130-15-4Relevant articles and documents
The Formation of 1,4-Quinones by Oxovanadium(IV)-Complexes Catalyzed Aerobic Oxygenation of Fused Aromatic Compounds
Takai, Toshihiro,Hata, Eiichiro,Mukaiyama, Teruaki
, p. 885 - 888 (1994)
In the presence of a catalytic amount of oxovanadium(IV) complexes coordinated with 1,3-diketone ligands, fused aromatic compounds such as naphthalenes and naphthol derivatives are smoothly oxygenated into the corresponding 1,4-naphthoquinones by combined use of molecular oxygen and crotonaldehyde under an atmospheric pressure.
2-Pyridyldimethylsilyl Group as a Removable Hydrophilic Group in Aqueous Organic Reactions: Formation of Molecular Aggregates and Dramatic Rate Enhancement in Diels-Alder Reactions
Itami, Kenichiro,Nokami, Toshiki,Yoshida, Jun-Ichi
, p. 441 - 451 (2002)
A novel methodology for aqueous organic reactions utilizing a 2-pyridyldimethylsilyl (2-PyMe2Si) group as a removable hydrophilic group has been developed. It was found that 1,3-dienes bearing the 2-PyMe2Si group form molecular aggregates in water when 1.0 equivalent of HCl was added, as evidenced by dynamic light-scattering experiments. The Diels-Alder reaction of 2-PyMe2Si-substituted 1,3-dienes with various dienophiles took place in water at room temperature. The Diels-Alder reaction in organic solvents (Et2O/toluene) under the same reaction temperature and time gave the cycloadduct in much lower yield, indicating the dramatic rate acceleration in water. The removal of the 2-PyMe2Si group was accomplished by desilylation, oxidation, and electrophilic substitution.
Copper(i)-based oxidation of polycyclic aromatic hydrocarbons and product elucidation using vacuum ultraviolet spectroscopy and theoretical spectral calculations
Ponduru, Tharun T.,Qiu, Changling,Mao, James X.,Leghissa, Allegra,Smuts, Jonathan,Schug, Kevin A.,Dias, H. V. Rasika
, p. 19442 - 19449 (2018)
Copper(i) complexes supported by fluorinated 1,3,5-triazapentadienyl ligands have been used as catalysts for the oxidation of anthracene, naphthalene, and pyrene to the corresponding quinones, using H2O2 as an oxidant under mild conditions without an acid co-catalyst. Gas chromatography-vacuum ultraviolet spectroscopy (GC-VUV) combined with time-dependent density functional theory theoretical computations of absorption spectra was demonstrated as a new and useful tool-set for unknown determination in complex reaction mixtures, especially when standards are not available for spectral comparisons and product mixtures involve closely related isomers. The anthracene has been converted to 9,10-anthraquinone in quantitative yield using this copper catalyzed process. The oxidation of naphthalene afforded 1,4-naphthoquinone as the major product, and 1-naphthol and 2-naphthol as minor products. The pyrene oxidation resulted in 4,5-, 1,6-, and 1,8-pyrenequinones, among other products. The X-ray crystal structure of [N{(CF3)C(C6F5)N}2]CuNCCH3 is also reported.
Sodium hypochlorite/Dowex 1X8-200: An effective oxidant for the oxidation of aromatic amines to quinones
Hashemi, Mohammed M.,Beni, Yousef A.
, p. 672 - 673 (1999)
Polymer supported hypochlorite ion is a useful oxidant for the oxidation of aromatic amines to the corresponding quinones.
Influence of the sulfinyl group on the chemoselectivity and π-facial selectivity of diels-alder reactions of (S)-2-(p Tolylsulfinyl)-1,4-benzoquinone
Carreno, M. Carmen,Garcia Ruano, José L.,Toledo, Miguel A.,Urbano, Antonio,Remor, Cynthia Z.,Stefani, Valter,Fischer, Jean
, p. 503 - 509 (1996)
Diels-Alder reactions of (S)-2-(p-tolylsulfmyl)-1,4-benzoquinone (1a) with cyclic (cyclopentadiene and cyelohexadiene) and acyclic dienes (1-[(trimethylsilyl)oxy]-1,3-butadiene and trans-piperylene) under different thermal and Lewis acid conditions are reported. Chemoselectivity (reactions on C2-C3 versus C5-C6 double bonds) is mainly related to the cyclic (on C5-C6) or acyclic (on C2-C3) structure of the diene. The high π-facial selectivity observed could be controlled by choosing adequate experimental conditions.
A novel process for selective Ruthenium-Catalyzed oxidation of naphthalenes and phenols
Wienhoefer, Gerrit,Schroeder, Kristin,Moeller, Konstanze,Junge, Kathrin,Beller, Matthias
, p. 1615 - 1620 (2010)
Arenes are selectively oxidized to the corresponding quinones employing ruthenium(2,2′,6′:2″-terpyridine)(2,6-pyridinedicarboxylate) [Ru(tpy)(pydic] as catalyst and hydrogen peroxide as the terminal oxidant. Applying alkylated naphthalenes and phenols, benzo- and naphthoquinones are obtained in up to 93% yield. The industrially interesting oxidation of 2-methylnaphthalene gave 74% of the corresponding quinones and 60% of menadione (vitamin K3). 2,3,5-Trimethylbenzoquinone which constitutes the key intermediate for vitamin E is obtained in 83% yield.
Preparation and photocatalytic activity of WO3-MWCNT nanocomposite for degradation of naphthalene under visible light irradiation
Farhadian, Mousa,Sangpour, Parvaneh,Hosseinzadeh, Ghader
, p. 39063 - 39073 (2016)
In this study, a WO3-multiwalled carbon nanotube nanocomposite has been prepared for the first time by in situ liquid phase process. The prepared nanocomposite was used for photodegradation of dilute solution of naphthalene under visible light irradiation. Based on our results, comparing photocatalytic activity of WO3 nanoparticle with WO3-multiwalled carbon nanotube nanocomposite showed that the photodegradation of naphthalene is negligible by using pure WO3 nanoparticles while, composition of WO3 nanoparticles with multi walled carbon nanotubes could improve significantly their photocatalytic activity under visible light. Due to its high electrical conductivity, carbon nanotube can transfer photogenerated electron on its surface and in this way decreases electron-hole recombination rate and increases photocatalytic activity. After the reaction, the irradiated solution has been analyzed by gas chromatography and mass spectrometry techniques for identification of the naphthalene photodegradation intermediates and products. 1-Naphthol, 1,4-naphthalenedione and 1,2-benzendicarboxilic acid have been determined as intermediates and based on these intermediates a suitable mechanism for photodegradation of naphthalene was suggested.
Exploiting photooxygenations mediated by porphyrinoid photocatalysts under continuous flow conditions
De Oliveira, Kleber T.,Miller, L. Zane,McQuade, D. Tyler
, p. 12717 - 12725 (2016)
Photooxygenation reactions are a powerful synthetic tool to produce oxidized organic compounds; however, these reactions often exhibit experimental limitations including the production of complex mixtures that hinder desired product isolation and scale-up. Herein, we present a photocatalysed protocol under continuous flow conditions using a simple home built photoreactor and porphyrinoids as photocatalysts. Reaction conditions, long-term experiments, and scope demonstrate a protocol that is cost-effective, safe, reproducible and robust, thus allowing the production of relevant substituted naphthoquinones with interest in natural product synthesis and biological activity.
The Oxidation of Methylbenzenes and Naphthalenes to Quinones with H2O2 in the Presence of Palladium Catalyst
Yamaguchi, Satoru,Inoue, Masami,Enomoto, Saburo
, p. 2881 - 2884 (1986)
Methylbenzenes and naphthalenes were oxidized to quinones with aqueous(60percent) H2O2 in acetic acid in the presence of a 0.24 wtpercent Pd(II)-sulfonated polystyrene type resin.The selectivities to quinones were higher in naphthalenes than in methylbenzenes.Among the naphthalenes used, 2-methylnaphthalene, 2,3-dimethylnaphthalene, and 2,6-dimethylnaphthalene gave 1,4-quinones in good yields (50-64percent).The increase in the reaction temperature increased the selectivity to quinones from 40percent at 20 deg C to 70percent at 70 deg C.
Direct photooxidation and xanthene-sensitized oxidation of naphthols: Quantum yields and mechanism
Oelgemoeller, Michael,Mattay, Jochen,Goerner, Helmut
, p. 280 - 285 (2011)
The photoinduced oxidation of 1-naphthol to 1,4-naphthoquinone and of 5-hydroxy-1-naphthol to 5-hydroxy-1,4-naphthoquinone was studied by steady-state and time-resolved techniques. The direct photooxidation of naphthols in methanol or water takes place by reaction of the naphoxyl radical ( ·ONaph) with the superoxide ion radical (O2 ·-), the latter of which results from the reaction of the solvated electron with oxygen after photoionization. The sensitized oxidation takes place by energy transfer from the xanthene triplet state to oxygen. From the two oxygen atoms, which are consumed, one is incorporated into the naphthol molecule giving naphthoquinone and the second gives rise to water. The effects of eosin, erythrosin, and rose bengal in aqueous solution, pH, and the oxygen and naphthol concentrations were studied. The quantum yield of the photosensitized transformation was determined, which increases with the naphthol concentration and is largest at pH > 10. The quantum yield of oxygen uptake is similar. The pathway involving singlet molecular oxygen is suggested to operate for the three sensitizers. The alternative pathway via electron transfer from the naphthol to the xanthene triplet state and subsequent reaction of ·ONaph with O2·-, the latter of which is formed by scavenging of the xanthene radical anion by oxygen, does also contribute.
