Abstract: Process for the production of a hydrocarbon fraction with a high octane number and a low sulfur content from a hydrocarbon feedstock, comprising at least the following stages: 1) a hydrodesulfurization stage of the hydrocarbon feedstock, and 2) at least one stage for extracting aromatic compounds on all or part of the effluent that is obtained from the hydrodesulfurization stage, whereby said extraction leads to a paraffin-enriched raffinate and an aromatic compound-enriched extract sent to a gasoline pool to improve its octane number, wherein a portion of the paraffinic raffinate can be used in a mixture with the aromatic extract; another portion can be used as a petrochemistry base either for producing aromatic compounds or for producing olefins.

Abstract: A catalytic composition comprising at least one nickel compound mixed or complexed with at least one tertiary phosphine or a phosphite carrying a functional group, at least partly dissolved in a non-aqueous medium with an ionic nature resulting from bringing at least one aluminum halide into contact with at least one quaternary ammonium halide and/or at least one quaternary phosphonium halide, is useful for dimerizing, co-dimerizing and oligomerizing olefins. Functional groups include, but are not limited to, an amine, a cyclic amine, a nitrogen-containing heterocycle, an ester, an acid, an alcohol, a quaternary ammonium, a quaternary phosphonium, a sulfonium, a sulfonate or a phosphonate group.