Abstract: For the conversion of an olefinic C.sub.4 or C.sub.5 cut to an alkyl-tertiobutylether or alkyl-tertioamylether and to propylene, by metathesis, the process comprises four successive steps: (1) selective hydrogenation of the diolefins with simultaneous isomerisation of the alpha olefins to internal olefins; (2) etherification of the isoolefins; (3) elimination of oxygen-containing impurities; (4) metathesis of internal olefins with ethylene. The process has application, e.g., to C.sub.4 and C.sub.5 steam cracking cuts.

Abstract: A supported catalyst with rhenium and also containing aluminium introduced by a compound of the formula (OR).sub.qAlR'.sub.r with R being a hydrocarbyl residue with from 1 to 40 carbon atoms, R' being an alkyl residue with from 1 to 20 carbon atoms, and with q and r equal to 1 or 2 with q+r=3. A process for the preparation of a catalyst comprising impregnating a compound of rhenium on a porous support formed by refractory oxides and/or alumino-silicates of an acid, neutral or basic nature, roasting at a temperature of form 200 to 950.degree. C. and impregnating with said aluminium compound. The catalyst is used for the metathesis of olefins.

Abstract: The invention concerns an improved process for the conversion of ethylene into butene-1, wherein the ethylene is brought into contact with a catalyst obtained by the reaction of an alkyl titanate, possibly mixed with an ether, with a compound of aluminium of the formula AlR.sub.3 or AlR.sub.2 H, and in the presence of an additive formed by at least one quaternary ammonium salt.

Abstract: The present invention concerns a process for the conversion of an olefinic C.sub.4 cut to polyisobutene and to propylene by metathesis. The process comprises three successive steps: (1) selective hydrogenation of diolefins with simultaneous isomerisation of 1-butene to 2-butenes, (2) polymerisation of the isobutene, including optional prior extraction of the isobutene, (3) metathesis of 2-butene with ethylene. Part or all of the C.sub.4 cut may originate from the metathesis of an olefinic C.sub.5 cut with ethylene after hydroisomerisation of the C.sub.5 cut. Application to C.sub.4 and C.sub.5 steam cracking cuts.

Abstract: The invention concerns an improved process for the conversion of ethylene into light alpha olefins wherein the ethylene is brought into contact with a catalyst obtained by mixing a compound of zirconium with an organic compound selected from the class of acetals and ketals, esters, ketones, ethers, amines, nitrites, anhydrides, chlorides of acids, amides, aldehydes, thioethers, sulphides and disulphides, thiophenes, thioureas and phosphines, and with a chloro or bromo compound of aluminium hydrocarbyl, in the presence of an additive formed by at least one quaternary ammonium salt.

Abstract: For obtaining of improved purity of light alpha olefines produced by oligomerization of ethylene, the ethylene is placed in contact with a catalyst obtained by mixture of a zirconium compound with an organic compound selected from the class of acetals and ketals and with a chlorinated or brominated aluminium hydrocarbyl compound, and that the raw oligomerization effluent is firstly treated with an amine, then subjected to vaporization so as to collect the alpha olefines in the vaporized fraction.

Abstract: The invention concerns an improved process for the conversion of ethylene into but-1-ene, wherein the ethylene is brought into contact with a catalyst obtained by the interaction of an alkyl titanate, possibly mixed with an ether, with a compound of aluminium of the formula AlR.sub.3 or AlR.sub.2 H, and in the presence of an additive formed by at least one polyethylene glycol and/or one of its derivatives such as a monoether or a monoester of polyethylene glycol.

Abstract: The present invention concerns new catalysts based on compounds containing both rhenium and aluminum, which are deposited on an organic or inorganic support. The compounds of rhenium and aluminum correspond to the general formula:O.sub.3 Re--O--?Al(OR)(L).sub.x --O!.sub.n --ReO.sub.3in which R is a hydrocarbyl residue, for example alkyl, cycloalkyl, alkenyl, aryl, and aryl or cycloalkyl which are substituted, containing from 1 to 40 carbon atoms, which residue can be substituted by alkoxy groups or by halogens, L is the synthesis solvent, x is equal to 0 or 1 and n is an integer of from 1 to 10. The invention also concerns the preparation of such catalysts and the use thereof for the metathesis of olefins.

Abstract: The present invention concerns new catalytic compositions containing at least one compound of rhenium and aluminium corresponding to the general formula: O.sub.3 Re--O--?Al(OR)(L).sub.x --O!.sub.n --ReO.sub.3 in which R is a hydrocarbyl residue, for example alkyl, cycloalkyl, alkenyl, aryl and aryl or cycloalkyl which are substituted, containing from 1 to 40 carbon atoms, which residue can be substituted by alkoxy groups or by halogens, L is the synthesis solvent, x is equal to 0 or 1 and n is an integer of from 1 to 10. The invention also concerns the preparation of such compositions and the use thereof for the metathesis of olefins in a homogeneous phase.

Abstract: The present invention concerns new compounds of rhenium and aluminum corresponding to the general formula: O.sub.3 Re--O--[Al(OR)(L).sub.x --O].sub.n --ReO.sub.3 in which R is a hydrocarbyl residue, for example alkyl, cycloalkyl, alkenyl, aryl and aryl or cycloalkyl which are substituted, containing from 1 to 40 carbon atoms, which residue can be substituted by alkoxy groups or by halogens, L is the synthesis solvent, x is equal to 0 or 1 and n is an integer of from 1 to 10. The invention also concerns derived compounds of the formula O.sub.3 Re(L')--O--[Al(OR)(L).sub.x --O].sub.n --ReO.sub.3 (L') in which L' is a stabilising ligand. The invention also concerns the preparation of such compounds and the use thereof in the preparation of catalysts.

Abstract: Process for oligomerizing ethylene into light alpha olefins, mainly 1-butene, 1-hexene, 1-octene and 1-decene, in which the ethylene is contacted with a catalyst obtained by mixing a zirconium compound with an organic compound chosen from within the class of acetals and ketals and with a chlorine or bromine-containing compound of aluminium hydrocarbyl.

Abstract: A process for the metathesis of olefins, wherein the olefins are reacted in contact with an improved catalyst comprising a niobium and/or tantalum compound and a rhenium compound on a porous support containing at least 75% alumina and having a surface area of at least 10 m.sup.2 /g.

Abstract: Process for oligomerizing ethylene into light alpha olefins, mainly 1-butene, 1-hexene, 1-octene and 1-decene, in which the ethylene is contacted with a catalyst obtained by mixing a zirconium compound with an organic compound chosen from within the class of acetals and ketals and with a chlorine or bromine-containing compound of aluminum hydrocarbyl.

Abstract: Process for the conversion of ethylene into light alpha olefins, mainly 1-butene, 1-hexene and 1-octene, in which the ethylene is contacted with a catalyst obtained by reacting a performed mixture of alkyl zirconate and ether with a chlorine or bromine-containing aluminum compound.

Abstract: A non-aqueous liquid composition with an ionic character resulting from the contacting of at least one alkylaluminum dihalide with at least one quaternary ammonium halide and/or at least one quaternary phosphonium halide, said composition being liquid below 80.degree. C., for example, between -70.degree. and +40.degree. C., is useful as a solvent of catalysts for the dimerization, codimerization and oligomerization of olefins.

Abstract: The invention concerns a catalytic composition resulting from placing at least one divalent nickel compound into contact with at least one hydrocarbylaluminum halide and at least one epoxy compound, in any order. It also concerns the use of the catalytic composition in a process of oligomerizing monoolefins.

Abstract: The invention concerns a catalytic composition resulting from placing at least one divalent nickel compound into contact with at least one hydrocarbylaluminum halide and at least one epoxy compound, in any order. It also concerns the use of the catalytic composition in a process of oligomerizing monoolefins.

Abstract: A process for producing organolanthanides by reaction of a rare-earth metal with an unsaturated compound in an ether medium, the resultant compounds and the use of these compounds in organic synthesis and for catalysis is disclosed. The process is conducted at -80.degree. to +100.degree. C., in the absence of oxygen and any compound having active protons. The resultant compounds are useful as catalysts, e.g., in the hydrogenation of olefins and diolefins and in the polymerization thereof, and are useful as chemical intermediates.

Abstract: Process for manufacturing a rhenium-containing catalyst comprising three steps of:dry impregnation of an alumina-containing porous carrier, at a temperature lower than 80.degree. C., for at least 10 hours,first thermal treatment at 85.degree.-250.degree. C., andsecond thermal treatment at 400.degree.-1000.degree. C.The obtained catalyst can be used for producing olefins by metathesis of other olefins.

Abstract: New nickel composition having substantial solubility in hydrocarbons and prepared by reacting at least one inorganic divalent nickel compound, at least one halogenoacetic acid and at least one ester of the formula R.sub.1 COO R.sub.2 wherein R.sub.1 is hydrogen or hydrocarbyl and R.sub.2 is hydrocarbyl. The resultant composition can be used in admixture with a hydrocarbylaluminum halide as catalyst for olefin dimerization.