Ligand compound, organochromium compound and catalyst composition containing the same

Abstract

The present invention relates to a ligand compound having a novel structure, which exhibits high catalytic activity and high 1-hexene and 1-octene selectivity, and is therefore capable of carrying out ethylene oligomerization with excellent efficiency; an organochromium compound; a catalyst composition containing the organochromium compound; and an ethylene oligomerization method using the same.

Description

[Technical field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0031616 filed on March 14, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a ligand compound, an organochromium compound, a catalyst composition containing the organochromium compound, and an ethylene oligomerization process using the same. [Background technology]

[0003] Linear alpha-olefins such as 1-hexene and 1-octene are used as detergents, lubricants, plasticizers, etc., and are particularly used as comonomers to adjust the density of polymers in the production of linear low density polyethylene (LLDPE).

[0004] In the conventional manufacturing process of LLDPE (Linear Low-Density Polyethylene), ethylene is copolymerized with comonomers such as alpha-olefins, e.g., 1-hexene and 1-octene, to form branches in the polymer backbone and adjust the density.

[0005] Therefore, in order to produce LLDPE with a high comonomer content, the price of the comonomer accounts for a large portion of the production cost. To solve this problem, various attempts have been made.

[0006] Such linear alpha-olefins are mainly produced through the Shell Higher Olefin Process, but this process has the disadvantage that alpha-olefins of various lengths are simultaneously synthesized due to the Schultz-Flory distribution, and therefore a separate separation process is required to obtain a specific alpha-olefin.

[0007] To solve these problems, methods have been proposed to selectively synthesize 1-hexene through the trimerization of ethylene or to selectively synthesize 1-octene through the tetramerization of ethylene. In addition, much research has been conducted on catalyst systems that enable such selective oligomerization of ethylene. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] U.S. Pat. No. 5,064,802 Summary of the Invention [Problem to be solved by the invention]

[0009] The problem to be solved by the present invention is to provide a ligand compound having a novel structure, an organochromium compound, and a catalyst composition containing the same, which exhibit high catalytic activity and high 1-hexene and 1-octene selectivity and are capable of carrying out ethylene oligomerization with excellent efficiency. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention provides a ligand compound, an organochromium compound, a catalyst composition and an ethylene oligomerization method.

[0011] (1) The present invention provides a ligand compound represented by the following chemical formula 1: [Chemical formula 1] [ka] In the above formula 1, R 1 ~R 4 are each independently an alkyl group having 5 to 20 carbon atoms or a trialkylsilyl group, the alkyl group of the trialkylsilyl group being an alkyl group having 1 to 4 carbon atoms, R 5 is an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms.

[0012] (2) The present invention relates to the above-mentioned (1), 1 ~R 4 provides a ligand compound, each of which is independently an alkyl group having 8 to 12 carbon atoms, a tripropylsilyl group, or a tributylsilyl group.

[0013] (3) The present invention relates to the above (1) or (2), 1 ~R 4 provides a ligand compound which is each independently an n-decyl group, a tripropylsilyl group, or a tributylsilyl group.

[0014] (4) The present invention relates to any one of the above (1) to (3), 5 provides a ligand compound which is an alkyl group having 3 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms.

[0015] (5) The present invention provides, in the above (1), the ligand compound represented by Chemical Formula 1, which is a ligand compound represented by Chemical Formula 2 below. [Chemical formula 2] [ka] In the above formula 2, R 5 is an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms.

[0016] (6) The present invention provides a ligand compound according to the above (5), wherein the ligand compound represented by Chemical Formula 2 is one selected from the group consisting of ligand compounds represented by the following Chemical Formulas 2-1 to 2-11: [Chemical formula 2-1] [ka] [Chemical formula 2-2] [ka] [Chemical formula 2-3] [ka] [Chemical formula 2-4] [ka] [Chemical formula 2-5] [ka] [Chemical formula 2-6] [ka] [Chemical formula 2-7] [ka] [Chemical formula 2-8] [ka] [Chemical formula 2-9] [ka] [Chemical formula 2-10] [ka] [Chemical formula 2-11] [ka]

[0017] (7) The present invention provides, in the above (1), that the ligand compound represented by Chemical Formula 1 is a ligand compound represented by Chemical Formula 3 below. [Chemical formula 3] [ka] In the above formula 3, R 5 is an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms.

[0018] (8) The present invention provides a ligand compound represented by the above (7), wherein the ligand compound represented by the above chemical formula 3 is a ligand compound represented by the following chemical formula 3-1: [Chemical formula 3-1] [ka]

[0019] (9) The present invention provides, in the above (1), that the ligand compound represented by Chemical Formula 1 is a ligand compound represented by the following Chemical Formula 4: [Chemical formula 4] [ka] In the above Chemical Formula 4, R 5is an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms.

[0020] (10) The present invention provides the ligand compound represented by Chemical Formula 4 in the above (9), which is a ligand compound represented by the following Chemical Formula 4-1 or 4-2: [Chemical formula 4-1] [ka] [Chemical formula 4-2] [ka]

[0021] (11) The present invention provides, in the above (1), the ligand compound represented by Chemical Formula 1, a ligand compound represented by Chemical Formula 5 below. [Chemical formula 5] [ka] In the above Chemical Formula 5, R 5 represents an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms, and n is 4 to 14.

[0022] (12) The present invention provides the ligand compound represented by the above chemical formula 5 in the above (11), which is a ligand compound represented by the following chemical formula 5-1: [Chemical formula 5-1] [ka]

[0023] (13) The present invention provides a ligand compound according to any one of (1) to (12) above, and an organochromium compound containing chromium coordinated to the ligand compound.

[0024] (14) The present invention provides an organochromium compound according to (13), in which at least one unshared electron pair of either N or two P in the ligand compound represented by Chemical Formula 1 is coordinated to chromium.

[0025] (15) The present invention provides a catalyst composition comprising a ligand compound according to any one of (1) to (12) above, chromium, and a co-catalyst.

[0026] (16) The present invention provides a catalyst composition according to the above (15), wherein the chromium is derived from a chromium source, and the chromium source includes one or more selected from the group consisting of chromium(III) acetylacetonate, chromium(III) chloride tetrahydrofuran, chromium(III) 2-ethylhexanoate, chromium(III) acetate, chromium(III) butyrate, chromium(III) pentanoate, chromium(III) laurate, chromium(III) tris(2,2,6,6-tetramethyl-3.5-heptanedionate), and chromium(III) stearate.

[0027] (17) The present invention provides a catalyst composition according to the above (15) or (16), wherein the co-catalyst is one or more selected from the group consisting of compounds represented by the following Chemical Formula 6 to Chemical Formula 9: [Chemical formula 6] -[Al(R 13 )-O] a - In the above Chemical Formula 6, R 13 are each independently a halogen group, a hydrocarbyl group having 1 to 20 carbon atoms, or a hydrocarbyl group having 1 to 20 carbon atoms substituted with a halogen group, and a is an integer of 2 or greater. [Chemical formula 7] E(R 14 )3 In the above formula 7, E is aluminum or boron, and R 14 are each independently a hydrogen atom, a halogen group, a hydrocarbyl group having 1 to 20 carbon atoms, or a hydrocarbyl group having 1 to 20 carbon atoms substituted with a halogen group. [Chemical formula 8] [LH] + [G(Y)4] - [Chemical formula 9] [L] + [G(Y)4] - In the above formulas 8 and 9, L is a neutral or cationic Lewis acid, [LH] + is a Bronsted acid, G is a Group 13 element, and each Y is independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, where, when the alkyl group or the aryl group is substituted, the substituent is a halogen group, a hydrocarbyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms.

[0028] (18) The present invention provides a method for producing linear alpha-olefins, comprising the step (S10) of oligomerizing ethylene in the presence of a catalyst composition according to any one of (15) to (17) above.

[0029] (19) The present invention provides a method for producing linear alpha-olefins according to the above (18), wherein the linear alpha-olefin is 1-hexene, 1-octene or a mixture thereof. Effect of the Invention

[0030] When ethylene oligomerization is carried out using the organochromium compound and catalyst composition containing the ligand compound of the present invention, linear alpha-olefins can be produced with excellent productivity due to high catalytic activity and high 1-hexene and 1-octene selectivity. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] The present invention will now be described in more detail to aid in understanding the present invention.

[0032] The terms and words used in the description of the present invention and the claims should not be interpreted in a limited manner to their ordinary or dictionary meanings, but should be interpreted in a manner that is consistent with the technical idea of ​​the present invention, based on the principle that the inventors can appropriately define the concepts of terms in order to best describe their invention.

[0033] Ligand Compound The present invention provides a ligand compound applicable to a catalyst used in an ethylene oligomerization reaction. When the ligand compound is applied to an ethylene oligomerization reaction, specifically, a catalyst composition for forming linear alpha-olefins, it exhibits excellent catalytic activity and high selectivity for linear alpha-olefins, and in particular, when compared with the existing PNP-based catalyst, it produces less solid polyethylene under the same reaction conditions, and can produce linear alpha-olefins more efficiently.

[0034] According to one embodiment of the present invention, the organochromium compound coordinated with the ligand compound can be used to produce linear alpha-olefins using ethylene, and can form liquid alpha-olefins, specifically, liquid 1-hexene or 1-octene, with high selectivity by oligomerization under ethylene conditions, because selectivity for alpha-olefins of a specific length is increased due to the transition state of forming a metal-containing ring compound (metallacycle) in the oligomerization reaction of ethylene.

[0035] According to one embodiment of the present invention, the ligand compound includes a diphosphino aminyl moiety, and an aryl having a specific substituent is connected to the end of the diphosphino aminyl moiety, so that it can have a form that can play a role of a strong electron donating group by itself. Due to such structural characteristics, the ligand compound can be applied to an ethylene oligomerization catalyst system and exhibit high activity, and in particular, can exhibit high selectivity for 1-hexene, 1-octene, etc. This is considered to be due to the interaction between the adjacent chromium active sites, and in particular, when an aryl substituted with a specific substituent is connected to the phosphorus (P) atom of the diphosphino aminyl, the electron density increases at the phosphorus (P) atom and nitrogen (N) atom contained in the diphosphino aminyl, and the electronic and steric properties of the entire ligand compound change. This causes a change in the bond between the ligand and the chromium atom, further stabilizing the catalyst structure and changing the transition state energy (activation energy) compared to the existing metallacycloheptane or metallacyclononane forms, enabling the formation of alpha-olefins with higher activity and selectivity, while reducing the amount of by-products such as solid alpha-olefins with high molecular weights, such as polyethylene wax (PE wax).

[0036] According to one embodiment of the present invention, the ligand compound is characterized in that the phenyl at the end of the diphosphinoaminyl residue has an alkyl group of a specific carbon number or a silyl group substituted with an alkyl group of a specific carbon number at the meta position as a substituent. The substituent substituted at the meta position of the phenyl prevents two molecules of the ligand compound from binding to the chromium atom to generate inactive species, and reduces the rotational possibility of the nitrogen-phosphorus bond to prevent the ligand compound from dissociating from the catalyst, thereby making it possible to prepare a chromium catalyst with high stability, activity, and selectivity.

[0037] According to one embodiment of the present invention, the ligand compound is bonded to a bulky substituent such as a cycloalkyl group or a phenyl group to a nitrogen atom to which two phosphorus atoms are bonded, and the bulky substituent bonded to the nitrogen prevents the nitrogen-phosphorus bond from rotating, thereby improving the catalyst stability and activity. Here, the activity, stability, and selectivity of the catalyst change depending on the steric properties of the substituent bonded to the nitrogen atom. If the steric strain of the substituent bonded to the nitrogen atom is too high, it becomes difficult to synthesize the ligand and form a metal complex compound, and the complex compound formed becomes unstable. In addition, if the steric strain of the substituent bonded to the nitrogen atom is too high, it becomes difficult to access raw materials such as ethylene, and the activity of the catalyst decreases. In addition, if the steric strain of the substituent bonded to the nitrogen atom is too low, it is not possible to prevent the bond between the nitrogen atom and the phosphorus atom from rotating, and the metal central atom cannot be protected, which causes the activity and stability of the catalyst to decrease. That is, if the steric strain of the substituent bonded to the nitrogen atom is too high or too low, the activity of the catalyst decreases, the stability decreases, and the amount of by-products such as polyethylene wax produced increases. Therefore, it is very important to select a substituent bonded to the nitrogen atom that has an appropriate level of steric strain relative to the substituent bonded to the phosphorus atom. In the ligand compound according to the present invention, the introduction of a substituent at the meta position of the phenyl group bonded to the phosphorus atom increases the steric strain around the PNP functional group, so that the steric strain of the substituent bonded to the nitrogen atom does not increase too much, the R in Formula 1 is selected. 5 By introducing a substituent represented by the formula (1), the yield and selectivity of the ethylene oligomerization reaction can be improved by using a catalyst composition containing the same. 5 When a secondary alkyl group is introduced as the substituent represented by the formula (I), the efficiency is further improved. In order to complement the low steric strain of the primary alkyl group, an aryl group such as a phenyl group can be introduced at the first or second carbon position to form an appropriate steric strain, thereby improving the yield and selectivity.

[0038] According to one embodiment of the present invention, the ligand compound may be represented by the following Formula 1:

[0039] [Chemical formula 1] [ka]

[0040] In the above formula 1, R 1 ~R 4 are each independently an alkyl group having 5 to 20 carbon atoms or a trialkylsilyl group, the alkyl group of the trialkylsilyl group being an alkyl group having 1 to 4 carbon atoms, R 5 is an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms.

[0041] In the present invention, the term "alkyl group" may mean a linear, cyclic or branched hydrocarbon residue, and specific examples thereof may include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, an isopentyl group, a hexyl group, etc., depending on the defined number of carbon atoms.

[0042] In the present invention, the term "trialkylsilyl group" refers to a substituent represented by -SiR, where each R is independently an alkyl group, and when referring to the number of carbon atoms of a trialkylsilyl group, it can refer to the total number of carbon atoms of R.

[0043] In the present invention, unless otherwise specified, "aryl" refers to an optionally substituted benzene ring or a ring system that may be formed by condensing one or more optional substituents. Exemplary optional substituents include substituted C1-2 alkyl groups, substituted C2-3 alkenyl groups, substituted C2-3 alkynyl groups, heteroaryl groups, heterocyclic groups, aryl groups, alkoxy, aryloxy, aralkoxy, acyl, aroyl, heteroaroyl, acyloxy, aroyloxy, heteroaroyloxy, sulfanyl, sulfinyl, sulfonyl, aminosulfonyl, sulfonylamino, carboxamido, aminocarbonyl, carboxy, oxo, hydroxy, mercapto, amino, nitro, cyano, halogen, or ureido, optionally having one or more fluorine substituents. Such rings or ring systems may be optionally fused to an aryl ring (e.g., a benzene ring), a carbocyclic ring, or a heterocyclic ring, optionally having one or more substituents. It can include, but is not limited to, phenyl, naphthyl, tetrahydronaphthyl, biphenyl, indanyl, anthracyl, or phenanthryl, and substituted derivatives thereof.

[0044] According to one embodiment of the present invention, R 1 ~R 4 may each independently be an alkyl group having 8 to 12 carbon atoms, a tripropylsilyl group, or a tributylsilyl group. Specific examples include R 1 ~R 4 may each independently be a tripropylsilyl group, a tributylsilyl group, or an n-decyl group. That is, the ligand compound may have, at the meta position of the phenyl located at the end of the diphosphinoaminyl residue, a silyl group substituted with an alkyl group having 10 carbon atoms or an alkyl group having 3 or 4 carbon atoms as a substituent.

[0045] According to one embodiment of the present invention, R 5can be an alkyl group having 3 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms.

[0046] According to one embodiment of the present invention, the ligand compound represented by Formula 1 may be represented by Formula 2 below.

[0047] [Chemical formula 2] [ka]

[0048] In the above formula 2, R 5 is an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms.

[0049] According to one embodiment of the present invention, the ligand compound represented by the formula 2 may be one selected from the group consisting of ligand compounds represented by the following formulas 2-1 to 2-11.

[0050] [Chemical formula 2-1] [ka]

[0051] [Chemical formula 2-2] [ka]

[0052] [Chemical formula 2-3] [ka]

[0053] [Chemical formula 2-4]

change

[0054] [Chemical formula 2-5]

change

[0055] [Chemical formula 2-6]

change

[0056] [Chemical formula 2-7]

change

[0057] [Chemical formula 2-8]

change

[0058] [Chemical formula 2-9]

change

[0059] [Chemical formula 2-10]

change

[0060] [Chemical formula 2-11]

change

[0061] According to one embodiment of the present invention, the ligand compound represented by Formula 1 may be represented by Formula 3 below.

[0062] [Chemical formula 3] [ka]

[0063] In the above formula 3, R 5 is an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms.

[0064] According to one embodiment of the present invention, the ligand compound represented by Formula 3 may be represented by Formula 3-1 below.

[0065] [Chemical formula 3-1] [ka]

[0066] According to one embodiment of the present invention, the ligand compound represented by Formula 1 may be represented by Formula 4 below.

[0067] [Chemical formula 4] [ka]

[0068] In the above Chemical Formula 4, R 5 is an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms.

[0069] According to one embodiment of the present invention, the ligand compound represented by Formula 4 may be represented by the following Formula 4-1 or 4-2.

[0070] [Chemical formula 4-1] [ka]

[0071] [Chemical formula 4-2] [ka]

[0072] According to one embodiment of the present invention, the ligand compound represented by Formula 1 may be represented by Formula 5 below.

[0073] [Chemical formula 5] [ka]

[0074] In the above Chemical Formula 5, R 5 represents an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms, and n is 4 to 14.

[0075] According to one embodiment of the present invention, the ligand compound represented by Formula 5 may be represented by Formula 5-1 below.

[0076] [Chemical formula 5-1] [ka]

[0077] According to one embodiment of the present invention, the ligand compound may be realized by various combinations other than the above specific examples as long as they satisfy the above conditions, and any compound represented by Chemical Formula 1 can be applied as the ligand compound of the present invention.

[0078] Organochromium compounds and catalyst compositions The present invention provides a ligand compound represented by Chemical Formula 1 and an organochromium compound comprising chromium (Cr) coordinated to the ligand compound.

[0079] According to one embodiment of the present invention, the organochromium compound may be a chromium complex compound of the ligand compound, in which chromium of the chromium source is a ligand compound represented by Chemical Formula 1, and at least one unshared electron pair of any of N and two P may be coordinated. That is, the phosphorus atom or nitrogen atom of the diphosphinoaminyl residue provides an unshared electron pair to the chromium atom, and among these, a bidentated state in which two unshared electron pairs are coordinated is particularly preferred. Such an organochromium compound may be applied to a catalyst system for ethylene oligomerization reaction, and may exhibit excellent catalytic activity and high selectivity for 1-hexene or 1-octene.

[0080] In the present invention, the term "catalyst composition" refers to a state in which three components including a chromium source, a ligand compound, and a cocatalyst, or two components including a transition metal compound and a cocatalyst are added simultaneously or in any order to obtain an active catalyst composition. Here, the catalyst composition can also be called a catalyst system, and in the present invention, the catalyst composition and the catalyst system have the same meaning. The three or two components of the catalyst composition can be added in the presence or absence of a solvent and a monomer, and can be used in a supported or unsupported state.

[0081] The present invention provides a catalyst composition comprising the ligand compound, chromium, and a cocatalyst. The ligand compound represented by Chemical Formula 1 and chromium can be coordinated to form an organochromium compound as described above. That is, the catalyst system can be a three-component catalyst system comprising chromium, the ligand compound represented by Chemical Formula 1, and a cocatalyst, or a two-component catalyst system comprising the organochromium compound and a cocatalyst. As a specific example, the catalyst composition can comprise the ligand compound, an organochromium compound comprising chromium coordinated to the ligand compound, and a cocatalyst. In addition, the catalyst composition can comprise a chromium compound in which a part of the cocatalyst is bound to the organochromium compound.

[0082] According to an embodiment of the present invention, the chromium may be derived from a chromium source, which may be an organic or inorganic chromium compound having an oxidation state of chromium of 0 to 6. As a specific example, the chromium source may be chromium metal or a compound in which any organic or inorganic radical is bonded to chromium. Here, the organic radical may be an alkyl, alkoxy, ester, ketone, amide, carboxylate radical, etc. having 1 to 20 carbon atoms per radical, and the inorganic radical may be a halide, sulfate, oxide, etc.

[0083] According to one embodiment of the present invention, the chromium source is a compound that exhibits high activity in olefin oligomerization and is easy to use and obtain, and may be one or more compounds selected from the group consisting of chromium (III) acetylacetonate, chromium (III) chloride tetrahydrofuran, chromium (III) 2-ethylhexanoate, chromium (III) acetate, chromium (III) butyrate, chromium (III) pentanoate, chromium (III) laurate, chromium (III) tris(2,2,6,6-tetramethyl-3.5-heptanedionate), and chromium (III) stearate.

[0084] According to one embodiment of the present invention, the co-catalyst may be at least one selected from the group consisting of compounds represented by the following Formulae 6 to 9.

[0085] [Chemical formula 6] -[Al(R 13 )-O] a -

[0086] In the above Chemical Formula 6, R 13 are each independently a halogen group, a hydrocarbyl group having 1 to 20 carbon atoms, or a hydrocarbyl group having 1 to 20 carbon atoms substituted with a halogen group, and a is an integer of 2 or greater.

[0087] [Chemical formula 7] E(R 14 )3

[0088] In the above formula 7, E is aluminum or boron, and R 14 are each independently a hydrogen atom, a halogen group, a hydrocarbyl group having 1 to 20 carbon atoms, or a hydrocarbyl group having 1 to 20 carbon atoms substituted with a halogen group.

[0089] [Chemical formula 8] [LH] + [G(Y)4] -

[0090] [Chemical formula 9] [L] + [G(Y)4] -

[0091] In the above formulas 8 and 9, L is a neutral or cationic Lewis acid, [LH] + is a Bronsted acid, G is a Group 13 element, and each Y is independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, where, when the alkyl group or the aryl group is substituted, the substituent is a halogen group, a hydrocarbyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms.

[0092] According to an embodiment of the present invention, the catalyst composition may be prepared by a number of methods. As a specific example, first, the catalyst composition may be prepared by contacting the organic chromium compound with the compound represented by Formula 6 or Formula 7. Second, the catalyst composition may be prepared by contacting the organic chromium compound with the compound represented by Formula 6 or Formula 7 to obtain a mixture, and adding the compound represented by Formula 8 or Formula 9 to the mixture. Third, the catalyst composition may be prepared by contacting the organic chromium compound with the compound represented by Formula 8 or Formula 9. Fourth, the catalyst composition may be prepared by contacting the organic chromium compound with the compound represented by Formula 8 or Formula 9 to obtain a mixture, and adding the compound represented by Formula 6 or Formula 7 to the mixture. Fifth, the catalyst composition may be prepared by contacting the chromium source with the compound represented by Formula 8 or Formula 9 to obtain a reactant, and contacting the ligand compound with the reactant.

[0093] According to an embodiment of the present invention, in the case of the first or third method among the methods for preparing the catalytic composition, the molar ratio of the compound represented by Formula 6 or Formula 7 to the organic chromium compound may be 1:2 to 5,000, specifically 1:100 to 3,000, and more specifically 1:300 to 1,500. Within this range, the alkylation of the organic chromium compound can be completed, the activity of the catalytic composition can be improved, the activity of the alkylated organic chromium compound can be prevented from being reduced due to a side reaction between the remaining alkylating agent, and the economy and the purity of the produced linear alpha-olefin can be improved.

[0094] According to one embodiment of the present invention, in the case of the second method of preparing the catalytic composition, the molar ratio of the compound represented by Formula 8 or Formula 9 to the organic chromium compound may be 1:1 to 500, specifically 1:1 to 50, and more specifically 1:1 to 1:25. Within this range, the amount of activator is sufficient, and activation of the metal compound is completely performed to improve the activity of the catalytic composition, and residual activator is minimized, thereby improving economy and the purity of the produced linear alpha-olefin.

[0095] According to an embodiment of the present invention, the compound represented by Chemical Formula 6 may be an alkylaluminoxane, specific examples of which include methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, butylaluminoxane, etc., and a more specific example of which is methylaluminoxane.

[0096] According to an embodiment of the present invention, the compound represented by Formula 7 may be trialkylaluminum, dialkylaluminum halide, alkylaluminum dihalide, dialkylaluminum hydride, alkylaluminum dihydride, trialkylboron, etc. Specific examples of the compound represented by Formula 6 include trialkylaluminum such as trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, triisopropylaluminum, tri-s-butylaluminum, tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum, trihexylaluminum, trioctylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum, and tri-p-tolylaluminum; dialkylaluminum halides such as diethylaluminum chloride;Diethylaluminum hydride, di-n-propylaluminum hydride, diisopropylaluminum hydride, di-n-butylaluminum hydride, dibutylaluminum hydride, diisobutylaluminum hydride (DIBAH), di-n-octylaluminum hydride, diphenylaluminum hydride, di-p-tolylaluminum hydride, dibenzylaluminum hydride, phenylethylaluminum hydride, phenyl-n-propylaluminum hydride, phenylisopropylaluminum hydride, phenyl-n-butylaluminum hydride, phenylisobutylaluminum hydride, phenyl-n-octylaluminum hydride, p-tolylethylaluminum hydride, p-tolyl-n-propylaluminum hydride, p-tolylisopropylaluminum hydride, p-tolyl-n-bu dialkylaluminum hydrides such as benzyl ethylaluminum hydride, p-tolyl isobutylaluminum hydride, p-tolyl-n-octylaluminum hydride, benzyl ethylaluminum hydride, benzyl-n-propylaluminum hydride, benzyl isopropylaluminum hydride, benzyl-n-butylaluminum hydride, benzyl isobutylaluminum hydride or benzyl-n-octylaluminum hydride; alkylaluminum dihydrides such as n-propylaluminum dihydride, isopropylaluminum dihydride, n-butylaluminum dihydride, isobutylaluminum dihydride or n-octylaluminum dihydride; trialkylborons such as trimethylboron, triethylboron, triisobutylboron, tripropylboron, tributylboron, etc.;

[0097] According to an embodiment of the present invention, the compound represented by Formula 8 or Formula 9 is trimethylammonium tetraphenylborate, triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tributylammonium tetraphenylborate, N,N-dimethylanilinium tetraphenylborate, N,N-diethylanilinium tetraphenylborate, trimethylammonium tetra(p-tolyl)borate, triethylammonium tetra(p-tolyl)borate, tripropylammonium tetra(p-tolyl)borate, tributylammonium tetra(p-tolyl)borate, N,N-dimethylanilinium tetra(p-tolyl)borate, N,N-diethylanilinium tetra(p-tolyl)borate, trimethylammonium tetra(o,p-dimethylphenyl)borate, triethylammonium tetra(o,p-dimethylphenyl)borate, tripropylammonium tetra(o,p-dimethylphenyl)borate, tributylammonium tetra(o,p-dimethylphenyl)borate, N,N-dimethylanilinium tetra(o,p-dimethylphenyl)borate, -dimethylphenyl)borate, N,N-diethylanilinium tetra(o,p-dimethylphenyl)borate, trimethylammonium tetrakis(p-trifluoromethylphenyl)borate, triethylammonium tetrakis(p-trifluoromethylphenyl)borate, tripropylammonium tetrakis(p-trifluoromethylphenyl)borate, tributylammonium tetrakis(p-trifluoromethylphenyl)borate, N,N-dimethylanilinium tetrakis(p-trifluoromethylphenyl)borate, N,N-diethylanilinium tetrakis(p-trifluoromethylphenyl)borate, trimethylammonium tetrakis(pentafluorophenyl)borate, triethylammonium tetrakis(pentafluorophenyl)borate, tripropylammonium tetrakis(pentafluorophenyl)borate, tributylammonium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, N,N-diethylanilinium tetrakis(pentafluorophenyl)borate, N,N-dioctadecylanilinium tetrakis(pentafluorophenyl)borate, trimethylphosphonium tetraphenylborate, triethylphosphonium tetraphenylborate, tripropylphosphonium tetraphenylborate, tributylphosphonium tetraphenylborate, trimethylcarbonium tetraphenylborate, triethylcarbonium tetraphenylborate, tripropylcarbonium tetraphenylborate, tributylcarbonium tetraphenylborate, trimethylammonium tetraphenylaluminate, triethylammonium tetraphenylaluminate, tripropylammonium tetraphenylaluminate, tributylammonium tetraphenylaluminate, trimethylammonium tetra(p-tolyl)aluminate, triethylammonium tetra(p-tolyl)aluminate, tripropylammonium tetra(p-tolyl)aluminate, tributylammonium tetra(p-tolyl)aluminate, etc.

[0098] According to an embodiment of the present invention, the content ratio of the components forming the catalyst composition may be determined in consideration of the catalytic activity and the selectivity for linear alpha-olefins. As a specific example, when the catalyst composition is a three-component catalyst composition, the molar ratio of the diphosphinoaminyl residue of the ligand compound: the chromium source: the cocatalyst may be adjusted to about 1:1:1 to about 10:1:10,000, or about 1:1:100 to 5:1:3,000. In addition, when the catalyst composition is a two-component catalyst composition, the molar ratio of the diphosphinoaminyl residue of the organochromium compound: the cocatalyst may be adjusted to 1:1 to 1:10,000, or 1:1 to 1:5,000, or 1:1 to 1:3,000.

[0099] According to an embodiment of the present invention, when preparing the catalyst composition, a reaction solvent may be used, such as a hydrocarbon solvent, for example, pentane, hexane, or heptane; or an aromatic solvent, for example, benzene or toluene.

[0100] According to one embodiment of the present invention, the components forming the catalyst composition can be added simultaneously or in any order in the presence or absence of a suitable solvent and monomer to act as an active catalyst composition, where suitable solvents can be heptane, toluene, cyclohexane, methylcyclohexane, 1-hexene, 1-octene, diethyl ether, tetrahydrofuran, acetonitrile, dichloromethane, chloroform, chlorobenzene, methanol, acetone, etc.

[0101] According to one embodiment of the present invention, the organochromium compound and the cocatalyst may be used in a form supported on a carrier, and the carrier may be silica or alumina.

[0102] According to an embodiment of the present invention, the catalyst composition may further include a carrier. As a specific example, the ligand compound represented by Chemical Formula 1 may be applied to an ethylene oligomerization reaction in a form supported on a carrier. The carrier may be a metal, metal salt, or metal oxide applied to a supported catalyst, and as a specific example, the carrier may be silica, silica-alumina, silica-magnesia, etc., and may include metal oxides, carbonates, sulfates, and nitrates such as Na2O, K2CO3, BaSO4, and Mg(NO3)2.

[0103] According to one embodiment of the present invention, the catalyst composition can be used for the trimerization or tetramerization reaction of ethylene, thereby producing 1-hexene or 1-octene with high selectivity.

[0104] Ethylene Oligomerization Process The present invention provides a method for producing linear alpha-olefins as an ethylene oligomerization method, comprising the step (S10) of oligomerizing ethylene in the presence of the catalyst composition.

[0105] In the present invention, "oligomerization" means that olefins are polymerized into small units. Depending on the number of olefins polymerized, it is called trimerization or tetramerization, which are collectively called multimerization. In particular, in this specification, it can mean the selective production of 1-hexene and 1-octene, which are the main comonomers of LLDPE, from ethylene.

[0106] According to one embodiment of the present invention, the ethylene oligomerization reaction may be a trimerization or tetramerization reaction of ethylene, and 1-hexene or 1-octene is formed as a reaction result, and the linear alpha-olefin may be 1-hexene, 1-octene, or a mixture thereof.

[0107] According to one embodiment of the present invention, the ethylene oligomerization method can be carried out by using ethylene as a raw material, applying the above catalyst composition, and a conventional apparatus and contacting technique. As a specific example, the ethylene oligomerization reaction can be carried out in the presence or absence of an inert solvent as a homogeneous liquid phase reaction, or a slurry reaction in which the catalyst composition is partially or entirely undissolved, or a bulk phase reaction in which the product alpha-olefin acts as a main medium, or a gas phase reaction.

[0108] According to an embodiment of the present invention, the ethylene oligomerization reaction may be carried out in an inert solvent, and specific examples of the inert solvent include benzene, toluene, xylene, cumene, chlorobenzene, dichlorobenzene, heptane, cyclohexane, methylcyclohexane, methylcyclopentane, n-hexane, 1-hexene, 1-octene, and 2,2,4-trimethylpentane.

[0109] According to an embodiment of the present invention, the ethylene oligomerization reaction may be carried out at a temperature of 0° C. to 200° C., or 0° C. to 150° C., or 30° C. to 100° C., or 50° C. to 100° C. Also, the reaction may be carried out under a pressure of 15 psig to 3000 psig, or 15 psig to 1500 psig, or 15 psig to 1,000 psig.

[0110] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to exemplary embodiments thereof, so that those skilled in the art can easily practice the present invention. However, the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[0111] Synthesis examples and comparative synthesis examples Synthesis Example 1: Synthesis of ligand compound represented by chemical formula 2-1 [Chemical formula 2-1] [ka]

[0112] 20 mmol (2 eq) of 3-(tripropylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Then, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Then, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Then, cyclopentylamine dissolved in 3.8 ml of dichloromethane was dissolved in 10 ml of dichloromethane, and 10 mmol (1 eq) of triethylamine was added. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration was performed using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 2-1.

[0113] <Ligand compound represented by chemical formula 2-1> N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-cyclopentyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine) N-(Bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-cyclopentyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine)

[0114] 1 H NMR (500 MHz, C6D6): δ 8.23-7.17(m, 16H), 3.50(pent, 1H), 2.27-2.14(m, 2H), 1.77-1.63(m, 2H), 1.42-1.15(m, 24H), 1.00-0.86(m, 36H), 0.87-0.81(m, 4H), 0.79-0.67(m, 24H)

[0115] Synthesis Example 2: Synthesis of the されるリガンド compound shown in Chemical Formula 2-2 [Chemical formula 2-2]

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[0116] 20 mmol (2 eq) of 3-(tripropylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Then, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Next, cyclohexylamine dissolved in 3.8 ml of dichloromethane was dissolved in 10 ml of dichloromethane. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 2-2.

[0117] <Ligand compound represented by chemical formula 2-2> N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-cyclohexyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine) N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-cyclopentyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine)

[0118] 1 H NMR (500 MHz, C6D6): δ 8.20-7.17(m, 16H), 3.52(pent, 1H), 2.29-2.15(m, 2H), 1.75-1.61(m, 4H), 1.40-1.15(m, 24H), 1.00-0.88(m, 36H), 0.86-0.80(m, 4H), 0.78-0.68(m, 24H)

[0119] Synthesis Example 3: Synthesis of the されるリガンド compound shown in Chemical Formula 2-3 [Chemical formula 2-3]

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[0120] 20 mmol (2 eq) of 3-(tripropylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Next, cycloheptylamine dissolved in 3.8 ml of dichloromethane was dissolved in 10 ml of dichloromethane, and 10 mmol (1 eq) of triethylamine was added. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 2-3.

[0121] <Ligand compound represented by chemical formula 2-3> N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-cycloheptyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine) N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-cycloheptyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine)

[0122] 1 H NMR (500 MHz, C6D6): δ 8.15-7.16(m, 16H), 3.65(pent, 1H), 2.35-2.22(m, 2H), 1.94-1.86(m, 2H), 1.60-1.45(m, 4H), 1.44-1.15(m, 24H), 1.00-0.86(m, 36H), 0.85-0.79(m, 4H), 0.78-0.68(m, 24H)

[0123] Synthesis Example 4: Synthesis of the されるリガンド compound shown in Chemical Formula 2-4 [Chemical formula 2-4]

change

[0124] 20 mmol (2 eq) of 3-(tripropylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Next, cyclooctylamine dissolved in 3.8 ml of dichloromethane was dissolved in 10 ml of dichloromethane, and 10 mmol (1 eq) of triethylamine was added. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 2-4.

[0125] <Ligand compound represented by chemical formula 2-4> N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-cyclooctyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine) N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-cyclooctyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine)

[0126] 1 H NMR (500 MHz, C6D6): δ 8.10-7.15(m, 16H), 3.78(pent, 1H), 2.40-2.28(m, 2H), 1.94-1.86(m, 2H), 1.67-1.49(m, 4H), 1.48-1.15(m, 24H), 1.00-0.86(m, 36H), 0.85-0.79(m, 6H), 0.78-0.68(m, 24H)

[0127] Synthesis Example 5: Synthesis of the されるリガンド compound shown in Chemical Formula 2-5 [Chemical formula 2-5]

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[0128] 20 mmol (2 eq) of 3-(tripropylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Next, 2,3-dihydro-1H-inden-2-ylamine dissolved in 3.8 ml of dichloromethane was dissolved in 10 ml of dichloromethane. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 2-5.

[0129] <Ligand compound represented by chemical formula 2-5> N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-(2,3-dihydro-1H-inden-2-yl)-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine) N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-(2,3-dihydro-1H-inden-2-yl)-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine)

[0130] 1 H NMR (500 MHz, C6D6): δ 7.80-7.15(m, 16H), 7.10-6.90(m, 4H), 4.65(pent, 1H), 3.73-3.61(m, 2H), 2.75-2.67(m, 2H), 1.43-1.29(m, 24H), 1.01-0.92(m, 36H), 0.80-0.71(m, 24H)

[0131] Synthesis Example 6: Synthesis of the されるリガンド compound shown in Chemical Formula 2-6 [Chemical formula 2-6]

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[0132] 20 mmol (2 eq) of 3-(tripropylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Next, 1,2,3,4-tetrahydronaphthalen-2-ylamine dissolved in 3.8 ml of dichloromethane was dissolved in 1,2,3,4-tetrahydronaphthalen-2-ylamine. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 2-6.

[0133] <Ligand compound represented by chemical formula 2-6> N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-(1,2,3,4-tetrahydronaphthalen-2-yl)-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine) N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-(1,2,3,4-tetrahydronaphthalen-2-yl)-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine)

[0134] 1 H NMR (500 MHz, C6D6): δ 8.10-7.15(m, 16H), 7.08-6.89(m, 4H), 3.86(pent, 1H), 3.42-3.29(m, 1H), 3.01-2.87(m, 3H), 1.69-1.50(m, 2H), 1.44-1.16(m, 24H), 0.99-0.85(m, 36H), 0.83-0.65(m, 24H)

[0135] Synthesis Example 7: Synthesis of the されるリガンド compound shown in Chemical Formula 2-7 [Chemical formula 2-7]

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[0136] 20 mmol (2 eq) of 3-(tripropylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Next, isopropylamine dissolved in 3.8 ml of dichloromethane was added. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 2-7.

[0137] <Ligand compound represented by chemical formula 2-7> N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-isopropyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine) N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-isopropyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine)

[0138] 1 H NMR (500 MHz, C6D6): δ 8.20-7.15(m, 16H), 3.45(pent, 1H), 1.67(d, 6H), 1.39-1.15(m, 24H), 1.01-0.89(m, 36H), 0.80-0.67(m, 24H)

[0139] Synthesis Example 8: Synthesis of ligand compound represented by chemical formula 2-8 [Chemical formula 2-8] [ka]

[0140] 20 mmol (2 eq) of 3-(tripropylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Next, 3-methylbutan-2-ylamine dissolved in 3.8 ml of dichloromethane was dissolved in 10 ml of dichloromethane. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 2-8.

[0141] <Ligand compound represented by chemical formula 2-8> N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-(3-methylbutan-2-yl)-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine) N-(bis(3-(tripylsilyl)phenyl)phosphanyl)-N-(3-methylbutan-2-yl)-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine)

[0142] 1 H NMR (500 MHz, C6D6): δ 8.10-7.20(m, 16H), 3.65-3.52(m, 1H), 1.82-1.70(m, 1H), 1.41-1.16(m, 24H), 1.07(d, 3H), 0.99-0.87(m, 36H), 0.80-0.69(m, 27H), 0.56(d, 3H)

[0143] Synthesis Example 9: Synthesis of the されるリガンド compound shown in Chemical Formula 2-9 [Chemical formula 2-9]

change

[0144] 20 mmol (2 eq) of 3-(tripropylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Next, benzylamine dissolved in 3.8 ml of dichloromethane was dissolved in 10 ml of dichloromethane, and 10 mmol (1 eq) of triethylamine was added. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 2-9.

[0145] <Ligand compound represented by chemical formula 2-9> N-benzyl-N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine N-benzyl-N-(bis(3-(tripropylsilyl)phenyl)phosphaneyl)-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine)

[0146] 1 H NMR (500 MHz, C6D6): δ 7.94-7.15(m, 16H), 7.12-6.85(m, 5H), 4.74(s, 2H), 1.39-1.15(m, 24H), 0.99-0.88(m, 36H), 0.80-0.68(m, 24H)

[0147] Synthesis Example 10: Synthesis of ligand compound represented by chemical formula 2-10 [Chemical formula 2-10] [ka]

[0148] 20 mmol (2 eq) of 3-(tripropylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Next, phenethylamine dissolved in 3.8 ml of dichloromethane was dissolved in 10 ml of dichloromethane. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 2-10.

[0149] <Ligand compound represented by chemical formula 2-10> N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-pentyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine) N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-phenethyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine)

[0150] 1 H NMR (500 MHz, C6D6): δ 8.18-7.14(m, 16H), 7.12-6.84(m, 5H), 3.48(t, 2H), 2.33(t, 2H), 1.40-1.14(m, 24H), 1.02-0.90(m, 36H), 0.81-0.67(m, 24H)

[0151] Synthesis Example 11: Synthesis of the されるるリガンド compound shown in Chemical Formula 2-11 [Chemical formula 2-11]

change

[0152] 20 mmol (2 eq) of 3-(tripropylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without any additional purification process was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the obtained intermediate was dissolved in 3.8 ml of dichloromethane, and triethylamine was added. 3 mmol (3 eq) of 4-phenylcyclohexylamine was added. Next, 1 mmol (1 eq) of 4-phenylcyclohexylamine dissolved in 3.8 ml of dichloromethane was gradually added to the reaction system, and the mixture was stirred overnight at room temperature. Next, the solvent was removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration was performed using hexane to which 1% by volume of triethylamine had been added, the resulting solution was concentrated to obtain the ligand compound represented by formula 2-11.

[0153] <Ligand compound represented by chemical formula 2-11> N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-(4-phenylcyclohexyl)-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine) N-(bis(3-(tripropylsilyl)phenyl)phosphanyl)-N-(4-phenylcyclohexyl)-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine)

[0154] 1 H NMR (500 MHz, C6D6): δ 8.15-7.18(m, 18H), 7.13-7.00(m, 3H), 3.64(pent, 1H), 2.88-2.72(m, 1H), 2.49(d, 1H), 2.46-2.34(m, 2H), 2.16(d, 1H), 1.87-1.74(m, 2H), 1.71-1.60(m, 1H), 1.58-1.49(m, 1H), 1.39-1.28(m, 24H), 0.99-0.90(m, 36H), 0.78-0.70(m, 24H)

[0155] Synthesis Example 12: Synthesis of the されるリガンド compound shown in Chemical Formula 3-1 [Chemical formula 3-1]

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[0156] 20 mmol (2 eq) of 3-(tributylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Next, 2,3-dihydro-1H-inden-2-ylamine dissolved in 3.8 ml of dichloromethane was dissolved in 10 ml of dichloromethane. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 3-1.

[0157] <Ligand compound represented by chemical formula 3-1> N-(bis(3-(tributylsilyl)phenyl)phosphanyl)-N-(2,3-dihydro-1H-inden-2-yl)-1,1-bis(3-(tributylsilyl)phenyl)phosphanamine) N-(bis(3-(tributylsilyl)phenyl)phosphanyl)-N-(2,3-dihydro-1H-inden-2-yl)-1,1-bis(3-(tributylsilyl)phenyl)phosphanamine)

[0158] 1 H NMR (500 MHz, C6D6): δ 7.83-7.17(m, 16H), 7.11-6.92(m, 4H), 4.59(pent, 1H), 3.68-3.57(m, 2H), 2.71-2.65(m, 2H), 1.39-1.27(m, 48H), 0.94-0.84(m, 36H), 0.83-0.75(m, 24H)

[0159] Synthesis Example 13: Synthesis of ligand compound represented by chemical formula 4-1 [Chemical formula 4-1] [ka]

[0160] In a dried flask, 11 mmol (2.2 eq) of cycloheptylamine and 10 ml of dichloromethane were added under a nitrogen atmosphere, and stirring was started. 5 mmol (1 eq) of chlorobis(3-(tripropylsilyl)phenyl)phosphane was gradually added to the flask in a diluted state in 10 ml of dichloromethane. The reaction was stirred for 4 hours, 1The conversion was confirmed by H NMR. After the reaction was completed, the precipitated solid was removed through a filter, the solvent was removed under reduced pressure, and 5 mmol of the intermediate compound N-cycloheptyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine was obtained by column chromatography.

[0161] Next, the intermediate compound N-cycloheptyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine (5 mmol (1 eq)) and 13 ml of methyl tert-butyl ether were added to a dried flask under a nitrogen atmosphere, cooled to -78°C, and stirring was started. 2.1 ml (5.25 mmol, 1.05 eq) of a 2.5 M solution of n-butyl lithium in hexane was gradually added to the flask and stirred for 1 hour, and then 5 mmol (1 eq) of chlorobis(3-(tributylsilyl)phenyl)phosphane diluted in 10 ml of methyl tert-butyl ether was gradually added. The reaction mixture was stirred for 4 hours, 1 The conversion was confirmed by H NMR. After the reaction was completed, the precipitated solid was removed through a filter, the solvent was removed under reduced pressure, and 4 mmol (yield 80%) of the ligand compound represented by formula 4-1 was obtained through column chromatography.

[0162] <Ligand compound represented by chemical formula 4-1> N-(bis(3-(tributylsilyl)phenyl)phosphanyl)-N-cycloheptyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine N-(bis(3-(tributylsilyl)phenyl)phosphanyl)-N-cycloheptyl-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine

[0163] 1 H NMR (500 MHz, C6D6): δ 8.16-7.15(m, 16H), 3.64(pent, 1H), 2.34-2.21(m, 2H), 1.93-1.85(m, 2H), 1.59-1.45(m, 4H), 1.43-1.15(m, 36H), 1.00-0.85(m, 36H), 0.85-0.79(m, 16H), 0.78-0.68(m, 12H)

[0164] Synthesis Example 14: Synthesis of ligand compound represented by chemical formula 4-2 [Chemical formula 4-2] [ka]

[0165] In a dried flask, 11 mmol (2.2 eq) of 4-phenylcyclohexylamine and 10 ml of dichloromethane were added under a nitrogen atmosphere, and stirring was started. 5 mmol (1 eq) of chlorobis(3-(tripropylsilyl)phenyl)phosphane was gradually added to the flask in a diluted state in 10 ml of dichloromethane. The reaction was stirred for 4 hours, 1The conversion was confirmed by H NMR. After the reaction was completed, the precipitated solid was removed through a filter, the solvent was removed under reduced pressure, and 5 mmol of the intermediate compound N-(4-phenylcyclohexyl)-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine was obtained by column chromatography.

[0166] Next, 5 mmol (1 eq) of N-(4-phenylcyclohexyl)-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine, which is the intermediate compound obtained above, and 13 ml of methyl tert-butyl ether were added to a dried flask under a nitrogen atmosphere, cooled to -78°C, and then stirring was started. 2.1 ml (5.25 mmol, 1.05 eq) of a solution of n-butyl lithium dissolved in hexane at 2.5 M was gradually added to the flask, and after stirring for 1 hour, 5 mmol (1 eq) of chlorobis(3-(tributylsilyl)phenyl)phosphane diluted in 10 ml of methyl tert-butyl ether was gradually added. The reaction was stirred for 4 hours. 1 The conversion was confirmed by H NMR. After the reaction was completed, the precipitated solid was removed through a filter, the solvent was removed under reduced pressure, and 4 mmol (yield 80%) of the ligand compound represented by formula 4-2 was obtained through column chromatography.

[0167] <Ligand compound represented by chemical formula 4-2> N-(bis(3-(tributylsilyl)phenyl)phosphanyl)-N-(4-phenylcyclohexyl)-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine N-(bis(3-(tributylsilyl)phenyl)phosphanyl)-N-(4-phenylcyclohexyl)-1,1-bis(3-(tripropylsilyl)phenyl)phosphanamine

[0168] 1 H NMR (500 MHz, C6D6): δ 8.14-7.17(m, 18H), 7.14-7.00(m, 3H), 3.61(pent, 1H), 2.87-2.72(m, 1H), 2.50(d, 1H), 2.47-2.33(m, 2H), 2.15(d, 1H), 1.88-1.75(m, 2H), 1.70-1.60(m, 1H), 1.59-1.49(m, 1H), 1.39-1.26(m, 36H), 0.99-0.87(m, 36H), 0.82-0.70(m, 24H)

[0169] Synthesis Example 15: Synthesis of ligand compound represented by chemical formula 5-1 [Chemical formula 5-1] [ka]

[0170] Referring to Org.Chem.Front,2015,2,536, 20mmol (1eq) of 1,3-dibromobenzene was dissolved in diethyl ether and cooled to -78℃. While maintaining the temperature, 20mmol (1eq) of n-butyl lithium was added dropwise and stirred for 1 hour. Next, 22mmol (1.1eq) of 1-bromodecane was added, and the temperature was raised to room temperature and further stirred for 4 hours. Next, water was added to quench, and the mixture was extracted with diethyl ether, washed with brine, dried with magnesium sulfate (MgSO4), and the solvent was removed in vacuum. Next, 3-(n-decyl)phenyl bromide was separated through a silica column using hexane.

[0171] 20 mmol (2 eq) of 3-(n-decyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Next, 2,3-dihydro-1H-inden-2-ylamine dissolved in 3.8 ml of dichloromethane was dissolved in 10 ml of dichloromethane. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 5-1.

[0172] <Ligand compound represented by chemical formula 5-1> N-(bis(3-decylphenyl)phosphanyl)-1,1-bis(3-decylphenyl)-N-(2,3-dihydro-1H-inden-2-yl)phosphanamine N-(bis(3-decylphenyl)phosphanyl)-1,1-bis(3-decylphenyl)-N-(2,3-dihydro-1H-inden-2-yl)phosphanamine)

[0173] 1 H NMR (500 MHz, C6D6): δ 7.76-7.12(m, 16H), 7.07-6.89(m, 4H), 4.49(pent, 1H), 3.67-3.55(m, 2H), 2.69-2.60(m, 2H), 2.43-2.28(t, 24H), 1.43-1.19(m, 192H), 0.98-0.85(t, 36H)

[0174] Comparative Synthesis Example 1: Synthesis of the chemical compound shown in Chemical Formula 10 [Chemical formula 10]

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[0175] 20 mmol (2 eq) of 3-(tributylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without any additional purification process was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the obtained intermediate was dissolved in 3.8 ml of dichloromethane, and triethylamine was added. 3 mmol (3 eq) of 6-undecanamine was added. Next, 1 mmol (1 eq) of 6-undecanamine dissolved in 3.8 ml of dichloromethane was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. Next, the solvent was removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration was performed using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 10.

[0176] Comparative Synthesis Example 2: Synthesis of ligand compound represented by formula 11 [Chemical formula 11] [ka]

[0177] 20 mmol (2 eq) of 3-(tripropylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without any additional purification process was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the obtained intermediate was dissolved in 3.8 ml of dichloromethane, and triethylamine was added. 3 mmol (3 eq) of 4,4'-methylenebis(cyclohexan-1-amine) was added. Then, 0.5 mmol (0.5 eq) of 4,4'-methylenebis(cyclohexan-1-amine) dissolved in 3.8 ml of dichloromethane was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. Next, the solvent was removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After filtering the mixture through silica gel using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 11.

[0178] Comparative Synthesis Example 3: Synthesis of Ligand Compound Represented by Chemical Formula 12 [Chemical formula 12] [ka]

[0179] Referring to ChemCatChem 2019,11,4351, 20 mmol (2 eq) of 4-(triisopropylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran and cooled to -78°C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise and stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Next, isopropylamine dissolved in 3.8 ml of dichloromethane was added. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration was performed using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 12.

[0180] Comparative Synthesis Example 4: Synthesis of ligand compound represented by formula 13 [Chemical formula 13] [ka]

[0181] 20 mmol (2 eq) of 3-(dimethyloctylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Next, isopropylamine dissolved in 3.8 ml of dichloromethane was added. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 13.

[0182] Comparative Synthesis Example 5: Synthesis of Ligand Compound Represented by Chemical Formula 14 [Chemical formula 14] [ka]

[0183] 20 mmol (2 eq) of 1-bromo-3,4-dimethylbenzene was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Next, 2-isopropylcyclohexylamine dissolved in 3.8 ml of dichloromethane was dissolved in 10 ml of dichloromethane. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 14.

[0184] Comparative Synthesis Example 6: Synthesis of Ligand Compound Represented by Chemical Formula 15 [Chemical formula 15] [ka]

[0185] 20 mmol (2 eq) of 3-(tributylsilyl)phenyl bromide was dissolved in 20 ml of tetrahydrofuran, and then cooled to -78° C. While maintaining the temperature, 20 mmol (2 eq) of n-butyl lithium was added dropwise, and the mixture was stirred for 3 hours. Next, 10 mmol (1 eq) of dichloro(diethylamino)phosphine dissolved in 10 ml of tetrahydrofuran was added dropwise, and the mixture was heated to room temperature and stirred overnight. Next, the solvent was removed using a vacuum, and the intermediate obtained without additional purification was dissolved in 30 ml of hexane, and 2 eq of HCl (in ether) was added. After stirring for 15 minutes, the mixture was filtered, and the filtrate was dried under vacuum. 2.1 mmol (2.1 eq) of the intermediate obtained was dissolved in 3.8 ml of dichloromethane, and 3 mmol (3 eq) of triethylamine was added. Next, cyclododecylamine dissolved in 3.8 ml of dichloromethane was dissolved in 10 ml of dichloromethane, and 10 mmol (3 eq) of triethylamine was added. 1 mmol (1 eq) of triethylamine was gradually added to the reaction system, and the mixture was stirred at room temperature overnight. The solvent was then removed using a vacuum, and the mixture was dissolved in 7.6 ml of hexane, which was then loaded onto the top of silica gel. After silica filtration using hexane containing 1% by volume of triethylamine, the resulting solution was concentrated to obtain the ligand compound represented by formula 15.

[0186] Examples and Comparative Examples Example 1-1 Under an argon gas atmosphere, 17.5 mg (0.05 mmol) of chromium (III) acetylacetonate (Cr(acac)3) and 0.5 mmol of the ligand compound represented by Chemical Formula 2-1 in Synthesis Example 1 were placed in a flask, and then 100 ml of methylcyclohexane was added and stirred to prepare a 5 mM (Cr basis) catalyst solution.

[0187] A 600ml Parr reactor was prepared and evacuated at 120°C for 2 hours, then argon was substituted and the temperature was lowered to 80°C. Then, 180ml of methylcyclohexane and 2ml of MMAO (isoheptane solution, Al / Cr=600) were poured in, and 2ml of the catalyst solution (1.0μmol Cr) was poured in. After stirring at 1,000rpm for 2 minutes, the valve of the ethylene line adjusted to 30bar was opened to fill the reactor with ethylene, and the reactor was stirred at 1,000rpm for 60 minutes. The ethylene line valve was closed, and the reactor was cooled to 0°C using a dry ice / acetone bath, and the unreacted ethylene was gradually vented, and 0.5ml of nonane (GC internal standard) was added. After stirring for 10 seconds, 2 ml of the liquid in the reactor was taken and quenched with water, and the obtained organic portion was filtered with a PTFE syringe filter to prepare a GC-FID sample. The distribution of the liquid product was analyzed by GC (Agilent, 6890N, Alltech AT-5 (30 m x 0.32 mm ID x 0.25 μm; series no. 12446)). In addition, 400 ml of ethanol / HCl (10 vol% of aqueous 12M HCl solution) was added to the remaining reaction solution, stirred, filtered, and the amount of solid product was analyzed. The obtained polymer was dried overnight in a vacuum oven at 80°C.

[0188] Examples 2-1 to 15-1 and Comparative Examples 1-1 to 6-1 The same procedure as in Example 1-1 was carried out, except that the type of catalyst was changed as shown in Table 1 below.

[0189] [Table 1]

[0190] Example 1-2 In an argon gas atmosphere, 0.5 mmol of chromium (III) chloride tetrahydrofuran (Cr(THF)3Cl3), 0.5 mmol of the ligand compound represented by formula 2-1 according to Synthesis Example 1, and 0.5 mmol of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate (AB) as a cocatalyst were placed in a flask, 30 ml of dichloromethane was added, and the mixture was stirred for 1 hour, after which the solvent was removed in a vacuum. The mixture was then dissolved in methylcyclohexane and filtered, after which the solvent was removed in a vacuum again, and the mixture was dissolved in methylcyclohexane to prepare a 0.15 mM (Cr basis) catalyst solution.

[0191] A 600ml Parr reactor was prepared and evacuated at 120°C for 2 hours, then purged with argon and cooled to 70°C. Then, 180ml of methylcyclohexane and 2ml of activator, 725μmol of diisobutylaluminum hydride, and 5ml of the catalyst solution (0.75μmol Cr) were injected. After stirring at 1,000 rpm for 2 minutes, the valve of the ethylene line adjusted to 40 bar was opened to fill the reactor with ethylene, and the mixture was stirred at 1,000 rpm for 60 minutes. The ethylene line valve was closed and the reactor was cooled to 0°C using a dry ice / acetone bath, and the unreacted ethylene was gradually vented, and 0.5ml of nonane (GC internal standard) was added. After stirring for 10 seconds, 2ml of the liquid portion of the reactor was taken and quenched with water, and the obtained organic portion was filtered with a PTFE syringe filter to prepare a GC-FID sample. The distribution of the liquid product was analyzed by GC (Agilent, 6890N, Alltech AT-5 (30m x 0.32mm ID x 0.25 μm; series no. 12446)). The remaining reaction solution was stirred with 400ml of ethanol / HCl (10 vol% of aqueous 12M HCl solution), filtered, and the amount of solid product was analyzed. The obtained polymer was dried overnight in a vacuum oven at 80°C.

[0192] Examples 2-2 to 15-2 and Comparative Examples 1-2 to 6-2 The same procedure as in Example 1-2 was carried out, except that the catalyst type was changed as shown in Table 2 below.

[0193] [Table 2]

[0194] Experimental Example The results of the ethylene oligomerization reactions according to the above examples and comparative examples are shown in Tables 3 and 4 below.

[0195] *Catalytic activity (ton / mol Cr / hr): The catalytic activity was calculated from the total weight (ton) of the products obtained by adding together the weights (tons) of the liquid and solid products obtained.

[0196] *1-C6 and 1-C8 selectivity (wt%): The contents of 1-hexene (1-C6) and 1-octene (1-C8) were calculated from the results of GC analysis of the distribution of the liquid products, and the weight percentage of 1-hexene or 1-octene relative to the total weight of the products was calculated.

[0197] *Solid (wt%): The weight percent of the solid product was calculated based on the total weight of the product. This indicates the degree to which polyethylene having a carbon number of about 40 or more was produced as an insoluble solid that was not dissolved in the solvent.

[0198] [Table 3]

[0199] [Table 4]

[0200] As shown in Tables 3 and 4, when an ethylene oligomerization reaction is carried out using a catalyst composition containing a ligand compound according to the present invention, the phenyl at the end of the diphosphinoaminyl residue has an alkyl group having a specific carbon number or a silyl group substituted with an alkyl group having a specific carbon number at the meta position as a substituent, and the steric strain around the PNP functional group is adjusted by the substituent substituted with a nitrogen atom, thereby improving the catalytic activity, selectivity, and stability.

[0201] From these results, it was confirmed that when ethylene oligomerization is carried out using the organochromium compound and catalyst composition containing the ligand compound of the present invention, linear alpha-olefins can be produced with high productivity due to high catalytic activity and high 1-hexene and 1-octene selectivity.

Claims

1. A ligand compound represented by the following chemical formula 1: [Chemical formula 1] 【Chemistry 1】 In the above Chemical Formula 1, R １ ~R ４ are each independently an alkyl group having 5 to 20 carbon atoms or a trialkylsilyl group, the alkyl group of the trialkylsilyl group being an alkyl group having 1 to 4 carbon atoms; R ５ is an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms.

2. R １ ~R ４ and each independently represent an alkyl group having 8 to 12 carbon atoms, a tripropylsilyl group, or a tributylsilyl group.

3. R １ ~R ４ The ligand compound according to claim 1, wherein each of the groups independently represents an n-decyl group, a tripropylsilyl group, or a tributylsilyl group.

4. R ５ is an alkyl group having 3 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms.

5. The ligand compound represented by the formula 1 is the ligand compound according to claim 1, which is represented by the following formula 2: [Chemical formula 2] 【Chemistry 2】 In the above Chemical Formula 2, R ５ is an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms.

6. The ligand compound according to claim 5, wherein the ligand compound represented by Chemical Formula 2 is one selected from the group consisting of ligand compounds represented by the following Chemical Formulas 2-1 to 2-11: [Chemical formula 2-1] 【Chemistry 3】 [Chemical formula 2-2] 【Chemistry 4】 [Chemical formula 2-3] 【Chemistry 5】 [Chemical formula 2-4] 【Chemistry 6】 [Chemical formula 2-5] 【Chemistry 7】 [Chemical formula 2-6] 【Chemistry 8】 [Chemical formula 2-7] 【Chemistry 9】 [Chemical formula 2-8] 【Chemistry 10】 [Chemical formula 2-9] 【Chemistry 11】 [Chemical formula 2-10] 【Chemistry 12】 [Chemical formula 2-11] 【Chemistry 13】

7. The ligand compound represented by the formula 1 is the ligand compound according to claim 1, which is represented by the following formula 3: [Chemical formula 3] 【Chemistry 14】 In the above Chemical Formula 3, R ５ is an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms.

8. The ligand compound represented by the formula 3 is a ligand compound represented by the following formula 3-1: [Chemical formula 3-1] 【Chemistry 15】

9. The ligand compound represented by the formula 1 is the ligand compound according to claim 1, which is represented by the following formula 4: [Chemical formula 4] 【Chemistry 16】 In the above Chemical Formula 4, R ５ is an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms.

10. The ligand compound represented by the formula 4 is a ligand compound represented by the following formula 4-1 or 4-2: [Chemical formula 4-1] 【Chemistry 17】 [Chemical formula 4-2] 【Chemistry 18】

11. The ligand compound represented by the formula 1 is the ligand compound according to claim 1, which is represented by the following formula 5: [Chemical formula 5] 【Chemistry 19】 In the above Chemical Formula 5, R ５ represents an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms substituted with an aryl group having 6 to 10 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms condensed with an aryl group having 6 to 10 carbon atoms, and n is 4 to 14.

12. The ligand compound represented by the formula 5 is a ligand compound represented by the following formula 5-1: [Chemical formula 5-1] 【Chemistry 20】

13. 13. An organochromium compound comprising the ligand compound of claim 1 and chromium coordinated to said ligand compound.

14. The organochromium compound according to claim 13, wherein in the ligand compound represented by Chemical Formula 1, at least one unshared electron pair of N and two P is coordinated to chromium.

15. A catalyst composition comprising the ligand compound of claim 1, chromium and a cocatalyst.

16. the chromium is derived from a chromium source; 16. The catalyst composition of claim 15, wherein the chromium source comprises one or more selected from the group consisting of chromium(III) acetylacetonate, chromium(III) chloride tetrahydrofuran, chromium(III) 2-ethylhexanoate, chromium(III) acetate, chromium(III) butyrate, chromium(III) pentanoate, chromium(III) laurate, chromium(III) tris(2,2,6,6-tetramethyl-3.5-heptanedionate), and chromium(III) stearate.

17. The catalyst composition according to claim 15, wherein the co-catalyst is at least one selected from the group consisting of compounds represented by the following formulas 6 to 9: [Chemical formula 6] <h2 style=";text-align:left;direction:ltr">-[Al(R<h2 style=";text-align:left;direction:ltr"> １３ <h2 style=";text-align:left;direction:ltr"> ()-O]<h2 style=";text-align:left;direction:ltr"> ａ <h2 style=";text-align:left;direction:ltr"> - In the above Chemical Formula 6, R １３ each independently represents a halogen group, a hydrocarbyl group having 1 to 20 carbon atoms, or a hydrocarbyl group having 1 to 20 carbon atoms substituted with a halogen group; a is an integer of 2 or greater; [Chemical formula 7] E(R １４ ) ３ In the above Chemical Formula 7, E is aluminum or boron; R １４ each independently represents a hydrogen atom, a halogen group, a hydrocarbyl group having 1 to 20 carbon atoms, or a hydrocarbyl group having 1 to 20 carbon atoms substituted with a halogen group, [Chemical formula 8] [L-H] ＋ [G(Y) ４ ] － [Chemical formula 9] [L] ＋ [G(Y) ４ ] － In the above Chemical Formulas 8 and 9, L is a neutral or cationic Lewis acid; [L-H] ＋ is a Brønsted acid, G is a group 13 element; Each Y is independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, where when the alkyl group or the aryl group is substituted, the substituent is a halogen group, a hydrocarbyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms.

18. A process for producing linear alpha-olefins comprising the step (S10) of oligomerizing ethylene in the presence of the catalyst composition of claim 15.

19. The method for producing linear alpha-olefins according to claim 18, wherein the linear alpha-olefin is 1-hexene, 1-octene or a mixture thereof.

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