FR3086552A1 - CATALYTIC COMPOSITION BASED ON NICKEL (I) - Google Patents

Abstract

The present invention relates to a catalytic composition comprising a nickel complex of degree of oxidation + I and an additional compound of formula Q + X-, as well as the use of said composition in catalytic reactions, in particular in reactions of oligomerization of an olefinic charge and more particularly of ethylene to obtain but-1-ene and hex-1-ene.

Description

Field of the invention

The present invention relates to a catalytic composition comprising a nickel complex of oxidation state +1 and an additional compound of formula Q. ⁺ X ′, as well as the use of said composition in catalytic reactions, in particular in reactions of oligomerization of an olefinic charge and more particularly of ethylene to obtain but-1-ene and hex-1-ene.

Prior art

The dimerization of ethylene to butenes by a homogeneous nickel-based catalyst has been studied since the 1950s.

Catalytic systems consisting of nickel at a zero oxidation state, denoted Ni (0), phosphine and Bronsted acid have been described in particular in patents US 5,237,118, US 4,478,847 and FR 2,835,447. The cost of Ni (0 ) and the difficulties linked to its implementation due to its instability, make it unattractive for operation on an industrial scale.

Other catalytic systems for the dimerization of ethylene, in particular described in patents US 4242531 and FR 1547921, have been developed and include nickel with an oxidation state of +11, denoted Ni (ll), and a compound with aluminum base. These compositions have the advantage of overcoming the processing problems associated with Ni (0) but are accompanied by handling difficulties linked to the pyrophoric nature of the aluminum-based compounds.

There is therefore always a need to develop new oligomerization catalytic compositions which do not present any handling difficulties.

The Applicant has discovered a new catalytic composition comprising a nickel complex of degree of oxidation +1, denoted Ni (1), and an additional compound of formula Q. ⁺ X '. Surprisingly, this catalytic composition makes it possible to obtain good yields of butenes and hexenes during its use in the oligomerization reaction of ethylene.

Subject of the invention

An object of the present invention therefore relates to a catalytic composition comprising:

- a Ni (l) complex of formula [Ni (L) _m Z] in which o Ni is nickel with an oxidation state +1, ο Z is chosen from hydrogen, halide such as fluorine, chlorine , bromine or iodine, an alkyl, a heteroalkyl, an aryl, a heteroaryl, an alcoholate, a phenolate, a carboxylate or an amide, where L, identical or different, is chosen from single-phosphorus compounds, phosphorous compounds bidentates, tridentate phosphorus compounds, olefinic compounds, bipyridines, diimines, monodentate ethers, bidentate ethers, monodentate thioethers, bidentate thioethers, monodentate or bidentate carbenes, mixed ligands such as phosphinopyridines, imin bis (imino) pyridines, om = 1, 2, 3 or 4,

- And at least one compound of formula Q. ⁺ X ', in which o Q ⁺ is an organic or inorganic cation, and ο X' is an organic or inorganic anion.

Another subject of the invention relates to a process for the preparation of said catalytic composition comprising a Ni (l) complex of formula [Ni (L) _m Z] and a compound Q. ⁺ X '.

Another subject of the invention relates to an oligomerization process using said catalytic composition in the presence of an olefinic filler.

Another object of the invention relates to a method comprising

a step for preparing the catalytic composition of [Ni (L) _m Z], and

- An oligomerization step using the catalytic composition of Ni (l) obtained in the previous step.

Definitions and Abbreviations

It is specified that, throughout this description, the expressions "comprised between ... and ..." "comprising between ... and ..." must be understood as including the bounds cited.

Ni (n) denotes a nickel with a degree of oxidation η, n being equal to 0, 1 or 2, also noted 0, I or II.

The term “oligomerization” means any transformation of an olefinic monomer unit into a compound or a mixture of unsaturated compounds of general formula C _n H _2n where n is between 4 and 80. For example, dimerization is defined as a reaction of oligomerization leading to the selective formation of butenes, in particular but-1-ene.

By heteroatom is meant an atom different from carbon and hydrogen. A heteroatom can be chosen from oxygen, sulfur, nitrogen, phosphorus, silicon and halides such as fluorine, chlorine, bromine or iodine.

The term “hydrocarbon” means an organic compound consisting exclusively of carbon (C) and hydrogen (H) atoms.

The term “alkyl group” is understood to mean a hydrocarbon chain comprising between 1 and 20 carbon atoms, denoted C ₁ -C ₂₀ alkyl, saturated or not, linear or branched, non-cyclic, cyclic or polycyclic. E.g., alkyl-C ₆ is alkyl selected in particular from methyl, ethyl, propyl, butyl, pentyl, cyclopentyl, hexyl and cyclohexyl.

The term “aryl group” is intended to mean an aromatic group, mono or polycyclic, fused or not, comprising between 5 and 30 carbon atoms, denoted C5-C30 aryl.

The term “heteroalkyl group” means an alkyl group comprising between 1 and 20 carbon atoms and at least one heteroatom, denoted C ₁ -C ₂₀ heteroalkyl.

The term “heteroaryl group” means an aromatic group comprising between 3 and 30 carbon atoms and at least within at least one aromatic ring, a heteroatom chosen from oxygen (O), sulfur (S), nitrogen (N) and silicon (Si), denoted C ₃ -C ₃₀ heteroaryl.

The term alcoholate group means a group -O-alkyl or -O-heteroalkyl.

The term “phenolate group” is intended to mean an —O-aryl or —O-heteroaryl group.

The term “carboxylate” means a group -O-C (O) -alkyl, O-C (O) -heteroalkyl, -O-C (O) -aryl or OC (O) -heteroaryl.

The term amide means a group -NH-alkyl, -NH-heteroalkyl, -NH-aryl, -NH-heteroaryl, N (alkyl) ₂ , -N (heteroalkyl) ₂ , -N (aryl) ₂ or -N ( heteroaryl) ₂ .

By solvent is meant a liquid which has the property of dissolving, diluting or extracting other substances without chemically modifying them and without itself being modified.

Denticity is understood to mean the number of atoms of a compound capable of binding to a metal center. For example, monodentate compounds have one atom that can bond to a metal center, bidentate compounds have two atoms that can bond to a metal center, tridentate compounds have three atoms that can bond to a metal center. Multidentate compounds have more than three atoms that can bond to a metal center.

Detailed description of the invention

Catalytic composition

The present invention therefore relates to a catalytic composition comprising, preferably consisting of:

- a Ni (l) complex of formula [Ni (L) _m Z] in which o Ni is nickel with an oxidation state +1, ο Z is chosen from hydrogen, halide such as fluorine, chlorine , bromine or iodine, an alkyl, a heteroalkyl, an aryl, a heteroaryl, an alcoholate, a phenolate, a carboxylate or an amide, where L, identical or different, is chosen from single-phosphorus compounds, phosphorous compounds bidentates, tridentate phosphorus compounds, olefinic compounds, bipyridines, diimines, monodentate ethers, bidentate ethers, monodentate thioethers, bidentate thioethers, monodentate or bidentate carbenes, mixed ligands such as phosphinopyridines, imin bis (imino) pyridines, om = 1, 2, 3 or 4,

- And at least one compound of formula Q. ⁺ X ', in which o Q ⁺ is an organic or inorganic cation, and ο X' is an organic or inorganic anion.

Nickel complex (l)

The catalytic composition according to the invention comprises a Ni (l) complex of formula [Ni (L) _m Z] in which

- Ni is nickel with an oxidation state +1,

Z is chosen from a hydrogen, a halide such as fluorine, chlorine, bromine or iodine, an alkyl, a heteroalkyl, an aryl, a heteroaryl, an alcoholate, a phenolate, a carboxylate or an amide,

- The same or different, is chosen from monodentated phosphorus compounds, bidentate phosphorus compounds, tridentate phosphorus compounds, olefinic compounds, bipyridines, diimines, monodentate ethers, bidentate ethers, monodentate thioethers, bidentate thioethers , monodentate or bidentate carbenes, mixed ligands such as phosphinopyridines, iminopyridines, bis (imino) pyridines,

- m = 1, 2, 3 or 4.

The complexes of general formula [Ni (L) _m Z] can be in a monomeric or dimeric form. Said complexes are formed by the coordination of one or more ligands (L) with a nickel (I).

Preferably, Z is chosen from F, Cl, Br, I, and a C ₁ -C ₂₀ alkyl optionally substituted by a C ₅ -Ci ₀ aryl. Preferably, Z is chosen from Cl, Br, I, and a Q-Cg alkyl substituted or not by a C ₅ -C ₆ aryl. Preferably, Z is chosen from Cl, Br, methyl, ethyl, propyl, and benzyl.

According to the invention, the ligand (s) (L) are independently chosen from one or more phosphorus, nitrogen, oxygen, sulfur, olefin, aromatic, carbene, monodentate, bidentate, tridentate or multidentate compounds, taken alone or as a mixture.

More preferably, L is chosen from monodentated phosphorus compounds, bidentate phosphorus compounds, tridentate phosphorus compounds, olefinic compounds, bipyridines, diimines, monodentate ethers, bidentate ethers, monodentate thioethers, bidentate thioethers, carbenes monodentate or bidentate, mixed ligands such as phosphinopyridines, iminopyridines, bis (imino) pyridines.

Monodentated phosphorus compounds advantageously correspond to the general formula P (A ¹ R ¹ ) (A ² R ² ) (A ³ R ³ ) in which:

> A ¹ , A ² and A ³ , identical or different, are independently chosen from S, O, NR ⁴ and a covalent bond between the phosphorus atom and a carbon atom or a hydrogen atom,> the R groups ^1, R ² and R ^3, identical or different, linked or not to each other, are independently selected from hydrogen, alkyl Ci-C ₂ o, heteroalkyl, Ci-C ₂₀ aryl, C ₅ -C ₃₀ and heteroaryl, C ₄ -C _30> the R ⁴ group is independently selected from hydrogen, alkyl _Ci-C20 heteroalkyl Ci-C ₂₀ aryl, C ₅ -C ₃₀ heteroaryl and C ₃ -C ₃₀ .

Preferably, the groups A ¹ , A ² and A ³ , identical or different, are chosen from O, NR ⁴ and a covalent bond between the phosphorus atom and a carbon atom of the groups R ¹ , R ² or R ³ , or a hydrogen atom, and preferably is a covalent bond between the phosphorus atom and a carbon atom of the groups R ¹ , R ² or R ³ or a hydrogen atom.

Preferably, the group R ⁴ is chosen from alkyl and heteroalkyl groups, comprising between 1 and 15 carbon atoms, preferably between 1 and 10 carbon atoms and preferably between 1 and 6 carbon atoms.

When at least one of the groups R ¹ , R ² and R ³ is chosen from alkyl and heteroalkyl groups, said groups preferably comprise between 1 and 15 carbon atoms, more preferably between 1 and 10 carbon atoms and preferably between 1 and 6 carbon atoms.

When at least one of the groups R ¹ , R ² and R ³ is chosen from aryls, said groups preferably comprise between 5 and 20 carbon atoms, preferentially between 5 and 15 carbon atoms and preferably between 6 and 10 atoms of carbon.

When at least one of the groups R ¹ , R ² and R ³ is chosen from heteroaryls, said groups preferably comprise between 3 and 20 carbon atoms, preferably between 3 and 15 carbon atoms and preferably between 4 and 10 atoms of carbon.

Preferably, at least one of the groups R ¹ , R ² and R ³ is independently chosen from the methyl, ethyl, propyl, / sopropyl, n-butyl, / sobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, adamantyl, norbornyl, phenyl, benzyl, o-tolyl, m-tolyl, p-tolyl, mesityl, 3,5-dimethylphenyl, 4-n-butylphenyl, 4methoxyphenyl, 2-methoxyphenyl, 3- methoxyphenyl, 4-methoxyphenyl, 2-isopropoxyphenyl, 4-methoxy-3,5-dimethylphenyl, 3,5-ditert-butyl-4-methoxyphenyl, 4-chlorophenyl, 3,5di (trifluoromethyl) phenyl, benzyl, naphthyl, bisnaphthyl, pyridyl, bisphenyl, furanyl, thiophenyl.

The preferred mono-phosphorus compounds are triisopropylphosphine, tributylphosphine, tert-butyldiisopropylphosphine, tricyclopentylphosphine, tricyclohexylphosphine and triphenylphosphine.

The olefinic compounds are advantageously chosen from ethylene, propylene, butenes, pentenes, hex-1-ene, cyclohexene, hexa-1,5-diene, cyclooctene, cycloocta-1,5 -diene and 1,3-divinyltetramethyledisiloxane.

The aromatic compounds are advantageously chosen from toluene and styrene.

The monodentate or bidentate carbenes are preferably N-heterocyclic carbenes corresponding to the formulas of type I or of type II in which

R ^5, R ^6, R ^7, R ^8, R ^9, R ^10, R ¹¹ and R ¹² are identical or different, are selected from hydrogen, alkyl Ci-C ₂ o, heteroalkyl, Ci-C _20, aryl, C ₅ -C ₃₀ heteroaryl and C ₃ -C _30, and

Y is a bivalent alkyl group comprising between 1 and 4 carbon atoms such as -CH ₂ -, -CH ₂ CH ₂ -, -CH ₂ -CH ₂ -CH ₂ - or -CH ₂ -CH ₂ -CH ₂ -CH ₂ - or bivalent aryl comprising between 5 and 10 carbon atoms, preferably a C ₅ or C ₆ aryl.

Type I

Type II

The N-heterocyclic carbenes are preferably compounds comprising a carbon divalent to 6 valence electrons, included in a heterocycle comprising at least one nitrogen atom, such as 1,3-bis- (2,6-diisopropylphenyl ) -imidazol-2-ylidene, 1,3-bis- (2,4,6-trimetylphenyl) -imidazol-25-ylidene, 1,3-bis- (cyanomethyl) -imidazol-2-ylidene, 3-bis- (3-cyanopropyl) -imidazol-2-ylidene, 1,3-diisopropylimidazol-2-ylidene, or 1,3-dicyclohexylimidazol-2-ylidene.

The preferred bidentate phosphorus compounds correspond to the type III formula

R ¹⁸ r14

I w I

KR ¹⁵ ^ R ¹⁶

Type III in which

R ^13, R ^14, R ¹⁵ and R ¹⁶ are identical or different, are selected from hydrogen, alkyl Ci-C ₂ o, heteroalkyl, Ci-C ₂₀ aryl, C ₅ -C ₃₀ heteroaryl and C ₃ -C ₃₀ , and

W is a bivalent alkyl group comprising between 1 and 4 carbon atoms such as -CH ₂ -, -CH ₂ CH ₂ -, -CH ₂ -CH ₂ -CH ₂ - or -CH ₂ -CH ₂ -CH ₂ -CH ₂ - or bivalent aryl comprising between 5 and 10 carbon atoms, preferably a C ₅ or C ₆ aryl.

The preferred bidentate phosphorus compounds are bis (diphenylphosphino) ethane, bis (dicyclohexylphosphino) ethane, bis (diphenylphosphino) propane and bis (dicyclohexylphosphino) propane.

Compound Q ⁺ X ~

The catalytic composition according to the invention also comprises a compound corresponding to the formula Q. ⁺ X 'in which

- Q ⁺ represents an organic or inorganic cation, and

- X ^- is an organic or inorganic anion.

Without being limited by any theory, the compound of formula Q. ⁺ X ′ plays the role of cationizing agent in the composition according to the invention, which makes it possible to activate the Ni (l) complex and therefore to be freed from the use of an activating agent such as triethylaluminum.

According to one embodiment, Q ⁺ is an organic cation chosen from carbeniums such as triphenylmethyl carbocation and from aniliniums such as the cation N, N-dimethylanilinium.

According to another embodiment, Q ⁺ is an inorganic cation chosen from Li ⁺ , Na ⁺ , K ⁺ , Ca ⁺ , Cs ⁺ , Ag ⁺ and ΤΓ.

X ^- is an anion, chosen from borates, aluminates, phosphates, carboxylates, antimonates, nitrate, cyanide, perchlorate, carbonate, thiocyanate, sulfate, sulfonates, amidates, sulfonamidates and halides, taken alone or as a mixture.

Preferably, the anion X ^- is chosen from tetrahalo-borate, tetraalkylborates, tetraarylborates, tetraalkylaluminates, tetraarylaluminates, hexahalogenophosphate, alkylphosphates, arylphosphates, alkylcarboxylates, arylheonimonylateboxylates, arylheononoxylate arylantimonates, alkylsulfonates, arylsulfonates, alkylamidates, arylamidates, alkylsulfonamidates, arylsulfonamidates, alkylsulfomethides and arylsulfomethides, whether or not containing one or more halogen atoms such as fluorine, chlorine, bromine or iodine.

Preferably, the anion X ^- is chosen from tetra (perfluoroalkyl) borates, tetra (perfluoroaryl) borates, tetra (perfluoroalkyl) aluminates, tetra (perfluoroaryl) aluminates,

perfluoroalkylphosphates, the perfluoroarylphosphates, the perfluoroalkyl carboxylates, the perfluoroarylcarboxylates, the perfluoroalkylantimonates, the perfluoroarylantimonates, the perfluoroalkylsulfonates, the perfluoroarylsulfonates, the perfluoroalkylamidates, the perfluoroarylamidates, the perfluoroalkylsulfonamidates, the perfluoroarylsulfonamidates, the

perfluoroalkylsulfomethides and perfluoroarylsulfomethides.

Preferably, the alkyl groups of the anions X ′ comprise between 1 and 15 carbon atoms, preferably between 1 and 10 carbon atoms and preferably between 1 and 6 carbon atoms.

Preferably, the aryl groups of the anions X ′ comprise between 4 and 20 carbon atoms, preferably between 4 and 15 carbon atoms and preferably between 4 and 10 carbon atoms.

Preferably, the anion X ^- is chosen from tetrafluoroborate, tetraphenylborate, tetra (pentafluorophenyl) borate, tetra (3,5-di (trifluoromethyl) phenyl) borate, anions [AI (OC (CF3) 3) 4] ', [AI (OCsF5) 4], [(3,5- (CF3) 2-C6H3O) 4AI] ^_ , hexafluorophosphate, hydrogen phosphate, dihydrogen phosphate, metaphosphate, hydrogen carbonate, trifluoroacetate, ethylenediaminetetraacetate, pentafluoropropanoate, heptafluorobutanoate, oxalate, formate, acetate, propanoate, butanoate, pentanoate, hexanoate, heptanoate, octanoate, nonanoate, decanoate, benzoate, benzenedicarboxylate, benzenetricarboxylate, benzene tetracarboxylate, chlorobenzoate, pentachlorobenzoate, pentafluorobenzoate, hexafluoroantimonate, hydrogen sulfonate, methylsulfonate, trifluoride 'bis-trifluoromethanesulfonyl amide of formula N (CF3SO ₂ ) ₂ ' and tris-trifluoromethanesulfonyl methylide of formula C (CF ₃ SO ₂ ) ₃ ).

Advantageously, the molar ratio between the compound Q. ⁺ X ′ and the complex of Ni (l) is between 0.2 and 100.0, preferably between 0.4 and 20.0, preferably between 0.5 and 10 , 0, more preferably between 0.5 and 5.0 and even more preferably between 0.5 and 2.0.

Possible solvent

The catalytic composition according to the invention can comprise a solvent or a mixture of solvents. Preferably, each constituent of the catalytic composition or mixture of constituents can be used in a solvent.

The solvent (s) are advantageously chosen from ethers, alcohols, halogenated solvents and hydrocarbons, saturated or unsaturated, cyclic or not, aromatic or not, comprising between 1 and 20 carbon atoms, preferably between 4 and 15 atoms carbon, preferably between 4 and 12 carbon atoms and even more preferably between 4 and 8 carbon atoms.

Preferably, the solvent is chosen from pentane, hexane, cyclohexane, methylcyclohexane, heptane, butane or isobutane, cycloocta-1,5-diene, benzene, toluene, ortho -xylene, mesitylene, ethylbenzene, diethyl ether, tetrahydrofuran, 1,4-dioxane, dichloromethane, dichloroethane, tetrachloroethane, hexachloroethane, chlorobenzene, dichlorobenzene, butene, hexene and l octene pure or mixed.

Preferably, the solvent can be advantageously chosen from the products of the oligomerization reaction.

Preparation process

Another subject of the invention relates to a process for the preparation of said catalytic composition comprising a complex of Ni (l) of formula [Ni (L) _m Z] and a compound Q. ⁺ X ', as described above.

The process for the preparation of said catalytic composition comprises bringing into contact:

a nickel (I) complex of formula [Ni (L) _m Z], and

- a compound of formula Q. ⁺ X '

In another embodiment, the preparation process preferably comprises:

- A step for the preparation of the Ni (l) complex of formula [Ni (L) _m Z] by bringing Ni (ll) into contact, an organic reducing agent and at least one ligand L as defined above and

- Step for bringing the Ni (1) complex obtained in the preparation step into contact with a compound Q ⁺ X ^_ .

Preferably, the organic reducing agent is chosen from one or more compounds having the following formulas:

In another embodiment, the preparation process preferably comprises,

- A step of preparing the Ni (l) complex of formula [Ni (L) _m Z] by bringing Ni (ll), Ni (0) and at least one ligand L as defined above into contact and

- Step for bringing the Ni (1) complex obtained in the preparation step into contact with a compound Q ⁺ X ^_ .

The nickel (II) compounds used in the step of preparing the complexes [Ni (L) _m Z] according to any one of the preparation methods are advantageously chosen from nickel chloride (II), chloride of nickel (ll) (dimethoxyethane), nickel bromide (ll), nickel bromide (ll) (dimethoxyethane), nickel fluoride (ll), nickel iodide (ll), nickel sulfate (ll ), nickel carbonate (ll), nickel dimethylglyoxime (ll), nickel hydroxide (ll), nickel hydroxyacetate (ll), nickel oxalate (ll), nickel carboxylates ( ll) such as for example nickel 2ethylhexanoate (ll), nickel alcoholates (ll) such as for example Ni (OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ ) ₂ , chlorinated nickel (ll) alcoholates such as for example Ni (OCH ₃ ) CI, nickel (ll) carboxylate alcoholates such as for example Ni (OEt) (OOCCH ₃ ), nickel phenates (ll), nickel naphthenates (l), l nickel (ll) acetate, trifluoroacetate nickel (ll), nickel triflate (ll), nickel stearate (ll), nickel formate (ll), nickel acetylacetonate (ll), nickel hexafluoroacetylacetonate (ll), chloride of nickel n-allylnickel (ll), πallylnickel bromide (ll), the dimer of methallylnickel chloride (ll), q ³ -allylnickel hexafluorophosphate (lI), r) ³ -methallylnickel hexafluorophosphate, nickel (1,5) 1,5-cyclooctadienyl, Ni (cyclopentadienyl) ₂ , (cyclopentadienyl) NiCI, NiCI ₂ (sulfolane), NiCI ₂ (POBu ₃ ) ₂ , NiCI ₂ (PBu ₃ ) ₂ , NiCI ₂ (PPh ₃ ) ₂ , NiCI ₂ (PCy ₃ ) ₂ , Ni (SCN) ₂ (PBu ₃ ) ₂ , Ni (SCN) ₂ (PPh ₃ ) ₂ , NiCI ₂ (TMEDA) (TMEDA) = Ν, Ν, Ν ', Ν'-tetramethylethylenediamine), NiCI ₂ (pyridine) ₂ , nickel xanthates (II) and nickel dicarbamates (II) in their hydrated form or not, taken alone or as a mixture.

Preferably, the nickel with oxidation state 0, denoted Ni (0), is Bis (1,5-cyclooctadiene) nickel (0), also denoted Ni (COD) ₂ , [Ni (PPh ₃ ) ₂ (CO ) ₂ ], [Ni (CO) ₄ ] and [Ni (PPh ₃ ) ₄ ],

According to one embodiment, the Ni (l) complex according to the invention can be formed in situ by any means known to those skilled in the art.

According to a preferred embodiment, the Ni (1) complex and the compound of formula Q. ⁺ X ′ can be used in the presence of a solvent or a mixture of solvents.

The preparation process is advantageously carried out at a temperature between 78 ° C and 250 ° C, preferably between -50 ° C and 150 ° C, preferably between -40 ° C and 100 ° C, and preferably between -20 to 80 ° C.

The preparation process can advantageously include a filtration step after the Ni (I) complex is brought into contact with the compound of formula Q. ⁺ X '.

The preparation process can advantageously be carried out in the presence of an olefin.

Oligomerization process for olefins

Another subject of the invention relates to the use of the catalytic composition according to the invention, in a process for the oligomerization of an olefinic filler, preferably ethylene, into a compound or mixture of unsaturated compounds of general formula C _n H _2n , in which n is between 4 and 80, preferably between 4 and 50, preferably between 4 and 26 and more preferably between 4 and 14. In particular, the catalytic composition is used in a process for the oligomerization of ethylene into but-1-ene, into hex-1-ene, into oct-1-ene. Preferably, the composition according to the invention is used in a process for dimerization of ethylene to but-1-ene.

The oligomerization process comprises bringing said catalyst composition of Ni (1) according to the invention into contact with an olefinic filler.

The olefins used in the oligomerization process are olefins having between 2 and 10 carbon atoms. Preferably, said olefins are chosen from ethylene, propylene, n-butenes and n-pentenes, alone or as a mixture, pure or diluted. In the case where said olefins are diluted, said olefins are diluted by one or more alkane (s) or any other petroleum cut, as found in “cuts” resulting from petroleum refining or petrochemical processes, like catalytic cracking or steam cracking.

Said olefins can come from non-fossil resources such as biomass. For example, the olefins used in the oligomerization process according to the invention can be produced from alcohols and in particular by dehydration of the alcohols. Preferably, the olefin used in the oligomerization process is ethylene.

When using the catalytic composition in an oligomerization process, the nickel concentration (l) is between 1.0.10 ¹² and 1.0 mol / L, preferably between 1.0.10 ^-9 and 0.4 mol / L, more preferably between 1.0.10 ^-8 and 0.1 mol / L and more preferably between 1.0.10 ^-7 and 1.0.10 ^-2 mol / L. The oligomerization process can advantageously be carried out in the presence of a solvent as described above.

The oligomerization process advantageously operates at a total pressure of between 0.1 and 20.0 MPa, preferably between 0.1 and 15.0 MPa, and preferably between 0.5 and 8.0 MPa, and at a temperature between -40 and 250 ° C, preferably between -20 ° C and 150 ° C, preferably between 20 ° C and 100 ° C, and preferably between 30 to 80 ° C.

The oligomerization reaction being exothermic, the heat generated during said reaction can be eliminated by any means known to those skilled in the art.

Preferably, the oligomerization process, and in particular, the dimerization process of ethylene into but-1-ene or into hex-1-ene, can be carried out continuously. The constituents of the catalytic composition according to the invention are injected into a reactor stirred by conventional mechanical means or by external recirculation.

The catalytic composition can be neutralized at the end of the process by any means known to those skilled in the art.

Another object of the invention relates to a method comprising

a step for preparing the catalytic composition of Ni (l), and

- An oligomerization step using the catalytic composition of Ni (l) obtained in the previous step.

The following examples illustrate the invention without limiting its scope.

Examples

The Ni (1) complexes are synthesized according to the protocols described below. The other reagents used are commercial and used without additional purification. The solvents are purified on molecular sieves.

NMR (Nuclear Magnetic Resonance) spectra are obtained using a Bruker AV 300MHz spectrometer. The RPE (Electronic Paramagnetic Resonance) analyzes are carried out with a Bruker Elexsys E500 device (in X-band). Deuterated solvents were supplied by Sigma-Aldrich or Euristop.

The examples below illustrate the preparation and use of compositions according to the invention in a process for the oligomerization of ethylene.

The productivity of the catalytic system is expressed in TON (Turnover Number) and corresponds to the ratio of the number of moles of product formed on the number of moles of nickel complex of oxidation state +1 introduced (molp _dts / mol _Ni ).

Butenes and hexenes are the only products formed. The selectivity of the reaction is expressed in% C4 and% C6, corresponding, respectively, to the mass percentage of products having 4 or 6 carbon atoms compared to the other products of the reaction and in% 1-C4 and% 1-C6, corresponding, respectively, to the percentage of but-l-ene in butenes and to the percentage of hex-l-ene in hexenes.

Definitions:

Depp = 1,3-bis (dicyclohexylphosphino) propane

THF = tetrahydrofuran

COD = cyclooctadiene dme = Dimethoxyethane δϊΜθβ

TMP = 2,3,5,6-tetrametyl-1,4-bis (trimethylsilyl) -1,4-dihydropyrazine SiMe ₃

Synthesis of the complex [Ni (NHC ^IPr ) (CI)] ₂ :

A solution of 8 mL of toluene comprising 126 mg of [Ni (DOC) ₂ ] at 1 equivalent, 100 mg of [Ni (dme) CI ₂ ] at 1 equivalent and 355 mg of NHC ^IPr at 2 equivalents is stirred for 18 h at 20 ° C. The solution is then filtered through celite and concentrated by evaporation under vacuum until a 3mL solution is obtained. 12mL of pentane are added and the solution is placed overnight at -34 ° C to crystallize the complex in the form of green crystals. The crystals are finally washed 3 times with cold pentane (0 ° C). The yield of complex [Ni (NHC ^IPr ) (CI)] ₂ is 46%.

¹ H-NMR (300 MHz, C ₆ D ₆ ) δ ppm 1.17 (d (6.7Hz), 24H), 2.52 (d (6.6Hz), 24H), 2.88 (hept (6.8Hz), 2H), 3.13 ( hept (6.7Hz), 8H), 6.74 (s, 2H), 6.9-7.5 (m, 12H).

¹³ C-NMR (75 MHz, C ₆ D ₆ ) δ ppm 24.32, 24.84, 29.73, 123.51, 129.56, 131.12, 139.57, 146.30, 242.2.

Synthesis of the complex [Ni (dcpp) CI] ₂ :

Cy ₂ Cy ₂

C _p x ^Nl 'cr ^Ni ^ _p _>

Cy ₂ Cy ₂

A solution of 4 mL of THF comprising 149.7 mg of TMP at 2.4 equivalents is added to a suspension of 126.0 mg of [Ni (dcpp) CI ₂ ], previously prepared to 1 equivalent in 4.0 mL THF at 20 ° C. The mixture is stirred for 6 hours at 20 ° C to obtain a light yellow solution. The solution is filtered by a disc filter and the THF is evaporated. The pale red solid obtained is washed 3 times with 4 ml of pentane. The yield of complex [Ni (dcpp) CI] ₂ is 70%.

Band X, RPE at 20 ° C: g = 2.14μ _Β , A _iS0 ( ³¹ P, n = 2) = 74 G.

General protocol for implementing the composition according to the invention> Stage for preparing the composition:

A solution comprising the nickel complex (I) (106 pmol) and the compound Q. ⁺ X 'is prepared in 10 ml of solvent, stirred for 1 h at 20 ° C and then filtered is injected into the reactor.

> Oligomerization step:

The solution prepared in the previous step and 30 ml of solvent are injected into a reactor. Said reactor is placed under 5 bar of ethylene and then heated (to 20 ° C or 40 ° C as the case may be) with stirring for 1 h 30 min. The gas phase is then removed. The liquid phase is collected and neutralized with an aqueous solution of sulfuric acid H ₂ SO ₄ (10% volume). The organic phase is dried over magnesium sulfate MgSO ₄ and analyzed by gas chromatography (GC Agilent 6850 Series II with a PONA column).

Example 1 (according to the invention):

The following catalytic composition is used according to the general protocol at 20 ° C with THF as solvent:

- A nickel complex (l) of formula corresponding to [Ni (NHC ^lp jCI] ₂ ;

- a thallium salt, TlPF ₆ as compound Q. ⁺ X ';

The catalytic composition is used with a TlPF _S / Ni molar ratio equal to 1.0.

The results obtained are presented in the summary table below.

Example 2 (according to the invention):

The following catalytic composition is implemented according to the general protocol at 40 ° C with the

THF as solvent:

- A nickel complex (l) of formula corresponding to [Ni (NHC ^IPr ) CI] ₂ ;

- a thallium salt, TlPF _S , as compound Q. ⁺ X ';

The catalytic composition is used with a TlPF _S / Ni molar ratio equal to 1.0.

The results obtained are presented in the summary table below.

Example 3 (according to the invention):

The following catalytic composition is used according to the general protocol at 40 ° C with toluene as solvent:

- A nickel complex (l) of formula corresponding to [Ni (NHC ^lp jCI] ₂ ;

- a thallium salt, TlPF _S , as compound Q. ⁺ X ';

The catalytic composition is used with a TlPF _S / Ni molar ratio equal to 1.0.

The results obtained are presented in the summary table below.

Example 4 (according to the invention):

The following catalytic composition is used according to the general protocol at 40 ° C with THF as solvent:

- A nickel complex (l) of formula corresponding to [Ni (dcpp) CI] ₂ ;

- a thallium salt, TIPF ₆ , as compound Q. ⁺ X ';

The catalytic composition is used with a TlPF _S / Ni molar ratio equal to 1.0.

The results obtained are presented in the summary table below.

Example 5 (according to the invention):

> Oligomerization step:

A THF solution (2mL) comprising a nickel complex (l) of formula corresponding to [Ni (dcpp) CI] ₂ (18.8 pmol) and AgNTf ₂ (1.0 eq) is stirred for 1 h at 20 ° C. then filtered.

> Stage of preparation of the composition:

The solution (0.4 mL) obtained in the preparation step is placed in a closed glass reactor of the “NMR tube” type and placed under 5 bars of ethylene. After 6 p.m., the reaction is stopped. The gas phase is then removed. The liquid phase is collected and neutralized with an aqueous solution of sulfuric acid H ₂ SO ₄ (10% volume). The organic phase is dried over magnesium sulfate MgSO ₄ and analyzed by gas chromatography (GC Agilent 6850 Series II with a PONA column).

The results obtained are presented in the summary table below.

Summary table of the examples according to the invention

Entrance Complex Nile) compound Q. ⁺ X '(molar / Ni ratio) T (° C) Ground TON (molpdts / mol _Ni ) % C4 % C6 % 1-C4 % 1-C6 1 [NiNHC ^IPr CI] ₂ TIPF ₆ (1.0) 20 THF 16.4 55 45 94 83 2 [NiNHC ^IPr CI] ₂ TIPF ₆ (1.0) 40 THF 69.4 56 44 93 80 3 [NiNHC ^IPr CI] ₂ TIPF ₆ (1.0) 40 You 3.03 > 99 <1 17 / 4 [NidcppCIh tipf ₆ (i, o) 40 THF 2.8 43 57 90 100 5 [NidcppCIh AgNTf ₂ (1.0) 20 THF 66.7 > 99 <1 58 /

Claims (15)

1. Catalytic composition comprising: - a complex of Ni (l) of formula [Ni (L) _m Z] in which o Ni is nickel with an oxidation state +1, ο Z is chosen from hydrogen, halide such as fluorine, chlorine , bromine or iodine, an alkyl, a heteroalkyl, an aryl, a heteroaryl, an alcoholate, a phenolate, a carboxylate or an amide, where L, identical or different, is chosen from single-phosphorus compounds, phosphorous compounds bidentates, tridentate phosphorus compounds, olefinic compounds, bipyridines, diimines, monodentate ethers, bidentate ethers, monodentate thioethers, bidentate thioethers, monodentate or bidentate carbenes, mixed ligands such as phosphinopyridines, imin bis (imino) pyridines, om = 1, 2, 3 or 4, - and at least one compound of formula Q. ⁺ X ', in which o Q ⁺ is an organic or inorganic cation, and ο X ^- is an organic or inorganic anion. 2. Composition according to claim 1 in which the Ligand L is chosen from phosphorus-containing compounds corresponding to the general formula P (A ¹ R ¹ ) (A ² R ² ) (A ³ R ³ ) in which: > A ¹ , A ² and A ³ , identical or different, are independently chosen from S, O, NR ⁴ or a covalent bond between the phosphorus atom and a carbon atom or a hydrogen atom,> the R groups ^1, R ² and R ^3, identical or different, linked or not to each other, are independently selected from hydrogen, an alkyl group having ₂ CiC o heteroalkyl CiC ₂₀ aryl, C ₅ -C ₃₀ heteroaryl C ₃ -C _30> the R ⁴ group is independently selected from hydrogen, alkyl _Ci-C20 heteroalkyl Ci-C ₂₀ aryl, C ₆ -C ₃₀ heteroaryl, C ₄ -C _30. 3. Composition according to any one of the preceding claims in which the ligand L is chosen from carbenes corresponding to the formulas of type I or of type II

Type II in which R ^5, R ^6, R ^7, R ^8, R ^9, R ^10, R ¹¹ and R ¹² are identical or different, are selected from hydrogen, alkyl Ci-C ₂ o, heteroalkyl, Ci-C _20, aryl, C ₅ -C ₃₀ heteroaryl and C ₃ -C _30, and Y is a bivalent alkyl group comprising between 1 and 4 carbon atoms or divalent aryl comprising between 5 and 10 carbon atoms. 4. Composition according to claim 1 in which the ligand L is chosen from bidentate phosphorus-containing compounds corresponding to the formula of type III

W

Type III in which R ^13, R ^14, R ¹⁵ and R ¹⁶ are identical or different, are selected from hydrogen, alkyl C ₁ -C ₂₀ heteroalkyl, C ₁ -C ₂₀ aryl, C ₅ -C ₃₀ heteroaryl and C ₃ -C ₃₀ and W is a bivalent alkyl group comprising between 1 and 4 carbon atoms such as -CH ₂ -, CH ₂ -CH ₂ -, -CH ₂ -CH ₂ -CH ₂ - or -CH ₂ -CH ₂ -CH ₂ -CH ₂ - or bivalent aryl comprising between 5 and 10 carbon atoms. 5. Composition according to claim 1 in which the ligand L is chosen from 1,3-bis- (2,6diisopropylphenyl) -imidazol-2-ylidene, 1,3-bis- (2,4,6-trimetylphenyl) -imidazol-2-ylidene, 1,3-bis- (cyanomethyl) -imidazol-2-ylidene, 1,3-bis- (3-cyanopropyl) -imidazol-2-ylidene, 1,3diisopropylimidazol-2- ylidene, 1,3-dicyclohexylimidazol-2-ylidene, ethylene, propylene, butenes, pentenes, hex-1-ene, cyclohexene, hexa-1,5-diene, cyclooctene, cycloocta-1,5-diene, 1,3-divinyltetramethyledisiloxane, bis (diphenylphosphino) ethane, bis (dicyclohexylphosphino) ethane bis (dicyclohexylphosphino) propane, triisopropylphosphine, tributylphosphine, tert-butylphosphine, tert-butylphosphine tricyclohexylphosphine and triphenylphosphine, bis (diphenylphosphino) ethane, bis (dicyclohexylphosphino) ethane, bis (diphenylphosphino) propane and bis (dicyclohexylphosphino) propane. 6. Composition according to any one of the preceding claims, in which the molar ratio between the ligand or the combination of ligands and the nickel (I) is between 0.5 and 4.0. 7. Composition according to any one of the preceding claims, in which the cation Q ⁺ is chosen from carbeniums, anilinium, Li ⁺ , Na ⁺ , K ⁺ , Ca ⁺ , Cs ⁺ , Ag ⁺ and Tl ⁺ . 8. Composition according to any one of the preceding claims, in which the anion X ^- is chosen from tetrahalogeno-borate, tetraalkylborates, tetraarylborates, tetraalkylaluminates, tetraarylaluminates, hexahalogenophosphate, alkylphosphates, arylphosphates, alkylcarboxylates, arylcarboxylates, hexahaloantimonates, alkylantimonates, arylantimonates, alkylsulfonates, arylsulfonates, alkylamidates, arylamidates, alkylsulfonamidates, arylsulfonamidates, alkylsulfomethides or arylsulfomides or arylsulfomides or arylsulfomides 'halogen such as fluorine, chlorine, bromine or iodine, in which> the alkyl groups of the anions X' comprise between 1 and 15 carbon atoms,> the aryl groups of the anions X 'comprise between 4 and 20 atoms of carbon. 9. Composition according to any one of the preceding claims, in which the anion X ^- is chosen from tetrafluoroborate, tetraphenylborate, tetra (pentafluorophenyl) borate, tetra (3,5-di (trifluoromethyl) phenyl) borate, anions [AI (OC (CF ₃ ) ₃ ) ₄ ], [AI (OC ₆ F ₅ ) ₄ ], [(3,5- (CF ₃ ) ₂ C ₆ H ₃ O) ₄ AI] ·, hexafluorophosphate , hydrogen phosphate, dihydrogen phosphate, metaphosphate, hydrogen carbonate, trifluoroacetate, ethylenediaminetetraacetate, pentafluoropropanoate, heptafluorobutanoate, oxalate, formate, acetate, propanoate, butanoate, pentanoate, l hexanoate, heptanoate, octanoate, nonanoate, decanoate, benzoate, benzenedicarboxylate, benzenetricarboxylate, benzenetetracarboxylate, chlorobenzoate, fluorobenzoate, pentachlorobenzoate, pentafluorobenzoate, hexafluoroanten, hexafluoroant methylsulfonate, trifluoromethylsulfonate, fluorosulfonate e, methylsulfonamidate, trifluoromethylsulfonamidate, fluorosulfonamidate, bistrifluoromethanesulfonyl amide of formula N (CF ₃ SO ₂ ) ₂ 'and tristrifluoromethanesulfonyl methylide of formula C (CF ₃ SO ₂ ) ₃ ). 10. Composition according to any one of the preceding claims, in which between the molar ratio the compound Q. + X- and the nickel complex (I) is between 0.2 and 100.0, preferably between 0.4 and 20 , 0. 11. Process for preparing the composition according to any one of claims 1 to 10, comprising bringing into contact: - a Ni (l) complex of formula [Ni (L) _m Z], and - a compound Q. ⁺ X '. 12. The preparation method according to claim 11 comprising a step of preparing the Ni (l) complex of formula [Ni (L) _m Z] by bringing Ni (II), an organic reducing agent and at least one ligand L. 13. The preparation method according to claim 12, in which the organic reducing agent is chosen from one or more compounds having the following formulas:

14. The preparation method according to claim 11 comprising a step of preparing the Ni (l) complex by bringing Ni (ll), Ni (0) and at least one ligand L. into contact. 15. Oligomerization process using a catalytic composition according to one 5 any of claims 1 to 10 or prepared according to any one of claims 11 to 14, comprising contacting said catalytic composition with an olefinic filler.