Process for oligomerization of olefins that uses a catalytic composition that comprises an organometallic complex that contains a phenoxy ligand that is functionalized by a heteroatom

A process comprising catalytic oligomerization of the olefins into compounds or into a mixture of compounds of general formula CpH2p with 4≦p≦80, the catalyst being a catalytic composition comprising at least one organometallic complex of an element of group IV selected from among titanium, zirconium or hafnium, whereby said organometallic complex contains at least one aryloxy ligand functionalized by a heteroatom selected from among nitrogen, oxygen, phosphorus or sulfur or by an aromatic group, said organometallic complex having the following formula:

• [M(OAr)nY(4-n)]
• wherein:
• M is an element from group IV selected from among titanium, zirconium, or hafnium,
• Y is an atom of chlorine, or bromine, or a hydrocarbyl radical that comprises 1 to 30 carbon atoms, or a radical selected from alkoxy R′O—, the amido R′2N—, or the carboxylates R′COO—, where R′ is a hydrocarbyl radical comprising 1 to 30 carbon atoms,
• n is an integer values of 1 to 4,
• the ligand —OAr is an aryloxy ligand of the formula:
• in which:
• the groups R2, R3, R4 and R5, identical or different, represent a hydrogen atom, a halogen, or a hydrocarbyl radical that comprises 1 to 30 carbon atoms,
• B is a functional group comprising a heteroatom selected from among nitrogen, oxygen, phosphorus or sulfur or an aromatic group, wherein said functional group B can be directly linked to aryloxy or linked to another group that is directly linked to aryloxy and represented by a spacer group A, wherein said spacer group A is an optionally cyclic hydrocarbon chain comprising 1 to 5 carbon atoms.