Abstract: The present invention relates to a process facilitating the regeneration of a catalyst based on a zeolite, employed in an acylation reaction.

Abstract: New optically active bis[1-phospha-2,3-diphenyl-4,5-dimethylnorbornadiene] diphosphines and new optically active transition metal complexes with said phosphines are described. The complexes are useful as catalysts to promote hydrogenation of substrates.

Abstract: Compounds of formula VII are described: 1

Abstract: The invention concerns optically active polymers, obtainable by polymerizing chiral diphosphine having a C2 axis of symmetry, excluding all other symmetry element, with one or several polymerizable monomers, said chiral diphosphine consisting of a chiral body bearing two identical functional groups capable of reacting with said polymerizable monomers.

Abstract: A process for separating the (d/l) and (meso) diastereoisomers of bis-[1-phospha-2,3-diphenyl-4,5-dimethylnorbornadiene] comprising converting the mixture of diastereoisomers of bis-[1-phospha-2,3-diphenyl-4,5-dimethylnorbornadiene] to a mixture of the corresponding diastereoisomers of diphosphine disulphide or dioxide, then in separating the two diastereoisomers in dioxide or disulphide form.

Abstract: The invention concerns a resolution method for a racemic mixture of aldehyde of formula (I). The aldehydes of formula I are useful in their enantiomeric form or their racemic form for preparing transition metal complexes useful as catalysts in hydroformylation reactions of olefins.

Abstract: A subject of the present invention is new 6,6′-bis-(1-phosphanorbornadiene) diphosphines, their preparation process and their use in asymmetrical catalysis.

Abstract: The invention concerns a method for preparing a compound of formula (1) wherein: A represents naphthyl or phenyl optionally substituted; and Ar1, Ar2 independently represent a saturated or aromatic carbocyclic group, optionally substituted.

Abstract: The invention concerns a method for preparing a benzylic-type ether from an aromatic compound. The inventive method for preparing a benzylic-type ether from an aromatic compound is characterised in that it consists in: in a first step, acylating an aromatic compound by reacting said aromatic compound with an acylating agent, in the presence of an efficient amount of zeolite or a Friedel-Crafts catalyst leading to a ketonic compound; in a second step, reducing the carbonyl group into carbinol leading to a benzylic alcohol; in a third step, etherifying the hydroxyl group, by reacting the benzylic alcohol with another alcohol, in the presence of an efficient amount of zeolite.

Abstract: The invention concerns a condensation method for at least a carbonyl compound bearing at least an electroattractive group on an aromatic derivative bearing at least a hydroxyl function, characterised in that the electroattractive group present on the carbonyl compound is selected among fluoroalkyl derivatives, esters including orthoesters and nitriles and said condensation is carried out in a basic medium.

Abstract: A process for condensing at least one carbonyl compound carrying at least one electron-withdrawing group with an aromatic derivative carrying at least one hydroxyl functional group, wherein the electron-withdrawing group present on the carbonyl compound is selected from fluoroalkyl derivatives, esters, including orthoesters, and nitriles and said condensation is carried out in a basic medium.

Abstract: A subject of the present invention is new 6,6′-bis-(1-phosphanorbornadiene) diphosphines, their preparation process and their use in asymmetrical catalysis. The new diphosphines correspond to general formula (I): in which R1, R2, R3, R4, R5 are as defined in claim 1.

Abstract: The present invention relates to a process facilitating the regeneration of a catalyst based on a zeolite, employed in an acylation reaction.

Abstract: The present invention relates to optically active diphosphines. It is also targeted at their preparation according to a process for the resolution of the racemic mixture of the said phosphines to optically active isomers.

Abstract: The present invention relates to optically active diphosphines. It is also targeted at their preparation according to a process for the resolution of the racemic mixture of the said phosphines to optically active isomers. The subject of the invention is new optically active bis[1-phospha-2,3-diphenyl-4,5-dimethylnorbornadiene] diphosphines and a process for resolving the racemic bis[1-phospha-2,3-diphenyl-4,5-dimethylnorbornadiene] mixture which comprises reacting it with a palladium or platinum complex as chiral auxiliary in an organic solvent, thus forming diastereoisomer complexes, and then resolving the said optically pure complexes. The invention also relates to new optically active metal complexes comprising the said phosphines and to their use in a process for the preparation of optically active carboxylic acids and/or derivatives according to a process for the hydrogenation of &agr;,&bgr;-unsaturated carboxylic acids and/or derivatives.

Abstract: A subject of the present invention is new 6,6′-bis-(1-phosphanorbornadiene) diphosphines, their preparation process and their use in asymmetrical catalysis.

Abstract: The present invention relates to a process for etherification of a benzyl type alcohol, to the products obtained and to their applications, in particular in the perfumery field. The etherification process of the invention consists of reacting a benzyl type alcohol with another alcohol in the presence of a catalyst, characterized in that the etherification reaction is carried out in the presence of an effective quantity of a zeolite.

Abstract: A subject of the present invention is a process for the reduction of a carbonyl compound. More precisely, the invention relates to a process for reduction of an aldehyde and/or of a ketone. The reduction process of the invention, which consists of reacting a carbonyl compound with an alcohol in the presence of a zeolite catalyst, is characterized by the fact that it comprises: mixing, in any manner whatever, the carbonyl compound and the alcohol, passing said mixture over a catalyst bed containing at least one zeolite, subjecting the reaction mixture leaving the catalyst bed to recirculation over the catalyst bed, for a number of times that is sufficient to obtain the desired degree of conversion of the substrate.

Abstract: A subject of the present invention is new 6,6′-bis-(1-phosphanorbornadiene) diphosphines, their preparation process and their use in asymmetrical catalysis.

Abstract: A process for condensing at least one carbonyl compound carrying at least one electron-withdrawing group with an aromatic derivative carrying at least one hydroxyl functional group, wherein the electron-withdrawing group present on the carbonyl compound is selected from fluoroalkyl derivatives, esters, including orthoesters, and nitrites and said condensation is carried out in a basic medium.