- Inter- and Intramolecular Aryl–Aryl Interactions in Partially Fluorinated Ethylenedioxy-bridged Bisarenes**
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Several ethylenedioxy-bridged bisarenes with a variety of type and number of aryl groups were synthesized to study non-covalent dispersion-driven inter- and intramolecular aryl–aryl interactions in the solid state and gas phase. Intramolecular interactions are preferably found in the gas phase. DFT calculations with and without dispersion correction show larger interacting aromatic groups increase the stabilization energy of folded conformers and decrease the intermolecular centroid–centroid distance. Single-molecule structures generally adopt folded conformations with short intramolecular aryl–aryl contacts. Gas electron diffraction experiments were performed exemplarily for 1-(pentafluorophenoxy)-2-(phenoxy)ethane. A new procedure for structure refinement was developed to deal with the conformational complexity of such molecules. The results are an experimental confirmation of the existence of folded conformations of this molecule with short intramolecular aryl–aryl distances in the gas phase. Solid-state structures are dominated by stretched structures without intramolecular aryl–aryl interactions but interactions with neighboring molecules.
- Weddeling, Jan-Henrik,Vishnevskiy, Yury V.,Neumann, Beate,Stammler, Hans-Georg,Mitzel, Norbert W.
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- Magnesiation of electron-rich aryl bromides and their use in nickel-catalyzed cross-coupling reactions
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Electron-rich aryl bromides are rapidly converted to the corresponding lithium triarylmagnesiates with (n-Bu)3MgLi, which undergo efficient nickel-catalyzed Kumada-Corriu cross-coupling reactions with a variety of aryl and alkenyl bromides, chlorides, tosylates, and triflates.
- Lau, Stephen Y. W.,Hughes, Greg,O'Shea, Paul D.,Davies, Ian W.
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- Diradicals Photogeneration from Chloroaryl-Substituted Carboxylic Acids
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With the aim of generating new, thermally inaccessible diradicals, potentially able to induce a double-strand DNA cleavage, the photochemistry of a set of chloroaryl-substituted carboxylic acids in polar media was investigated. The photoheterolytic cleavage of the Ar?Cl bond occurred in each case to form the corresponding triplet phenyl cations. Under basic conditions, the photorelease of the chloride anion was accompanied by an intramolecular electron-transfer from the carboxylate group to the aromatic radical cationic site to give a diradical species. This latter intermediate could then undergo CO2 loss in a structure-dependent fashion, according to the stability of the resulting diradical, or abstract a hydrogen atom from the medium. In aqueous environment at physiological pH (pH=7.3), both a phenyl cation and a diradical chemistry was observed. The mechanistic scenario and the role of the various intermediates (aryl cations and diradicals) involved in the process was supported by computational analysis.
- Di Terlizzi, Lorenzo,Protti, Stefano,Ravelli, Davide,Fagnoni, Maurizio
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- Thermo-sensitive paper sensitizer ethylene glycol diphenyl ether preparation method
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The invention relates to a thermo-sensitive paper sensitizer ethylene glycol diphenyl ether preparation method. According to the preparation method, halogeno benzene and ethylene glycol are utilized as raw materials, any one or several of 2,2'-dipyridyl and derivatives of the 2,2'-dipyridyl is utilized as ligand, and under the existence of alkali and a solvent, Cu(I) or Cu(II) is utilized as a catalyst to prepare and obtain ethylene glycol diphenyl ether. Compared with the prior art, ethylene glycol and bromobenzene are utilized reaction raw materials, so that ethylene glycol diphenyl ether production cost is greatly reduced; in addition, the ligand 2,2'-dipyridyl can be recycled, so that production cost cannot be increased; thus, larger implement value and social economic benefit are achieved.
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Paragraph 0030; 0031
(2019/08/03)
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- Synthesis method of 1,2-diphenoxyethane thermosensitive sensitizer
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The invention relates to the field of sensitizers for thermosensitive paper, particularly a synthesis method of a high-purity 1,2-diphenoxyethane thermosensitive sensitizer. The method comprises the following steps: adding phenol and dichloroethane into a reaction kettle, performing heating under reflux, dropwisely adding an acid-binding agent into the reaction kettle, performing reaction until no phenol is detected, performing reduced pressure distillation to remove the dichloroethane, supplementing the acid-binding agent, performing heating, dropwisely adding the phenol, performing tracking detection until 2-chlorophenetole reacts completely, stopping dropwisely adding the phenol, performing water washing to remove the salt, and performing ethanol recrystallization to obtain the product. The reaction condition is mild: the maximum temperature is controlled at 120-150 DEG C, so the condition is accessible. The method has the advantages of short reaction time, accessible raw materials, simple technical operation process, recyclable raw materials and high product purity, and is suitable for industrial production.
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Paragraph 0018; 0019; 0020; 0021; 0022; 0023; 0024
(2017/10/13)
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- 1. 2 - [...] ethane and the like industrial preparation method
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The invention relates to an industrial preparation method of 1,2-diphenoxyl ethane and its analog. The method comprises the following steps: continuously adding 1,2-dichloroethane to a hot reaction system comprising phenol (or methyl phenol), an acid binding agent and polyethylene glycol in a dropwise manner under normal pressure at a uniform speed to guarantee continuous escape of 1,2-dichloroethane steam from the reaction system (or continuously introducing the 1,2-dichloroethane steam into the reaction system), and stopping the addition of 1,2-dichloroethane when phenol (or methyl phenol) is completely reacted to terminate the above reaction; and post-processing to obtain a final product. The method has the advantages of thorough conversion of raw materials, and high yield.
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Paragraph 0018; 0019
(2018/04/01)
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- From insertion to multicomponent coupling: Temperature dependent reactions of arynes with aliphatic alcohols
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The temperature dependent selectivity switch in the reaction of arynes with aliphatic alcohols in THF has been reported. At -20°C, arynes smoothly insert into the O-H bond of alcohols to form alkyl aryl ethers. Interestingly, at 60°C, a highly selective multicomponent coupling occurs with the solvent THF acting as the nucleophilic trigger affording (4-(alkoxy)butoxy)arenes.
- Thangaraj, Manikandan,Bhojgude, Sachin Suresh,Mane, Manoj V.,Biju, Akkattu T.
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supporting information
p. 1665 - 1668
(2016/01/30)
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- A clean and selective radical homocoupling employing carboxylic acids with titania photoredox catalysis
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A titania photoredox catalysis protocol was developed for the homocoupling of C-centered radicals derived from carboxylic acids. Intermolecular reactions were generally efficient and selective, furnishing the desired dimers in good yields under mild neutral conditions. Selective cross-coupling with two acids proved unsuccessful. An intra-molecular adaptation enabled macrocycles to be prepared, albeit in modest yields. (Chemical Equation Presented).
- Manley, David W.,Walton, John C.
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supporting information
p. 5394 - 5397
(2015/02/19)
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- Nanosized ferric hydroxide catalyzed c-o cross-coupling of phenol and halides to generate phenoxy ether
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The iron-based catalyst can effectively catalyze the phenolic hydroxyl C-O bond formation reaction to give the corresponding phenoxy ethers. The reaction of phenol and methyl chloroacetate, for example, gives phenoxy acetic acid methyl ester in 98 % yield under the optimal reaction conditions. Among the iron-based catalysts, nanosized ferric hydroxide prepared through sol-gel method gives the best catalytic activity.
- Sun, Hongbin,Sun, Yuanhua,Tian, Xiaohua,Zhao, Yunxia,Qi, Xuan
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p. 6189 - 6191
(2013/07/26)
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- Photocatalysis in an NMR tube: Carbon-carbon coupling ofphenoxyacetic acid with n-substituted maleimides
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The semiconductor-sensitised photocatalytic (SPC) carbon-carbon coupling of phenoxyacetic acid (PAA)and N-methylmaleimide (NMI) or maleimide (MI) has recently been reported and is studied in moredetail. Irradiations are performed on a much smaller scale than commonly used, i.e. 1 mL of reac-tion solution in a sol-gel titania coated NMR tube, and NMR is used to monitor the progress of thevarious photoreactions. Use of an NMR tube as the photoreactor allows much faster reaction times(ca. 10 times faster than the 40 mL scale reaction), and helps avoid the more usual need for sample-taking and pre-treatment, before analysis by NMR, HPLC etc. The photochemistries and photocatalyticprocesses associated with the individual reactants (i.e. PAA and NMI or MI) reveal the productionof significant products which are largely absent in the SPC-sensitised coupling reaction. Thus, whenboth PAA and NMI or MI are irradiated together, in the study of the coupling reaction the two mainproducts formed are: 1-methyl-3-(phenoxymethyl)pyrrolidine-2,5-dione (the adduct product), and 2-methyl-3a,4-dihydrochromeno[3,4-c]pyrrole-1,3(2H,9bH)-dione (the cyclic product), which are formedin reasonable yields up to 67% and 15% respectively after only 15 min (I = 3.5 mW cm-2per photoreac-tor hemisphere). Despite the well-known photochemical feature of NMI to form dimers efficiently, thiswork demonstrates that the background photochemistry and photocatalysis associated with the individ-ual reactants, PAA and NMI, in the photocatalysed coupling reaction are minimal due to the faster SPCkinetics for the coupling reaction, and the UV-filter effect of the sol-gel titania coating. The additionalformation of organic polymeric material in all the photocatalytic processes studied is discussed briefly.
- Mills, Andrew,O'rourke, Christopher
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- Unconventional titania photocatalysis: Direct deployment of carboxylic acids in alkylations and annulations
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Under dry, anaerobic conditions, TiO2 photocatalysis of carboxylic acid precursors resulted in carbon-carbon bond-forming processes. High yields of dimers were obtained from TiO2 treatment of carboxylic acids alone. On inclusion of electron-deficient alkenes, efficient alkylations were achieved with methoxymethyl and phenoxymethyl radicals. In reactions with maleic anhydride or maleimides, phenoxyacetic acid produced chromenedione derivatives in addition to adducts. These photocatalytic reactions are simple and cheap to perform, and the TiO2 is easily removed by filtration. The anaerobic photocatalysis strategy offers a range of synthetic possibilities.
- Manley, David W.,McBurney, Roy T.,Miller, Phillip,Howe, Russell F.,Rhydderch, Shona,Walton, John C.
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supporting information; experimental part
p. 13580 - 13583
(2012/10/08)
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- Dipole Moments and UV Spectra of some Long-chain Molecules
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About one hundred compounds with long-chain molecular structure have been prepared (most of them are new).The dipole moments of four α,ω-bis(p-methoxyphenylthio)alkanes and five α,ω-bis(p-methoxyphenylsulphonyl)alkanes have been determined to find the effect of chain-length.In the case of sulphones, the observed values are compared with the values calculated for free rotation around all bonds intervening the end dipoles.The uv spectra of some 1,2-(distyrylsulphonyl)ethanes, and a number of α,ω-bis(arylsulphonyl)- and α,ω-bis(aryloxy)alkanes have been recorded to examine the applicability of the principle of chromophore additivity.
- Baliah, V.,Aparajithan, K.
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p. 255 - 259
(2007/10/02)
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- Selective Kolbe Electrolytic Coupling Using Glasslike-Hard Carbon Anodes
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The use of some kinds of glasslike-hard carbons was found to lead to selective synthesis of the corresponding Kolbe coupled products in high yields comparable to the use of a Pt anode in anodic oxidation of some carboxylic acids.
- Ohno, Toshinobu,Fukumoto, Tatsumi,Hirashima, Tsuneaki,Nishiguchi, Ikuzo
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p. 1085 - 1088
(2007/10/02)
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- SYNTHETIC APPLICATION OF MICELLAR CATALYSIS. WILLIAMSON'S SYNTHESIS OF ETHERS
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A simple, rapid and efficient procedure for the preparation of di-alkyl, simple phenyl-alkyl and hindered phenyl-alkyl ethers has been developed.Based on the principle of micellar catalysis the method involves alkylation of the alkoxide or the phenoxide ion with an alkyl chloride at 80 deg C in the presence of cationic micelles.For the preparation of phenyl-alkyl ethers normal micelles were used, while for the di-alkyl ethers reverse micelles were more effective.By increasing the ionic strength of the solution the rate of formation of phenyl-alkyl ethers could be increased.
- Jursic, Branko
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p. 6677 - 6680
(2007/10/02)
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- The Catalytic Effect of Copper Ions in the Phenylation Reaction of David and Thieffry
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Several types of bifunctional molecules are smoothly phenylated by triphenylbismuth diacetate in a reaction which has an induction period, a curious solvent dependence, and the need for illumination; however, the addition of a small amount of Cu(OAc)2 removes all these limitations and accelerates greatly the reaction.
- Barton, Derek H. R.,Finet, Jean-Pierre,Pichon, Clotilde
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