Abstract:
The present invention relates to a process for the acylation of an aromatic thioether. In its preferred variant, the invention resides in a process for the condensation of acetic anhydride or acetyl chloride with thioanisole. The process for the acylation of an aromatic thioether according to the invention is characterised in that it consists in reacting said thioether with an acylating agent chosen from the group formed by the halides of carboxylic acids and the anhydrides of carboxylic acids, in the presence of an effective quantity of an acid zeolite.
Abstract:
The present invention relates to a process for the hydroxylation of phenolic compounds and, more particularly, to a process for the hydroxylation of phenols and phenolic ethers with hydrogen peroxide. The invention relates to a process for the hydroxylation of phenolic compounds using hydrogen peroxide, said process being characterized in that the reaction is carried out in the presence of an effective quantity of at least one rare earth or bismuth triflate.
Abstract:
The present invention concerns a process for acylation of an aromatic compound. The acylation process of the invention consists of reacting the aromatic compound with an acylation agent in the presence of a zeolitic catalyst, and is characterized in that it consists of: mixing the aromatic compound and the acylation compound in any manner; passing said mixture over a catalytic bed comprising at least one zeolite; recirculating the reaction mixture from the catalytic bed over the catalytic bed for a number of times which is sufficient to obtain the desired degree of conversion of the substrate.
Abstract:
The present invention concerns a process for the acylation of an aromatic ether.Preferably the invention relates to a process for the acylation of a substituted aromatic ether, in particular veratrol.The acylation process of the invention consists of reacting the ether with an acylation agent in the presence of a zeolitic catalyst, and is characterized in that the acylation reaction is carried out in the presence of an effective quantity of a catalyst comprising a faujasite type zeolite or a Y zeolite with the following physico-chemical characteristics:an atomic ratio denoted "global Si/Me.sup.1 " between the number of atoms of the element silicon and the number of atoms of every trivalent element Me.sup.1 contained in the zeolite in the range 2.4 to 90, preferably in the range 2.4 to 75, and more preferably in the range 2.4 to 60;an Me.sup.2 alkali metal content such that the atomic ratio Me.sup.2 /Me.sup.1(IV) between the number of atoms of alkali metal Me.sup.2 and the number of atoms of every trivalent element Me.sup.1(IV) included in the zeolitic network is less than 0.2, preferably less than 0.1, and more preferably less than 0.05.
Abstract:
The present invention concerns a process for the acylation of an aromatic ether. Preferably, the invention relates to a process for the acylation of an unsubstituted aromatic ether, in particular anisole. The acylation process of the invention consists of reacting the ether with an acylation agent in the presence of a zeolitic catalyst, and is characterized in that the acylation reaction is carried out in the presence of an effective quantity of a catalyst comprising a beta zeolite with an atomic ratio denoted "global Si/Me.sup.1 " between the number of atoms of the element silicon and the number of atoms of every trivalent element Me.sup.1 contained in the zeolite of no less than 15, preferably in the range 15 to 55, and more preferably in the range 18 to 35.
Abstract:
Ketones having at least one hydrogen atom or ester group in the .alpha.-position with respect to a ketonic carbonyl group thereof, for example cyclopentanone, 2-methylcyclopentanone and other substituted cyclopentanones, are effectively C- or .alpha.-alkylated, especially on an industrial scale, by reacting same with an alkylating agent in the presence of a catalytically effective amount of a condensed or uncondensed orthophosphate anion.
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 concerns the aminomethylation of pentenoic acid derivatives, by reaction with carbon monoxide, hydrogen and ammonia, for preparing caprolactam. More precisely, it is directed to a method for preparing caprolactam wherein the aminomethylation of pentenoic acid derivatives is carried out by reaction with carbon monoxide, hydrogen, and ammonia, at a temperature higher than 30° C. and in the presence of a catalyst with a base of at least one metal of Group VIII of the Periodic Table.
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 .alpha.,.beta.-unsaturated carboxylic acids and/or derivatives.
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.