- METHODS OF PREPARING a,?-UNSATURATED OR a-HALO KETONES AND ALDEHYDES
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Copper(II) bromide mediated oxidation of acylated enol and use of the reaction in the synthesis of α,β-unsaturated or α-bromo ketones or aldehydes are disclosed. The method provides an efficient and practical process for manufacturing dehydrohedione (DHH) and many other versatile α,β-unsaturated or α-bromo ketones or aldehydes in large scales to avoid using precious metal compounds.
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Paragraph 0116; 0117; 0130; 0131; 0138; 0139
(2017/07/14)
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- α,β-Unsaturated ketones via copper(II) bromide mediated oxidation
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A protocol for effecting a rapid Saegusa-type oxidation of enol acetates is reported. This new method relies on the in situ elimination of an α-bromo intermediate to generate α,β-unsaturated ketones using copper(II) bromide. The methodology developed was applied to a range of substrates including a cyclohexanone, which could be directly converted to the corresponding phenol derivative. A catalytic system in which a non-masked ketone was successfully oxidised using substoichiometric CuBr2 was also developed as a proof of principle.
- Sharley, James S.,Collado Pérez, Ana María,Ferri, Estela Espinos,Miranda, Amadeo Fernandez,Baxendale, Ian R.
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p. 2947 - 2954
(2016/05/19)
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- Stereocontrolled 1,3-phosphatyloxy and 1,3-halogen migration relay toward highly functionalized 1,3-dienes
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A double migratory cascade reaction of α-halogen-substituted propargylic phosphates to produce highly functionalized 1,3-dienes has been developed. This transformation features 1,3-phosphatyloxy group migration followed by 1,3-shifts of bromine and chlorine as well as the unprecedented 1,3-migration of iodine. The reaction is stereodivergent: (Z)-1,3-dienes are formed in the presence of a copper catalyst, whereas gold-catalyzed reactions exhibit inverted stereoselectivity, producing the corresponding E products.
- Kazem Shiroodi, Roohollah,Dudnik, Alexander S.,Gevorgyan, Vladimir
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supporting information; experimental part
p. 6928 - 6931
(2012/06/15)
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- Facile synthesis of 3,3-dialkyl-6-phenyl-imidazopyridinones
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A series of novel 3,3-dialkylated imidazopyridinones bearing 6-aryl groups were designed as mimetics of active progesterone antagonists, 3,3-disubstituted-5-arylindoles. The four-step synthetic route is described. The key steps are base-catalyzed cyclizat
- Jiang, Weiqin,Fiordeliso, James J.,Sui, Zhihua
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p. 1237 - 1249
(2008/02/01)
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- Synthesis and SAR studies of 3-phenoxypropyl piperidine analogues as ORL1 (NOP) receptor agonists
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A series of 3-phenoxypropyl piperidine analogues have been discovered as novel ORL1 receptor agonists. Structure-activity relationships have been explored around the 3-phenoxypropyl region with several potent and selective analogues identified.
- Palin, Ronald,Barn, David R.,Clark, John K.,Cottney, Jean E.,Cowley, Phillip M.,Crockatt, Marc,Evans, Louise,Feilden, Helen,Goodwin, Richard R.,Griekspoor, Frank,Grove, Simon J.A.,Houghton, Andrea K.,Jones, Philip S.,Morphy, Richard J.,Smith, Alasdair R.C.,Sundaram, Hardy,Vrolijk, David,Weston, Mark A.,Wishart, Grant,Wren, Paul
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p. 589 - 593
(2007/10/03)
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- Studies on quinones. Part 32.1 Regioselective synthesis of benz[b]phenantridines related to phenantroviridone
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The Diels-Alder reaction of juglone (4) and bromojuglone 18 with 1- cyclohexenecarboxaldehyde dimethylhydrazone (3) is described. Through these cycloaddition reactions 8-hydroxy-1,2,3,4-tetrahydrobenz[b]phenantridin- 7,12-dione (5) was obtained in 55 and
- Valderrama, Jaime A.,Gonzalez, M. Florencia,Valderrama, Claudio
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p. 6039 - 6050
(2007/10/03)
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- Enhanced D1 Affinity in a Series of Piperazine Ring Substituted 1-Piperazino-3-Arylindans with Potential Atypical Antipsychotic Activity
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A study of the effect of aromatic substitution on D1 and D2 affinity in a series of previously reported trans-1-piperazino-3-phenylindans shows similar structure-activity relationships for the two receptor sites. 6-Substituted derivatives have affinity for both receptors, and 6-chloro-or 6-fluoro-substituted derivatives show preference for D1 receptors.D1 affinity and selectivity are significantly increased in a series of new piperazine ring substituted derivatives.Potent D1 and D2 antagonism in vivo are confined to derivatives with relatively small substituents in the 2-position of the piperazine ring (e.g. 2-methyl, 2,2-dimethyl, 2-spirocyclobutyl or 2-spiro-cyclopentyl).Consequently, the effect of aromatic substitution is examined in a series of 1-(2,2-dimethylpiperazino)-3-arylindans.All these compounds except the 4-, 5-, 7- and 4'-chloro-substituted derivatives have potent D1 affinity (IC50's below 10 nM) and the majority of the compounds antagonize SKF 38393-induced circling in 6-OHDA-lesioned rats with ED50 values about 1μmol/kg.In vitro all compounds show preference for D1 receptors, but in vivo they are equally effective as D1 and D2 antagonists.The compounds have high affinity for 5-HT2 receptors and selected compounds show high affinity for α1 adrenoceptors.Furthermore, a subgroup consisting of (-)-38, (-)-39, (-)-41, and (-)-54 does not induce catalepsy in rats.These compounds have the potential of being "atypical" antipsychotics and have consequently been selected for further studies.The non-receptor-blocking enantiomers are shown to be inhibitors of DA and NE uptake in accordance with previous observations in compounds unsubstituted in the piperazinering.Two compounds, (+)-38 and (+)-40, block DA uptake with IC50 values below 10nM.Finally, the observed structure-activity relationships are discussed in relation to previously published pharmacophore models for D2 and 5-HT2 receptors.It is concluded that the piperazine substituents might induce a different binding mode at the dopamine receptor sites, perhaps only at the D1 receptor site.
- Boegesoe, Klaus P.,Arnt, Joern,Frederiksen, Kristen,Hansen, Hans Otto,Hyttel, John,Pedersen, Henrik
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p. 4380 - 4392
(2007/10/02)
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- THE MUKAIYAMA REACTION OF KETENE BIS(TRIMETHYLSILYL)ACETALS WITH α-HALO ACETALS - A CONVENIENT BUTENOLIDE SYNTHESIS
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Ketene bis(trimethylsilyl) acetals were reacted with α-halo acetals giving β-alkoxy-γ-halo acids which were converted to butenolides by reaction with equivalents of base.This constitutes a novel and short butenolide synthesis.
- Demnitz, F. W. J.
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p. 6109 - 6112
(2007/10/02)
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- 5,5-Dibromobarbituric Acid, a Convenient New Reagent for the Bromination of Saturated and α,β-Unsaturated Carbonyl Compounds
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5,5-Dibromobarbituric acid (1) was used for the bromination of saturated and α,β-unsaturated aldehydes and keto compounds.
- Grundke, Guenter,Keese, Wolfgang,Rimpler, Manfred
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p. 4288 - 4291
(2007/10/02)
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- Rates of Acid- and Base-Catalyzed Enolization of trans-Hexahydrofluorenone. Concerning Stereoelectronic Control of Enolization
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Rates of both acid-catalyzed and base-catalyzed enolization of trans-hexahydrofluorenone (trans-HHF) have been measured and compared with those for a variety of other ketones.It was found that trans-HHF enolizes substantially faster than cyclohexyl phenyl ketone (CPK) in both acid (1800-fold) and base (2650-fold).This rate variation is thought to be due to two factors. (1) In trans-HHF the cleaving C-H bond is held rigidly parallel to the ? orbital of the ketone.About a factor of 25- to 60-fold is attributed to this stereoelectronic effect. (2) There are stericinteractions in the enol of CPK which decrease its rate of enolization by about 40- to 50-fold.
- Pollack, Ralph M.,Kayser, Robert H.,Cashen, Michael J.
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p. 3983 - 3987
(2007/10/02)
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- Preparation stereoselective de methyle cetones α-bromees: stereochimie de l'addition d'anions en α d'un groupe sulfone sur des cyclohexanones monocycliques et steroidiques
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This work describes stereochemical results obtained for the preparation of α-bromomethyl ketones or α-bromoaldehydes starting from monocyclic and steroid cyclohexanones, using the Durst method.In all the cases studied here, the bromine is introduced selectively in the equatorial position.However, for monocyclic compounds, the yields of α-bromocarbonyl compounds are limited by the competitive formation of α-ethylenic carbonyl compounds.
- Begue, Jean-Pierre,Bonnet-Delpon, Daniele,Charpentier-Morize, Micheline,Sansoulet, Jean
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p. 2087 - 2092
(2007/10/02)
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