NEW TITANIUM-BASED CATALYTIC COMPOSITION FOR THE SELECTIVE TRIMERIZATION OF ETHYLENE TO HEXENE-1

Abstract

The present invention relates to a catalytic composition for the selective oligomerization of ethylene, preferably for the trimerization of ethylene to hexene-1, comprising: - a titanium-based metallic precursor corresponding to the following formula:

Description

Title of the invention: NEW TITANIUM-BASED CATALYTIC COMPOSITION FOR THE SELECTIVE TRIMERIZATION OF ETHYLENE TO HEXENE-1 technical field

[0001] The present invention relates to a new titanium-based catalytic composition, and its use for the selective oligomerization of ethylene, in particular for the trimerization of ethylene to hexene-1.

[0002] The invention also relates to a process for oligomerizing ethylene, preferably for selective trimerizing ethylene into hexene-1, implementing the catalytic composition according to the invention. Previous technique

[0003] Hexene-1 plays a very important role as a reaction intermediate in the chemical and petrochemical industries. Its main use is in the production of various grades of polyethylene, in which it is involved as a co-monomer. This compound is primarily obtained by oligomerization of ethylene. Systems capable of selectively trimerizing ethylene to hexene-1 are currently mainly chromium-based (DS McGuinness, Chem. Rev. 2011, 111, 2321). Among the systems known to lead to the selective production of hexene-1 are those described, for example, in documents US5198563, US5288823, US5382738, EP608447, EP611743, and EP614865. These catalysts are prepared from a chromium salt and a metal amide, in particular a pyrrolide. Other catalysts involve an aluminoxane and a chromium complex in association with phosphorus ligands as described in document US5550305.

[0004] Recent work tends to demonstrate the potential of titanium (Ti) based systems to selectively produce hexene-1. Since the discovery by Deckers et al. In 2001 (Angew. Chem. Int. Ed. 2001, 40, 2516-2519), systems derived from cyclopentadienyl (Cp) ligands activated by methylaluminoxane (MAO) were very widely described in the literature ([(q5-CpCMe2Ph)TiCl3] / MAO) (Organometallics, 2002, 21, 5122; Organometallics 2002, 21, 5122-5135; J. Am. Chem. Soc. 2009, 131, 5298-5312; Chem. Commun., 2003, 2816-2817; J. Mol. Cat. A.: Chem., 2004, 214, 227-229; WO2012 / 133928; WO2012 / 133929).

[0005] Mitsui also offers a new titanium-based system for the selective trimerization of ethylene to 1-hexene (EP2174928; Organometallics 2010, 29, 2394-2396). This catalytic system, once activated by MAO (300-10000 eq. / Ti), leads to a C6 selectivity of approximately 92% (of which 99.5% of hexene-1).

[0006] The object of the present invention is to provide a new titanium-based catalytic composition for the selective trimerization of ethylene to hexene-1. Summary of the invention

[0007] The present invention relates to a catalytic composition for the selective oligomerization of ethylene, preferably for the trimerization of ethylene to hexene-1, comprising:

[0008] - a titanium-based metallic precursor conforming to the following formula:

[0009] [Chem.l]

[0010] in which: • L is at least one bond linking Rx with x chosen between 1 and 12 and Rx with x chosen between 14 and 25, L being a hydrocarbon group having from 1 to 20 carbon atoms (in C1-C20) cyclic or not, aromatic or not, containing or not a heteroatom, or L being a covalent bond, • R1 to R12 on the one hand and R14 to R25 on the other hand, when they are not linked together, are each chosen from among a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a substituted or unsubstituted aryl group, a cyclic or uncyclic alkyl group, and a cyclic or uncyclic aralkyl group, said groups having from 1 to 15 carbon atoms (in Cl-Cl 5) and containing or not a heteroelement, • R13 and R26 are each chosen from a substituted or unsubstituted aryl group, a cyclic or non-cyclic alkyl group, and a cyclic or non-cyclic aralkyl group, said groups having from 1 to 15 carbon atoms (in Cl-Cl 5) and containing or not a heteroelement, • X1 and X2 are each an identical or different heteroatom, and • X3 and X4 are each an identical or different ligand X,

[0011] - and an aluminoxane-type activator.

[0012]

[0013]

[0014]

[0015]

[0016]

[0017] DETAILED DESCRIPTION OF THE INVENTION According to the present invention, the expressions "between ... and ..." and "between ... and ..." are equivalent and mean that the limit values ​​of the interval are included within the described range of values. If this is not the case and the limit values ​​are not included within the described range, such clarification will be provided by the present invention. In the sense of the present invention, the different parameter ranges for a given step, such as pressure ranges and temperature ranges, can be used alone or in combination. For example, in the sense of the present invention, a preferred range of pressure values ​​can be combined with a more preferred range of temperature values. In the following, specific embodiments of the invention may be described. They may be implemented separately or in combination with each other, without limitation as to the number of combinations where technically feasible. Titanium-based metallic precursor: The term “metallic precursor” means: a compound comprising a metallic center and at least one precursor stabilizing ligand which may be charged or neutral, organic or inorganic. The composition according to the present invention comprises a titanium-based metallic precursor corresponding to the formula below: [Chem. 2]

[0018] L is at least one bond linking Rx with x chosen between 1 and 12 and Rx with x chosen between 14 and 25, L being a hydrocarbon group having from 1 to 20 carbon atoms (in C1-C20) cyclic or non-cyclic, aromatic or non-aromatic, containing or not a heteroatom, or L being a covalent bond, R1 to R12 on the one hand and R14 to R25 on the other hand, when they are not connected between They are each chosen from among a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a substituted or unsubstituted aryl group, a cyclic or non-cyclic alkyl group, and a cyclic or non-cyclic aralkyl group, said groups having from 1 to 15 carbon atoms (in Cl-Cl 5) and containing or not a heteroelement, • R13 and R26 are each chosen from a substituted or unsubstituted aryl group, a cyclic or non-cyclic alkyl group, and a cyclic or non-cyclic aralkyl group, said groups having from 1 to 15 carbon atoms (in Cl-Cl 5) and containing or not a heteroelement, • X1 and X2 are each an identical or different heteroatom, and • X3 and X4 are each an identical or different ligand X.

[0019] Advantageously, R2, R4, R5, R6, R7, R8, R9, R10, R11, R12, R15, R17, R18, R19, R20, R21, R22, R23, R24 and R25, when not connected to each other, are each a hydrogen atom.

[0020] Advantageously, R13 and R26 are each selected from an alkyl group having 1 to 6 carbon atoms (C1-C6) containing or not a heteroatom, a cycloalkyl group having 3 to 6 carbon atoms (C3-C6) containing or not a heteroatom, and a substituted or unsubstituted aryl group having 6 to 15 carbon atoms (C6-C15) containing or not a heteroatom. Preferably, R13 and R26 are each a methyl group.

[0021] Advantageously, R1, R3, R14, and R16, when not linked together, are each selected from an alkyl group having from 1 to 10 carbon atoms (in the Cl-ClO configuration) containing or not a heteroatom, a cycloalkyl group having from 3 to 10 carbon atoms (in the C3-C10 configuration) containing or not a heteroatom, and a substituted or unsubstituted aryl group having from 4 to 15 carbon atoms (in the C4-C15 configuration) containing or not a heteroatom. Preferably, R1, R3, R14, and R16, when not linked together, are each selected from a methyl, tert-butyl, and adamantyl group.

[0022] Advantageously, X1 and X2 are each an oxygen atom.

[0023] The term "ligand X" refers to a ligand that has a formal negative charge in the ionic electron-counting model. The metal-ligand complex is described as a ligand X interacting with a metal cation M+, thus providing a purely ionic description of the metal-ligand bond. Ligands X are described, for example, in "The Organometallic Chemistry of the Transition Metals," Sixth Edition, by Robert H. Crabtree. Ligands X are also well known to those skilled in the art in the field of organometallic chemistry.

[0024] Advantageously, X3 and X4 are each selected from fluoride, chloride, bromide, iodide, hydroxide, methyl, n-ethyl, n-propyl, i-propyl, n-butyl, i-butyl, tert-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, the methoxy, ethoxy, propoxy, isopropoxy, butoxy, tert-butoxy, formate, acetate, propionate, and carbonate. Preferably, X3 and X4 are each an identical ligand X selected from chloride, bromide, and iodide. Most preferably, X3 and X4 are each a chloride.

[0025] By way of non-limiting example, some structures of titanium-based metallic precursors according to the invention are described below:

[0026] [Chem.3]

[0027] In this titanium-based metallic precursor structure, L is a phenylene group linking R3 and R16.

[0028] [Chem.4]

[0029] In this titanium-based metallic precursor structure, L is a methylene group linking R7 and R20.

[0030] [Chem. 5]

[0031] In this titanium-based metallic precursor structure, L is a bond covalent linking R10 and R23 [Chem. 6] tBu tBu o TiCI3

[0033] In this titanium-based metallic precursor structure, L is a covalent bond linking R2 and R20. Aluminoxane-type activator

[0034] The composition according to the present invention comprises an aluminoxane type activator.

[0035] The term “aluminoxane type activator” means either a soluble aluminoxane compound, or an aluminoxane compound that has been immobilized on a solid support, or a solid aluminoxane compound, or a mixture of these 3 compounds. soluble aluminoxane

[0036] In one embodiment, the aluminoxane-type activator is a soluble aluminoxane compound. Preferably, the soluble aluminoxane is selected from methylalu-minoxane (MAO), modified methylaluminoxane (MMAO), and ethylaluminoxane. (EAO), alone or in mixtures.

[0037] The description of a soluble aluminoxane usable in the catalytic composition according to the invention can be found in the document Eur. J. Inorg. Chem. 2015, 2015, 19-43.

[0038] Preferably, the molar ratio of aluminum of the soluble aluminoxane to titanium of the metallic precursor, denoted Al^o / Ti, is between 1 and 15000, preferably between 50 and 10000, most preferably between 250 and 5000, most preferably between 1000 and 3000.

[0039] The AlMA0 / Ti molar ratio is calculated as the ratio between the number of moles of aluminium contained in the soluble aluminoxane and the number of moles of titanium in the metallic precursor. Aluminoxane supported

[0040] In one embodiment, the aluminoxane-type activator is an aluminoxane compound that has been immobilized on a solid support also called supported aluminoxane.

[0041] The supported aluminoxane, when used in the catalytic composition, allows the formation of the catalyst via ionic interactions between the titanium-based metallic precursor and the supported aluminoxane; such a catalyst structure can be called a floating cation. The catalytic reaction takes place on the surface or within the pores of the formed catalyst.

[0042] Advantageously, the supported aluminoxane is a methylaluminoxane immobilized on an inorganic support (denoted SMAO). The description of an SMAO usable in the catalytic composition according to the invention, as well as its manufacturing process, can be found in the book Tailor-Made Polymers Via Immobilisation of Alpha-Olefin Polymerisation Catalysts, document US2015353658 on behalf of KING FAHD UNIVERSITY PET & MINERALS, document US20180354870 on behalf of SAUDI ARABIAN OIL COMPANY, or document US6211311 on behalf of EQUISTAR CHEM LP.

[0043] SMAO is advantageously obtained by direct reaction of an MAO solution with an inorganic support in an organic solvent.

[0044] Advantageously, the inorganic support is chosen from silica, alumina, silica-alumina, zeolites, titanium dioxide (TiO2), etc. Preferably, the support is silica. Advantageously, the silica contains Si-OH or Si-O-Si groups.

[0045] In one embodiment, the silica is selected from high-purity silicas that do not contain traces of metals. Preferably, the silica contains less than 10 ppm of Fe, Na, Al and / or Ti.

[0046] In one embodiment, the silica may have a crystalline, amorphous structure or partially crystalline. Preferably, silica has an amorphous structure.

[0047] Advantageously, the inorganic support is in the form of particles defined by an average diameter less than or equal to 200 pm, preferably less than or equal to 150 pm, preferably less than or equal to 100 pm, and most preferably less than or equal to 50 pm.

[0048] In a preferred embodiment, the inorganic support has a granular or spherical morphology. Most preferably, the inorganic support has a spherical morphology.

[0049] In a preferred embodiment, the inorganic support is in the form of particles defined by an average diameter between 1 and 100 pm, preferably between 10 and 50 pm, preferably between 20 and 40 pm, preferably between 30 and 35 pm.

[0050] In one embodiment, the inorganic support is mesoporous. Preferably, it has an average pore diameter of between 2 and 50 nm, preferably between 10 and 40 nm, more preferably between 15 and 30 nm, and most preferably between 20 and 25 nm. The pore diameter is calculated using the Barrett-Joyner-Halenda (BJH) method and measured by nitrogen adsorption analysis.

[0051] In one embodiment, the inorganic support has a pore volume of between 0.5 and 2.5 mL / g, preferably between 1 and 2 mL / g, more preferably between 1.25 and 1.75 mL / g, and most preferably between 1.4 and 1.6 mL / g. The pore volume is calculated by the Barrett-Joyner-Halenda (BJH) method and measured by nitrogen adsorption analysis.

[0052] In one embodiment, the inorganic support has a specific surface area of ​​between 1 and 600 m² / g, preferably between 100 and 500 m² / g, more preferably between 200 and 400 m² / g, and most preferably between 300 and 350 m² / g. The specific surface area is calculated by the Brunauer-Emmett-Teller (BET) method and measured by nitrogen adsorption analysis.

[0053] Advantageously, the aluminum content of the SMAO is between 1 and 25% by mass, preferably between 5 and 15% by mass, preferably between 8 and 12% by mass, and most preferably between 9 and 11% by mass, relative to the total mass of the SMAO. This ensures that the SMAO will possess good properties such as the ability to prevent leaching of the catalyst into the solution.

[0054] Advantageously, the molar ratio of aluminum from SMAO to titanium from the metallic precursor, denoted AlSMAo / Ti, is between 50 and 5000, preferably between 100 and 2500, most preferably between 100 and 1000.

[0055] The AlSMAo / Ti molar ratio is calculated as the ratio between the number of moles of aluminium contained in the SMAO and the number of moles of titanium in the metallic precursor. solid aluminoxane

[0056] In one embodiment, the aluminoxane-type activator is a solid aluminoxane compound.

[0057] Advantageously the solid aluminoxane compound is a solid methylaluminoxane also called solid MAO.

[0058] The description of a solid MAO usable in the catalytic composition according to the invention as well as its manufacturing process can be found in documents US20110282017, US2015057418 or US2018355077 in the name of TOSOH FINECHEM CORPORATION, or document US6518445 in the name of ALBEMARLE CORPORATION.

[0059] Solid MAO, by definition, is a particulate compound which, at room temperature (30 °C or lower), exists as a solid suspension in hydrocarbon-type solvents (aromatic or paraffinic), such as, for example, toluene, cyclohexane, pentane, heptane, etc. Any solid MAO insoluble in a hydrocarbon solvent can act as an activator according to the invention.

[0060] The solid MAO advantageously comprises polymeric chains (denoted PM AO) formed by Al and O atoms and methyl groups (-Me or -CH3) defined by the formula below:

[0061] -[(Me)A10]n-

[0062] of which n can advantageously take a value between 1 and 60, preferably between 10 and 50.

[0063] The solid MAO essentially comprises PMAO chains according to the above formula, but may also include in its structure trimethylaluminum (denoted TMA) associated, free, or interacting with the PMAO chains. The PMAO may have a linear, cyclic, or branched structure, as long as the polymer chains conform to the above formula.

[0064] The solid MAO used in this invention may contain PMAO of linear and / or branched structure, but also cyclic fragments and residual molecules of the solvent interacting with the TMA.

[0065] Advantageously, the mass aluminum content of the solid MAO is between 36 and 52% by mass. This ensures that the solid MAO will possess good properties such as optimal size and resistance to fragmentation during the various synthesis stages.

[0066] Preferably, the solid MAO is defined by an aluminum content of between 38 and 43% by mass. Preferably, the solid MAO contains an aluminum content of between 40 and 42% by mass. Most preferably, the solid MAO contains an aluminum content of between 40.5 and 41.5% by mass.

[0067] Advantageously, the solid MAO is in the form of particles defined by a average diameter less than or equal to 200 µm, preferably less than or equal to 150 µm, preferably less than or equal to 100 µm, and most preferably less than or equal to 50 µm.

[0068] In a preferred embodiment, the solid MAO is in the form of particles defined by an average diameter between 1 and 50 pm, preferably between 5 and 40 pm, preferably between 10 and 30 pm, preferably between 15 and 25 pm.

[0069] Advantageously, the molar ratio of solid MAO to titanium-based metallic precursor, denoted Al^os / Ti, is between 1 and 10000, preferably between 25 and 5000, preferably between 50 and 2500, most preferably between 100 and 1500.

[0070] The Al^os / Ti molar ratio is calculated as the ratio between the number of moles of Aluminium contained in the solid MAO and the number of moles of titanium contained in the metallic precursor.

[0071] Optional additive in the form of an aluminium-based compound

[0072] In one embodiment, the composition according to the present invention further comprises an additive in the form of an aluminum-based compound.

[0073] In one embodiment, the additive in the form of an aluminum-based compound is a compound of formula AIR(3-a)R'a, in which R and R' are independently selected from a Cl-Cl2 alkyl, a Cl-Cl2 alkoxy, or a halogen. Advantageously, a can take the value of 0 or 1. Preferably, R and R' are independently selected from a Cl-ClO alkyl, a Cl-ClO alkoxy, preferably a C1-C6 alkyl, a C1-C6 alkoxy, and a chlorine or bromine atom. Preferably, a takes the value of 0. Preferably, R is an alkyl and / or alkoxy group selected from methyl, ethyl, propyl, n-propyl, i-propyl, isopropyl, n-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, and the corresponding alkyloxy groups. Preferably, R is an alkyl and / or alkoxy group selected from ethyl, propyl, i-propyl, isopropyl, n-butyl, and tert-butyl, and the corresponding alkyloxy groups.

[0074] Preferably, the additive in the form of an aluminium-based compound is selected from trimethylaluminium (TMA), triethylaluminium (TEA), triisopropylaluminium, tri-n-butylaluminium, triisobutylaluminium, tri-tert-butylaluminium, trihexylaluminium, trioctylaluminium, diethylethoxyaluminium, dimethylethoxyaluminium, methylaluminium dichloride, ethylaluminium dichloride, dimethylaluminium chloride, diethylaluminium chloride, and ethylaluminium sesquichloride, alone or in mixture.

[0075] Preferably, the additive in the form of an aluminium-based compound is chosen from trimethylaluminium (TMA), triethylaluminium (TEA) and triisobutylaluminium, alone or in mixture.

[0076] Preferably, the molar ratio of the aluminum in the additive in the form of a The aluminum-based compound on the titanium of the metallic precursor, denoted Aladd / Ti, is between 1 and 1500, preferably between 10 and 1000, preferably between 20 and 500, most preferably between 50 and 300.

[0077] The Aladd / Ti molar ratio is calculated as the ratio between the number of moles of Aluminium contained in the additive in the form of an aluminium-based compound and the number of moles of titanium contained in the metallic precursor. Optional solvent

[0078] The catalytic composition according to the invention may further comprise a solvent. A solvent may be chosen from among organic solvents and in particular from among saturated, unsaturated, cyclic or non-cyclic hydrocarbons.

[0079] The solvent(s) is / are advantageously chosen from among halogenated solvents and hydrocarbons, saturated or unsaturated, cyclic or non-cyclic, comprising between 1 and 20 carbon atoms, preferably between 1 and 15 carbon atoms and preferably between 4 and 15 carbon atoms.

[0080] Preferably, the solvent is selected from isobutane, butane, pentane, hexane, cyclohexane, heptane, methylcyclohexane, dichloromethane, toluene, xylene, dichloroethane, chlorobenzene, and dichlorobenzene, pure or in mixtures. Most preferably, the solvent is selected from isobutane, butane, cyclohexane, methylcyclohexane, toluene, and xylene. Most preferably, the solvent is cyclohexane.

[0081] In a preferred embodiment, the solvent can advantageously be chosen from among the products of the oligomerization reaction. Formulation of the catalytic composition

[0082] The catalytic composition according to the invention can be formulated by preparing a mixture comprising the titanium-based metallic precursor, the alu-minoxane type activator and optionally the aluminum-based compound used as an additive in any order.

[0083] Implementation of the composition in an oligomerization process

[0084] Another object of the invention relates to a process for oligomerizing ethylene, preferably for selective trimerizing ethylene into hexene-1, implementing the catalytic composition according to the invention.

[0085] Advantageously, the feedstock used in the oligomerization process is gaseous ethylene.

[0086] In one embodiment, the gaseous ethylene may contain up to 5% dihydrogen, preferably less than 3% dihydrogen, most preferably less than 1% dihydrogen.

[0087] Advantageously, the concentration of titanium-based metallic precursor put into the work in the oligomerization process is between 0.01 and 10000 pmol / L, preferably between 0.1 and 1000 pmol / L, most preferably between 1 and 100 pmol / L.

[0088] The process can advantageously be implemented in the presence of a solvent as described above.

[0089] Advantageously, the oligomerization process is carried out 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 of between 15 and 200°C, preferably between 20°C and 100°C and most preferably between 25°C and 80°C.

[0090] The heat generated by the reaction can be eliminated by all means known to a person skilled in the art.

[0091] Advantageously, the oligomerization process and in particular the trimerization of ethylene into hexene-1 can be carried out continuously.

[0092] In a first embodiment, the constituents of the catalytic composition according to the invention are injected into a reactor stirred by conventional mechanical means or by external recirculation, in which the ethylene reacts, preferably with temperature control.

[0093] In another embodiment, a solution comprising a mixture of the titanium-based metallic precursor and the aluminoxane-type activator, and a solution comprising the optional additive in the form of an aluminum-based compound, are injected separately into a reactor stirred by conventional mechanical means or by external recirculation, in which ethylene reacts, preferably with temperature control.

[0094] The catalytic composition can be neutralized downstream of the reactor by any means known to those skilled in the art.

[0095] The following examples illustrate the invention without limiting its scope. EXAMPLES

[0096] Example 1: Synthesis of the titanium-based metallic precursor Cl according to the invention:

[0097] The synthesis of Cl requires the following steps:

[0098] a) Synthesis of 3-tert-Butylsalicylaldehyde:

[0099] 6.36 g (21.8 mmol, 6 eq) of paraformaldehyde and 5.00 g (52.5 mmol, 1.5 eq) of ultra-dry MgCl2 (supplied in an ampoule) are weighed into a 250 mL round-bottom flask. 70 mL of tetrahydrofuran (THF) and 5.26 g (35.0 mmol) of 2-tert-butylphenol are added. The mixture is stirred, and 18.5 mL (132.7 mmol, 3.75 eq) of triethylamine is added. The mixture is heated at 85°C for 4 hours. It is allowed to cool to room temperature (25°C), and then 270 mL of dichloromethane is added. The solution is neutralized in a separatory funnel. Adding 60 mL of HCl to IM. The organic phase is washed with 2 x 100 mL of saturated salt water and 100 mL of deionized water. The organic phase is dried over Na2SO4, and the volatiles are evaporated. A yellow oil is obtained. The product is purified on a silica column (nCl5 / CH2Cl2, 80:20, Rf (retention factor) = 0.55). 4.70 g of slightly yellow oil is obtained (yield ≈ 75%).

[0100] The NMR characterization of the 3-tert-Butylsalicylaldehyde compound obtained is as follows:

[0101] H NMR (300 MHz, CDC13): ô = 11.8 (s, 1H), 9.9 (s, 1H), 7.54 (dd, 1H), 7.40 (dd, 1H), 6.95 (t, 1H), 1.43 (s, 9H).

[0102] 13C {>H] NMR (75 MHz, CDC13): ô = 197.2; 161.3; 138.4; 134.2; 132.1; 120.8; 119.3; 35.0; 29.3.

[0103] b) Synthesis of 5-Bromo-3-tert-Butylsalicylaldehyde:

[0104] In a 50 mL flask, 2.5 g (14.0 mmol, leq) of the 3-tert-Butylsalicylaldehyde obtained in step a) and 5 mL of acetic acid are added. A solution containing 4 mL (78.1 mol, 5.5 eq) of dibromine and 4 mL of acetic acid is then added dropwise. The mixture is stirred at room temperature for 3 hours. 100 mL of dichloromethane is then added. The organic phase is washed with 3 x 50 mL of saturated sodium metabisulfite (Na₂S₂O₅) solution, 3 x 50 mL of saturated NaHCO₃ solution, and 3 x 50 mL of saturated salt solution. The organic phase is dried over Na₂SO₄. The solvent is evaporated. 3.0 g of a light yellow solid (q ~ 83%) is obtained.

[0105] The NMR characterization of the 5-Bromo-3-tert-Butylsalicylaldehyde compound obtained is as follows:

[0106] 'H NMR (300 MHz, CDC13): ô = 11.7 (s,lH), 9.8 (s,lH), 7.58 (d,lH), 7.52 (d, 1H), 1.40 (s,9H).

[0107] 13C {*H] NMR (75 MHz, CDC13): ô = 196.15; 160.35; 141.29; 137.14; 133.75; 121.83; 111.28; 35.29; 29.15.

[0108] c) Synthesis of 5,5'-di(3-tert-butyl-2-hydroxy-benzaldehyde)-1,4-Phenyl

[0109] In a 100 mL flask, 1.5 g (5.8 mmol eq) of 5-Bromo-3-tert-Butylsalicylaldehyde obtained in step b), 0.86 g (2.61 mmol eq) of 2-methoxyphenylboronic acid, and 0.81 g (5.8 mmol eq) of K₂CO₃ are weighed out. In a glove box, 337 mg (0.29 mmol eq) of Pd[P(Ph)₃]₄ is weighed out. A 17 / 5 mL dichloromethane (DME) / H₂O mixture, degassed for 0.5 h with argon, is added. The mixture is heated at 100°C for 24 h. 30 mL of water is added, and the mixture is then extracted with dichloromethane (DCM). The product is dried over MgSO4 and the volatiles are evaporated. It is purified on a silica column (AcOEt / nCl5, 5:95). 350 mg of a slightly yellow product (q ~ 14%) is obtained.

[0110] NMR characterization of the compound The 5,5'-di(3-tert-butyl-2-hydroxy-benzaldehyde)-1,4-Phenyl obtained is as follows: [YES] 1H NMR (300 MHz, CDC13): δ = 11.81 (s, 2H); 10.00 (s, 2H); 7.81 (d, 2H); 7.65 (m, 6H); 1.50 (s, 18H).

[0112] 13C {'H] NMR (75 MHz, CDC13): ô = 197.3; 160.9; 139.14; 139.09; 133.14; 131.97; 130.05; 127.35; 120.97; 35.23; 29.41.

[0113] d) Synthesis of 2-(2-methoxyphenyl)aniline

[0114] In a Schlenk, 6.09 g (35.4 mmol) of aniline and 34 mL of N,N-dimethylformamide (DMF) are introduced. 1 mL of saturated Na₂CO₃ solution is added. The mixture is stirred for 10 min, and then 5.38 g of boronic acid (35.4 mmol) is added. In another Schlenk, 0.675 g (3.8 mmol) of PdCl₂ and 2.00 g (7.6 mmol) of triphenylphosphine are weighed out. The mixture is purged by performing 3 vacuum / argon cycles, and then 5.5 mL of dry DMF is added. The solution is stirred for 10 min and then added via cannula to the first Schlenk. The mixture is heated to 90°C overnight. The mixture is cooled and then extracted with 3 x 40 mL of AcOEt. The volatiles are evaporated and then purified on a silica column (nC5 / AcOEt, 90:10). 3.75g of white solid is obtained (q ~ 53%).

[0115] The NMR characterization of the 2-(2-methoxyphenyl)aniline compound obtained is as follows:

[0116] 'H NMR (CH2C12): 7.38 (td, 1H), 7.23 (dd, 1H), 7.15 (td, 1H), 7.10-7.00 (m, 3H), 6.83-6.72 (m, 2H), 3.81 (s, 3H), 3.68 (br s, 2H).

[0117] 13C NMR {*H] (CH2C12): 157.2; 145.2; 132.1; 131.5; 129.4; 128.8; 128.7; 125.4; 121.4; 118.5; 115.8; 111.6; 55.9.

[0118] e) Synthesis of intermediate compound 1 with the following formula:

[0119] [Chem.7]

[0120] In a schlenk, 316.3 mg (0.73 mmol; leq) of 5,5'-di(3-tert-butyl-2-hydroxybenzaldehyde)-1,4-Phenyl obtained in step c), 324.6 mg (1.62 mmol; 2.2 eq) of 2-(2-methoxyphenyl)aniline obtained in step d), a spatula tip of para-toluenesulfonic acid, and 15 mL of EtOH. The mixture is heated at 95°C for two nights. It is filtered and washed with nC5. 378.7 mg of orange / red solid is obtained (q ~ 65%).

[0121] The NMR characterization of the intermediate compound 1 obtained is as follows:

[0122] 'H NMR (300 MHz, CD2C12): ô = 13.69 (br s; 2H); 8.66 (s; 2H); 7.67 (d; 2H); 7.63 (s; 4H); 7.53-7.43 (m,4H); 7.43-7.33 (m.6H); 7.30 (d; 2H); 7.25 (dd; 2H); 7.04 (td; 2H); 6.98 (d; 2H); 3.74 (s; 6H); 1.43 (s; 18H).

[0123] f) Synthesis of the titanium-based metallic precursor Cl of the following formula:

[0124] [Chem.8]

[0125] In a Schlenk, 300.0 mg (0.38 mmol) of the intermediate compound 1 obtained in step e), 4 mL of toluene, and 4 mL of dichloromethane are introduced. This solution is added via cannula to a solution containing 9 mL of toluene and 0.9 mL of TiCl4 at IM in CH2Cl2 (0.9 mmol) cooled to -78°C. The mixture is allowed to rise to room temperature. After 2 hours of stirring, the volatiles are evaporated. The complex is washed with 3 x 1 0 mL of nCl5. It is drawn under vacuum at 45°C for 2 hours to dry the solid. 335 mg of reddish-brown solid (q ~ 80%) is obtained.

[0126] The NMR characterization of the titanium-based Cl-based metallic precursor obtained is as follows:

[0127] 'H NMR (300 MHz, CD2C12): ô = 8.27 (s, 2H); 7.90 (d, 2H); 7.62 (s, 4H); 7.59 (d, 2H); 7.56-7.50 (m, 4H); 7.45-7.36 (m, 6H); 7.36-7.27 (m, 4H); 7.25-7.10 (m, 2H); 4.36 (s, 6H); 1.57 (s.18H).

[0128] 13C NMR {*H] NMR (75 MHz, CD2C12): ô = 169.2; 163.2; 158.5; 151.9; 139.1; 137.7; 136.5; 133.4; 131.7; 131.6; 131.3; 131.0; 130.5; 130.3; 129.6; 129.4; 128.9; 128.6; 127.9; 127.85; 127.8; 126.1; 125.7; 123.4; 72.7; 35.7; 29.9.

[0129] Example 2: Synthesis of the titanium-based metallic precursor C2 according to the invention:

[0130] The synthesis of C2 requires the following steps:

[0131] a) Synthesis of 3,3'-dibromo-4,4'-dimethoxybiphenyl

[0132] In a 100 mL flask, 1.17 g (5.46 mmol, eq) of 4,4'-dimethoxybiphenyl is weighed. 29 mL of glacial acetic acid is added. 0.6 mL (11.7 mmol, 2.15 eq) of dibromine is added. The mixture is heated to 120°C. It is allowed to cool to temperature The product is filtered at room temperature and then washed with 2 x 2 mL of glacial acetic acid. 1.1 g of white solid is obtained (q ~ 54%).

[0133] The NMR characterization of the 3,3'-dibromo-4,4'-dimethoxybiphenyl obtained is as follows:

[0134] H NMR (300 MHz, CDC13): ô = 7.68 (d, 1H); 7.37 (dd, 2H); 6.90 (d, 2H); 3.90 (s, 6H).

[0135] 13C {>H] NMR NMR (75 MHz, CDC13): ô = 155.3; 133.4; 131.5; 126.7; 112.2; 112.1; 56.4.

[0136] b) Synthesis of 3,3'-di(2-aminophenyl)-4,4'-dimethoxybiphenyl

[0137] In a 100 mL flask, 0.60 g (1.61 mmol, 0.45 eq) of 3,3'-dibromo-4,4'-dimethoxybiphenyl obtained in step a), 0.78 g (3.56 mmol, eq) of 2-pinacol ester of aminobenzeneboronic acid, and 0.49 g (3.56 mmol, eq) of K₂CO₃ are weighed out. In a glove box, 207 mg (0.179 mmol, 0.05 eq) of Pd[P(Ph)₃]₄ is weighed out. A DME / H₂O (10 / 3 mL) mixture degassed for 0.5 h with argon is added. The mixture is heated to 100°C overnight. 20 mL of water is added, and the mixture is extracted using DCM. The product is dried over MgSO4 and the volatiles are evaporated. It is purified on a silica column (nC5 / DCM). 400 mg of orange-white solid (62%) is obtained.

[0138] The NMR characterization of the 3,3'-di(2-aminophenyl)-4,4'-dimethoxybiphenyl obtained is as follows:

[0139] 'H NMR (300 MHz, CD2C12): ô = 7.60 (dd, 2H), 7.47 (d, 2H), 7.15 (td, 2H), 7.10 (dd, 2H), 7.08 (d, 2H), 6.79 (td, 2H), 6.75 (dd, 2H), 3.84 (s, 6H), 3.73 (br s, 4H).

[0140] 13C NMR {*H] NMR (75 MHz, CD2C12): ô = 156.4; 145.2; 133.7; 131.5; 130.4; 129.0; 128.9; 127.3; 125.3; 118.5; 115.8; 112.0; 56.2.

[0141] c) Synthesis of intermediate compound 2 with the following formula:

[0142] [Chem.9]

[0143] Into a schlenk, 319 mg (0.80 mmol, leq) of 3,3'-di(2-aminophenyl)-4,4'-dimethoxybiphenyl obtained in step b), 415 mg (1.77 mmol, 2.2 eq) of 3,5-Di-tert-butyl-2-hydroxybenzaldehyde and 15 mL of dry ethanol. The mixture is heated to 95 °C overnight. It is filtered and washed with 3 mL of ethanol. and 3 mL of nC5. We dry under vacuum at 40°C. We obtain 510 mg of orange solid Cq «76%.

[0144] The NMR characterization of the intermediate compound 2 obtained is as follows:

[0145] ¹H NMR (300 MHz, CD2C12): δ = 13.4 (br s; 2H); 8.54 (s; 2H); 7.57 (dd; 2H); 7.50-7.28 (m; 10H); 7.24 (d; 2H); 7.18 (d; 2H); 7.00 (d; 2H); 3.77 (s; 6H); 1.32 (s; 18H) 1.29 (s; 18H).

[0146] 13C NMR {*H] NMR (75 MHz, CD2C12): ô = 163.9; 158.5; 156.2; 147.8; 140.7; 137.1; 134.5; 133.4; 131.7; 130.3; 129.1; 129.0; 128.1; 127.5; 127.1; 126.7; 118.8; 118.4; 111.3; 55.7; 35.3; 34.4; 31.6; 29.5.

[0147] d) Synthesis of the titanium-based C2 metallic precursor of the following formula:

[0148] [Chem. 10]

[0149] In a Schlenk, 250 mg (0.30 mmol) of intermediate compound 2 obtained in step c) and 5 mL of toluene are introduced. This solution is added via cannula to a solution containing 8 mL of toluene and 0.75 mL of TiCl4 IM in CH2Cl2 (0.75 mmol) cooled to -78°C. The mixture is allowed to rise to room temperature. After 2 h with stirring, the volatiles are evaporated. The complex is washed with 3 x 0 mL of nCl5. It is drawn under vacuum at 45°C for 2 h to dry the solid. 280 mg of orange-brown solid (q ~ 82%) is obtained.

[0150] The NMR characterization of the C2 titanium-based metallic precursor obtained is as follows:

[0151] 'H NMR (300 MHz, CDC13): ô = 8.21 (s, 2H); 7.72 (d, 2H); 7.68-7.59 (m, 2H); 7.59-7.38 (m, 10H); 7.37-7.29 (m, 2H); 7.19-7.09 (m, 2H); 4.40 (s, 6H); 1.51 (s, 18H); 1.29 (s, 18H).

[0152] Example 3: Process for the preparation of an SMAO with 10.1% wt Al.

[0153] In a Schlenk, in a glove box, 3 g of polymerization silica (Average diameter = 33 pm; Average pore diameter DP = 21 nm; Pore volume VP = 1.56 mL / g; Specific surface area SBet = 315 m2 / g) previously dried at 80°C under vacuum for 2h are weighed.

[0154] Under argon flow, the silica is impregnated with 4.7 mL (corresponding to the total pore volume) of dry toluene. Then 13 mL of MAO is added to the toluene (4.65% pds Al, d = 0.895 g / mL, 0.54 g Al theoretical). The mixture becomes a translucent liquid gel.

[0155] The mixture is heated to 80°C for 4 hours with manual stirring every 15 minutes. After 4 hours, the toluene is evaporated and the resulting white powder is dried under vacuum at 80°C for 1 hour.

[0156] The Al content in the SMAO is determined by ICP-AES: %wt Al = 10.1 ± 0.5%.

[0157] Example 4: Process for the trimerization of ethylene, using the titanium-based metallic precursor Cl activated by a soluble MAO (3000 eq. / Ti)

[0158] In a 100 mL reactor previously purged with argon, 43 mL of toluene is introduced, along with 5 mL of a 1.2 mol / L soluble MAO solution in toluene obtained from a 10 wt% solution in toluene. Next, 2 mL of a solution of the titanium-based metallic precursor Cl₂ of Example 1, previously diluted in toluene to 1 mmolTi / L (AlMAo / Ti molar ratio = 3000), is introduced. The reactor is pressurized with 0.5 MPa of ethylene and the temperature raised to 30°C with gentle stirring (250 rpm). When the temperature reaches 28°C, the reactor pressure is adjusted to the desired pressure of IMPa and the stirring speed is increased to 1000 rpm, marking the start of the catalytic test.

[0159] The reaction temperature is maintained at 30°C and the pressure at a constant value of IMPa. After 30 minutes of reaction, the reactor is cooled to 15°C before being slowly depressurized. The contents of the reactor are collected in a flask and weighed. The organic phase is neutralized with a 10% wt. aqueous solution of H2SO4 and then analyzed by gas chromatography (GC). The solid (polyethylene) is dried at 100°C overnight and then weighed.

[0160] Example 5: Process for the trimerization of ethylene, using the titanium-based C2 metallic precursor activated by soluble MAO (3000 eq. / Ti)

[0161] This test is carried out under the conditions described in Example 4, except that 2 mol of the titanium-based metallic precursor C2 from Example 2 is introduced instead of CL

[0162] Example 6: Process for the trimerization of ethylene, using SMAO-activated Cl (molar ratio Al5MAn / Ti = 171) with TEA as an additive (molar ratio Al^ / Ti = 50).

[0163] In a Schlenk flask under argon, 200 mg of SMAO at 9.2 wt% Al (0.68 mmol Al) is introduced. 2.00 mL of a 2.0 mM (4 pmol) Cl solution is added to the Schlenk containing the SMAO. An orange gel forms at the bottom of the Schlenk. The mixture is heated at 50°C for 1 h with manual stirring every 15 min.

[0164] The heating setpoint for the thermostatically controlled reactor bath is set to 25°C. Then, 92.0 ml of cyclohexane solvent is introduced into the reactor, which has been The solvent was first conditioned by introducing an atmosphere of 0.05 MPa of ethylene. Next, the solvent was saturated with ethylene by introducing 0.5 MPa of gaseous ethylene while stirring at 1500 rpm for one minute. The reactor pressure was then reduced to 0.05 MPa and stirring was stopped. Five mL of sieve-dried nonane (3.6 g) and 1.00 mL of a 0.20 M TEA solution (0.2 mmol) were added. Finally, the entirety of the previously prepared oligomerization catalyst, which was suspended in toluene, was added. The ethylene inlet valve (3 MPa pressure) was opened, stirring was started, and the reactor temperature set to 28 °C was then increased.

[0165] At the end of the test, the ethylene supply is shut off, the medium is cooled to 20°C, and then the gas phase is vented. The reactor is then opened. The liquid is transferred to a flask containing 1.00 mL of 10% H2SO4 solution. A sample of the organic phase is taken and filtered for analysis.

[0166] The results of examples 4 to 6 are described in the table below.

[0167] [Tables 1] Example Time (h) Productivity (g / gTi-h) C6 (%) 1-C6 (% in C6) C10 (%) C10+ (%) PE (%) 4 0.5 161 968 86.1 99.8 11.6 0.6 1.7 5 0.5 182 649 82.7 99.9 15.7 0.7 0.9 6 1.0 103 509 74.8 99.9 19.6 1.3 3.7

[0168] These examples demonstrate that the catalytic compositions according to the invention are functional for the selective production of hexene-1 (obtaining more than 70% of C6 molecules of which almost 100% is hexene-1) whether with a soluble alu-minoxane activator or with an aluminoxane activator immobilized on a solid support.

Claims

Demands

1. Catalytic composition for the selective oligomerization of ethylene, preferably for the trimerization of ethylene to hexene-1, including: - a titanium-based metallic precursor conforming to the following formula: L is at least one bond linking Rx with x chosen between 1 and 12 and Rx with x chosen between 14 and 25, L being a hydrocarbon group having from 1 to 20 carbon atoms, cyclic or not, aromatic or not, containing or not a heteroatom, or L being a covalent bond, R1 to R12 on the one hand and R14 to R25 on the other hand, when they are not linked together, are each chosen from a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a substituted or unsubstituted aryl group, a cyclic or uncyclic alkyl group, and a cyclic or uncyclic aralkyl group, said groups having from 1 to 15 carbon atoms (in Cl-Cl 5) and containing or not a heteroelement, R13 and R26 are each chosen from a substituted or unsubstituted aryl group, a cyclic or unsubstituted alkyl group, and a cyclic or unsubstituted aralkyl group, said groups having from 1 to 15 carbon atoms and containing or not a heteroatom, X1 and X2 are each an identical or different heteroatom, and X3 and X4 are each an identical or different ligand X, - and an aluminoxane-type activator.

2. Catalytic composition according to claim 1, wherein R2, R4, R5, R6, R7, R8, R9, R10, R11, R12, R15, R17, R18, R19, R20, R21, R22, R23, R24 and R25, when not bonded together, are each a hydrogen atom.

3. Catalytic composition according to claim 1 or 2, wherein R13 and R26 are each selected from an alkyl group having 1 to 6 carbon atoms containing or not a heteroelement, a cycloalkyl group having 3 to 6 carbon atoms containing or not a heteroelement, and a substituted or unsubstituted aryl group having 6 to 15 carbon atoms containing or not a heteroelement.

4. Catalytic composition according to claim 3, wherein R13 and R26 are each a methyl group.

5. Catalytic composition according to any one of the preceding claims, wherein R1, R3, R14 and R16, when not linked together, are each selected from an alkyl group having from 1 to 10 carbon atoms containing or not a heteroelement, a cycloalkyl group having from 3 to 10 carbon atoms containing or not a heteroelement, and a substituted or unsubstituted aryl group having from 4 to 15 carbon atoms containing or not a heteroelement.

6. Catalytic composition according to claim 5, wherein R1, R3, R14 and R16, when not linked together, are each selected from a methyl, ter-butyl and adamantyl group.

7. Catalytic composition according to any one of the preceding claims, wherein X1 and X2 are each an oxygen atom.

8. Catalytic composition according to any one of the preceding claims, wherein X3 and X4 are each an identical ligand X selected from chloride, bromide and iodide.

9. Catalytic composition according to any one of the preceding claims, wherein the aluminoxane-type activator is a soluble aluminoxane compound selected from methylaluminoxane, modified methylalu-minoxane and ethylaluminoxane, alone or in mixture.

10. Catalytic composition according to claim 9, wherein the molar ratio of aluminum of soluble aluminoxane to titanium of metallic precursor is between 1000 and 3000.

11. Catalytic composition according to any one of claims 1 to 8, in which the aluminoxane-type activator is a methylalu-minoxane immobilized on an inorganic support.

12. Catalytic composition according to claim 11, wherein the molar ratio of aluminum of methylaluminoxane immobilized on an inorganic support to titanium of the metallic precursor, is between 100 and 1000.

13. Catalytic composition according to claim 11 or 12, further comprising an additive in the form of an aluminium-based compound selected from trimethylaluminium, triethylaluminium and triisobutylaluminium, alone or in mixture.

14. Catalytic composition according to claim 13, wherein the molar ratio of aluminum of the additive in the form of an aluminum-based compound to titanium of the metallic precursor is between 50 and 300.

15. A process for the selective trimerization of ethylene to hexene-1, implementing the catalytic composition according to any one of the preceding claims.