A. Foucaud

Knoevenagel condensation catalysed by aluminium oxide.

Abstract The Knoevenagel condensation of carbonyl compounds with active methylene compounds was readily carried out with aluminium oxide as catalyst.

Knoevenagel, wittig and wittig-horner reactions in the presence of magnesium oxide or zinc oxide.

Abstract Alkenes are prepared by Wittig, Knoevenagel and Wittig-Horner reactions in solid-liquid systems, with magnesium oxide or zinc oxide as catalyst. When Wittig-Horner reaction is competitive with Knoevenagel reaction, the catalyst can be modified to give a highly selective reaction ; the addition of dimethylsulfoxide on MgO or heiamethylphosphoric triamide on ZnO gives more efficient catalysts for the Wittig-Homer reaction. The addition of a small amount of HgCl 2 , or CdCl 2 , on ZnO gives more efficient catalysts for the Knoevenagel reaction.

Preparation and oxidation of α-nitro alcohols with supported reagents.

Abstract Preparation of 2-nitro alkanols has been achieved by condensation of aldehydes with nitroalkanes in the presence of alumina-supported potassium fluoride. Nitroketones are produced by oxidation of nitroalkanols with montmorillonite - supported chromium trioxide.

Reactions de wittig, wittig-horner et knoevenagel par activation anionique avec l'alumine ou le fluorure de potassium depose sur l'alumine, sans solvant

Abstract Wittig, Wittig-Horner and Knoevenagel reactions are achieved in the presence of alumina or potassium fluoride supported on alumina, without organic solvent. The presence of a small amount of water increases the rate of the Wittig and Wittig-Horner reactions. The reaction of the diethyl cyanomethylphosphonate with an aldehyde in the presence of dry alumina is oriented towards the Knoevenagel reaction.

Reactions en milieu heterogene liquide-solide : Reactions de wittig-horner et addition du phosphite de diethyle sur les composes carbonyles en presence de KF, 2H2O.

Resume Potassium fluoride dihydrate in solid-liquid two phase systems, eventually with phase transfer catalysis, is a moderate base which can be used for Wittig-Horner reaction and synthesis of hydroxyphosphonates.

Sonochemical switching from ionic to radical pathways in the reactions of styrene and trans-β-Methylstyrene with lead tetraacetate

Abstract The reactions of styrene and trans-β-methylstyrene with lead tetraacetate in acetic acid are greatly influenced by ultrasonic irradiation to give products resulting mostly from radical chain pathways, whereas mechanical agitation gives products only from ionic processes.

Alumina supported potassium fluoride promoted reaction of nitroalkanes with electrophilic alkenes : synthesis of 4,5-dihydro furans and isoxazoline n-oxides

Abstract The reaction of secondary nitro alkanes 1 with α,β-unsaturated ketones 2 in the presence of alumina-supported potassium fluoride in acetonitrile gave 4,5-dihydrofurans 3 in high yields ; 1-nitropropane reacted with 2 to give a mixture of 4,5-dihydrofurans and furans. Nitroalkenes 17 reacted with nitroalkanes to give isoxazoline N-oxides 18 and 19 in good overall yields.

Clay Catalyzed Ene-Reactions. Synthesis of γ-Lactones

Ene-reactions occur generally at high temperature. Lewis acid catalysis allows ene-reactions under mild conditions. The ene-reaction of diethyloxomalonate, which is a very reactive enophile with olefins is catalyzed by kaolin, montmorillonite or H+ doped montmorillonite. The ene-reaction products are converted into γ-lactones, especially by acidic montmorillonite. The conversion of citronellal into isopulegol is catalyzed by montmorillonite.

Reaction des isonitriles avec les β-nitrostyrenes β-substitues. Nouvelle synthese des hydroxy-1 indoles.

Resume The reaction of alkylisonitriles with β-substituted β-nitrostyrenes yields 1-hydroxyindoles.

Réactions des dérivés du phosphore trivalent avec les composés à halogéne positif—IV : Phosphite de triphényle avec les α-cyano α-halonitriles et α-cyano α-halo esters: Synthèse et propriétés de triphénoxyiminophosphoranes

Resume Les α-bromo α,β-dicyano nitriles reagissent avec le phosphite de triphenyle pour donner des triphenoxyiminophosphoranes stables. Les α-bromo α,β-dicyano esters conduisent, dans les memes conditions, aux triphenoxyiminophosphoranes correspondants. Ces phosphoranes sont cyclises, par les acides, en Δ2-pyrrolines substituees.