- One-pot synthesis of substituted catechols from the corresponding phenols
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Phenols are converted to salicylaldehydes with paraformaldehyde, MgCl 2-Et3N in THF, and when subsequently treated with aqueous NaOH and H2O2 afford the corresponding catechols. The sequence is conveniently carried out as a one-pot procedure.
- Hansen, Trond Vidar,Skatteb?l, Lars
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Read Online
- Synthesis of 5,6-methylenedioxy-1-tetralone. An aryl Grignard approach from guaiacol
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A convenient synthesis of 5,6-methylenedioxy-1-tetralone (1) is described. The main features of this synthesis are the formation of 6 via a Grignard reaction using succinic anhydride followed by selective reduction and Friedel-Crafts cyclization to generate the desired tetralone 1.
- Klix, Russell C.,Cain, Michael H.,Bhatia, Ashok V.
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Read Online
- Novel preparation process of medical intermediate 3-bromocatechol
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The invention discloses a synthesis process of a medical intermediate 3-bromocatechol, which is characterized in that cheap 1,2-dihydroxybenzene (catechol) is used as a raw material, and the 3-bromocatechol is prepared through a one-step substitution reaction. The synthetic route is simple, the production cost is low, and the synthetic process of 3-bromocatechol is suitable for industrial large-scale production.
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Paragraph 0039-0043
(2020/11/01)
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- Vicinal Diamination of Arenes with Domino Aryne Precursors
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Vicinal diamination of domino aryne precursors was achieved with sulfamides. The reaction proceeds through a two-aryne pathway, accepting two N-nucleophiles at the 1,2-positions of an arene ring. Symmetrical and unsymmetrical diaminobenzenes were readily obtained.
- Li, Lu,Qiu, Dachuan,Shi, Jiarong,Li, Yang
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supporting information
p. 3726 - 3729
(2016/08/16)
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- A new avenue to the Dakin reaction in H2O2-WERSA
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We have developed a novel protocol to realize the Dakin reaction in a more greener way. In fact, by the use of H2O2-WERSA, we can oxidize aromatic arylaldehydes to phenols at room temperature. It is remarkable that the catalytic system does not require activation or any toxic ligand, additive/promoter, transition metal catalyst, base, organic solvent and so on. A range of substituted hydroxylated benzaldehydes were screened to investigate the scope of this protocol.
- Saikia, Bishwajit,Borah, Parinita
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p. 105583 - 105586
(2015/12/30)
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- Selective ortho-hydroxylation-defluorination of 2-fluorophenolates with a Bis(μ-oxo)dicopper(III) species
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The bis(μ-oxo)dicopper(III) species [CuIII 2(μ-O)2(m-XYLMeAN)]2+ (1) promotes the electrophilic ortho-hydroxylation-defluorination of 2-fluorophenolates to give the corresponding catechols, a reaction that is not accomplishable with a (η2:η2-O2) dicopper(II) complex. Isotopic labeling studies show that the incoming oxygen atom originates from the bis(μ-oxo) unit. Ortho-hydroxylation-defluorination occurs selectively in intramolecular competition with other ortho-substituents such as chlorine or bromine. O in, F out: [CuIII2(μ-O) 2(m-XYLMeAN)]2+ is a bis(μ-oxo)dicopper(III) species and promotes the electrophilic ortho-hydroxylation-defluorination of 2-fluorophenolates to give the corresponding catechols. Isotopic labeling shows that the incoming oxygen atom originates from the bis(μ-oxo) unit. Ortho-hydroxylation-defluorination occurs selectively in intramolecular competition with other ortho-substituents such as chlorine or bromine.
- Serrano-Plana, Joan,Garcia-Bosch, Isaac,Miyake, Ryosuke,Costas, Miquel,Company, Anna
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p. 9608 - 9612
(2014/10/15)
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- Structure, stereochemistry and synthesis of enantiopure cyclohexenone cis-diol bacterial metabolites derived from phenols
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Biotransformation of 3-substituted and 2,5-disubstituted phenols, using whole cells of P. putida UV4, yielded cyclohexenone cis-diols as single enantiomers; their structures and absolute configurations have been determined by NMR and ECD spectroscopy, X-ray crystallography, and stereochemical correlation involving a four step chemoenzymatic synthesis from the corresponding cis-dihydrodiol metabolites. An active site model has been proposed, to account for the formation of enantiopure cyclohexenone cis-diols with opposite absolute configurations.
- Boyd, Derek R.,Sharma, Narain D.,Malone, John F.,McIntyre, Peter B. A.,Stevenson, Paul J.,Allen, Christopher C. R.,Kwit, Marcin,Gawronski, Jacek
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scheme or table
p. 6217 - 6229
(2012/09/05)
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- Synthesis of bulky 1,2-dialkoxy- and 1,2,3-trialkoxy-arenes
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A large series of bulky 1,2-dialkoxy- and 1,2,3-trialkoxy-benzenes was efficiently prepared via Williamson etherification. Preparation of their contiguous bromine-containing derivatives was also achieved.
- Stephan, Michel,Zupancic, Borut,Mohar, Barbara
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experimental part
p. 6308 - 6315
(2011/09/19)
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- Synthesis of ACAT inhibitors through substitution using allylic picolinate and copper reagent
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Amide of an octanoic acid possessing an aryl group at C3 position is a highly potent ACAT inhibitor. In this paper, we describe a synthetic access to this class of compounds as optically active forms. The key reaction is substitution of the allylic picoli
- Kobayashi, Yuichi,Lalitnorasate, Paveena,Kaneko, Yuki,Kiyotsuka, Yohei,Endo, Yoshiki
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scheme or table
p. 6018 - 6021
(2010/11/21)
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- PROCESS FOR THE PREPARATION OF GUANIDINO SUBSTITUTED BI-AND POLYPHENYLS THAT ARE SUITABLE AS SMALL MOLECULE CARRIERS
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A process for the production of a compound of formula (I), or a pharmaceutically acceptable salt thereof, Formula (I) which process comprises:(a) coupling a compound of formula (II) to a compound of formula (III) to form a compound of formula (IV).
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Page/Page column 52-53
(2009/04/25)
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- A comparative study of the synthesis of 3-substituted catechols using an enzymatic and a chemoenzymatic method
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A series of cis-dihydrodiol metabolites, available from the bacterial dioxygenase-catalysed oxidation of monosubstituted benzene substrates using Pseudomonas putida UV4 , have been converted to the corresponding catechols using both a heterogeneous catalyst (Pd/c) and a naphthalene cis-diol dehydrogenase enzyme present in whole cells of the recombinant strain Escherichia coli DH5α(pUC129: nar B). A comparative study of the merits of both routes to 3-substituted catechols has been carried out and the two methods have been found to be complementary. A similarity in mechanism for catechol formation under both enzymatic and chemoenzymatic conditions, involving regioselective oxidation of the hydroxyl group at C-1, has been found using deuterium labelled toluene cis-dihydrodiols. The potential, of combining a biocatalytic step (dioxygenase-catalysed cis-dihydroxylation) with a chemocatalytic step (Pd/C-catalysed dehydrogenation), into a one-pot route to catechols, from the parent substituted benzene substrates, has been realised.
- Berberian,Allen,Sharma,Boyd,Hardacre
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p. 727 - 739
(2008/02/09)
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- Medium-scale preparation of useful metabolites of aromatic compounds via whole-cell fermentation with recombinant organisms
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The whole-cell fermentation of aromatic coumpounds with Escherichia coli JM109 (pDTG601) on a medium scale (10-15L) produces enantiopure cyclohexadienediols. A detailed procedure for the fermentation is described, and yields for several metabolites are provided. A similar procedure using E. coli JM109 (pDTG602) affords catechols. The dienediols are useful for asymmetric synthesis, and several important targets originating from these metabolites are tabulated.
- Endoma, Mary Ann,Bui, Vu P.,Hansen, Jeff,Hudlicky, Tomas
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p. 525 - 532
(2013/09/06)
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- Aromatic heterocyclic derivatives as enzyme inhibitors
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The present invention discloses peptide aldehydes which are potent and specific inhibitors of thrombin, their pharmaceutically acceptable salts, pharmaceutically acceptable compositions thereof, and methods of using them as therapeutic agents for disease states in mammals characterized by abnormal thrombosis.
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Page column 123
(2010/02/04)
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- Progress toward the synthesis of a biomimetic membrane
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Ubiquinone has antioxidant properties and is important in the conversion of products from glycolysis and the citric acid cycle to ATP. We report the synthesis of the necessary components of a biological membrane mimic that can serve as a model system for elucidating the third step in the prokaryotic biosynthesis of ubiquinone. (C) 2000 Elsevier Science Ltd.
- Gano, Kyle W.,Myles, David C.
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p. 4247 - 4250
(2007/10/03)
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- Chemoenzymatic synthesis of the morphine skeleton via radical cyclization and a C10-C11 closure
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A short synthesis of a morphinan skeleton has been accomplished. The key steps involve enzymatic dihydroxylation of β-bromoethyl benzene, vinyl and aryl radical cyclizations, and Friedel-Crafts closure of an aziridinium ion or an acid-catalyzed closure of an aldehyde to form the C10-C11 bond.
- Butora, Gabor,Hudlicky, Tomas,Fearnley, Stephen P.,Gum, Andrew G.,Stabile, Michele R.,Abboud, Khalil
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p. 8155 - 8158
(2007/10/03)
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