- Efficient demethylation of aromatic methyl ethers with HCl in water
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A green, efficient and cheap demethylation reaction of aromatic methyl ethers with mineral acid (HCl or H2SO4) as a catalyst in high temperature pressurized water provided the corresponding aromatic alcohols (phenols, catechols, pyrogallols) in high yield. 4-Propylguaiacol was chosen as a model, given the various applications of the 4-propylcatechol reaction product. This demethylation reaction could be easily scaled and biorenewable 4-propylguaiacol from wood and clove oil could also be applied as a feedstock. Greenness of the developed methodversusstate-of-the-art demethylation reactions was assessed by performing a quantitative and qualitative Green Metrics analysis. Versatility of the method was shown on a variety of aromatic methyl ethers containing (biorenewable) substrates, yielding up to 99% of the corresponding aromatic alcohols, in most cases just requiring simple extraction as work-up.
- Bomon, Jeroen,Bal, Mathias,Achar, Tapas Kumar,Sergeyev, Sergey,Wu, Xian,Wambacq, Ben,Lemière, Filip,Sels, Bert F.,Maes, Bert U. W.
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supporting information
p. 1995 - 2009
(2021/03/26)
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- Copper and l-sodium ascorbate catalyzed hydroxylation and aryloxylation of aryl halides
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CuSO4·5H2O and NaAsc catalyzed hydroxylation and C-O/C-S cross-coupling reactions of aryl halides with phenols or 4-methylbenzenethiol were described. A wide range of substrates and test cases highlight the synthetic utility of the approach. A series of phenols, diaryl ethers, alkylaryl ethers, and diaryl thioethers were synthesized in high yield.
- Song, Guang-Lin,Zhang, Zhang,Da, Yu-Xia,Wang, Xi-Cun
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supporting information
p. 8823 - 8829
(2015/10/20)
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- NOVEL 3-AMINOALKYL-1,3-DIHYDRO-2H-INDOL-2-ONE DERIVATIVES, PREPARATION THEREOF AND THERAPEUTIC USE THEREOF
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The present invention relates to novel 3-aminoalkyl-1,3-dihydro-2H-indol-2-one derivatives, to their preparation and to their therapeutic application. The compounds of the present invention correspond to the formula (I): in which the variables are as set forth in the specification. These compounds exhibit a strong affinity and a high selectivity for human arginine-vasopressin (AVP) V1a receptors and some compounds additionally exhibit a strong affinity for AVP V1b receptors.
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Page/Page column 19
(2011/04/18)
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- General, mild, and intermolecular Ullmann-type synthesis of diaryl and alkyl aryl ethers catalyzed by diol-copper(I) complex
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(Chemical Equation Presented) A wide range of diaryl ethers and alkyl aryl ethers are synthesized through intermolecular C(aryl)-O bond formation from the corresponding aryl iodides/aryl bromides and phenols/alcohols through Ullmann-type coupling reaction in the presence of a catalytic amount of easily available (±)-diol L3-CuI complex under very mild reaction conditions. Less reactive aryl bromides can also be used for O-arylation of phenols under the same reaction conditions without increasing the reaction temperature, catalyst loading, and time. The catalytic system not only is capable of coupling hindered substrate but also tolerates a broad range of a series of functional groups.
- Naidu, Ajay B.,Jaseer,Sekar, Govindasamy
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supporting information; experimental part
p. 3675 - 3679
(2009/09/26)
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- An efficient intermolecular BINAM-copper(I) catalyzed Ullmann-type coupling of aryl iodides/bromides with aliphatic alcohols
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A wide range of alkyl aryl ethers are synthesized from the corresponding aryl iodides and aliphatic alcohols through Ullmann-type intermolecular coupling reactions in the presence of a catalytic amount of easily available BINAM-CuI complex. Less reactive aryl bromides have also been shown to react with aliphatic alcohols under identical reaction conditions to give good yields of the alkyl aryl ethers without increasing the reaction temperature and time.
- Naidu, Ajay B.,Sekar
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p. 3147 - 3151
(2008/09/20)
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- Solvent-free Williamson synthesis: An efficient, simple, and convenient method for chemoselective etherification of phenols and bisphenols
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Etherification of phenols with dimethyl- and diethylsulfates and benzyl chloride was performed efficiently in the presence of a suitable solid base, NaHCO3 or K2CO3, under solvent-free conditions. The reaction proceeded rapidly at low temperature, and the corresponding ethers were obtained with high purity and excellent yield. Selective etherification of electron-poor phenols in the presence of electron-rich ones and also selective mono-etherification of bisphenols are the noteworthy advantages of this method. This method is environmentally friendly. Copyright Taylor & Francis Group, LLC.
- Massah, Ahmad R.,Mosharafian, Masumeh,Momeni, Ahamad R.,Aliyan, Hamid,Naghash, H. Javaherian,Adibnejad, Mohamad
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p. 1807 - 1815
(2008/02/02)
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- CARBON-13 NUCLEAR MAGNETIC RESONANCE SPECTRAL STUDY. EFFECT OF O-METHYLATION OF ortho-SUBSTITUTED PHENOLS ON THE ARYL CARBON SHIELDING AND ITS APPLICATION TO INTERPRETATION OF THE SPECTRA OF SOME FLAVONOIDS
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The O-methylation effect on the carbon-13 nuclear magnetic resonance ((13)C-NMR) chemical shifts of aryl carbons of the ortho-monosubstituded phenols has been investigated.In phenols with nonconjugated substituents (2-11), O-methylation caused an upfield shift by an averange of 4.1 ppm for the ortho-methine carbon (C-6), whereas it caused a downfield shift by an averange of 1.1 ppm for the substituted ortho-carbon (C-2).This regularity is very useful for the spectral interpretation of some natural products with an ortho-substituted phenol group, such as flavonoids (16-20 and 22).The O-methylation effect of phenols 12-15 with conjugated ortho-substituents on the aryl carbons, especially C-1, C-2 and C-5, differed significantly from that observed in 2-11.On the basis of a limited number of examples, the O-ethylation effect on aromatic carbons seems similar to the O-methylation effect.Keywords---(13)C-NMR; O-methylation shift; phenol (NMR); ortho-substituted phenol (NMR); flavonoid; puerarin; 4',7-di-O-methylpuerarin; O-ethylation shift
- Fujita, Masao,Nagai, Masahiro,Inoue, Takao
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p. 1151 - 1156
(2007/10/02)
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- Photodehalogenation of the Monochloro- and Monofluoroanisoles
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Evidence is presented for a plurality of mechanisms in the photoreduction and photonucleophilic substitution of the monochloroanisoles in alcohol solvents. 4-Chloroanisole appears to react partly via a radical anion and partly by radicals, while the reactions of 3-chloroanisole are more consistent with aryl cations and aryl radicals.The intermediates in the reaction of 2-chloroanisole, which gives no photosubstitution, are as yet not identified but are probably not radical anions.In the case of 4-chloroanisole, substitution and reduction may proceed from different states.Preliminary results on the fluoroanisoles show the 2-F isomer giving both reduction and substitution and the 3- and 4-F isomers only substitution.
- Siegman, John R.,Houser, John J.
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p. 2773 - 2779
(2007/10/02)
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