- Diaryl Ether Formation Merging Photoredox and Nickel Catalysis
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Photoredox and Ni catalysis are combined to produce diaryl ethers under mild conditions. A broad range of aryl halides and phenol derivatives are cross-coupled in the presence of a readily available organic photocatalyst and NiBr2(dtbpy). Symmetrical diaryl ethers have also been directly obtained from aryl bromides in the presence of water. Mechanistic investigations support the involvement of Ni(0) species at the outset of the reaction and a Ni(II)/Ni(III)-photocatalyzed single electron transfer process preceding the productive C(sp2)-OAr reductive elimination.
- Liu, Le,Nevado, Cristina
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supporting information
p. 2188 - 2193
(2021/05/04)
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- Synthesis method of 4,4'-diphenyl ether dicarboxylic acid
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The invention discloses a 4,4'-diphenyl ether dicarboxylic acid synthesis method, which comprises: S1, carrying out a dehydration reaction on p-hydroxybenzoate, an alkali and a solvent at a temperature of 110-120 DEG C for 2-4 h under a protection gas to obtain a mixed solution; S2, adding a catalyst and p-halo benzoate into the mixed solution obtained in the step S1, carrying out a heating coupling reaction at a reaction temperature of 145-195 DEG C, adding a solvent after the reaction is finished, and performing extraction, liquid separation and crystallization to obtain a solid 4,4'-diphenyl ether dicarboxylic acid diester; and S3, carrying out heating hydrolyzing on the 4,4'-diphenyl ether dicarboxylic acid diester obtained in the step S2 in an aqueous alkali solution and a solvent, adding an acid to adjust the pH value to be acidic, and carrying out crystallization and filtration to obtain the 4,4'-diphenyl ether dicarboxylic acid. The method is simple in process operation, low inequipment requirement, high in product purity, less in three wastes generated in the production process, environment-friendly and high in industrial feasibility, and the total yield of the two-step reaction can reach more than 80%.
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Paragraph 0044; 0046-0047
(2020/05/01)
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- The Delicate Balance of Preorganisation and Adaptability in Multiply Bonded Host–Guest Complexes
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Rigidity and preorganisation are believed to be required for high affinity in multiply bonded supramolecular complexes as they help reduce the entropic penalty of the binding event. This comes at the price that such rigid complexes are sensitive to small geometric mismatches. In marked contrast, nature uses more flexible building blocks. Thus, one might consider putting the rigidity/high-affinity notion to the test. Multivalent crown/ammonium complexes are ideal for this purpose as the monovalent interaction is well understood. A series of divalent complexes with different spacer lengths and rigidities has thus been analysed to correlate chelate cooperativities and spacer properties. Too long spacers reduce chelate cooperativity compared to exactly matching ones. However, in contrast to expectation, flexible guests bind with chelate cooperativities clearly exceeding those of rigid structures. Flexible spacers adapt to small geometric host–guest mismatches. Spacer–spacer interactions help overcome the entropic penalty of conformational fixation during binding and a delicate balance of preorganisation and adaptability is at play in multivalent complexes.
- von Krbek, Larissa K. S.,Achazi, Andreas J.,Schoder, Stefan,Gaedke, Marius,Biberger, Tobias,Paulus, Beate,Schalley, Christoph A.
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supporting information
p. 2877 - 2883
(2017/03/08)
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- Method for the preparation of diphenyl ether compounds
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The invention relates to a method for preparing a diphenyl ether compound. The method is characterized by comprising the following technical steps of: (1) adding a halogenated benzene derivative and a bis(pinacolato)diboron into a reaction vessel, adding copper chloride or aluminum chloride and 1,2-bi(diphenylphosphine) ethane as a catalyst, then adding alkaline and an organic solvent, and reacting at 25-160 DEG C for 6-24 hours; and (2) after extracting a reaction solution obtained from the step (1) by using ethyl acetate, purifying by a 200-300 meshes silica gel column, pre-eluting the silica gel column by using 20-50 mL of normal hexane, eluting by adopting an eluent at a flow speed of 1-2 mL/min for 3-6 hours, and removing the solvent to obtain the diphenyl ether compound. The method for preparing the diphenyl ether compound, disclosed by the invention, no only overcomes the disadvantage of the use of phenolic substances in a reaction process, but also has the advantages of mild reaction condition and high yield.
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Paragraph 0020-0022
(2016/12/01)
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- Palladium-catalysed and phosphine-promoted synthesis of diaryl ethers through self-coupling
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An efficient, palladium acetate-catalysed, tributylphosphine-promoted direct synthesis of symmetrical diaryl ethers through the self-coupling of aryl fluorides has been developed with K2CO3/ZrO2 as a base. This provides an alternative method to prepare aromatic polymers, important synthetic intermediates and natural products for use in the field of pharmaceuticals and industrial materials.
- Wang, Dawei,Xu, Zhaojun,Yu, Xiaoli,Li, Yongliang,Wan, Huida
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p. 691 - 693
(2016/11/18)
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- Iridium-catalyzed synthesis of diaryl ethers by means of chemoselective C-F bond activation and the formation of B-F bonds
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Transition-metal-catalyzed C-F activation, in comparison with C-H activation, is more difficult to achieve and therefore less fully understood, mainly because carbon-fluorine bonds are the strongest known single bonds to carbon and have been very difficult to cleave. Transition-metal complexes are often more effective at cleaving stronger bonds, such as C(sp2)-X versus C(sp2)-X. Here, the iridium-catalyzed C-F activation of fluorarenes was achieved through the use of bis(pinacolato)diboron with the formation of the B-F bond and self-coupling. This strategy provides a convenient method with which to convert fluoride aromatic compounds into symmetrical diaryl ether compounds. Moreover, the chemoselective products of the C-F bond cleavage were obtained at high yields with the C-Br and C-Cl bonds remaining.
- Chen, Jianping,Zhao, Keyan,Ge, Bingyang,Xu, Chongying,Wang, Dawei,Ding, Yuqiang
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supporting information
p. 468 - 473
(2015/02/05)
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- Diaminotriazine substituted diphenyl ether: Reversible structural transformation and solvent dependent solid state fluorescence
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The effect of molecular shape and position of hydrogen bonding functionality in the solid state structural self-assembly was investigated using diaminotriazine substituted diphenyl ether based positional isomers (1-5). The molecular shape was modulated by changing diaminotriazine position that produced channel supramolecular structures in 1, 3 and 5. There exists a direct correlation between the molecular shape and three dimensional structures; more linear molecules resulted in close-packing whereas molecules with a labyrinthine topology formed a channel structure. Supramolecular aspects pertaining to the influence of solvent of crystallization in structure formation and reversible structural transformation in solid state were also explored. 1-5 exhibited tunable solid state fluorescence (λmax = 437-496 nm) depending on the diaminotriazine substitutional position and 3 showed solvent-dependent solid state fluorescence. The present study describes the generation of a supramolecular channel structure with functional properties such as tunable fluorescence by varying the position of hydrogen bond functionality and solvent of crystallization.
- Anthony, Savarimuthu Philip,Varughese, Sunil
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p. 4117 - 4123
(2013/08/25)
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- Diels-alder trapping of photochemically generated o-quinodimethane intermediates: An alternative route to photocured polymer film development
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Photolysis of o-methylphenyl ketones generates o-quinodimethane intermediates that can be trapped in situ by dienophiles through Diels-Alder cycloadditions. This well-known photochemical process is applied to a series of six new photoreactive monomers containing bis(o-methylphenyl ketone) functionalities combined with diacrylate and triacrylate esters for the development of acrylic ester copolymer blends. Irradiation of cyclohexanone solutions of the bis(o-methylphenyl ketone)s and acrylate esters produce thin polymer films. Solid state 13C NMR data indicated 47-100% reaction of the bis(o-methylphenyl ketone)s, depending on experimental conditions, to yield the desired products. DSC and TGA analyses were performed to determine the glass transition temperature, Tg, and onset of decomposition, T d, of the resulting polymer films. A statistical "design of experiments" approach was used to obtain a systematic understanding of the effects of experimental variables on the extent of polymerization and the final polymer properties.
- Tyson, Daniel S.,Ilhan, Faysal,Meador, Mary Ann B.,Smith, Dee Dee,Scheiman, Daniel A.,Meador, Michael A.
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p. 3638 - 3646
(2008/02/01)
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- Correlation between molecular dipole moment and centrosymmetry in some crystalline diphenyl ethers
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The presence of a large molecular dipole moment in diphenyl ethers leads unequivocally to a centrosymmetric crystal structure. The Royal Society of Chemistry 2005.
- Dey, Archan,Desiraju, Gautam R.
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p. 2486 - 2488
(2007/10/03)
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- Synthesis of diaryl ethers, diaryl sulfides, heteroaryl ethers and heteroaryl sulfides under microwave dielectric heating
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This paper describes the synthesis of diaryl ethers and sulfides by utilizing microwave heating methodology. The methodology is shown to be rapid and efficient for the coupling of phenols or thiophenol with electron-deficient aryl halides through a SNAr reaction. The scope of the protocol can be expanded to six-membered heterocycles bearing a hydroxyl group as well as to the reaction of 2-pyrimidinethiol with mildly activated aryl halides, providing heteroaryl ethers and sulfides, respectively. The advantages of the present method include the wide substrate scope, the obviation of metal catalysts, ease of product isolation, and high purity of products. Georg Thieme Verlag Stuttgart.
- Li, Feng,Meng, Qingqing,Chen, Huansheng,Li, Zhiming,Wang, Quanrui,Tao, Fenggang
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p. 1305 - 1313
(2007/10/03)
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- Microwave-assisted synthesis of diaryl ethers without catalyst
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(Matrix presented) Diaryl ethers have been prepared by direct coupling of phenols including those that bear a strong electron-attracting substituent to electron-deficient aryl halides through SNAr-based addition reactions with assistance of microwave irradiation in high to excellent yields within 5-10 min. No catalysts were required under our conditions.
- Li, Feng,Wang, Quanrui,Ding, Zongbiao,Tao, Fenggang
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p. 2169 - 2171
(2007/10/03)
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- Synthesis of 5-Aryloxyisophthalonitriles by Nitro Group Substitution in 5-Nitrosophthalonitrile under the Action of Phenols
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A series of 5-aryloxyisophthalodinitrile is obtained by the nitro group substitution in the reaction of either unsubstituted phenole, or substituted phenoles with 5-nitroisophthalodinitrile in the presence of potassium carbonate in DMF or in toluene under conditions of phase-transfer catalysis.
- Tabatskaya,Vlasov
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p. 1505 - 1509
(2007/10/03)
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- Ether Synthesis from Activated Aromatic Halides and Alkali-metal Carbonates
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Aromatic halides activated by an electron-withdrawing group at the ortho or para position has been found to react with alkali-metal carbonates or hydrogencarbonates at elevated temperatures to form ethers.The ether yield is markedly enhanced by catalysts such as silica and aluminium silicate.The rate of the etherification is dependent on the kind of activating groups 2Y-Ar-X + M2CO3 -> Y-Ar-O-Ar-Y + 2MX + CO2 (Y = NO2 > CN > ArSO2 > ArCO), halides (X = F > Cl ca.= Br ca.= I) and alkali metals (M = K > Na > Li).Cuprous and cupric compounds act as cocatalysts with silica and further promote the reaction.The reaction of p-chlorobenzophen one with potassium carbonate or sodium carbonate to bis(4-benzoylphenyl) ether in the presence of silica or silica-cuprous oxide catalyst was investigated in detail and the reaction mechanism is proposed.The silyl ether formed from an aromatic halide and the silanol group on the surface of silica is presumed to be the intermediate of the etherification.
- Fukawa, Isaburo,Tanabe, Tsuneaki,Dozono, Tetsuro
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p. 377 - 382
(2007/10/02)
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- Preparation of diphenyl ether
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A process for the production of diaryl ethers which comprises heating, to a temperature of 80° C. to 220° C., a compound of the formula STR1 wherein X and Y are selected from the group consisting of H, CN, CO2 H, CHO, NO2, and CF3, provided that both X and Y may not simultaneously be H, in a solvent, in the presence of an inorganic base selected from the group consisting of the alkali metal carbonates, bicarbonates, and hydroxides, and in the presence of a catalyst selected from the group consisting of benzoic acid, substituted benzoic acids, C2-C4 aliphatic carboxylic acids, and alkali metal salts of said acids.
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- THERMOLYSE DES CARBONATES D'ARYLE INITIEE PAR LES BASES : I-MECANISME PAR SNAR DANS LE CAS DES CARBONATES D'ARYLE PORTEURS DE GROUPES ELECTRO-ATTRACTEURS IDENTIQUES.
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The base-initiated thermolysis of diaryl carbonates leads to diaryl ethers.Kinetics evidences (Ea= 26 kcal.mole-1 )are given, showing that reaction proceeds via SNAr mechanism.Phenoxide is recognised as the active species.
- Jost, Philippe,Forestiere, Alain,Sillion, Bernard,Le Perchec, Pierre
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p. 4311 - 4314
(2007/10/02)
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