Concept

Diène

Publications associées (39)

Synthesis and glycosidase inhibitory activity of new penta-substituted C8-glycomimetics

The syntheses of new C8-carbasugars and -aminocyclitols related to miglitol and voglibose are described. The key step involves the ring closing metathesis of 1,9-dienes derived from D-mannitol. Chemical transformations of the newly created double bond of t ...

2005

Synthesis of long-chain polyketide fragments by reaction of 1,3-dioxy-1,3-dienes with allylsilanes: Umpolung with sulfur dioxide

Pierre Vogel, Maris Turks, Freddy Fonquerne

In the presence of a Lewis or protic acid and at low temperature, 1,3-dioxy-1,3-dienes add to sulfur dioxide generating zwitterionic intermediates that can react with carbon nucleophiles such as allylsilanes. After a retro-ene elimination of SO2, valuable ...

2004

First asymmetric synthesis of the cyclohexanone subunit of baconipyrones A and B. Revision of its structure

Pierre Vogel, Rosario Scopelliti, Maris Turks

An asymmetric synthesis of the 3,5-dihydroxycyclohexanone subunit of baconipyrones A and B, as well as that of the hydroxydiketone subunit of baconipyrones C and D ((-)-(4S,6S)-4,6-dimethyl-5-hydroxynonan-3,7-dione), is described. Key steps include sulfur ...

2004

Palladium-catalyzed conversion of beta,gamma-unsaturated silyl sulfinates into (E)-alkenes: Asymmetric synthesis of polypropionate fragments

Pierre Vogel, Cotinica Craita, Xiaogen Huang

At low temperature, 1-alkoxy-1,3-dienes add to sulfur dioxide activated by a Lewis or protic acid generating zwitterionic intermediates that can be quenched by enoxysilanes. The resulting beta,gamma-unsaturated silyl sulfinates can be desilylated by 1:1 Pd ...

2004

On the catalytic activity of cluster anions in styrene hydrogenation: considerable enhancements in ionic liquids compared to molecular solvents

Paul Joseph Dyson, Gabor Laurenczy, Dongbin Zhao

Many low oxidation state transition metal (carbonyl) clusters are salts and are highly soluble in ionic liquids. Since many are also effective catalysts/precatalysts for hydrogenation reactions, we have conducted a catalytic study of these compounds in ion ...

2004

Competition between hetero-Diels-Alder and cheletropic additions of sulfur dioxide to 2-substituted buta-1,3-dienes. Synthesis of 2-(1-naphthyl)and 2-(2-naphthyl)buta-1,3-diene

Pierre Vogel

Chloroprene (= 2-chlorobuta-1,3-diene; 4b) and electron-rich dienes such as 2-methoxy-(4c), 2-acetoxy(dd), and 2-(phenylseleno)buta-1,3-diene (4e) refused to equilibrate with the corresponding sultines 5 or 6 between -80 and -10degrees in the presence of e ...

2002

The hetero-Diels-Alder addition of sulfur dioxide to 1-fluorobuta-1,3-dienes: The sofa conformations preferred by 6-fluorosultines (6-fluoro-3,6-dihydro-1,2-oxathiin-2-oxides) enjoy enthalpic and conformational anomeric effects

Pierre Vogel, Rosario Scopelliti

The reactivity of (E)- and (Z)-1-fluorobuta-1,3-diene ((E)- and (Z)-11), 2-fluorobutadiene (12). (E)and (Z)-1-(fluoromethylidene)-2-methylidenecyclohexane ((E)- and (Z)-13) toward SO2 has been explored and compared with that of (Z)- and (E)-1-(fluoromethyl ...

2002

The basicity gradient-driven migration of iodine: conferring regioflexibility on the substitution of fluoroarenes

Thierry Rausis

Six different fluoroarenes were submitted to the same transformations. Direct deprotonation with alkyllithium or lithium dialkylamide as reagents and subsequent carboxylation afforded acids. These included 2,6-difluorobenzoic acid, 3,6-difluoro-2-iodobenzo ...

2002

Development of a new carbon-carbon bond forming reaction. New organic chemistry of sulfur dioxide. Asymmetric four-component synthesis of polyfunctional sulfones

Pierre Vogel, Kurt Schenk

At low temperature 1-alkoxy-1,3-dienes add to sulfur dioxide activated by a Lewis or Bronstedt acid and generate zwitterionic intermediates that can be quenched by enoxysilanes. The resulting beta,gamma -unsaturated silyl sulfinates can be desilylated and ...

2001

Dimetalation: the acidity of monometalated arenes towards superbasic reagents

Kirstin Friedrich

Twofold H/metal interconversions (dimetalations) can be accomplished with spiny arenes (tert-butylbenzene, 1,4-di-tert-butylbenzene, 1,1,3,3-tetramethylindane and congeners) and N,N-crowded anilines (2,2,6,6-tetramethyl-1-phenylpiperidine and N,N-bis[triet ...

2001

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