Ruthenium coordination compound, ligand for its preparation and use thereof

Abstract

In the ruthenium coordination compound according to the present invention, the NHC ligand has excellent electron-donating ability to stabilize the methylene species due to the steric interaction between the substituents of relatively different sizes. The asymmetric structure of the ruthenium coordination compound can improve selectivity when used as a catalyst, and the activity of the ruthenium coordination compound can be improved by adjusting the substituents and additives. Therefore, even under relatively mild conditions, the ruthenium coordination compound can be used as a catalyst for cross-metathesis reactions, including the decomposition of ethylene alcohol, to produce desired compounds such as linear α-olefins in high yield.

Description

Technical Field

[0001] The present invention relates to a ruthenium coordination compound, a ligand for preparing the same, and uses thereof. Specifically, the present invention relates to a novel ruthenium coordination compound used as a catalyst with high selectivity and stability, a ligand for preparing the same, and a method for preparing linear α-olefins using the same. Background Art

[0002] Linear α-olefins (LAOs) having an olefinic bond at the terminal end are used as essential raw materials for various chemical products.

[0003] As methods for producing linear α-olefins from petrochemical raw materials, the Ziegler process of Scheme 1 and the Shell Higher Olefins Process (SHOP) process of Scheme 2 shown below are known.

[0004] [Scheme 1]

[0005]

[0006] [Scheme 2]

[0007]

[0008] However, these conventional methods have problems in that they require high temperature and high pressure conditions, and the synthesized linear α-olefin has a wide carbon number distribution due to the oligomerization reaction of ethylene.

[0009] At the same time, natural seed oils can be used to replace petroleum feedstocks to produce linear α-olefins. For example, linear α-olefins with terminal olefinic bonds, such as 1-decene as shown in Scheme 3 below, can be produced by cross-metathesis of methyl oleate obtained from renewable seed oil feedstock with ethylene, i.e., an ethenolysis reaction in the presence of a catalyst to cleave internal carbon-carbon double bonds and form new carbon-carbon double bonds.

[0010] [Scheme 3]

[0011]

[0012] This ethenolysis reaction can be carried out under mild conditions of a temperature of 25-100° C. and a pressure of 1-10 bar. Its advantage is that the carbon number distribution of the synthesized linear α-olefin is narrow.

[0013] Ruthenium coordination compounds comprising a symmetrical N-heterocyclic carbene (NHC) ligand and a methylene species are known as catalysts for the ethenolysis of ethylene (see Richard L. Pederson et al., Clean 2008, 36(8), 669-673).

[0014] Furthermore, ruthenium coordination compounds with asymmetrically substituted N-heterocyclic carbene ligands are known as promising ethenolysis catalysts with high selectivity for products via ethylene cross-metathesis compared to self-metathesis by-products (see RM Thomas et al., J. Am. Chem. Soc. 2011, 133, 7490-7496).

[0015] However, these conventional ruthenium coordination compounds have the problem that they lack the electron-donating ability to stabilize unstable methylene species, resulting in low stability and low selectivity for the desired linear α-olefins. There is also room for improvement in their activity. Summary of the Invention

[0016] Technical issues

[0017] Imidazo[1,5-a]pyridin-3-ylidene (ImPy), first described in 2005, is a structurally asymmetric NHC ligand with diverse electronic properties. In particular, ImPy ligands can be synthesized as anomalous carbene (anomalous ImPy, aImPy) ligands with improved electron-donating properties.

[0018] By studying the structure of ruthenium catalysts based on aImPy ligands and the effects of their electronic properties on catalytic activity, selectivity, and stability, the inventors have been able to synthesize a novel ruthenium catalyst that is stable at high temperatures and has high activity and selectivity. Furthermore, the inventors have discovered that the activity can be further enhanced by the addition of additives.

[0019] It is therefore an object of the present invention to provide a novel ruthenium coordination compound which can be advantageously used as a catalyst having high activity, selectivity and stability.

[0020] Another object of the present invention is to provide a ligand for preparing a ruthenium coordination compound.

[0021] Another object of the present invention is to provide a catalyst having high activity and stability and high selectivity for forming α-olefins, which comprises the ruthenium coordination compound.

[0022] Another object of the present invention is to provide a method for efficiently preparing linear α-olefins using the catalyst.

[0023] Problem Solution

[0024] In accordance with the above objectives, the present invention provides a ruthenium coordination compound as shown in the following formula 1:

[0025] [Formula 1]

[0026]

[0027] In the above formula,

[0028] R 1 For halogen, amino, C 1-3 Alkyl or C 1-3 alkoxy;

[0029] R 2 、R 3 and R 4 are independently hydrogen, halogen, amino, C 1-5 Alkyl or C 1-5 alkoxy;

[0030] R 5 and R 6 Each independently is C 5-10 Carbocyclic ring or 5-10 membered heterocyclic ring;

[0031] R 7 and R 8 are each independently halogen;

[0032] R 9 C 1-10 Alkyl, C 5-10 Carbocyclic ring or 5-10 membered heterocyclic ring;

[0033] R 10 and R 11 Each independently is C 1-10 Alkyl groups or condensed with each other to form C 5-10 carbocyclic or 5-10 membered heterocyclic ring; and

[0034] R 12 is N or O;

[0035] wherein the alkyl group and the alkoxy group are each independently unsubstituted or substituted with at least one of halogen, hydroxyl and amino;

[0036] The carbocyclic ring and the heterocyclic ring are each independently a saturated or unsaturated ring, and the saturated or unsaturated ring is unsubstituted or selected from halogen, nitro, C 1-5 Alkyl, halogenated C 1-5 Alkyl, C 1-5 substituted with at least one member selected from the group consisting of an alkoxy group and a phenyl group; and

[0037] The heterocyclic ring contains at least one heteroatom selected from N, S and O.

[0038] According to another object, the present invention provides a ligand for preparing a ruthenium coordination compound, which includes a compound represented by the following formula 2:

[0039] [Formula 2]

[0040]

[0041] In the above formula, R 1 to R 6 As defined in Formula 1 above.

[0042] According to yet another object, the present invention provides a catalyst comprising a ruthenium coordination compound.

[0043] According to still another object, the present invention provides a process for preparing linear α-olefins, which comprises adding ethylene to unsaturated fatty acids in the presence of a catalyst.

[0044] Advantageous Effects of the Invention

[0045] The ruthenium coordination compounds of the present invention exhibit high activity, selectivity, and stability when used as catalysts. Specifically, the ruthenium coordination compounds, when used as catalysts, can provide enhanced selectivity due to their asymmetric structure with substituents of relatively different sizes. Furthermore, due to the unusual structure of the ruthenium coordination compounds, their activity can be enhanced through their enhanced electron-donating properties. The activity can be further improved by controlling the additives. Therefore, even under relatively mild conditions, the ruthenium coordination compounds can be used as catalysts for cross-metathesis reactions, including the decomposition of ethylene glycol, to produce desired compounds, such as linear α-olefins, in high yields. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 The preparation and structure of the compound of Formula 1 according to the Examples are shown.

[0047] Figure 2 The results of X-ray crystallographic analysis of the compounds of Comparative Example 1 and Example 1 are shown.

[0048] Figure 3 The NHC ligands prepared in Comparative Example 1 and Example 1 are shown. 77 Se-NMR analysis results. DETAILED DESCRIPTION

[0049] The present invention will be described in detail below.

[0050] As used herein, the term "halogen" may be fluorine, chlorine, bromine or iodine, and it may refer to fluorine, chlorine, bromine or iodine as a substituent.

[0051] The term "alkyl" may refer to a straight or branched chain hydrocarbon moiety. An alkyl group may consist of, for example, 1 to 10 carbons. In this case, it may be represented as "C 1-10 alkyl".

[0052] The terms "haloalkyl", "haloalkoxy" and the like may refer to an alkyl group, an alkoxy group, and the like substituted with one or more halogens.

[0053] The term "carbocycle" refers to a saturated or unsaturated hydrocarbon ring, which may be aromatic or non-aromatic and may be monocyclic or polycyclic. A carbocycle may be, for example, a monocyclic / polycyclic ring consisting of 5 to 10 carbon atoms. In this case, it may be represented by "C 5-10 Carbon ring".

[0054] The term "heterocycle" refers to a saturated or unsaturated ring having one or more heteroatoms, which may be aromatic or non-aromatic and may be monocyclic or polycyclic. A heterocycle may be, for example, a monocyclic / polycyclic ring consisting of 5 to 10 heteroatoms and / or carbon atoms. In this case, it may be represented as a "5-10 membered heterocycle."

[0055] The term "heteroatom" may be an atom selected from N, O and S.

[0056] Ruthenium coordination compounds

[0057] The present invention provides a novel ruthenium coordination compound.

[0058] The ruthenium coordination compound according to an embodiment of the present invention is represented by the following Formula 1:

[0059] [Formula 1]

[0060]

[0061] In the above formula,

[0062] R 1 For halogen, amino, C 1-3 Alkyl or C 1-3 alkoxy;

[0063] R 2 、R 3 and R 4 are independently hydrogen, halogen, amino, C 1-5 Alkyl or C 1-5 alkoxy;

[0064] R 5 and R 6 Each independently is C 5-10 Carbocyclic ring or 5-10 membered heterocyclic ring;

[0065] R 7 and R 8 are each independently halogen;

[0066] R 9 C 1-10 Alkyl, C 5-10 Carbocyclic ring or 5-10 membered heterocyclic ring;

[0067] R 10 and R 11 Each independently is C1-10 Alkyl groups or condensed with each other to form C 5-10 carbocyclic or 5-10 membered heterocyclic ring; and

[0068] R 12 is N or O;

[0069] wherein the alkyl group and the alkoxy group are each independently unsubstituted or substituted with at least one of halogen, hydroxyl and amino;

[0070] The carbocyclic ring and the heterocyclic ring are each independently a saturated or unsaturated ring, and the saturated or unsaturated ring is unsubstituted or selected from halogen, nitro, C 1-5 Alkyl, halogenated C 1-5 Alkyl, C 1-5 substituted with at least one member selected from the group consisting of an alkoxy group and a phenyl group; and

[0071] The heterocyclic ring contains at least one heteroatom selected from N, S and O.

[0072] In one embodiment of Formula 1, R 1 is a halogen, more particularly fluorine.

[0073] In another example of Formula 1, R 2 and R 4 It's hydrogen.

[0074] In another example of Formula 1, R 3 is hydrogen or C 1-5 alkyl.

[0075] In yet another example of Formula 1, R 5 and R 6 Each independently is an aromatic C 6-10 Carbocyclic or 5-10 membered heterocyclic ring, wherein the carbocyclic ring and the heterocyclic ring are each independently unsubstituted or selected from halogen, nitro, C 1-5 Alkyl, halogenated C 1-5 Alkyl and C 1-5 The alkoxy group is substituted with at least one member selected from the group consisting of alkoxy groups.

[0076] In yet another example of Formula 1, R 5 and R 6 Each independently an aromatic C 6-10 Carbocyclic rings, wherein each carbocyclic ring is independently unsubstituted or substituted with one or more C 1-5 Alkyl substitution.

[0077] In another example of Formula 1, R 7 and R 8 It's chlorine.

[0078] In yet another example of Formula 1, R 9 It is C 1-10Alkyl or C 5-10 Carbocyclic rings, more specifically branched C 3-5 Alkyl or aromatic C 6-10 Carbon ring.

[0079] In yet another example of Formula 1, R 10 and R 11 Fused together to form aromatic C 6-10 Carbocyclic ring, the aromatic C 6-10 The carbocycle is unsubstituted or substituted with a phenyl group.

[0080] The ruthenium coordination compound of Formula 1 may include a mesoionic structure.

[0081] Furthermore, the ruthenium coordination compound of Formula 1 may include a carbene ligand having an unusual structure.

[0082] Specifically, the ruthenium coordination compound of Formula 1 includes an unusual imidazo[1,5-a]pyridin-3-ylidene (aImPy) structure having enhanced electron-donating properties.

[0083] In Formula 1, since aImPy has excellent electron-donating ability to stabilize the methylene species, the stability of the compound of Formula 1 can be enhanced.

[0084] In addition, the substituents in Formula 1 such as R can be adjusted 1 、R 5 、R 6 etc. to adjust the spatial effect.

[0085] In addition, since the aImPy ligand has an asymmetric structure, the selectivity can be improved when the compound of Formula 1 is used as a catalyst.

[0086] A ruthenium coordination compound according to another embodiment of the present invention is represented by the following formula 1a:

[0087] [Formula 1a]

[0088]

[0089] In the above formula,

[0090] R 1 For halogen, amino, C 1-3 Alkyl, halogenated C 1-3 Alkyl or C 1-3 alkoxy;

[0091] R 5 and R 6 Each independently is an aromatic C 5-10 Carbocyclic ring or 5-10 membered heterocyclic ring;

[0092] R 9 C 1-3an alkyl group or a phenyl group; and

[0093] R d and R e are each independently hydrogen, nitro or phenyl;

[0094] wherein the carbocyclic ring and the heterocyclic ring are each independently unsubstituted or selected from halogen, nitro, C 1-5 Alkyl, halogenated C 1-5 Alkyl and C 1-5 substituted with at least one member selected from the group consisting of alkoxy; and

[0095] The heterocyclic ring contains at least one heteroatom selected from N, S and O.

[0096] In one embodiment of Formula 1a, R 1 is a halogen, more particularly fluorine.

[0097] In another embodiment of Formula 1a, R 5 and R 6 Each independently is an aromatic C 6-10 Carbocyclic or 5-10 membered heterocyclic ring, wherein the carbocyclic ring and the heterocyclic ring are each independently unsubstituted or selected from halogen, nitro, C 1-5 Alkyl, halogenated C 1-5 Alkyl and C 1-5 The alkoxy group is substituted with at least one member selected from the group consisting of alkoxy groups.

[0098] In yet another example of Formula 1a, R 5 and R 6 Each independently an aromatic C 6-10 A carbon ring (e.g., a benzene ring or a naphthalene ring), wherein each carbon ring is independently unsubstituted or substituted with one or more C 1-5 Alkyl substitution.

[0099] A ruthenium coordination compound according to another embodiment of the present invention is represented by the following formula 1b:

[0100] [Formula 1b]

[0101]

[0102] In the above formula,

[0103] R 1 is a halogen; and

[0104] R a 、R b and R c Each is independently hydrogen, halogen, C 1-5 Alkyl, halogenated C 1-5 Alkyl or C 1-5 Alkoxy.

[0105] In one embodiment of Formula 1b, R a and R b Each independently is C 1-5 alkyl.

[0106] In another embodiment of Formula 1b, R a and R b Each independently is a branched C 3-5 alkyl.

[0107] In yet another example of Formula 1b, R c It's hydrogen.

[0108] X-ray crystal structure

[0109] Figure 2 The results of X-ray crystal structure analysis of the compound of Example 1 are shown.

[0110] In X-ray crystal structure analysis, ruthenium coordination compounds can show the presence of ruthenium (Ru) and substituents R 1 Between 2.85 and or 2.7 to distance.

[0111] Furthermore, in X-ray crystal structure analysis, ruthenium coordination compounds can show a 2.28 to 3.5 Å ratio between ruthenium (Ru) and oxygen (O). distance.

[0112] ligand

[0113] The invention also provides a ligand for preparing a ruthenium coordination compound.

[0114] The ligand comprises a compound represented by Formula 2:

[0115] [Formula 2]

[0116]

[0117] In the above formula, R 1 to R 6 As defined in Formula 1 above.

[0118] In addition, R 1 -R 6 More specific examples are as described above for the ruthenium coordination compounds.

[0119] The ligand of Formula 2 can be synthesized as a carbene ligand (aImPy) with a mesoionic structure or an abnormal structure. It has enhanced electron-donating properties. As a result, the stability of the ruthenium coordination compound can be enhanced because the ligand has excellent electron-donating ability to stabilize the methylene species.

[0120] In addition, the substituents in Formula 2 such as R can be adjusted 1 、R 5 、R 6 In addition, since the ligand of Formula 2 has an asymmetric structure, when the ruthenium coordination compound is used as a catalyst, the selectivity can be improved.

[0121] catalyst

[0122] The present invention also provides a catalyst comprising a ruthenium coordination compound.

[0123] The catalyst can be used for the cross-metathesis reaction. For example, the catalyst can be used for the cross-metathesis reaction using an olefin compound.

[0124] As a specific example, the catalyst can be used for alkenolysis reactions. Specifically, the catalyst can be used for ethenolysis reactions using ethylene. More specifically, the catalyst can be used for ethenolysis reactions of unsaturated fatty acids such as methyl oleate.

[0125] As another specific example, the catalyst can be used for a metathesis reaction via ethenolysis of a linear or cyclic olefin compound.

[0126] As another specific example, the catalyst can be used for an intramolecular cross metathesis reaction, a ring-opening metathesis reaction, a ring-closing metathesis reaction, a ring-opening metathesis polymerization reaction, or an acrylic diene metathesis polymerization reaction.

[0127] As another specific example, the catalyst can be used for the depolymerization reaction or ethenolysis reaction of an unsaturated linear polymer containing double bonds.

[0128] In addition to the ruthenium coordination compound, the catalyst may also contain one or more additional compounds for enhancing catalytic activity. Specifically, when used as a catalyst, the ruthenium coordination compound may be used in combination with one or more additional compounds to enhance activity. The additional compounds are not particularly limited as long as they contribute to enhancing catalytic activity and may be, for example, metal-based compounds such as metal halides.

[0129] As an example, the catalyst may further comprise a copper compound. The copper compound may be a compound in which an anionic species such as a halogen is combined with a copper cation. Specifically, the copper compound is one or more selected from the group consisting of tricyclohexylphosphine-copper chloride (PCy3CuCl), copper chloride (CuCl), copper iodide (CuI), and copper (I) thiophene-2-carboxylate (CuTc).

[0130] As another example, the catalyst may further include a sodium compound. The sodium compound may be a compound in which an anionic substance such as a halogen is combined with a sodium cation. Specifically, the sodium compound may be one or more selected from the group consisting of sodium bromide (NaBr), sodium iodide (NaI), sodium acetate (NaOAc), and sodium benzoate (PhCOONa).

[0131] The catalyst may be used in an amount ranging from 1 ppm to 100 ppm, from 1 ppm to 50 ppm, or from 5 ppm to 20 ppm.

[0132] The catalysts are excellent in selectivity and turnover number (TON). For example, the catalysts may have a selectivity of 80% or greater, 85% or greater, 90% or greater, or 95% or greater. In addition, the catalysts may have a TON of 10,000 or greater, 15,000 or greater, 20,000 or greater, or 25,000 or greater.

[0133] Additionally, the catalyst may have a conversion of 30% or more, 40% or more, 50% or more, 60% or more, or 70% or more.

[0134] Method for preparing linear alpha-olefins

[0135] The present invention also provides a process for preparing linear α-olefins, which comprises adding ethylene to unsaturated fatty acids in the presence of a catalyst.

[0136] In the method of preparing the linear α-olefin, the unsaturated fatty acid includes a compound represented by the following Formula 3, and the linear α-olefin may have 2 to 10 carbon atoms.

[0137] [Formula 3]

[0138]

[0139] In the above formula, R is C 1-6 an alkyl group; and p and q are each independently an integer from 1 to 10.

[0140] Additionally, in the method for producing a linear α-olefin, the unsaturated fatty acid may be methyl oleate, and the linear α-olefin may be 1-decene.

[0141] In the preparation method, the catalyst may be used at a concentration of 1 ppm to 100 ppm.

[0142] Specifically, the catalyst may be used at a concentration of 1 ppm to 50 ppm.

[0143] More specifically, the catalyst may be used at a molar concentration of 1 ppm to 50 ppm, 1 ppm to 40 ppm, 10 ppm to 40 ppm, or 5 ppm to 20 ppm based on the number of moles of the unsaturated fatty acid.

[0144] The preparation method can be carried out under conditions of lower pressure and lower temperature.

[0145] For example, the pressure conditions of the preparation method may be in the range of 50 psi to 300 psi or 100 psi to 200 psi.

[0146] In addition, the temperature conditions of the preparation method may be in the range of 20°C to 100°C or 30°C to 60°C.

[0147] In addition, in the preparation method, after adding ethylene to the unsaturated fatty acid, the reaction may be performed for 30 minutes to 20 hours, 30 minutes to 10 hours, 30 minutes to 5 hours, or 1 hour to 3 hours.

[0148] In the preparation method, the selectivity may be 80% or more, 85% or more, 90% or more, or 95% or more.

[0149] Furthermore, in the preparation method, TON may be 10,000 or more, 15,000 or more, 20,000 or more, or 25,000 or more.

[0150] Furthermore, in the preparation method, the conversion rate may be 30% or more, 40% or more, 50% or more, 60% or more, or 70% or more.

[0151] Furthermore, in the preparation method, the conversion rate may be 20% or more, 30% or more, 40% or more, 50% or more, or 60% or more.

[0152] Methods for calculating selectivity, TON, conversion, and yield are exemplified in the test examples described below.

[0153] Modes for Carrying Out the Invention

[0154] The present invention will be described in detail below with reference to Examples. However, the following Examples are intended to illustrate the present invention. The scope of the present invention is not limited thereto.

[0155] Example 1: Preparation of ruthenium coordination compounds (compounds c25 to c32)

[0156]

[0157] 3-Fluoropyridine (Compound C1) was selectively lithiated and reacted with dimethylformamide (DMF) to produce an aldehyde (Compound C2). The aldehyde (Compound C2) reacted with 2,6-diethylaniline, 2,6-diisopropylaniline, and 2,6-di(3-pentyl)aniline, respectively, to form imines (Compounds C3 to C5), which were then reduced with NaBH4 to produce amines (Compounds C6 to C8). The amines (Compounds C6-C8) reacted with aromatic acid chlorides to form amides (Compounds C9 to C16), which were cyclized in the presence of trifluorosulfonyl anhydride (Tf2O) and an amine base to produce carbene ligands (Compounds C17 to C24). These carbene ligands (Compounds C17 to C24) were then exchanged with the phosphine ligands of the first-generation Grubbs-Hoveyda catalyst (GH1) to synthesize ruthenium catalysts (Compounds C25 to C32).

[0158] More specific procedures and reaction conditions for each step are described below.

[0159] Step (1) Preparation of compound c2

[0160] n-Butyl lithium (1.1 equivalents) was added to a 1.1 M ether solution of 1,4-diazabicyclo[2.2.2]octane (DABCO) (1 equivalent) and stirred for 1 hour. The mixture was cooled at -60°C, and a solution of 3-fluoropyridine (Compound c1) (2 M, 1 equivalent) was added dropwise. The mixture was stirred at -60°C for 2 hours, and dimethylformamide (DMF, 2 M, 2 equivalents) was added. The mixture was stirred at -60°C for 1 hour and purified by column chromatography to obtain Compound c2.

[0161] Step (2) Preparation of compounds c3 to c5

[0162] Compound c2 (1 equivalent) and aniline (1 equivalent) were dissolved in ethanol (0.5 M). The mixture was stirred and kept at 80° C. for 4 hours. The product was used in the next step without purification.

[0163] Step (3) Preparation of compounds c6 to c8

[0164] NaBH₄ was slowly added to a methanol solution of compounds C3 to C5 at 0°C. The reaction mixture was stirred at reflux overnight. The organic phase was extracted, collected, and dried over MgSO₄. The solvent was removed, and the product was purified by column chromatography to yield compounds C6 to C8.

[0165] Step (4) Preparation of compounds C9 to C16

[0166] Compounds C6 to C8 and the acid chloride were dissolved in 1,2-dichloroethane (DCE). The reaction mixture was stirred under reflux overnight and then cooled to room temperature. The solvent was removed and the product was purified by column chromatography to obtain the corresponding compounds C9 to C16.

[0167] Step (5) Preparation of compounds c17 to c24

[0168] Each of compounds C9 to C16 (1 equivalent) was dissolved in dichloromethane (DCM). Triethylamine (Et3N, 1 equivalent) was added dropwise to the solution at -40°C. After 5 minutes, trifluoromethanesulfonic anhydride (Tf2O, 1 equivalent) was carefully added. The mixture was warmed to room temperature and stirred for 4 hours. The solvent was removed and the product was purified by column chromatography to obtain the corresponding compounds C17 to C24 as carbene ligands.

[0169] Step (6) Preparation of compounds C25 to C32

[0170] A benzene solution of compounds C17 to C24 (2 equivalents) and potassium bis(trimethylsilyl)amide (KHMDS, 2.2 equivalents) was stirred at room temperature for 30 minutes. The solution was filtered and added to a benzene solution of a first-generation Grubbs-Hoveyda catalyst. The mixture was filtered through a pad of celite and eluted with benzene, and the filtrate was concentrated. Thereafter, purification by column chromatography gave the corresponding compounds C25 to C32.

[0171] Example 2: Preparation of ruthenium coordination compounds (compounds c36 to c38)

[0172]

[0173] A benzene solution of compound c17 (2 equivalents) prepared in Example 1 and potassium bis(trimethylsilyl)amide (KHMDS, 2.2 equivalents) was stirred at room temperature for 30 minutes. The solution was filtered and added to a benzene solution of the first-generation Grubbs catalyst. The mixture was filtered through a celite pad and eluted with benzene, and the filtrate was concentrated. Thereafter, styrene compounds c33 to c35 were each added thereto. The mixture was heated to 40° C. and stirred for 2 hours. Thereafter, purification by column chromatography gave corresponding compounds c36 to c38.

[0174] The structural formulas, yields and 1 H-NMR data are shown in the table below.

[0175] [Table 1]

[0176]

[0177]

[0178]

[0179] Comparative Example 1

[0180]

[0181] The bromopyridine derivative is selectively fluorinated with AgF2 (see P.S. Fier and J.F. Hartwig, Science 2013, 342, 956), subjected to bromine-lithium exchange, and reacted with DMF to obtain fluoropyridine carboxaldehyde. Thereafter, it reacts with aniline to form an imine, which is then cyclized with silver trifluoromethanesulfonate (AgOTf) and chloromethyl pivalate (tBuCOOCH2Cl) to obtain a carbene ligand. Thereafter, the carbene ligand is exchanged with the phosphine ligand of the first-generation Grubbs-Hoveida catalyst to synthesize a ruthenium catalyst.

[0182] Test Example 1: X-ray crystallography

[0183] X-ray crystallography was performed on the compounds prepared in the above examples. Single crystals for X-ray crystallography were grown at 25°C by slow diffusion of hexane in a dichloromethane solution of the catalyst.

[0184] Figure 2 The X-ray crystallographic analysis results of the compounds of Comparative Example 1 and Example 1 are shown. For clarity, hydrogen atoms are not indicated. The interaction between ruthenium and fluorine can be confirmed by the distance between them. This interaction between ruthenium and fluorine is related to the stabilization of the methylene ruthenium intermediate.

[0185] like Figure 2 As shown, it was confirmed that the complex showed a distorted tetragonal pyramid orientation and the N-aryl group was located above the O-chelated benzylidene group. In particular, compared with the ruthenium coordination compound of Comparative Example 1, it was confirmed that the Ru-F1 distance and Ru-O1 ​​distance of the ruthenium coordination compound of Example 1 were further increased, and the N1-C1-Ru angle was increased. It can be understood that in the compound of Example 1, R in Formula 1 1 is fluorine, and R 5 and R 6 is a benzene ring, thus R 5 Compared to the case of hydrogen, the steric interaction is maximized.

[0186] Test Example 2: NMR analysis

[0187] In order to analyze the electronic properties of the carbene ligands prepared in Example 1 and Comparative Example 1, Se complexes were synthesized and subjected to 77SE-NMR. The results are shown in Figure 3 middle.

[0188] like Figure 3 As shown, the selenium complexes of each carbene ligand prepared in Comparative Example 1 and Example 1 77 Se-NMR signals were measured at 166.74 ppm and 103.43 ppm, respectively. That is, the selenium complex of the carbene ligand prepared in Example 1 exhibited a signal at a higher-field chemical shift than the carbene ligand prepared in Comparative Example 1. Therefore, it is expected to function as a weak π-acceptor and a strong electron-donating ligand.

[0189] Test Example 3: Evaluation of Catalyst Performance in the Ethylene Decomposition Reaction of Methyl Oleate

[0190] The ethenolysis reaction of methyl oleate was carried out using each compound described in Examples as a catalyst.

[0191] Specifically, as shown in the following reaction scheme, methyl oleate (compound 11, 1 mmol) is reacted with 150 psi of C2H4 (purity 99.95%) in the presence of a catalyst (0.005 mol%, 50 ppm) at 40°C for 1 hour to carry out ethylene decomposition reaction to obtain linear α-olefins (compounds 12 and 13) and other products (compounds 14 and 15).

[0192]

[0193] In the above reaction, the catalyst performance was evaluated as follows. The results are summarized in the following table.

[0194] -Conversion rate (%) = [1-(final mole number of compound 11 / initial mole number of compound 11)] × 100

[0195] -Selectivity (%) = (total moles of compounds 12 and 13) / [(total moles of compounds 12 and 13) + (total moles of compounds 14 and 15) × 2]

[0196] (Conversion and selectivity were determined by GC using tridecane as an internal standard.)

[0197] - Yield (%) = conversion rate × selectivity / 100

[0198] -TON (turnover number) = yield × (initial moles of compound 11 / moles of catalyst) / 100

[0199] [Table 2]

[0200] serial number catalyst Conversion rate (%) Selectivity (%) Yield %) TON 1 Compound C25 72 94 67 13400 2 Compound C26 64 95 61 12200 3 Compound C27 73 94 68 13600 4 Compound C28 71 95 68 13600 5 Compound C29 72 94 68 13600 6 Compound C30 71 95 67 13500 7 Compound C31 23 86 20 4000

[0201] As can be seen from the above table, when compound c25 having an asymmetric NHC ligand is used as a catalyst, it exhibits high selectivity in the α-olefin synthesis method compared to the known selectivity (30-40%) of conventional Grubbs-Hoveyda type Ru catalysts with symmetric NHC ligands. In addition, when compounds c26 to c30 having NHC ligands with asymmetric structures are used as catalysts (numbers 2 to 6), similar to compound c25, high selectivity is shown in the α-olefin synthesis method. In addition, in order to study the steric effect of the aImPy ligand, compound c31 (number 7) was tested under the same reaction conditions. As a result, it exhibited low conversion, low selectivity, and low turnover number compared to compound c25. It can be understood that as the steric hindrance of the aromatic group decreases, the stability of the catalyst decreases and the self-metathesis reaction is higher.

[0202] Test Example 4: Evaluation of catalyst performance according to reaction conditions

[0203] Using Compound C25 prepared in Example 1 as a catalyst, the ethylene decomposition reaction of methyl oleate was carried out in the same manner as in Test Example 3, except that the amount of catalyst added, the temperature, and the reaction time were adjusted as shown in the following table. The catalyst performance during the reaction was evaluated using the same method and criteria as in Test Example 3. The results are summarized in the following table.

[0204] [Table 3]

[0205]

[0206] As can be seen from the table above, a high TON of 20,000 was achieved at 40°C when the catalyst dosage was 30 ppm (number 2). When the catalyst dosage was less than this (numbers 3 and 4), the catalytic effect gradually decreased. Furthermore, even when the reaction temperature was increased to 60°C and 80°C, the catalyst activity did not significantly decrease. Therefore, this catalyst exhibits high thermal stability in an ethylene atmosphere (numbers 5 and 6).

[0207] Test Example 5: Evaluation of catalyst performance based on additives

[0208] Using Compound C25 prepared in Example 1 as a catalyst, the ethylene decomposition reaction of methyl oleate was carried out in the same manner as in Test Example 3, except that various catalysts were used and the catalyst addition amount, temperature, and time during the reaction were adjusted as shown in the table below. The catalyst performance during the reaction was evaluated using the same method and criteria as in Test Example 3. The results are summarized in the table below.

[0209] [Table 4]

[0210]

[0211] As can be seen from the table above, even relatively low catalyst amounts (numbers 2 and 3) exhibit excellent performance when used in combination with additives. In particular, when combined with PCy3CuCl, a high TON of 63,000 was achieved at 40°C using a catalyst amount of 3 ppm (number 4). Furthermore, the catalyst remained active even when the catalyst amount was reduced to 1 ppm, confirming its stability (numbers 5 and 6).

[0212] Test Example 6: Evaluation of catalyst performance based on ligand changes

[0213] The ethylene decomposition reaction of methyl oleate was carried out in the same manner as in Test Example 3, except that the catalyst type, catalyst addition amount, pressure, temperature, and time during the reaction were adjusted as shown in the table below. The catalyst performance during the reaction was evaluated in the same manner and under the same conditions as in Test Example 3. The results are summarized in the table below.

[0214] [Table 5]

[0215]

[0216] As can be seen from the above table, when the catalyst dosage was 10 ppm, a high TON of up to 28,000 was exhibited at 40° C. When the amount of the catalyst was less than this, the catalyst activity did not decrease significantly (No. 1-8).

[0217] Test Example 7: Evaluation of catalyst performance according to changes in catalyst and additives

[0218] The ethylene decomposition reaction of methyl oleate was carried out in the same manner as in Test Example 3, except that the catalyst type, catalyst addition amount, pressure, temperature, and time during the reaction were adjusted as shown in the table below. The catalyst performance during the reaction was evaluated in the same manner and under the same conditions as in Test Example 3. The results are summarized in the table below.

[0219] [Table 6]

[0220]

[0221] As can be seen from the table above, when used in combination with PCy3CuCl as an additive, excellent performance was demonstrated even when the catalyst amount was reduced to 5 ppm in most catalysts. It showed a selectivity of 97% or higher (up to 99% or higher) and a high TON of 28,000 or higher (up to 58,000) at 40°C (Nos. 1-9).

[0222] Comparison of performance with conventional ruthenium coordination compounds

[0223] The following compounds 21 to 23 can be synthesized by the method of Richard L. Pederson et al. [Clean 2008, 36(8), 669-673], and the following compound 24 can be synthesized by the method of Robert H. Grubbs et al. [J. Am. Chem. Soc. 2011, 133, 7490-7496].

[0224]

[0225] Based on the test results described in these documents, the catalytic performance of compounds 21-24 in the ethenolysis reaction of methyl oleate is summarized in the following table.

[0226] [Table 7]

[0227]

[0228]

[0229] As can be seen from the table above, compounds 21 to 23 having symmetrical NHC ligands are inferior in selectivity and yield to the ruthenium coordination compound of the present invention of formula 1. For compound 24, the reaction yield and TON are very poor.

Claims

1. A ruthenium coordination compound represented by the following formula C25, C26, C27, C28, C29, C30, C32, C36, C37 or C38:

2. A catalyst comprising the ruthenium coordination compound according to claim 1.

3. The catalyst according to claim 2, further comprising a copper compound, wherein the copper compound is one or more selected from the group consisting of tricyclohexylphosphine-copper chloride, copper chloride, copper iodide and copper (I) thiophene-2-carboxylate.

4. Use of the catalyst according to claim 2 in olefin alcohol decomposition reaction.

5. Use of the catalyst according to claim 2 in the metathesis reaction of ethenolysis of linear or cyclic olefin compounds.

6. Use of the catalyst according to claim 2 in an intramolecular cross metathesis reaction, a ring-opening metathesis reaction or a ring-closing metathesis reaction. The use according to claim 6 , wherein the ring-opening metathesis reaction is a ring-opening metathesis polymerization reaction.

8. Use of the catalyst according to claim 2 in the metathesis polymerization of acrylic acid diene.

9. Use of the catalyst according to claim 2 in the depolymerization reaction of an unsaturated linear polymer containing double bonds or in the ethylene alcohol decomposition reaction.

10. A method for preparing a linear α-olefin, comprising adding ethylene to an unsaturated fatty acid in the presence of the catalyst according to claim 2, wherein the unsaturated fatty acid comprises a compound represented by the following formula 3, and the linear α-olefin has 2 to 10 carbon atoms: Formula 3 In the above formula, R is C 1-6 an alkyl group; and p and q are each independently an integer from 1 to 10.

11. The method for producing linear α-olefins according to claim 10, wherein the catalyst is used at a molar concentration of 1 ppm to 50 ppm based on the number of moles of the unsaturated fatty acid.

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