Imidazole-coordinated ruthenium carbene olefin metathesis catalysts, their preparation and applications

Abstract

This invention discloses an imidazole-coordinated ruthenium carbene olefin metathesis catalyst, as shown in formula (I): wherein R is selected from benzyl, 2,4,6-trimethylphenyl, or methyl. This invention also discloses its preparation and application. The method provided by this invention is simple in procedure and requires mild conditions.

Description

Technical Field

[0001] This invention relates to an imidazole-coordinated ruthenium carbene olefin metathesis catalyst, its preparation, and its application. Background Technology

[0002] Dimethyl octadecanoate is an important chemical raw material with significant applications in the synthesis of high-grade lubricants, high-grade nylon, and high-grade fragrances. The most efficient synthesis method for dimethyl octadecanoate is through the ethyleneolysis of methyl oleate to obtain methyl 9-decenoate or directly to obtain dimethyl octadecanoate. This reaction is a special case of olefin metathesis.

[0003] Since the 1990s, the development of ruthenium metal olefin metathesis catalysts has been very rapid. The most representative and epoch-making catalysts are those developed by the Grubbs group, using alkylphosphine and halogen atoms as ligands. These catalysts, known as Grubbs' first-generation catalysts, are stable in air, exhibit high catalytic activity, and good functional group compatibility, representing a very classic catalyst structure. In 1999, Grubbs et al. modified the first-generation catalyst by replacing one of the tricyclohexylphosphine ligands in its structure with a sterically hindered and electron-donating N-heterocyclic carbene (NHC) ligand, resulting in a new catalyst structure later called the Grubbs II catalyst. The catalytic activity of Grubbs II was two orders of magnitude higher than that of Grubbs I, significantly reducing the amount of catalyst required for the catalytic reaction. Furthermore, this type of catalyst has high thermal stability and better functional group compatibility. Subsequently, the Grubbs group replaced the tricyclohexylphosphine ligand in the Grubbs II catalyst with pyridine, obtaining the Grubbs III catalyst, which contains two pyridines and has a high initiation rate. In 2009, Hoveyda et al. prepared a phenol-oxygen chelate-type ruthenium carbene complex based on the Grubbs I catalyst. This complex exhibited significant activity and excellent stability, making it suitable for large-scale preparation of various olefin compounds. Furthermore, this catalyst is recyclable and can be recovered after the reaction via a simple chromatographic method. It was the first recyclable olefin metathesis catalyst, capable of efficiently catalyzing homogeneous olefin metathesis reactions without loss of activity during reuse. This catalyst was later named the Hoveyda-Grubbs I catalyst. In 2010, based on the Grubbs II catalyst, Hoveyda's group successfully developed the Hoveyda-Grubbs II catalyst. Compared to other previous ruthenium catalysts, this type of catalyst exhibits higher initiation rates and stability (air-stable), and requires milder reaction conditions, achieving high yields at room temperature. It also shows high catalytic activity for electron-deficient olefins such as acrylonitrile and fluoroolefins. Most importantly, this type of catalyst can be immobilized and recovered using chemical and physical methods with high recovery efficiency.

[0004] However, these catalysts have not performed satisfactorily in the ethyleneolysis of methyl oleate, failing to meet industrial requirements. In 2014, Grubbs' group discovered a novel mono-nitrogen ring carbene (CAAC) ruthenium catalyst. This catalyst alters the nitrogen heterocyclic carbene ligand of traditional catalysts, replacing one nitrogen atom with a carbon atom, which greatly enhances its performance in this type of reaction. The products are mainly methyl 9-decenoate and 9-decenoic acid, with selectivity exceeding 95% for these two compounds, but very low selectivity for dimethyl 9-octadecenoate. However, this type of catalyst exhibits weak activity for cross- and ring-closing metathesis reactions. Therefore, if dimethyl 9-octadecenoate is desired, a cross-metathesis reaction of methyl 9-decenoate with a traditional olefin metathesis catalyst is required. Thus, this type of catalyst remains limited to basic research and has not been applied to industrial production. Grubbs III catalysts mainly produce dimethyl 9-octadecenoate and 9-octadecene products in the ethylene hydrolysis of methyl oleate, with a product selectivity of ≥97%. However, the catalytic activity is low. Therefore, it is of great significance to change the structure of Grubbs III catalysts to improve the yield of dimethyl 9-octadecenoate. Summary of the Invention

[0005] To further improve the catalytic activity of Grubbs III catalyst, a series of studies were conducted. The results showed that the low catalytic activity of Grubbs III catalyst is due to the easy dissociation of the pyridine ligand. After dissociation, the methyl group on the trimethylphenyl group of the nitrogen-containing heterocyclic carbene readily reacts with the Ru active center to obtain structure b. Structure b then destroys the benzylmethylene carbene structure through proton transfer, yielding structure c. At this point, the catalyst has lost its catalytic activity. Structure c further removes the benzylmethylene structure, forming a stable, inactive dimer with structure a. See the diagram below for details.

[0006]

[0007] Based on this discovery, it is proposed to replace pyridine with ligands that have stronger coordination ability and are more difficult to dissociate, thereby suppressing the catalyst decomposition process and significantly improving the stability and activity of the catalyst. The novel catalyst provided by this invention shows significant application potential in the catalytic conversion of unsaturated octadecanoic acid dimethyl ester, 1-decene, and 9-decenoic acid methyl ester. Furthermore, the structure of the catalytic products can be controlled by adding a co-catalyst, which is of great significance in practical applications.

[0008] Studies have found that replacing pyridine with imidazole yields better results. Imidazole, a five-membered aromatic heterocyclic compound, has two double bonds and is rich in π electrons. In its molecular structure, the two nitrogen atoms are in the meta position, and the nitrogen atom at position 1 participates in ring conjugation, causing its hydrogen atom to readily convert to hydrogen via H.+ Because the nitrogen atom at position 3 is delocalized, the imidazole ring exhibits weak acidity; however, it does not participate in ring conjugation and can accept proton attack, thus the imidazole ring also possesses some basicity. The amphoteric nature of the imidazole ring can be explained by resonance interactions. The imidazole ring has six electrons, which are delocalized among five atoms, resulting in a higher electron cloud density and stronger basicity and coordination ability than pyridine. Furthermore, due to the amphoteric nature of the imidazole ring, when imidazole is used as a ligand, both nitrogen atoms on the imidazole ring can act as coordinating atoms, thereby forming complexes with other metals. First, when the imidazole ring acts as a neutral ligand, it can coordinate with the nitrogen atom at position 1 to form a monodentate chelate ligand. Second, when imidazole loses a proton to become a monovalent imidazole salt, it can self-assemble with a transition metal through the two nitrogen atoms in the molecule, thus forming a bidentate chelate ligand. Third, the imidazole ring accepts a proton to form a monovalent imidazole salt, in which case the carbon atom at position 2 participates in coordination. Therefore, the characteristics of imidazole under different conditions make its coordination modes more diverse. The protonation and deprotonation of imidazole can be understood with reference to the following formula. See the diagram below for details:

[0009]

[0010] In the cyclic metathesis of olefins, the chemoselectivity of the catalyst can be controlled by adding 3-bromo-1-propyne, resulting in a single catalytic product. Firstly, without the addition of 3-bromo-1-propyne, the catalyst exhibits substrate competition during the catalytic process, as shown in the following diagram:

[0011]

[0012] By adding 3-bromo-1-propyne, the structure and chemoselectivity of the product can be controlled, and the mechanism is shown in the figure below:

[0013]

[0014] As one aspect of the present invention, there is a ruthenium carbene olefin metathesis catalyst with imidazole coordination, as shown in formula (I):

[0015]

[0016] R is selected from benzyl (Bn), 2,4,6-trimethylphenyl (Mes), or methyl (Me).

[0017] As another aspect of the present invention, a method for preparing the above-mentioned imidazole-coordinated ruthenium carbene olefin metathesis catalyst is provided, comprising: reacting the Grubbs II catalyst with a benzyl-substituted imidazole salt, a trimethylphenyl-substituted imidazole salt, or a methyl-substituted imidazole salt in an organic solvent system.

[0018] In a specific embodiment, the method includes: dissolving the Grubbs II catalyst in an organic solvent (such as dichloromethane, chloroform, tetrahydrofuran, or toluene), and adding a benzyl-substituted imidazole salt, a trimethylphenyl-substituted imidazole salt, or a methyl-substituted imidazole salt to the reaction system at 10-60°C, preferably 30°C-60°C.

[0019] In specific embodiments, the molar ratio of the added benzyl-substituted imidazole salt, trimethylphenyl-substituted imidazole salt, or methyl-substituted imidazole salt to the Grubbs II catalyst is 1:1-4:1, preferably 2:1-3:1.

[0020] In a specific embodiment, the benzyl-substituted imidazole salt is specifically N-benzylimidazole, the trimethylphenyl-substituted imidazole salt is specifically N-2,4,6-trimethylphenylimidazole, and the methyl-substituted imidazole salt is specifically N-methylimidazole.

[0021] In a specific embodiment, the above method further includes: after the reaction is complete, removing part of the solvent under reduced pressure, adding n-hexane, and centrifuging, filtering, and drying the precipitated product. In a specific embodiment, after adding a benzyl-substituted imidazole salt, a trimethylphenyl-substituted imidazole salt, or a methyl-substituted imidazole salt, the reaction is maintained at the temperature for at least 2 hours.

[0022] The reaction process of the preparation method provided by this invention is illustrated below:

[0023]

[0024] Wherein, Bn is benzyl; Mes is 2,4,6-trimethylphenyl; and Me is methyl.

[0025] As another aspect of the present invention, the application of the above-mentioned imidazole-coordinated ruthenium carbene olefin metathesis catalyst in the catalytic conversion of saturated octadecanoic acid dimethyl ester, 1-decene, and 9-decenoate methyl ester is discussed.

[0026] As another aspect of the invention, a catalytic conversion process is provided for unsaturated octadecanoic acid dimethyl ester, 1-decene, and methyl 9-decenoate, using the aforementioned imidazole-coordinated ruthenium carbene olefin metathesis catalyst. In a specific embodiment, 3-bromo-1-propyne may also be added.

[0027] The method provided by this invention has simple steps and requires mild conditions.

[0028] In the cyclic metathesis of olefins, the present invention can improve catalytic efficiency and control the configuration of the product by adding 3-bromo-1-propyne.

[0029] The imidazole-coordinated ruthenium carbene olefin metathesis catalyst provided by this invention exhibits higher stability and a higher total number of oxidation states (TON) for the ethylene hydrolysis of methyl oleate compared to the Grubbs III catalyst, resulting in significantly improved catalytic activity. For details, please refer to [reference needed]. Figure 1 . Attached Figure Description

[0030] Figure 1 The figure shows the stability test results of the imidazole-coordinated ruthenium carbene olefin metathesis catalyst and the Grubbs III catalyst provided in this invention. The figure uses benzophenone as an internal standard, and the results were obtained at 40°C using… 1 ¹H NMR was used to monitor the decomposition of complexes Grubbs III, I, II, and III in THF-d8. The results showed that the catalyst stability was: II > I > III > Grubbs III. Detailed Implementation

[0031] Synthesis of Ruthenium Complexes I-III

[0032] Example 1

[0033] Synthesis of the ruthenium complex [1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(pheny-lmethylene)bis(N-benzylimidazole)ruthenium(I):

[0034] Synthesis Method 1: Add 0.42 g (0.50 mmol, 1.0 equiv.) of Grubbs II catalyst to a round-bottom flask, and dissolve it in 20 mL of organic solvent (such as toluene, tetrahydrofuran, acetonitrile, dichloromethane, and diethyl ether, all of which can be used to synthesize target catalyst I). Heat the reaction system to 30 °C, and slowly add N-benzylimidazolium salt (0.08 g, 0.5 mmol, 1.0 equiv.). Continue the reaction for 2 h. The mixture color changes from reddish-brown to brownish-green. The reaction progress is monitored using TLC and silica gel plate analysis (developing solvent ratio PE:DCM = 1:1). Stop stirring when the Grubbs II catalyst has completely reacted. Place the flask on a rotary evaporator. Under water pump pressure (-0.1 MPa) and a rotary evaporation water bath temperature of 24 °C, 18 mL of solvent is distilled off. Add an appropriate amount of n-hexane and sonicate; solid precipitates out. Add filter paper to a Buchner funnel and place it on a suction flask connected to a water pump. Pour the reaction mixture containing the solid into the Buchner funnel and filter out the solid. Wash the solid in the Buchner funnel with n-hexane (3 × 20 mL), collect the solid in a dry flask, and evaporate the solvent under vacuum to obtain green solid I (ruthenium complex I). The yield of the target compound is 33% with toluene as solvent; 41% with tetrahydrofuran as solvent; 26% with acetonitrile as solvent; 53% with dichloromethane as solvent; and 15% with diethyl ether as solvent.

[0035] Synthesis Method 2: Add 0.42 g (0.50 mmol, 1.0 equiv.) of Grubbs II catalyst to a round-bottom flask, dissolve it in 20 mL of dichloromethane, heat the reaction system to 40 °C, and slowly add N-benzylimidazolium salt (0.08 g, 0.5 mmol, 1.0 equiv.; 0.16 g, 1.0 mmol, 2.0 equiv.; 0.24 g, 1.5 mmol, 3.0 equiv.; 0.32 g, 2.0 mmol, 4.0 equiv.). Continue the reaction for 2 h. The color of the mixture changes from reddish-brown to brownish-green. The reaction progress is judged by TLC, and the reaction progress is monitored by silica gel plate (developing solvent ratio PE:DCM = 1:1). When the Grubbs II catalyst has completely reacted, stop stirring. The flask was placed on a rotary evaporator. Under water pump pressure (-0.1 MPa) and a rotary evaporation water bath temperature of 24°C, 18 mL of solvent was distilled off. An appropriate amount of n-hexane was added, and the mixture was ultrasonically vibrated, resulting in the precipitation of a solid. Filter paper was placed in a Buchner funnel, which was then placed on a suction flask connected to a water pump. The reaction mixture containing the solid was poured into the Buchner funnel, and the solid was filtered out. The solid was washed in the Buchner funnel with n-hexane (3 × 20 mL), and then collected in a dry flask. The solvent was removed using a vacuum pump, yielding green solid I (ruthenium complex I). The yield of the catalyst was 53% when the molar ratio of catalyst to N-benzylimidazolium salt was 1:1; 76% when the molar ratio was 1:2; 74% when the molar ratio was 1:3; and 75% when the molar ratio was 1:4.

[0036] Synthesis Method 3: Add 0.42 g (0.50 mmol, 1.0 equiv.) of Grubbs II catalyst to a round-bottom flask, dissolve it in 20 mL of dichloromethane, and heat the reaction system to a certain temperature (e.g., 10℃, 20℃, 30℃, 40℃, 50℃, 60℃). Slowly add a certain proportion of N-benzylimidazolium salt and continue the reaction for 2 hours. The color of the mixture changes from reddish-brown to brownish-green. The reaction progress is judged by TLC, and the reaction progress is monitored by silica gel plate (developing solvent ratio PE:DCM = 1:1). When the Grubbs II catalyst has completely reacted, stop stirring. Place the flask on a rotary evaporator. Under water pump pressure (-0.1 MPa) and a rotary evaporation water bath temperature of 24℃, distill off 18 mL of solvent. Add an appropriate amount of n-hexane and sonicate; solid precipitates out. Add filter paper to a Buchner funnel and place it on a suction flask connected to a water pump. The reaction mixture containing the solid was poured into a Buchner funnel, and the solid was filtered off. The solid was washed with n-hexane (3 × 20 mL) in the Buchner funnel, and then collected in a dry flask. The solvent was removed by vacuum pumping to obtain green solid I (ruthenium complex I). Yield of the target product: 34% at 10°C; 48% at 20°C; 64% at 30°C; 76% at 40°C; 72% at 50°C; and 55% at 60°C.

[0037] Tests showed that ruthenium complex I... 1 H NMR (400MHz, CDCl3): δ19.15(s,1H),7.67(d,J=31.0Hz,3H),7.44(t,J=7.4Hz,1H),7.30(s,4H),7.16(s,4H),7.06(d,J= 7.2Hz,4H),6.99-6.59(m,8H),6.38(s,1H),5.02(s,2H),4.75(s,2H),4.00(s,4H),2.56(d,J=35.0Hz,6H),2.24(s,12H). 13 C NMR (101MHz, CDCl3) δ219.47,152.51,138.69,137.42,136.40,135.56,130.35,128.80,128.73 ,128.58,128.10,127.93,127.49,127.25,126.66,117.60,51.50,50.84,21.10,19.35,19.06.

[0038] The structural formula of the resulting ruthenium complex I is shown in formula (I), where R is benzyl (Bn).

[0039] Example 2

[0040] Ruthenium complex [1,3-bis(2,4,6-trimethylphenyl)-2-imidazoliummethylene]dichloro(benzylmethylene)bis(N-(2,4,6-trimethylphenyl)imidazolium)ruthenium

[0041] Synthesis of [1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(phenylmethylene)bis(N-(2,4,6-trimethylphenyl)imidazole)ruthenium(II):

[0042] Synthesis Method 1: Add 0.42 g (0.50 mmol, 1.0 equiv.) of Grubbs II catalyst to a round-bottom flask, followed by 20 mL of organic solvent (such as toluene, tetrahydrofuran, acetonitrile, dichloromethane, and diethyl ether can all be used to synthesize target catalyst I) to dissolve it. Heat the reaction system to 50 °C, then slowly add N-2,4,6-trimethylphenylimidazolium salt (0.095 g, 0.5 mmol, 1.0 equiv.). Continue the reaction for 2 hours. The mixture color changes from reddish-brown to brownish-green. The reaction progress is monitored using TLC and silica gel plate analysis (developing solvent ratio PE:DCM = 1:1). Stop stirring when the Grubbs II catalyst has completely reacted. Place the flask on a rotary evaporator. Under water pump pressure (-0.1 MPa) and a rotary evaporation water bath temperature of 24 °C, 18 mL of solvent is distilled off. Add an appropriate amount of n-hexane and sonicate; solid precipitates out. Add filter paper to a Buchner funnel and place it on a suction flask connected to a water pump. Pour the reaction mixture containing the solid into the Buchner funnel and filter out the solid. Wash the solid in the Buchner funnel with n-hexane (3 × 20 mL), collect the solid in a dry flask, and evaporate the solvent under vacuum to obtain green solid II (ruthenium complex II). The yield of the target compound is 35% with toluene as solvent; 48% with tetrahydrofuran as solvent; 18% with acetonitrile as solvent; 57% with dichloromethane as solvent; and 12% with diethyl ether as solvent.

[0043] Synthesis Method 2: Add 0.42 g (0.50 mmol, 1.0 equiv.) of Grubbs II catalyst to a round-bottom flask, dissolve it in 20 mL of dichloromethane, heat the reaction system to 40 °C, and slowly add N-2,4,6-trimethylphenylimidazolium salt (0.095 g, 0.5 mmol, 1.0 equiv.; 0.19 g, 1.0 mmol, 2.0 equiv.; 0.285 g, 1.5 mmol, 3.0 equiv.; 0.38 g, 2.0 mmol, 4.0 equiv.). Continue the reaction for 2 h. The color of the mixture changes from reddish-brown to brownish-green. The reaction progress is judged by TLC and the reaction liquid is monitored by silica gel plate (developing solvent ratio PE:DCM = 1:1). When the reaction is complete and the Grubbs II catalyst has reacted, stop stirring. The flask was placed on a rotary evaporator. Under water pump pressure (-0.1 MPa) and a rotary evaporation water bath temperature of 24°C, 18 mL of solvent was distilled off. An appropriate amount of n-hexane was added, and the mixture was ultrasonically vibrated, resulting in the precipitation of a solid. Filter paper was placed in a Buchner funnel, which was then placed on a suction flask connected to a water pump. The reaction mixture containing the solid was poured into the Buchner funnel, and the solid was filtered out. The solid was washed in the Buchner funnel with n-hexane (3 × 20 mL), and then collected in a dry flask. The solvent was removed using a vacuum pump, yielding green solid II (ruthenium complex II). The yield of the catalyst was 57% when the catalyst was fed with N-2,4,6-trimethylphenylimidazolium salt in a 1:1 molar ratio; 77% when the catalyst was fed with N-2,4,6-trimethylphenylimidazolium salt in a 1:2 molar ratio; 78% when the catalyst was fed with N-2,4,6-trimethylphenylimidazolium salt in a 1:3 molar ratio; and 74% when the catalyst was fed with N-2,4,6-trimethylphenylimidazolium salt in a 1:4 molar ratio.

[0044] Synthesis Method 3: Add 0.42 g (0.50 mmol, 1.0 equiv.) of Grubbs II catalyst to a round-bottom flask and dissolve it in 20 mL of dichloromethane. Heat the reaction system to a specific temperature (e.g., 10℃, 20℃, 30℃, 40℃, 50℃, 60℃), then slowly add a certain proportion of N-2,4,6-trimethylphenylimidazolium salt (e.g., 0.19 g, 1 mmol, 2.0 equiv.). Continue the reaction for 2 hours. The mixture color changes from reddish-brown to brownish-green. The reaction progress is assessed using TLC and monitored by silica gel plate analysis (developing solvent ratio PE:DCM = 1:1). Stop stirring when the Grubbs II catalyst has completely reacted. Place the flask on a rotary evaporator. Under water pump pressure (-0.1 MPa) and a rotary evaporation water bath temperature of 24℃, distill off 18 mL of solvent. Add an appropriate amount of n-hexane and sonicate; solid precipitates out. Add filter paper to a Buchner funnel and place it on a suction flask connected to a water pump. Pour the reaction mixture containing the solid into the Buchner funnel and filter out the solid. Wash the solid in the Buchner funnel with n-hexane (3 × 20 mL), collect the solid in a dry flask, and evaporate the solvent under vacuum to obtain green solid II (ruthenium complex II). The yield of the target product was 38% at 10°C; 42% at 20°C; 59% at 30°C; 77% at 40°C; 71% at 50°C; and 66% at 60°C.

[0045] The NMR spectra of ruthenium complex II were as follows: 1 H NMR (400MHz, CDCl3) δ19.08(s,1H),7.67(d,J=7.7Hz,2H),7.61(s,1H),7.47(s,1H),7.41(t,J=7.3Hz,1H),7.23(s,1H),7.03(t,J=7.6Hz,2H ),6.96(s,3H),6.83(d,J=5.8Hz,7H),6.46(s,1H),4.06(s,4H),2.44( d,J=31.3Hz,8H),2.33(s,5H),2.26(s,11H),1.98(s,6H),1.70(s,6H). 13 C NMR (101MHz, CDCl3) δ219.44,152.27,139.00,138.75,138.60,138.28,137.90,137.59,135.04,13 4.89,130.06,129.27,128.97,128.76,127.48,119.22,118.84,51.49,21.02,19.36,17.66,16.99.

[0046] The resulting product (ruthenium complex II) has the structural formula shown in formula (I), where R is 2,4,6-trimethylphenyl (Mes).

[0047] Example 3

[0048] Synthesis of the ruthenium complex [1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(phen-ylmethylene)bis(N-methylimidazole)ruthenium(III):

[0049] Synthesis Method 1: Add 0.42 g (0.50 mmol, 1.0 equiv.) of Grubbs II catalyst to a round-bottom flask, followed by 20 mL of organic solvent (such as toluene, tetrahydrofuran, acetonitrile, dichloromethane, and diethyl ether can all be used to synthesize target catalyst I) to dissolve it. Heat the reaction system to 40 °C, then slowly add 0.075 g (0.5 mmol, 1.0 equiv.) of methylimidazolium salt. Continue the reaction for 2 hours. The mixture color changes from reddish-brown to brownish-green. The reaction progress is monitored using TLC and silica gel plate sampling (PE:DCM ratio 1:1). Stop stirring when the Grubbs II catalyst has completely reacted. Place the flask on a rotary evaporator. Under water pump pressure (-0.1 MPa) and a rotary evaporation water bath temperature of 24 °C, distill off 18 mL of solvent. Add an appropriate amount of n-hexane and sonicate; solid precipitates out. Add filter paper to a Buchner funnel and place it on a suction flask connected to a water pump. Pour the reaction mixture containing the solid into the Buchner funnel and filter out the solid. Wash the solid in the Buchner funnel with n-hexane (3 × 20 mL), collect the solid in a dry flask, and evaporate the solvent under vacuum to obtain green solid III (ruthenium complex III). The yield of the target compound was 18% with toluene as solvent; 42% with tetrahydrofuran as solvent; 11% with acetonitrile as solvent; 48% with dichloromethane as solvent; and 10% with diethyl ether as solvent.

[0050] Synthesis Method 2: Add 0.42 g (0.50 mmol, 1.0 equiv.) of Grubbs II catalyst to a round-bottom flask, dissolve it in 20 mL of dichloromethane, heat the reaction system to 40 °C, and slowly add methylimidazolium salts (0.075 g, 0.5 mmol, 1.0 equiv.; 0.15 g, 1.0 mmol, 2.0 equiv.; 0.225 g, 1.5 mmol, 3.0 equiv.; 0.30 g, 2.0 mmol, 4.0 equiv.). Continue the reaction for 2 hours. The color of the mixture changes from reddish-brown to brownish-green. The reaction progress is judged by TLC, and the reaction progress is monitored by silica gel plate (developing solvent ratio PE:DCM = 1:1). When the Grubbs II catalyst has completely reacted, stop stirring. The flask was placed on a rotary evaporator. Under water pump pressure (-0.1 MPa) and a rotary evaporation water bath temperature of 24°C, 18 mL of solvent was distilled off. A suitable amount of n-hexane was added, and the mixture was ultrasonically vibrated, resulting in the precipitation of a solid. Filter paper was placed in a Buchner funnel, which was then placed on a suction flask connected to a water pump. The reaction mixture containing the solid was poured into the Buchner funnel, and the solid was filtered out. The solid was washed in the Buchner funnel with n-hexane (3 × 20 mL), and then collected in a dry flask. The solvent was removed using a vacuum pump to obtain green solid III (ruthenium complex III). The yield of the catalyst was 48% when the catalyst was followed by methylimidazolium salt in a 1:1 molar ratio; 71% when the catalyst was followed by methylimidazolium salt in a 1:2 molar ratio; 73% when the catalyst was followed by methylimidazolium salt in a 1:3 molar ratio; and 59% when the catalyst was followed by methylimidazolium salt in a 1:4 molar ratio.

[0051] Synthesis Method 3: Add 0.42 g (0.50 mmol, 1.0 equiv.) of Grubbs II catalyst to a round-bottom flask and dissolve it in 20 mL of dichloromethane. Heat the reaction system to a specific temperature (e.g., 10℃, 20℃, 30℃, 40℃, 50℃, 60℃), then slowly add a certain proportion of methylimidazolium salt (e.g., 0.15 g, 1 mmol, 2.0 equiv.). Continue the reaction for 2 hours. The mixture color changes from reddish-brown to brownish-green. The reaction progress is monitored using TLC and silica gel plate analysis (developing solvent ratio PE:DCM = 1:1). Stop stirring when the Grubbs II catalyst has completely reacted. Place the flask on a rotary evaporator. Under water pump pressure (-0.1 MPa) and a rotary evaporation water bath temperature of 24℃, distill off 18 mL of solvent. Add an appropriate amount of n-hexane and sonicate; solid precipitates out. Add filter paper to a Buchner funnel and place it on a suction flask connected to a water pump. Pour the reaction mixture containing the solid into the Buchner funnel and filter out the solid. Wash the solid in the Buchner funnel with n-hexane (3 × 20 mL), collect the solid in a dry flask, and evaporate the solvent under vacuum to obtain green solid III (ruthenium complex III). The yield of the target product was 27% at 10°C; 38% at 20°C; 54% at 30°C; 71% at 40°C; 70% at 50°C; and 59% at 60°C.

[0052] The NMR spectra of ruthenium complex III were as follows: 1 H NMR (400MHz, CDCl3) δ19.13(s,1H),7.67(d,J=7.7Hz,2H),7.44(d,J=7.1Hz,2H),7.17-6.87(m,7H),6.82(s, 1H),6.69(s,2H),6.49(s,1H),4.05(d,J=44.6Hz,4H),3.66(s,3H),3.41(s,3H),2.64(s,6H),2.25(s,12H). 13 C NMR (101MHz, CDCl3) δ219.37,152.23,138.58,138.18,137.32,130.01,128.91,128.45,127.29,118.70,51.40,33.65,31.46,21.04,19.05.

[0053] The resulting product (ruthenium complex III) has the structural formula shown in formula (I), where R is a methyl group.

[0054] Example 4

[0055] The ethyleneolysis reaction of methyl oleate using catalysts I-III (ruthenium complexes I-III) of this invention:

[0056] This reaction requires high purity of methyl oleate; therefore, commercially available methyl oleate needs to be purified.

[0057] First, commercially available methyl oleate may contain residual impurities such as acids or alkalis. This significantly affects the catalytic efficiency of the catalyst, so it is necessary to eliminate the influence of these factors. The specific procedure is as follows: The bottom layer of the column is packed with 7-12 cm of neutral alumina, and the top layer with 7-12 cm of basic alumina. Dissolve 10 mL of methyl oleate in 50-100 mL of petroleum ether, add this solution to the column, and flush the column directly with petroleum ether until the methyl oleate is completely flushed out. After removing the petroleum ether, use a vacuum pump to evacuate for 3-8 hours to remove any remaining petroleum ether.

[0058] Secondly, gases such as oxygen in methyl oleate can also affect the catalyst; therefore, methyl oleate needs to be degassed. The specific procedure is as follows: methyl oleate, after removing acid and alkali impurities, is placed in liquid nitrogen until it transforms from a liquid to a solid state. Then, it is evacuated to room temperature under vacuum, at which point the methyl oleate changes from a solid to a liquid state. This process is repeated 3-5 times to remove dissolved gases such as oxygen from the methyl oleate. After degassed, nitrogen is introduced, and the mixture is stored in a glove box for later use.

[0059]

[0060] Method 1 for the ethylene hydrolysis of methyl oleate: Add a stir bar, 50 mL of n-dodecane (chromatographic grade, internal standard), and 1 mL of methyl oleate treated as described above to a 10 mL high-pressure reactor. Then add 10 μL of a toluene solution of catalyst I-III or Grubbs III (1 mg catalyst dissolved in 1 mL of toluene, resulting in a catalyst concentration of 100 ppm). Evacuate the reactor for 1 minute using a vacuum pump, then introduce ethylene gas to create a slight positive pressure. Repeat this process three times. Then evacuate the reactor again for one minute to increase the ethylene pressure to a certain level (e.g., 150 psi). Place the reactor in a reaction module maintained at a constant temperature (20℃, 30℃, 40℃, 50℃), and stir the reaction. Take samples every half hour for gas chromatography analysis. After 6 hours, the yield will not continue to increase, and the selectivity for the products 9-octadecene and dimethyl octadecene-9-enedioate is greater than 99%.

[0061] At 20℃, catalyst I catalyzed a methyl oleate conversion rate of 31.0% with a TON value of 2973; at 30℃, catalyst I catalyzed a methyl oleate conversion rate of 35.0% with a TON value of 3359; at 40℃, catalyst I catalyzed a methyl oleate conversion rate of 49.3% with a TON value of 3742; and at 50℃, catalyst I catalyzed a methyl oleate conversion rate of 46.3% with a TON value of 3515. At 20℃, catalyst II catalyzed a methyl oleate conversion rate of 32.8% with a TON value of 3147; at 30℃, catalyst II catalyzed a methyl oleate conversion rate of 39.6% with a TON value of 3793; at 40℃, catalyst II catalyzed a methyl oleate conversion rate of 58.4% with a TON value of 4431; and at 50℃, catalyst II catalyzed a methyl oleate conversion rate of 49.9% with a TON value of 3793. At 20°C, catalyst III catalyzed a methyl oleate conversion of 23.9% with a TON value of 2291; at 30°C, the conversion rate reached 26.6% with a TON value of 2546; at 40°C, it reached 43.9% with a TON value of 3328; and at 50°C, it achieved a methyl oleate conversion of 38.4% with a TON value of 2916. At 20°C, Grubbs III catalyzed a methyl oleate conversion of 20.8% with a TON value of 1994; at 30°C, it reached 24.7% with a TON value of 2368; at 40°C, it reached 34.7% with a TON value of 2631; and at 50°C, it achieved 32.2% with a TON value of 2446. At different reaction temperatures, the conversion rate and TON value of catalysts I-III were higher than those of Grubbs III.

[0062] Method 2 for the ethylene hydrolysis of methyl oleate: Add a stir bar, 50 mL of n-dodecane (chromatographic grade, internal standard), and 1 mL of methyl oleate treated as described above to a 10 mL high-pressure reactor. Then add 10 μL of a toluene solution of catalyst I-III or Grubbs III (1 mg catalyst dissolved in 1 mL of toluene, resulting in a catalyst concentration of 100 ppm). Evacuate the reactor for 1 minute using a vacuum pump, then introduce ethylene gas to create a slight positive pressure. Repeat this process three times. Then, evacuate the reactor again for one minute to increase the ethylene pressure to a certain level (50 psi, 100 psi, 150 psi, 200 psi). The reaction vessel was placed in a reaction module at a constant temperature (e.g., 40°C), and the reaction was stirred. Samples were taken every half hour for gas chromatography analysis. The yield did not continue to increase after 6 hours, and the selectivity for the products 9-octadecene and dimethyl octadecene-9-enedioate was greater than 99%.

[0063] At an ethylene pressure of 50 psi, catalyst I achieved a methyl oleate conversion rate of 32.1% with a TON value of 2431; at 100 psi, the conversion rate reached 36.9% with a TON value of 2795; at 150 psi, the conversion rate was 49.3% with a TON value of 3742; and at 200 psi, the conversion rate was 40.9% with a TON value of 3103. At an ethylene pressure of 50 psi, catalyst II achieved a methyl oleate conversion rate of 39.7% with a TON value of 3011; at 100 psi, the conversion rate was 50.7% with a TON value of 3844; at 150 psi, the conversion rate was 58.4% with a TON value of 4431; and at 200 psi, the conversion rate was 50.6% with a TON value of 3804. At an ethylene pressure of 50 psi, catalyst III catalyzed a methyl oleate conversion rate of 34.2% with a TON value of 2591; at an ethylene pressure of 100 psi, catalyst III catalyzed a methyl oleate conversion rate of 47.6% with a TON value of 3608; at an ethylene pressure of 150 psi, catalyst III catalyzed a methyl oleate conversion rate of 43.9% with a TON value of 3328; and at an ethylene pressure of 200 psi, catalyst III catalyzed a methyl oleate conversion rate of 35.5% with a TON value of 2694. At an ethylene pressure of 50 psi, Grubbs III catalyst achieved a methyl oleate conversion of 23.8% with a TON value of 1804; at 100 psi, the conversion reached 25.1% with a TON value of 1902; at 150 psi, it reached 34.7% with a TON value of 2631; and at 200 psi, it achieved 26.7% with a TON value of 2026. Under different ethylene pressures, catalysts I-III showed higher conversion rates and TON values ​​than Grubbs III.

[0064] Example 5

[0065] Ring-closure metathesis reaction: 0.5 mmol of N,N-diallyl-p-toluenesulfonamide was dissolved in 0.5 mL of toluene, and 1% catalyst (I-III, GIII) was added. The reaction was carried out at 80 °C for 4 h. After the reaction was completed, the solution was transferred to a 10 cm high silica gel column (300 mesh), and purified using a petroleum ether:ethyl acetate = 10:1 solvent as the developing solvent to obtain the target product. When catalyst I-III was added, the catalytic products were 1-tosyl-2,5-dihydro-1H-pyrrole (yield: 43%) and 3-methyl-4-methylene-1-tosylpyrrolidine (yield: 52%). When catalyst GIII was added, the catalytic product was 1-tosyl-2,5-dihydro-1H-pyrrole (yield: 97%).

[0066] When 0.5 mmol of N,N-diallyl-p-toluenesulfonamide was dissolved in 0.5 mL of toluene, 1% (I-III) catalyst was added, followed by 3% bromo-1-propyne. The reaction was carried out at 80 °C for 4 h. After the reaction, the product was purified by column chromatography. The added 3-bromo-1-propyne provided selective control of the reaction, and the product was only 1-toluenesulfonyl-2,5-dihydro-1H-pyrrole.

[0067] 1-Toluenesulfonyl-2,5-dihydro-1H-pyrrole: Yields: 95% (I), 97% (II), 93% (III), 92% (Grubbs III). 1 H NMR (400MHz, CDCl3) δ7.72(d,J=8.2Hz,2H),7.32(d,J=7.9Hz,2H),5.65(s,2H),4.12(s,4H),2.43(s,3H). 13 C NMR (101MHz, CDCl3) δ143.45,134.20,129.78,127.43,125.46,54.86,21.56.

[0068] Catalysts I-III directly catalyze N,N-diallyl-p-toluenesulfonamide to simultaneously yield 1-toluenesulfonyl-2,5-dihydro-1H-pyrrole and 3-methyl-4-methylene-1-tolylpyrrole, while catalyst GIII only yields 1-toluenesulfonyl-2,5-dihydro-1H-pyrrole. Adding 3-bromo-1-propyne to the catalyst I-III catalytic system also yields 1-toluenesulfonyl-2,5-dihydro-1H-pyrrole in higher yields than catalyst GIII.

[0069] Example 6

[0070] Ring-closure metathesis reaction: 0.5 mmol of N,N-di(3-en-1-butyl)-4-p-toluenesulfonamide was dissolved in 0.5 mL of toluene, followed by the addition of 1% (I-III, GIII) catalyst, and then 3-bromo-1-propyne (3%). The reaction was carried out at 80 °C for 4 h. After the reaction was completed, the reaction solution was added to a 10 cm high silica gel column (300 mesh), and purified using a petroleum ether:ethyl acetate = 10:1 solvent as the developing solvent to obtain the target product.

[0071] 1-Tosyl-2,3,6,7-tetrahydro-1H-azepine: Yields: 93% (I), 90% (II), 89% (III), 87% (Grubbs III). 1 H NMR (400MHz, CDCl3) δ7.67(d,J=8.2Hz,2H),7.30(d,J=8.0Hz,2H),5.75(t,J=3.4Hz,2H),3.30-3.25(m,4H),2.42(s,3H),2.31(q,J=4.2Hz,4H). 13 C NMR (101MHz, CDCl3) δ143.11,136.22,130.26,129.68,127.07,48.28,29.91,21.53.

[0072] The addition of 3-bromo-1-propyne to catalysts I-III can yield 1-p-toluenesulfonyl-2,3,6,7-tetrahydro-1-H-azapyridine in higher yields than that of catalyst GIII.

[0073] Example 7

[0074] Ring-closure metathesis reaction: 0.5 mmol of N-allyl,N-3-en-1-butyl-4-p-toluenesulfonamide was dissolved in 0.5 mL of toluene, followed by the addition of 1% (I-III,GIII) catalyst, and then 3-bromo-1-propyne (3%). The reaction was carried out at 80 °C for 4 h. After the reaction was completed, the reaction solution was added to a 10 cm high silica gel column (300 mesh), and purified using a petroleum ether:ethyl acetate = 10:1 solvent as the developing solvent to obtain the target product.

[0075] 1-Tosyl-1,2,3,6-tetrahydropyridine: Yields: 88% (I), 84% (II), 89% (III), 81% (Grubbs III).1 H NMR (400MHz, CDCl3) δ7.58(d,J=8.2Hz,2H),7.23(d,J=8.0Hz,2H),5.66(d,J=13.9Hz,1H ),5.52(d,J=13.3Hz,1H),3.48(s,2H),3.08(t,J=5.7Hz,2H),2.33(s,3H),2.11(s,2H). 13 C NMR (101MHz, CDCl3) δ143.54,133.26,129.63,127.64,125.04,122.72,44.79,42.65,25.25,21.50.

[0076] The addition of 3-bromo-1-propyne to catalysts I-III can yield 1-toluenesulfonyl-1,2,3,6-tetrahydropyridine with a higher catalytic yield than that of catalyst GIII.

[0077] Example 8

[0078] Ring-closure metathesis reaction: 0.5 mmol of N-allyl,N-4-en-1-pentyl-4-p-toluenesulfonamide was dissolved in 0.5 mL of toluene, followed by the addition of 1% (I-III,GIII) catalyst, and then 3-bromo-1-propyne (3%). The reaction was carried out at 80 °C for 4 h. After the reaction was completed, the reaction solution was added to a 10 cm high silica gel column (300 mesh), and purified using a petroleum ether:ethyl acetate = 10:1 solvent as the developing solvent to obtain the target product.

[0079] 1-Tosyl-2,3,4,7-tetrahydro-1H-azepine: Yields: 89% (I), 90% (II), 89% (III), 86% (Grubbs III). 1 H NMR (400MHz, CDCl3) δ7.67(d,J=7.9Hz,2H),7.29(d,J=8.0Hz,2H),5.82–5.71(m,1H),5.71–5.58(m,1H) ,3.82(d,J=5.0Hz,2H),3.38(t,J=6.1Hz,2H),2.41(s,3H),2.17(d,J=6.0Hz,2H),1.79(p,J=5.7Hz,2H). 13C NMR (101MHz, CDCl3) δ143.07,136.20,132.94,129.55,127.16,126.59,49.63,46.37,26.81,26.75,21.50.

[0080] The addition of 3-bromo-1-propyne to catalysts I-III can yield 1-p-toluenesulfonyl-2,3,4,7-tetrahydro-1H-azapyridine in higher yields than that of catalyst GIII.

[0081] Example 9

[0082] Ring-closure metathesis reaction: 0.5 mmol of N,N-diallyl-4-fluorobenzamide was dissolved in 0.5 mL of toluene, and 1% (I-III, GIII) catalyst was added. Then, 3-bromo-1-propyne (3%) was added to the reaction system. The reaction was carried out at 80 °C for 4 h. After the reaction was completed, the reaction solution was added to a 10 cm high silica gel column (300 mesh), and purified using a petroleum ether:ethyl acetate = 10:1 solvent as the developing solvent to obtain the target product.

[0083] (2,5-dihydro-1H-pyrrol-1-yl)(4-fluorophenyl)methanone: Yields: 87% (I), 85% (II), 84% (III), 80% (Grubbs III). 1 HNMR (400MHz, CDCl3) δ7.59–7.38(m,2H),7.02(t,J=8.6Hz,2H),5.83(s,1H),5.68(s,1H),4.37(s,2H),4.14(s,2H). 13 C NMR (101MHz, CDCl3) δ168.86, 163.48 (d, J CF = 249.7Hz), 132.86 (d, J CF = 3.5Hz), 129.18 (d, J CF=8.7Hz),126.00,125.11,115.53,115.31,55.85,53.53. 19 F NMR (376MHz, CDCl 3)δ-110.12.

[0084] The addition of 3-bromo-1-propyne to catalysts I-III can yield (2,5-dihydro-1H-pyrrole-1-yl)(4-fluorophenyl) methyl ketone in higher yields than that obtained by catalyst GIII.

[0085] Example 10

[0086] Ring-closure metathesis reaction: 0.5 mmol of N,N-diallyl-2,4,6-trimethylbenzamide was dissolved in 0.5 mL of toluene, followed by the addition of 1% (I-III, GIII) catalyst, and then 3-bromo-1-propyne (3%). The reaction was carried out at 80 °C for 4 h. After the reaction was completed, the reaction solution was added to a 10 cm high silica gel column (300 mesh), and purified using a petroleum ether:ethyl acetate = 10:1 solvent as the developing solvent to obtain the target product.

[0087] (2,5-dihydro-1H-pyrrol-1-yl)(mesityl)methanone: Yields: 86% (I), 84% (II), 88% (III), 84% (Grubbs III). 1 H NMR (400MHz, CDCl3) δ6.85(s,2H),5.96–5.84(m,1H),5.78–5.67(m,1H),4.43(s,2H),3.80(s,2H),2.26(s,3H),2.22(s,6H). 13 C NMR (101MHz, CDCl3) δ169.96,137.98,134.55,132.83,128.27,125.89,125.35,54.11,52.16,21.07,18.83.

[0088] Adding 3-bromo-1-propyne to catalyst systems I-III can yield (2,5-dihydro-1H-pyrrole-1-yl)(trimethyl) methyl ketone with a catalytic yield no less than that of catalyst GIII.

[0089] Example 11

[0090] Cross-metathesis reaction: 0.5 mmol of 4-phenoxy-1-propene and 0.5 mmol of styrene were dissolved in 1 mL of dichloromethane, followed by the addition of 2.5 mol% (I-III, GIII) catalyst. The reaction was stirred at 40 °C for 12 h. After the reaction was completed, the reaction solution was added to a 10 cm high silica gel column (300 mesh), and purified using a petroleum ether:ethyl acetate = 10:1 solvent as the developing solvent to obtain the target product.

[0091] (cinnamyloxy)benzene: Yields: 86% (I), 89% (II), 81% (III), 86% (Grubbs III). 1H NMR (400MHz, CDCl3) δ7.52–7.19(m,7H),6.96(d,J=7.9Hz,3H),6.73(d,J=15.9Hz,1H),6.42(d,J=15.1Hz,1H),4.69(d,J=5.8Hz,2H). 13 CNMR(101MHz, CDCl3)δ158.64,136.48,133.00,129.54,128.63,127.93,126.62,124.54,120.93,114.80,68.58.

[0092] The catalyst I-II catalytic system can produce (cinnamyloxy)benzene with a catalytic yield no less than that of catalyst GIII.

[0093] Example 12

[0094] Cross-metathesis reaction: 0.5 mmol of 4-phenoxy-1-propene and 0.5 mmol of 4-fluorostyrene were dissolved in 1 mL of dichloromethane, followed by the addition of 2.5 mol% (I-III, GIII) catalyst. The reaction was stirred at 40 °C for 12 h. After the reaction was completed, the reaction solution was added to a 10 cm high silica gel column (300 mesh), and purified using a petroleum ether:ethyl acetate = 10:1 solvent as the developing solvent to obtain the target product.

[0095] (E)-1-fluoro-4-(3-phenoxyprop-1-en-1-yl)benzene: Yields: 85% (I), 86% (II), 84% (III), 82% (Grubbs III). 1 H NMR(400MHz, CDCl3)δ7.39–7.33(m,2H),7.33–7.26(m,2H),7.04–6.92(m,5H) ,6.68(d,J=15.9Hz,1H), 6.33(dt,J=16.0,5.8Hz,1H), 4.67(d,J=4.7Hz,2H). 13 C NMR (101MHz, CDCl3) δ162.51 (d,J CF=247.2Hz), 158.59, 132.65 (d,J CF=3.3Hz), 131.85, 129.56, 128.16 (d,J CF=8.0Hz), 124.25 (d,J CF=2.2Hz),120.99,115.56(d,J CF=21.6Hz),114.76,68.44. 19F NMR (376MHz, CDCl3) δ-113.92.

[0096] Catalysts I-III can all produce (E)-1-fluoro-4-(3-phenoxyprop-1-en-1-yl)benzene with higher catalytic yields than catalyst GIII.

[0097] Example 13

[0098] Cross-metathesis reaction: 0.5 mmol of 4-phenoxy-1-propene and 0.5 mmol of 4-methylstyrene were dissolved in 1 mL of dichloromethane, followed by the addition of 2.5 mol% (I-III, GIII) catalyst. The reaction was stirred at 40 °C for 12 h. After the reaction was completed, the reaction solution was added to a 10 cm high silica gel column (300 mesh), and purified using a petroleum ether:ethyl acetate = 10:1 solvent as the developing solvent to obtain the target product.

[0099] (E)-1-methyl-4-(3-phenoxyprop-1-en-1-yl)benzene: Yields: 79% (I), 82% (II), 77% (III), 75% (Grubbs III). 1 H NMR(400MHz, CDCl3)δ7.30(d,J=7.8Hz,4H),7.12(d,J=7.7Hz,2H),6.99–6.90(m,3H),6 .69(d,J=15.9Hz,1H),6.36(dt,J=16.0,5.9Hz,1H),4.67(d,J=5.9Hz,2H),2.33(s,3H). 13 CNMR (101MHz, CDCl3) δ158.68,137.81,133.69,133.07,129.53,129.34,126.55,123.42,120.88,114.80,68.72,21.29.

[0100] Catalyst systems I-III can all yield (E)-1-methyl-4-(3-phenoxyprop-1-en-1-yl)benzene with higher catalytic yields than catalyst GIII.

[0101] Example 14

[0102] Cross-metathesis reaction: 0.5 mmol of 4-(4'-methoxy)phenoxy-1-propene and 0.5 mmol of styrene were dissolved in 1 mL of dichloromethane, followed by the addition of 2.5 mol% (I-III, GIII) catalyst. The reaction was stirred at 40 °C for 12 h. After the reaction was completed, the reaction solution was added to a 10 cm high silica gel column (300 mesh), and purified using a petroleum ether:ethyl acetate = 10:1 solvent as the developing solvent to obtain the target product.

[0103] 1-(cinnamyloxy)-4-methoxybenzene: Yields: 86% (I), 87% (II), 81% (III), 84% (Grubbs III). 1 H NMR (400MHz, CDCl3) δ7.41(d,J=7.2Hz,2H),7.32(t,J=7.5Hz,2H),7.26(d,J=7.4Hz,1H),6.90(d,J=9.0Hz,2H),6. 84(d,J=9.1Hz,2H),6.71(d,J=16.0Hz,1H),6.41(dt,J=15.9,5.8Hz,1H),4.65(dd,J=5.8,1.6Hz,2H),3.77(s,3H). 13 C NMR (101MHz, CDCl3) δ153.96,152.78,136.51,132.85,128.60,127.87,126.58,124.79,115.82,114.67,69.39,55.74.

[0104] The catalyst I-II catalytic system can produce 1-(cinnamoyloxy)-4-methoxybenzene in a higher yield than that of catalyst GIII.

[0105] Example 15

[0106] Cross-metathesis reaction: 0.5 mmol of 4-(4'-methoxy)phenoxy-1-propene and 0.5 mmol of 4-fluorostyrene were dissolved in 1 mL of dichloromethane, followed by the addition of 2.5 mol% (I-III, GIII) catalyst. The reaction was stirred at 40 °C for 12 h. After the reaction was completed, the reaction solution was added to a 10 cm high silica gel column (300 mesh), and purified using a petroleum ether:ethyl acetate = 10:1 solvent as the developing solvent to obtain the target product.

[0107] (E)-1-fluoro-4-(3-(4-methoxyphenoxy)prop-1-en-1-yl)benzene: Yields: 78% (I), 83% (II), 70% (III), 75% (Grubbs III). 1 H NMR (400MHz, CDCl3) δ7.36 (s, 2H), 7.09–6.80 (m, 6H), 6.76–6.62 (m, 1H), 6.45–6.19 (m, 1H), 4.61 (t, J = 5.7Hz, 2H), 3.88–3.69 (m, 3H). 13 C NMR (101MHz, CDCl3) δ154.00, 152.74, 132.68, 131.70, 128.12 (d, J CF = 7.9Hz), 124.53, 115.79, 115.64, 115.43, 114.69, 69.26, 55.73. 19 F NMR (376MHz, CDCl 3)δ-114.01.

[0108] The catalyst I-II catalytic system can produce (E)-1-fluoro-4-(3-(4-methoxyphenoxy)prop-1-en-1-yl)benzene with a higher catalytic yield than the GIII catalyst.

[0109] Example 16

[0110] Cross-metathesis reaction: 0.5 mmol of 4-(4'-methoxy)phenoxy-1-propene and 0.5 mmol of 4-methylstyrene were dissolved in 1 mL of dichloromethane, followed by the addition of 2.5 mol% (I-III, GIII) catalyst. The reaction was stirred at 40 °C for 12 h. After the reaction was completed, the reaction solution was added to a 10 cm high silica gel column (300 mesh), and purified using a petroleum ether:ethyl acetate = 10:1 solvent as the developing solvent to obtain the target product.

[0111] (E)-1-methoxy-4-((3-(p-tolyl)allyl)oxy)benzene: Yields: 77% (I), 74% (II), 66% (III), 71% (Grubbs III). 1HNMR (400MHz, CDCl3) δ7.30(d,J=7.7Hz,2H),7.13(d,J=7.7Hz,2H),6.90(d,J=9.0Hz,2H),6.84(d,J=9.3Hz,2H ),6.68(d,J=16.0Hz,1H),6.36(dt,J=16.1,5.8Hz,1H),4.67–4.60(m,2H),3.77(d,J=1.8Hz,3H),2.34(s,3H). 13 CNMR(101MHz, CDCl3)δ153.92,152.81,137.74,133.70,132.90,129.28,126.49,123.67,115.82,114.64,69.53,55.74,21.25.

[0112] The catalyst I-II catalytic system can yield (E)-1-methoxy-4-((3-(p-tolyl)allyl)oxy)benzene in a higher yield than that of catalyst GIII.

[0113] Example 17

[0114] Cross-metathesis reaction: 0.5 mmol of 4-(4'-phenyl)phenoxy-1-propene and 0.5 mmol of styrene were dissolved in 1 mL of dichloromethane, followed by the addition of 2.5 mol% (I-III, GIII) catalyst. The reaction was stirred at 40 °C for 12 h. After the reaction was completed, the reaction solution was added to a 10 cm high silica gel column (300 mesh), and purified using a petroleum ether:ethyl acetate = 10:1 solvent as the developing solvent to obtain the target product.

[0115] 4-(cinnamyloxy)-1,1'-biphenyl: Yields: 60% (I), 64% (II), 61% (III), 56% (Grubbs III). 1 H NMR (400MHz, CDCl3) δ7.55(t,J=8.1Hz,4H),7.43(d,J=7.7Hz,4H),7.33(q,J=6.5,5.7Hz,3H),7.28(s,1 H),7.07-7.02(m,2H),6.76(d,J=16.0Hz,1H),6.45(dt,J=15.9,5.7Hz,1H),4.75(dd,J=5.9,1.6Hz,2H). 13C NMR (101MHz, CDCl3) δ158.22,140.80,136.44,134.01,133.12,128.73,128.62,128.20,127.95,126.76,126.70,126.61,124.43,115.09,68.77.

[0116] Catalysts I-III can all produce 4-(cinnamoyloxy)-1,1'-biphenyl in higher yields than catalyst GIII.

[0117] Example 18

[0118] Cross-metathesis reaction: 0.5 mmol of 4-(4'-phenyl)phenoxy-1-propene and 0.5 mmol of 4-fluorostyrene were dissolved in 1 mL of dichloromethane, followed by the addition of 2.5 mol% (I-III, GIII) catalyst. The reaction was stirred at 40 °C for 12 h. After the reaction was completed, the reaction solution was added to a 10 cm high silica gel column (300 mesh), and purified using a petroleum ether:ethyl acetate = 10:1 solvent as the developing solvent to obtain the target product.

[0119] (E)-4-((3-(4-fluorophenyl)allyl)oxy)-1,1'-biphenyl: Yields: 58% (I), 56% (II), 38% (III), 52% (Grubbs III). 1 HNMR(400MHz, CDCl3)δ7.47(t,J=7.9Hz,4H),7.37–7.28(m,4H),7.22(t,J=7.3Hz,1H),6.95( d,J=8.3Hz,4H),6.64(d,J=15.9Hz,1H),6.27(dt,J=16.0,5.8Hz,1H),4.64(d,J=5.8Hz,2H). 13 C NMR (101MHz, CDCl3) δ158.16, 140.76, 134.05, 131.97, 128.76, 128.22, 128.13, 126.76, 124.14 (d, J CF = 2.1Hz), 115.68, 115.46, 115.05, 68.64. 19 F NMR (376MHz, CDCl3) δ -113.93.

[0120] The catalyst I-II catalytic system can yield (E)-4-((3-(4-fluorophenyl)allyl)oxy)-1,1'-biphenyl in higher yield than that of catalyst GIII.

[0121] Example 19

[0122] Cross-metathesis reaction: 0.5 mmol of 4-(4'-phenyl)phenoxy-1-propene and 0.5 mmol of 4-methylstyrene were dissolved in 1 mL of dichloromethane, followed by the addition of 2.5 mol% (I-III, GIII) catalyst. The reaction was stirred at 40 °C for 12 h. After the reaction was completed, the reaction solution was added to a 10 cm high silica gel column (300 mesh), and purified using a petroleum ether:ethyl acetate = 10:1 solvent as the developing solvent to obtain the target product.

[0123] (E)-4-((3-(p-tolyl)allyl)oxy)-1,1'-biphenyl: Yields: 53% (I), 55% (II), 33% (III), 49% (Grubbs III). 1 H NMR (400MHz, CDCl3) δ7.54(t,J=8.7Hz,4H),7.41(t,J=7.7Hz,3H),7.34–7.30(m,2H),7.14(d,J=7.6Hz,2H),7. 06–7.01(m,2H),6.72(d,J=16.0Hz,1H),6.39(dt,J=16.0,5.9Hz,1H),4.73(dd,J=5.9,1.5Hz,2H),2.35(s,3H). 13 C NMR (101MHz, CDCl3) δ158.24,140.81,137.84,133.94,133.17,129.32,128.73,128.18,126.75,126.68,126.53,123.29,115.08,68.90,21.26.

[0124] The catalyst I-II catalytic system can yield (E)-4-((3-(p-tolyl)allyl)oxy)-1,1'-biphenyl in higher yield than that of catalyst GIII.

Claims

1. Use of an imidazolide ruthenium carbene olefin metathesis catalyst in the catalytic conversion of dimethyl octadeca- dienoate, 1-decene or methyl 9-decenoate, characterized in that, The application is ethylene reaction of methyl oleate, and the imidazole-coordinated ruthenium carbene olefin metathesis catalyst is shown as formula (I): ， Wherein, R is selected from benzyl, 2,4,6-trimethylphenyl or methyl, and Mes is 2,4,6-trimethylphenyl.

2. Use according to claim 1, characterized in that, The preparation method of the imidazole-coordinated ruthenium carbene olefin metathesis catalyst comprises: In an organic solvent system, the Grubbs II catalyst is reacted with a benzyl-substituted imidazole salt, a trimethylphenyl-substituted imidazole salt or a methyl-substituted imidazole salt. The structure of the Grubbs II catalyst is as follows: 。 3. Use according to claim 2, characterized in that, The preparation method of the imidazole-coordinated ruthenium carbene olefin metathesis catalyst comprises: dissolving the Grubbs II catalyst in an organic solvent, and adding the benzyl-substituted imidazole salt, the trimethylphenyl-substituted imidazole salt or the methyl-substituted imidazole salt to the reaction system at 10-60 ℃.

4. Use according to claim 3, characterized in that, In the preparation method of the imidazole-coordinated ruthenium carbene olefin metathesis catalyst, the reaction temperature is 30-60 ℃.

5. Use according to claim 2, characterized in that, In the preparation method of the imidazole-coordinated ruthenium carbene olefin metathesis catalyst, the organic solvent is dichloromethane, acetonitrile, tetrahydrofuran, diethyl ether or toluene.

6. Use according to claim 2, characterized in that, In the preparation method of the imidazole-coordinated ruthenium carbene olefin metathesis catalyst, the molar ratio of the benzyl-substituted imidazole salt, the trimethylphenyl-substituted imidazole salt or the methyl-substituted imidazole salt to the Grubbs II catalyst is (1:1)-(4:1).

7. Use according to claim 6, characterized in that, In the preparation method of the imidazole-coordinated ruthenium carbene olefin metathesis catalyst, the molar ratio of the benzyl-substituted imidazole salt, the trimethylphenyl-substituted imidazole salt or the methyl-substituted imidazole salt to the Grubbs II catalyst is (2:1)-(3:1).

8. The use according to claim 2, characterized in that, In the preparation method of the imidazole-coordinated ruthenium carbene olefin metathesis catalyst, after the benzyl-substituted imidazole salt, the trimethylphenyl-substituted imidazole salt or the methyl-substituted imidazole salt is added, the temperature is kept for more than 2 hours.

9. Use according to any one of claims 2 to 8, characterized in that, The preparation method of the imidazole-coordinated ruthenium carbene olefin metathesis catalyst further comprises: after the reaction is completed, part of the solvent is removed under reduced pressure, n-hexane, cyclohexane, petroleum ether or acetonitrile is added, and the precipitated product is centrifuged, filtered and dried.

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