- Decatungstate-mediated solar photooxidative cleavage of CC bonds using air as an oxidant in water
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With the increasing attention for green chemistry and sustainable development, there has been much interest in searching for greener methods and sources in organic synthesis. However, toxic additives or solvents are inevitably involved in most organic transformations. Herein, we first report the combination of direct utilization of solar energy, air as the oxidant and water as the solvent for the selective cleavage of CC double bonds in aryl olefins. Various α-methyl styrenes, diaryl alkenes as well as terminal styrenes are well tolerated in this green and sustainable strategy and furnished the desired carbonyl products in satisfactory yields. Like heterogeneous catalysis, this homogeneous catalytic system could also be reused and it retains good activity even after repeating three times. Mechanism investigations indicated that both O2- and 1O2 were involved in the reaction. Based on these results, two possible mechanisms, including the electron transfer pathway and the energy transfer pathway, were proposed.
- Du, Dongdong,Luo, Junfei,Shi, Sanshan,Xie, Pan,Xue, Cheng
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p. 5936 - 5943
(2021/08/23)
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- Photo-induced oxidative cleavage of C-C double bonds for the synthesis of biaryl methanoneviaCeCl3catalysis
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A Ce-catalyzed strategy is developed to produce biaryl methanonesviaphotooxidative cleavage of C-C double bonds at room temperature. This reaction is performed under air and demonstrates high activity as well as functional group tolerance. A synergistic Ce/ROH catalytic mechanism is also proposed based on the experimental observations. This protocol should be the first successful Ce-catalyzed photooxidation reaction of olefins with air as the oxidant, which would provide inspiration for the development of novel Ce-catalyzed photochemical synthesis processes.
- Xie, Pan,Xue, Cheng,Du, Dongdong,Shi, SanShan
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supporting information
p. 6781 - 6785
(2021/08/20)
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- Metal-Free Photoinduced Transformation of Aryl Halides and Diketones into Aryl Ketones
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The acylation of aryl halides to prepare aryl ketones without metal catalyst represents an important yet challenging topic towards more sustainable ketone synthesis. Herein, we describe a simple and efficient metal-free protocol for the acylation of aryl halides with diketone under the irradiation of light utilizing N-methylpiperidine as base under an air atmosphere. This reaction can tolerate a wide range of functional groups and the corresponding ketones can be obtained in modest to good yields.
- Yao, Qiuli,Liu, Wenbo,Liu, Peng,Ren, Linjing,Fang, Xuehong,Li, Chao-Jun
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supporting information
p. 2721 - 2724
(2019/01/14)
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- Preparation method of aromatic ketone
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The invention discloses a preparation method of aromatic ketone. Under the effects of a palladium catalyst and a nitrogen-containing ligand, nitrile compounds and arylsulfonylhydrazide take desulfurization addition reaction in an organic solvent; after the reaction is completed, post treatment is performed to obtain aromatic ketone. The reaction is applicable to aromatic nitrile compounds, and isalso applicable to aliphatic nitrile compounds; the reaction realizes the wide substrate applicability and functional group tolerance; the potential application value is realized in the aspect of aryl-carbonyl building.
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-
Paragraph 0056; 0057; 0058; 0060
(2018/09/11)
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- Pd(II)-Catalyzed Denitrogenative and Desulfinative Addition of Arylsulfonyl Hydrazides with Nitriles
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A Pd(II)-catalyzed denitrogenative and desulfinative addition of arylsulfonyl hydrazides with nitriles has been successfully achieved under mild conditions. This transformation is a new method for the addition reaction to nitriles with arylsulfonyl hydrazides as arylating agent, thus providing an alternative synthesis of aryl ketones. The reported addition reaction is tolerant to many common functional groups, and works well in the presence of electron-donating and electron-withdrawing substituents. Notably, the reported denitrogenative and desulfinative addition was also appropriate for alkyl nitriles, making this newly developed transformation attractive.
- Meng, Mengting,Yang, Liangfeng,Cheng, Kai,Qi, Chenze
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p. 3275 - 3284
(2018/03/25)
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- 2-AMINO-1,3,4-THIADIAZINE AND 2-AMINO-1,3,4-OXADIAZINE BASED ANTIFUNGAL AGENTS
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The invention provides a compound which is a diazine of formula (I) or a tautomer thereof, or a pharmaceutically acceptable salt thereof, for use as an antifungal agent: (I) wherein X, N', C', A and E are as defined herein. The invention also provides a compound of Formula (I) as defined herein.
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Page/Page column 57
(2017/02/09)
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- SUBSTITUTED HETEROCYCLIC ACETAMIDES AS KAPPA OPIOID RECEPTOR (KOR) AGONISTS
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The present invention relates to a series of substituted compounds having the general formula (I), including their ste reoisomers and/or their pharmaceutically acceptable salts, wherein R1, R2, R3. R4, R5, and R6 are as defined herein. This invention also relates to methods of making these compounds including intermediates. The compounds of this invention are effective at the kappa (κ) opioid receptor (KOR) site. Therefore, the compounds of this invention are useful as pharmaceutical agents, especially in the treatment and/or prevention of a variety of central nervous system disorders (CNS), including but not limited to acute and chronic pain, and associated disorders, particularly functioning peripherally at the CNS.
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Page/Page column 135
(2013/09/26)
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- A convenient conversion of substituted cyclohexenones into aryl methyl ketones
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This work describes a straightforward multistep conversion of substrates containing a cyclohexenone moiety into mono-, bi- and tricyclic aryl methyl ketones in one single working process. Crucial steps are the addition of 1-ethoxyvinyllithium to the carbonyl group, followed by acid-catalyzed enol ether hydrolysis, dehydration, and dehydrogenation. Georg Thieme Verlag Stuttgart · New York.
- Gehring, Andrep.,Bracher, Franz
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experimental part
p. 2441 - 2447
(2012/09/07)
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- The synthesis of arylketones via Friedel-Crafts acyldegermylation
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Electron-rich and electron-neutral aryl trialkylgermanes are shown to be competent precursors to aryl ketones via Friedel-Crafts acyldegermylation. Given the previously demonstrated greater stability towards basic/nucleophilic conditions of arylgermanes as compared to arylsilanes/stannanes, these reactions significantly expand the utility of group 14 acyldemetalation in synthesis. This is exemplified by the cleavage of Ge-based linker models for solid-phase synthesis (SPS). Georg Thieme Verlag Stuttgart.
- Spivey, Alan C.,Gripton, Christopher J. G.,Noban, Catherine,Parr, Nigel J.
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p. 2167 - 2170
(2007/10/03)
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- Acetylation of aromatic compounds over H-BEA zeolite: The influence of the substituents on the reactivity and on the catalyst stability
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The acylation with acetic anhydride of six aromatic substrates with different features (degree of activation of the aromatic ring towards electrophilic substitution, number of rings, i.e., 1 or 2) was carried out in a batch reactor at 373 K over a H-BEA zeolite (Si/Al = 15) with nitrobenzene as a solvent. The acetylation rate was found to be very dependent on the degree of ring activation, with diffusion limitations playing only a limited role. The decrease of the rate with reaction time, which was very pronounced with poorly activated and deactivated substrates, is mainly due to the inhibiting effect of acetic acid and of the products of acetic anhydride condensation.
- Guidotti, Matteo,Canaff, Christine,Coustard, Jean-Marie,Magnoux, Patrick,Guisnet, Michel
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p. 375 - 383
(2007/10/03)
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- Antimony(V) chloride-benzyltriethylammonium chloride complex as an efficient catalyst for friedel-crafts acylation reactions
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A novel catalytic system, the complex of antimony(V) chloride (SbCl 5) and benzyltriethylammonium chloride (TEBA), C6H 5CH2NEt3(SbCl5)2Cl complex, is described for Friedel-Crafts acylation reactions of aromatics with acyl and sulfonyl chlorides. The catalyst has a number of useful characteristics, such as ready access, minimal toxicity, reusability, insensitivity to atmosphere and moisture, rapid acylation with high yield, and ease of operation.
- Huang, An-Ping,Liu, Xue-Yuan,Li, Lian-Hua,Wu, Xiao-Li,Liu, Wei-Min,Liang, Yong-Min
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p. 599 - 602
(2007/10/03)
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- Palladium-catalyzed reaction of aryl iodides with acetic anhydride. A carbon monoxide-free synthesis of acetophenones
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(Matrix presented) The palladium-catalyzed reaction of aryl iodides with acetic anhydride provides a straightforward and experimentally simple carbon monoxide-free route to acetophenones. The reaction tolerates a wide range of funcfionalized aryl iodides. Acetophenones are isolated in excellent yield with a variety of neutral, slightly electron-rich, and slightly electron-poor aryl iodides, whereas moderate yields are obtained with aryl iodides containing strongly electron-withdrawing substituents.
- Cacchi, Sandro,Fabrizi, Giancarlo,Gavazza, Federica,Goggiamani, Antonella
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p. 289 - 291
(2007/10/03)
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- A traceless perfluoroalkylsulfonyl (PFS) linker for the deoxygenation of phenols
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(Equation presented) The synthesis of a novel perfluoroalkylsulfonyl (PFS) fluoride is described for use as a traceless linker in solid-phase organic synthesis. Attachment to the resin and subsequent coupling of a phenol affords a stable arylsulfonate that behaves as a support-bound aryl triflate. Palladium-mediated reductive cleavage of a wide variety of phenols generated the parent arenes. The resin-bound aryl triflate was shown to be stable to reductive amination conditions, and the traceless synthesis of Meclizine is reported.
- Pan, Yijun,Holmes, Christopher P.
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p. 2769 - 2770
(2007/10/03)
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- Practical synthesis of acetophenones from phenoltriflates
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A new practical method for the preparation of acetophenone from aryl triflates is reported. The acyl group is installed by a mixture of SnMe4, Pd(0) and CO (balloon), using a three-component procedure.
- Garrido, Fabrice,Raeppel, Stéphane,Mann, André,Lautens, Mark
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p. 265 - 266
(2007/10/03)
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- Methyl Group Effect on the Proton Affinity of Methylated Acetophenones Studied by Two Mass Spectrometric Techniques
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The proton affinities (PA) of all isomeric dimethylacetophenones were determined using the "kinetic method" with a tandem mass spectrometer and by measurements of the proton transfer equilibrium in the gas phase by Fourier transform ion cyclotron resonance mass spectrometry.For both methods acetophenone and p-methylacetophenone, with well known PA values, were used as reference bases.Both methods yielded identical PA values for all dimethylacetophenones.The PA of the dimethylacetophenones were in a narrow range between 872 and 880 kJ mol-1 except for 2,6-dimethylacetophenone, for which a PA of 856 kJ mol-1 was found.The results are discussed in terms of possible mesomeric structures stabilizing the positive charge with regard to the substitution pattern in the phenyl ring.Obviously, the significant smaller PA of 2,6-dimethylacetophenone compared with the other isomers is due to the distortion of the conjugation of the C-O double bond with the aromatic ? system.
- Kukol, A.,Strehle, F.,Thielking, G.,Gruetzmacher, H.-Fr.
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p. 1107 - 1110
(2007/10/02)
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- Anisotropy Effects of Conjugated Cyclic Systems, VI. Structure and Magnetic Anisotropy of Mesityl-substituted Ferrocens
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Two isomeric ferrocene derivatives have been obtained from 2-(2-ethyl-4,6-dimethylphenyl)-1,3-dimethylcyclopentadiene (22a).The exo,exo- (9) as well as the endo,endo-configuration (10) of these were determined by X-ray structure analysis.The assignment of the 1H NMR signals of the methyl groups in the spectrum of 1,1',3,3'-tetramethyl-2,2'-dimesitylferrocen (7) is derived from the spectra of 9 and 10.Signals of methyl groups in exo-position of the mesitylferrocene are shifted by -0.74 ppm to higher magnetic field.Signals of methyl groups in endo-position directed towards the iron atom are shifted downfield by +0.71 ppm.Therefore, ferrocene develops a diamagnetic anisotropy which is similar to that of benzene.
- Fuchs, Bernhard,Froehlich, Roland,Musso, Hans
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p. 1968 - 1982
(2007/10/02)
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