- GENERATION AND TRAPPING OF 2,3-NAPHTHOQUINONE
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2,3-Naphthoquinone generated from 2,3-dihydroxynaphthalene was trapped with cyclopentadiene and its properties examined by dc polarography and cyclic voltametry.
- Horak, V.,Foster, F. V.,Levie, R. de,Jones, J. W.,Svoronos, P.
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- Copper(I)-catalyzed asymmetric oxidative coupling polymerization of 2,3-dihydroxynaphthalene using bisoxazoline ligands
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The asymmetric oxidative coupling polymerization of 2,3-dihydroxynaphthalene with the complexes of Cu(I) - bisoxazoline as a catalyst under an O2 atmosphere was successfully accomplished to produce poly(2,3-dihydroxy-1,4-naphthylene) having a continuous 1,1′-bi-2-naphthol main chain structure. For example, the polymerization with (S)-2,2′-isopropylidenebis(4-phenyl-2-oxazoline) as a ligand at room temperature for 24 h afforded a methanol-insoluble polymer in 30% yield with a molecular weight of approximately 4.1 × 103 as estimated by 13C NMR analysis, and the polymer was quantitatively obtained after 48 h. The obtained polymer was rich in the S-configuration. The structure of the bisoxazoline ligands significantly affected the catalyst activity and stereoselectivity.
- Habaue, Shigeki,Seko, Tomoaki,Okamoto, Yoshio
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- Oxidative Coupling Reactions of Phenols with FeCl3 in the Solid State
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Some oxidative coupling reactions of phenols with FeCl3 are faster and more efficient in the solid state than in solution.Some coupling reactions in the solid state are accelerated by irradiation with ultrasound.Some coupling reactions are achieved by using a catalytic amount of FeCl3.
- Toda, Fumio,Tanaka, Koichi,Iwata, Shinji
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- The Interrupted Pummerer Reaction in a Sulfoxide-Catalyzed Oxidative Coupling of 2-Naphthols
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A benzothiophene S-oxide catalyst, generated in situ by sulfur oxidation with H2O2, mediates the oxidative coupling of 2-naphthols. Key to the catalytic process is the capture and inversion of reactivity of a 2-naphthol partner, using an interrupted Pummerer reaction of an unusual benzothiophene S-oxide, followed by subsequent coupling with a second partner. The new catalytic manifold has been showcased in the synthesis of the bioactive natural products, (±)-nigerone and (±)-isonigerone. Although Pummerer reactions are used widely, their application in catalysis is rare, and our approach represents a new catalytic manifold for metal-free C?C bond formation.
- He, Zhen,Pulis, Alexander P.,Procter, David J.
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supporting information
p. 7813 - 7817
(2019/05/15)
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- Solvent-controlled selective synthesis of biphenols and quinones: Via oxidative coupling of phenols
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A regioselective synthesis of unsymmetrical and symmetrical biphenols and binaphthols via oxidative coupling of phenols or naphthols in the presence of K2S2O8 in CF3COOH under ambient conditions is described. Interestingly, the 1:1 ratio of H2O and CH3CN solvent mixtures at 80 °C instead of CF3COOH provided substituted unsymmetrical quinones. A gram-scale synthesis of biphenols and binaphthols was demonstrated.
- More, Nagnath Yadav,Jeganmohan, Masilamani
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supporting information
p. 9616 - 9619
(2017/09/01)
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- LADDER POLYMERS WITH INTRINSIC MICROPOROSITY AND PROCESS FOR PRODUCTION THEREOF
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A polymer of formula (I): where: n is an integer from 10 to 5,000; m is an integer from 10 to 5,000; Ar1 and Ar3 are the same or different and are residues derived from a tetra-hydroxy aromatic monomer, the tetra-hydroxy aromatic monomer being wherein R i
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Page/Page column 15; 28
(2010/05/14)
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- Polymers of intrinsic microporosity with dinaphthyl and thianthrene segments
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Novel intrinsically microporous homopolymers and copolymers derived from PIM-1 monomers (5,5,6,6-tetrahydroxy-3,3,3,3-tetramethylspirobisindane and 2,3,5,6-tetrafluoroterephthalonitrile) with two additional monomers- tetrahydroxydinaphthyl and tetrafluorotetraoxide thianthrene-are reported as potential materials for membrane-based gas separations. The resulting copolymers prevent efficient space packing of the stiff polymer chains and consequently exhibit analogous behavior to that of PIM-1, the most widely reported polymer in this class of materials. In addition, the copolymerization provides high molecular weight copolymers and low polydispersity if the polymerization reactions were conducted at elevated temperature for an extended period of time. Detailed structural characterization of the new monomers and polymers was determined by 1H and 19F nuclear magnetic resonance spectroscopy (NMR). The thermal properties were detected by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Polymer free volume was calculated from the polymer density and specific van der Waals volume. Under the same testing conditions, the homopolymer containing thianthrene units and most of the analogous copolymers have an excellent combination of properties with good film-forming characteristics. The gas transport properties show higher selectivity for gas pairs such as O 2/N2, CO2/N2, and H 2/N2 with a corresponding decrease in permeability compared to PIM-1. This work also demonstrates that significant improvements in properties may be obtained through copolymers of intrinsic microporosity (CoPIM)s. Furthermore, this work extends the spectrum of high molecular weight soluble PIMs beyond those reported previously.
- Du, Naiying,Robertson, Gilles P.,Pinnau, Ingo,Guiver, Michael D.
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experimental part
p. 8580 - 8587
(2011/11/12)
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- Synthesis of phenol, aromatic ether, and benzofuran derivatives by copper-catalyzed hydroxylation of aryl halides
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A smooth operator: The copper-catalyzed synthesis of phenols from aryl halides was carried out under relatively mild reaction conditions. Alkyl aryl ethers and benzofurans could also be prepared smoothly by one-pot domino protocols based on hydroxylation of aryl iodides (see scheme).
- Zhao, Dongbing,Wu, Ningjie,Zhang, Shuai,Xi, Peihua,Su, Xiaoyu,Lan, Jingbo,You, Jingsong
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supporting information; experimental part
p. 8729 - 8732
(2010/01/16)
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- TLC plates as a convenient platform for solvent-free reactions
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Solvent-free oxidative couplings of naphthols have been optimized by co-spotting catalysts and substrates directly on silica TLC plates and heating, followed by chromatography, staining, and qualitative visualization. The Royal Society of Chemistry.
- Stoddard, Jonathan M.,Nguyen, Lien,Mata-Chavez, Hector,Nguyen, Kelly
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p. 1240 - 1241
(2008/02/02)
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- Efficient solvent-free oxidative coupling of 2-naphthols by copper(II) oxymetasilicate under microwave irradiation
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Solvent-free oxidative coupling of 2-naphthols by copper(II) oxymetasilicate without solvent under microwave irradiation gives the corresponding 1,1′-binaphthalene-2,2′-diols in 75-97% yields.
- Adibi, Mina,Mohajeri, Ali
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p. 230 - 231
(2007/10/03)
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- Oxidative coupling of dichloroaluminium phenolates: Highly selective synthesis of hydroxylated Bi- and tetraaryls
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Dichloroaluminium phenolates 4 undergo highly selective FeCl3-promoted oxidative coupling. Variously substituted symmetric 2,2′-dihydroxy biaryls 2 are obtained in good yields and excellent selectivities. The chelation control in the final reaction products 7 promotes the chemoselectivity of the process.
- Sartori, Giovanni,Maggi, Raimondo,Bigi, Franca,Arienti, Attilio,Casnati, Giuseppe,Bocelli, Gabriele,Mori, Giovanni
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p. 9483 - 9494
(2007/10/02)
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- OXIDATIVE COUPLING REACTIONS OF PHENOLS WITH FeCl3 IN THE SOLID STATE
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Some oxidative coupling reactions of phenols with FeCl3 are faster and more efficient in the solid state than in solution.Some coupling reactions in solution.Some coupling reactions in the solid state are accelerated by irradiation with ultrasound.Some coupling reactions are achieved by using a catalytic amount of FeCl3.
- Tanaka, Koichi,Toda, Fumio
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