yamaguchi, Kentaro,Otsubo, Saika,Sakai, Yoshimasa,Ono, Yuuki,Ohno, Akira,Kobayashi, Kenji
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- Synthesis method of anthraquinone derivatives and tetracenedione derivatives through benzannulation reaction
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The present invention relates to a method for synthesizing anthraquinone derivatives and tetracene dione derivatives through a benzannulation reaction, which presents a novel synthesis method, capable of processing synthesis easily, conveniently, and efficiently under mild conditions by an organic catalyst. The synthesis method uses an L-proline catalyst which is nontoxic, economical and easily available, compared to conventional production methods, thereby providing the anthraquinone derivatives and the tetracene dione derivatives through the one-pot benzannulation reaction of an α, β-unsaturated aldehyde compound, various 1,4-naphthoquinone compounds or 1,4-anthracenedione compounds. Various forms of anthraquinone derivatives or tetracene dione derivatives prepared by the synthesis method can be widely used for synthesis of natural products, dyes, and pharmaceutical products.COPYRIGHT KIPO 2017
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Paragraph 0029-0030; 0061; 0071
(2017/08/09)
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- Organocatalyzed benzannulation for the construction of diverse anthraquinones and tetracenediones
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An efficient one-pot synthesis of anthraquinones and tetracenediones was achieved vial-proline catalyzed [4+2] cycloaddition of in situ generated azadiene from α,β-unsaturated aldehydes and 1,4-naphthoquinones or 1,4-anthracenedione in good to excellent yield. This protocol constitutes an unprecedented tandem benzannulation that allows one-pot construction of diverse anthraquinones and tetracenediones in the presence of organocatalysts. This methodology was applied successfully to the synthesis of naturally occurring molecules and photochemically interesting phenanthrenequinone derivatives.
- Somai Magar, Krishna Bahadur,Xia, Likai,Lee, Yong Rok
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supporting information
p. 8592 - 8595
(2015/05/20)
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- Facile Sc(OTf)3-catalyzed generation and successive aromatization of isobenzofuran from o -dicarbonylbenzenes
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Isobenzofuran can be prepared from o-phthalaldehyde using hydrosilane. The formed isobenzofuran is trapped by an alkene via a Diels-Alder reaction. Further dehydration proceeds to furnish the conjugated aromatic compound. This multistep reaction was promoted by catalytic amounts of Sc(OTf)3.
- Nishina, Yuta,Kida, Tatsuya,Ureshino, Tomonari
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supporting information; experimental part
p. 3960 - 3963
(2011/10/01)
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- Synthesis of polyacenequinones via crossed aldol condensation in pressurized hot water in the absence of added catalysts
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Phthalaldehyde and 1,4-cyclohexanedione react in the 2:1 molar ratio via a crossed aldol condensation in sub- and supercritical water to produce 6,13-pentacenequinone. The reaction conditions were optimized at 77% yield at 250 °C for 60 min with the starting molar ratio of 2:1:800 for phthalaldehyde, 1,4-cyclohexanedione and water, respectively. Whereas the initial rate of the reaction increased at higher pH, as suggested by earlier studies of the crossed aldol condensation of the two carbonyl compounds using a base catalyst in an organic solvent, the present results of successful reactions without the addition of any acid or base show the role of the increased solubility of the starting materials and the higher ion product in pressurized hot water. 6,13-Pentacenequinone was obtained as fine needles from the cooled reaction mixture just by filtration. Under similar conditions, 7,16-heptacenequinone and 5,12-naphthacenequinone were obtained in 46 and 70% isolated yields, respectively. The Royal Society of Chemistry 2009.
- Sawada, Takenori,Nakayama, Shu,Kawai-Nakamura, Akiko,Sue, Kiwamu,Iwamura, Hiizu,Hiaki, Toshihiko
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experimental part
p. 1675 - 1680
(2010/06/11)
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- Synthesis of the tetracyclic core of anthracycline antibiotics by an intramolecular dehydro diels-alder approach
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(Matrix presented) A conceptually new approach to the tetracyclic core of the anthracycline antibiotics is reported. With use of this approach, the 7,8,9,10-tetrahydronaphthacene-5,12-dione skeleton has been synthesized in three steps, from commercially available reagents, in yields of up to 85%.
- Rodriguez, David,Castedo, Luis,Dominguez, Domingo,Saa, Carlos
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p. 3119 - 3121
(2007/10/03)
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- Acid-Catalyzed Cyclization of o-Aroylbenzoic and Diarylcarboxylic Acids upon Heating in Vacuum
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The cyclization of 1,1′-dinaphthyl-8,8′-dicarboxylic acid, diphenic anhydride, o-benzoylbenzoic acid, and 1-naphthoyl-o-benzoic acid into, respectively, anthanthrone, fluorenone-4-carboxylic acid, anthraquinone, and 1,2-benzanthraquinone occurs upon heating to 150-200°C in vacuum in the presence of catalytic amounts (1-3%) of H2SO4 or P2O5.
- Nefedov
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p. 375 - 377
(2007/10/03)
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- Synthesis and Evaluation of Fluorescent Materials for Colour Control of Peroxyoxalate Chemiluminescence. III. Yellow and Red Fluorescent Emitters
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A number of bis(phenylethynyl)-substituted anthracenes and naphthacenes have been synthesized and their suitability as fluorescent additives for peroxyoxalate chemiluminescence evaluated.Fluorescence and chemiluminescence emission data for all compounds are presented.Both 2-chloro- and 6-chloro-5,12-bis(phenylethynyl)naphthacene provide effective scarlet chemiluminescence with the peroxyoxalate system (λmax 609 and 614 nm respectively).Althgough solutions of both compounds decolorize slowly in the presence of air and light, when used in concentrations 0f 1-5*10-3 M they allow efficient chemiluminescence for greater than 5 h.
- Hanhela, Peter J.,Paul, Brenton D.
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p. 1701 - 1717
(2007/10/02)
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- γ-Radiation-Oxidation of Polycyclic Aromatic Hydrocarbons: Involvement of Singlet Oxygen
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Oxidation of organic compounds in the presence of high-energy radiation is generally understood in terms of organic free-radical mechanisms.We investigated the chemistry of certain polycyclic aromatic hydrocarbons in oxygenated solutions submitted to γ-radiation from a cobalt-60 source in an effort t identifity and study other pathways in radiation-oxidation.Products obtained could be explained either through singlet oxygen (1O2) production, through superoxide (O2-.) production, or through a cation radical mediated reaction with O2.Quenching experiments clearly established singlet oxygen as the intermediate involved.The oxidation products varied markedly depending on the starting compound.This resulted because the primary endoperoxide adducts were subject to radiation-induced decomposition both by retrograde O2 expulsion and by breakdown to quinones.It was also found that certain common 1O2 quenchers were ineffective in the radiation environment because of decomposition.
- Clough, Roger L.
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p. 5242 - 5245
(2007/10/02)
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