Monophosphine ligand as well as preparation method and application thereof

Abstract

The invention relates to a monophosphine ligand and a preparation method and application thereof, the monophosphine ligand shows lower chemical shift in a nuclear magnetic resonance phosphorus spectrum, and reflects that the monophosphine ligand has stronger power supply capability on P, thereby having stronger metal coordination capability, being capable of more effectively exerting a catalysis-assisting effect, improving the conversion rate of hydroformylation reaction, and improving the yield of the hydroformylation reaction. A high conversion rate can be achieved even for olefins having large steric hindrance. Meanwhile, the stability of the catalyst composition formed by the phosphine ligand is stronger due to stronger metal coordination capability, so that the homogeneous catalyst composition can be recycled for multiple times, and the reaction cost is reduced. Moreover, according to a dynamic experiment, the monophosphine ligand participates in olefin hydroformylation reaction, the reaction activation energy is lower, the reaction activity is higher, the reaction cost is further reduced, and the industrial application of the hydroformylation reaction is promoted.

Description

Technical Field

[0001] The invention relates to the field of hydroformylation reaction catalysts, and in particular to a monophosphine ligand and a preparation method and application thereof. Background Art

[0002] Hydroformylation is a reaction process in which olefins react with synthesis gas under the action of a catalyst to produce an aldehyde with one more molecule than the original olefin. The aldehydes and their derivatives produced are widely used as plasticizers, fabric additives, surfactants, solvents and fragrances. At present, hydroformylation has become one of the most important chemical reactions in industrial applications.

[0003] Phosphine ligands play an important role in the catalyst system of hydroformylation reaction, which helps to improve the reaction efficiency and reduce the process cost of hydroformylation reaction. Therefore, a large number of phosphine ligand studies have been carried out in recent years.

[0004] The tris(2,4-di-tert-butylphenyl)phosphite disclosed in patent CN115066429A of BASF has been commercialized. However, when this monophosphine ligand is used for large hindered olefins, such as diisobutylene hydroformylation reaction, although a high aldehyde formation rate can be obtained, the conversion rate and reaction activity are still low, resulting in an increase in reaction cost. In addition, increasing the reaction temperature and reaction pressure can improve its conversion rate to a certain extent, but it also increases the reaction cost and reduces safety, which is not conducive to large-scale production and application. Summary of the invention

[0005] One object of the present invention is to provide a monophosphine ligand, which, through reasonable skeleton design, enables the P atom to have a stronger power supply capacity, thereby having a stronger metal coordination ability. The catalytic system composed of the monophosphine ligand and the rhodium complex can show better conversion rate and reaction activity in the hydroformylation reaction of large sterically hindered olefins, thereby effectively reducing the reaction cost, and the reaction conditions are milder, which is conducive to large-scale industrial application.

[0006] The present invention is achieved through the following technical solutions:

[0007] A monophosphine ligand, wherein the monophosphine ligand is a compound represented by formula I:

[0008]

[0009] In formula I, ring X is a substituted or unsubstituted C6-C8 cycloalkyl group, wherein when ring X has a substituent, the substituent of ring X is a C1-C8 alkyl group; and the R group is H, a C1-C8 alkyl group, a C1-C6 alkoxy group, a halogen group or an aryl group.

[0010] In the technical scheme, the monophosphine ligand has the structural formula shown in Formula I. This type of structural formula shows a lower chemical shift in the nuclear magnetic resonance phosphorus spectrum, reflecting that P has a stronger power supply capability, and then has a stronger metal coordination ability, can more effectively play a catalytic role, improve the conversion rate of the hydroformylation reaction, even for large sterically hindered olefins can also achieve a high conversion rate. At the same time, the stronger metal coordination ability makes the stability of the catalyst composition composed of this type of phosphine ligand stronger, and then allows the homogeneous catalyst composition to be recycled for many times, reducing the reaction cost. Not only that, according to kinetic experiments, it is found that the reaction activation energy of the olefin hydroformylation reaction in which this type of monophosphine ligand participates is lower, and the reaction activity is stronger, which is conducive to further reducing the reaction cost and promoting the industrial application of the hydroformylation reaction.

[0011] In the technical scheme, ring X is a cycloalkyl group sharing the same edge with the furan ring, and the cycloalkyl group may be a cyclohexyl group, a cycloheptyl group or a cyclooctyl group. In some embodiments, ring X may or may not have a substituent. In one or more embodiments, the substituent group on ring X may be a C1-C8 straight chain alkyl group or a branched chain alkyl group. In some preferred embodiments, the substituent group on ring X is preferably a C1-C8 straight chain alkyl group, and more preferably, the substituent group on ring X is preferably a C1-C4 straight chain alkyl group. In some preferred embodiments, ring X is monosubstituted or disubstituted.

[0012] In some preferred embodiments, the monophosphine ligand has any of the following structural formulas:

[0013]

[0014] In the technical scheme, the R group is selected from H, C1-C8 alkyl, C1-C6 alkoxy, halogen, and aryl. In some embodiments, the R group is a C1-C8 alkyl, preferably, the R group is a C1-C4 alkyl, and more preferably, the R group is a methyl, ethyl, propyl, isopropyl, n-butyl, or tert-butyl group. In some embodiments, the R group is a C1-C6 alkoxy, and in more preferred embodiments, the R group can be a methoxy, ethoxy, or propoxy group. In some embodiments, the R group is a halogen, and in more preferred embodiments, the R group can be chlorine or bromine. In some embodiments, the R group can also be an aryl, and in more preferred embodiments, the R group is a phenyl or naphthyl.

[0015] In some preferred embodiments, the monophosphine ligand has any of the following structural formulas:

[0016]

[0017] In the technical solution, the ring X is an unsubstituted or alkyl-substituted cyclohexyl or cyclooctyl group, and the R group is a tert-butyl group. The inventors have found through experiments that this type of skeleton structure can further improve the power supply capacity on P, enhance the conversion rate and reaction activity of the hydroformylation reaction involving the monophosphine ligand, and in the hydroformylation reaction of large sterically hindered olefins, such as diisobutylene, the conversion rate can reach more than 70%, which is significantly higher than the existing monophosphine ligand.

[0018] Another object of the present invention is to provide a method for preparing any of the above-mentioned monophosphine ligands, comprising the following steps:

[0019] Dissolving the compound represented by Formula II in a solvent to obtain a first solution;

[0020] mixing phosphorus trichloride, a base, and a solvent to obtain a second solution;

[0021] Under an inert atmosphere, slowly adding the second solution to the first solution to obtain the monophosphine ligand;

[0022] Formula II:

[0023] In the technical scheme, the compound shown in formula II is dissolved in a solvent to obtain a first solution, and then phosphorus trichloride and alkali are dissolved in the solvent to obtain a second solution, and then the second solution is added to the first solution under an inert atmosphere, for example, under argon protection, to react to obtain a monophosphine ligand. The reaction path is as follows:

[0024]

[0025] In some embodiments, the solvent may be at least one of tetrahydrofuran, toluene, xylene, dichloromethane, chloroform, carbon tetrachloride, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0026] In some embodiments, the base can be at least one of triethylamine, diisopropylethylamine, pyridine, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, potassium tert-butoxide, and sodium hydride.

[0027] In some preferred embodiments, the compound of formula II is dissolved in tetrahydrofuran to form a first solution, phosphorus trichloride, triethylamine and tetrahydrofuran are mixed to obtain a second solution; then, the second solution is added dropwise to the first solution at 0-5°C under an argon atmosphere, and after the addition is complete, the temperature is raised to room temperature for reaction for 1-3 hours. After the reaction is completed, the insoluble matter is filtered out, and the obtained solution is decompressed to remove low-boiling compounds to obtain an oily crude product, which is separated and purified by column chromatography to obtain a white solid, which is the monophosphine ligand shown in formula I.

[0028] The preparation process of the monophosphine ligand provided in the technical solution has a short synthesis path and mild reaction conditions, and is suitable for large-scale production.

[0029] The present invention also provides a catalyst composition based on any of the aforementioned monophosphine ligands. The catalyst composition comprises a rhodium complex and a monophosphine ligand. The excellent metal coordination ability of the monophosphine ligand is utilized to effectively improve the catalytic ability and stability of the catalytic system, thereby increasing the conversion rate of the hydroformylation reaction and reducing its production cost.

[0030] Furthermore, the molar ratio of phosphine to rhodium in the catalyst composition is 3 to 50. Experiments have found that with the increase of the phosphine to rhodium ratio in the catalyst composition, the conversion rate of the hydroformylation reaction of large hindered olefins can be significantly increased. However, when the phosphine to rhodium ratio reaches 6 or more, the growth of the conversion rate slows down significantly, and even declines to a certain extent. In order to maintain a high conversion rate while reducing the amount of monophosphine ligand and controlling the reaction cost, in the present technical solution, the phosphine to rhodium ratio is controlled at 3 to 50. In some preferred embodiments, the phosphine to rhodium ratio is 3 to 15, and more preferably, the phosphine to rhodium ratio is 6 to 12.

[0031] Furthermore, the method comprises the following steps: after the raw olefin is mixed with the catalyst composition, the air in the reaction system is replaced by synthesis gas, and then a hydroformylation reaction is carried out.

[0032] In some embodiments, after the raw olefin and the catalyst composition are mixed, the synthesis gas composed of hydrogen and carbon monoxide is charged into the reactor for several times, and then the synthesis gas is charged again to make the reactor under high pressure, and then the temperature is increased to carry out the hydroformylation reaction until the reaction is completed.

[0033] In some preferred embodiments, the molar ratio of the raw olefin to the rhodium complex in the catalyst composition is 100 to 100,000.

[0034] In some preferred embodiments, the pressure of the synthesis gas is 1.0-4.0 MPa. Preferably, considering the production cost, the pressure of the synthesis gas is 1.5-2.5 MPa.

[0035] In some preferred embodiments, the reaction temperature is 90-120°C, preferably, the reaction temperature is 90-100°C.

[0036] In some embodiments, the rhodium precursor is at least one of a rhodium (I) salt, a rhodium (II) salt, and a rhodium (III) salt. In one or more markets, the rhodium (I) salt can be at least one of Rh (acac) (CO) 2, Rh (acac) (CO) (PPh3), HRh (CO) (PPh3) 3, [Rh (cod) Cl] 2, [Rh (CO) 2Cl] 2, Rh (acac) (C2H4), and Rh (C2H4) 2Cl] 2. Wherein, acac is acetylacetone, cod is 1,5-cyclooctadiene, and the rhodium (III) salt can be RhCl3.

[0037] In some preferred embodiments, the raw olefin may be C2-C 18 Olefins.

[0038] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0039] 1. The monophosphine ligand of the present invention has stronger metal coordination ability, can play a more effective role in promoting catalysis, improve the conversion rate of the hydroformylation reaction, and can achieve a high conversion rate even for olefins with large steric hindrance;

[0040] 2. The monophosphine ligand of the present invention has a stronger metal coordination ability, which makes the catalyst composition composed of it more stable, thereby allowing the homogeneous catalyst composition to be recycled multiple times, thereby reducing the reaction cost;

[0041] 3. The monophosphine ligand of the present invention has lower reaction activation energy and stronger reaction activity for olefin hydroformylation reaction, which is beneficial to further reduce reaction cost and promote industrial application of hydroformylation reaction;

[0042] 4. The present invention can further improve the power supply capacity on P and enhance the conversion rate and reaction activity of the hydroformylation reaction involving the monophosphine ligand by further selecting the R group as tert-butyl and using the unsubstituted or alkyl-substituted cyclohexyl or cyclooctyl ring X;

[0043] 5. The preparation process of the monophosphine ligand provided by the present invention has a short synthesis path and mild reaction conditions, and is suitable for large-scale production;

[0044] 6. The present invention sets the phosphine to rhodium ratio in the catalyst composition to 3-50, which can reduce the amount of monophosphine ligand and control the reaction cost while maintaining a high conversion rate. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. The illustrative embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0046] All raw materials of the present invention are not particularly limited in their sources, and can be purchased on the market or prepared according to conventional methods well known to those skilled in the art. All raw materials of the present invention are not particularly limited in their purity, and the present invention preferably adopts analytically pure or conventional purity requirements in the field of hydroformylation catalysts. All raw materials of the present invention, their brands and abbreviations are conventional brands and abbreviations in the field, and each brand and abbreviation is clear and definite in the field of its related use. Those skilled in the art can purchase them from the market or prepare them by conventional methods according to the brands, abbreviations and corresponding uses.

[0047] The present invention has no particular limitation on the expression of the substituents, and all expressions familiar to those skilled in the art are adopted. Based on common sense, those skilled in the art can correctly understand the meanings according to the expressions.

[0048] The terms "first", "second", etc. (e.g., first solution, second solution, etc.) used herein are only used to distinguish the corresponding components for the sake of clarity of description, and are not intended to limit any order or emphasize importance, etc. In addition, the term "connected" used herein, unless otherwise specified, may be directly connected or indirectly connected via other substituents.

[0049] 1. Preparation of Monophosphine Ligands

[0050] [Example 1]

[0051]

[0052] Under argon atmosphere, 3-tert-butyl-6,7,8,9-tetrahydrodibenzo[b,d]furan-2-ol (18.6mmol) and tetrahydrofuran (20mL) were added to a 100mL three-necked flask, and a mixed solution of phosphorus trichloride (5mmol), triethylamine (20mmol) and tetrahydrofuran (20mL) was added dropwise at 0-5°C. After the addition was completed, the mixture was heated to room temperature and reacted for 2 hours. The reaction was stopped, the insoluble matter was removed by filtration, and the low-boiling point compounds were removed from the obtained solution under reduced pressure to obtain an oily crude product, which was separated and purified by column chromatography to obtain a white solid, which was the monophosphine ligand 1.

[0053] Structural characterization by NMR spectroscopy: 31 P NMR (162 MHz, deuterated chloroform) δ 121.67.

[0054] [Example 2]

[0055]

[0056] Under argon atmosphere, 3-tert-butyl-8-methyl-6,7,8,9-tetrahydrodibenzo[b,d]furan-2-ol (18.6mmol) and tetrahydrofuran (20mL) were added to a 100mL three-necked flask, and a mixed solution of phosphorus trichloride (5mmol), triethylamine (20mmol) and tetrahydrofuran (20mL) was added dropwise at 0-5°C. After the addition was completed, the mixture was heated to room temperature and reacted for 2 hours. The reaction was stopped, the insoluble matter was removed by filtration, and the low-boiling point compounds were removed from the obtained solution by decompression to obtain an oily crude product, which was separated and purified by column chromatography to obtain a white solid, which was the monophosphine ligand 2.

[0057] Structural characterization by NMR spectroscopy: 31 P NMR (162 MHz, deuterated chloroform) δ 127.51.

[0058] [Example 3]

[0059]

[0060] Under argon atmosphere, 3-tert-butyl-8-propyl-6,7,8,9-tetrahydrodibenzo[b,d]furan-2-ol (18.6mmol) and tetrahydrofuran (20mL) were added to a 100mL three-necked flask, and a mixed solution of phosphorus trichloride (5mmol), triethylamine (20mmol) and tetrahydrofuran (20mL) was added dropwise at 0-5°C. After the addition was completed, the mixture was heated to room temperature and reacted for 2 hours. The reaction was stopped, the insoluble matter was removed by filtration, and the low-boiling point compounds were removed from the obtained solution under reduced pressure to obtain an oily crude product, which was separated and purified by column chromatography to obtain a white solid, namely the monophosphine ligand 3.

[0061] Structural characterization by NMR spectroscopy: 31 P NMR (162 MHz, deuterated chloroform) δ 125.07.

[0062] [Example 4]

[0063]

[0064] Under argon atmosphere, 3-tert-butyl-6,7,8,9,10,11-hexahydrocyclooctane [b] benzofuran-2-ol (18.6 mmol) and tetrahydrofuran (20 mL) were added to a 100 mL three-necked flask, and a mixed solution of phosphorus trichloride (5 mmol), triethylamine (20 mmol) and tetrahydrofuran (20 mL) was added dropwise at 0-5°C. After the addition was completed, the mixture was heated to room temperature and reacted for 2 hours. The reaction was stopped, the insoluble matter was removed by filtration, and the low-boiling point compounds were removed from the obtained solution under reduced pressure to obtain an oily crude product, which was separated and purified by column chromatography to obtain a white solid, namely the monophosphine ligand 4.

[0065] Structural characterization by NMR spectroscopy:31 P NMR (162 MHz, deuterated chloroform) δ 128.12.

[0066] 2. Testing of Monophosphine Ligands

[0067] Diisobutylene is a typical large sterically hindered olefin, so the performance tests involving monophosphine ligands are all based on the hydroformylation reaction of diisobutylene. The reaction pathway of the hydroformylation reaction of diisobutylene is:

[0068]

[0069] [Example 5]

[0070] In this example, monophosphine ligand 1 and Rh(acac)(CO)2 were used as catalyst compositions to test the effects of different phosphine to rhodium ratios on the hydroformylation reaction of diisobutylene.

[0071] In a 50mL high-pressure reactor, add 7.5mg Rh(acac)(CO)2, a certain amount of monophosphine ligand 1, and 30mL diisobutylene, then charge the reactor with synthesis gas (CO:H2=1:1) three times, charge the reactor with synthesis gas again, keep the total pressure in the reactor at 2.5MPa, quickly heat to 100℃ and start stirring, stop stirring after 3 hours of reaction, and quickly cool to room temperature, take out the reaction liquid for analysis. The experimental results are shown in Table 1:

[0072] Table 1:

[0073] Experimental Group Phosphine to Rhodium Ratio Conversion rate (%) Formaldehyde rate (%) 1 1 43.8 97.9 2 2 61.6 98.2 3 3 73.3 98.2 4 5 76.6 98.1 5 6 82.6 98.2 6 10 81.3 98.1 7 15 82.3 97.8 8 25 82.1 98.2

[0074] As can be seen from Table 1, when the phosphine-rhodium ratio is 1 to 25, the aldehyde formation rate of the hydroformylation reaction can be maintained at more than 97%. With the increase of the phosphine-rhodium ratio in the catalyst composition, the conversion rate reaches 82.6 when the phosphine-rhodium ratio is 6. Continuing to increase the phosphine-rhodium ratio will not only increase the reaction cost, but also the conversion rate will not change significantly. Therefore, in some preferred embodiments, the phosphine-rhodium ratio of the reaction is determined to be 3 to 50, and in a more preferred embodiment, the phosphine-rhodium ratio is determined to be 3 to 15.

[0075] [Example 6]

[0076] In this example, monophosphine ligand 1 and Rh(acac)(CO)2 were used as catalyst compositions to test the effects of different synthesis gas pressures on the hydroformylation reaction of diisobutylene.

[0077] In a 50mL high-pressure reactor, add 7.5mg Rh(acac)(CO)2, a certain amount of monophosphine ligand 1, so that the phosphine / rhodium molar ratio is 3, 30mL diisobutylene, then charge the reactor with synthesis gas (CO:H2=1:1) three times, charge the reactor with synthesis gas again, keep the total pressure in the reactor at the pressure shown in Table 2, quickly heat to 100℃ and start stirring, stop stirring after 3 hours of reaction, and quickly cool to room temperature, take out the reaction liquid for analysis. The experimental results are shown in Table 2:

[0078] Table 2:

[0079] Experimental Group Syngas pressure(MPa) Conversion rate (%) Formaldehyde rate (%) 9 1.0 58.8 96.9 10 1.5 71.5 97.2 11 2.0 71.2 97.4 3 2.5 73.3 98.2 12 3.0 69.1 97.9 13 3.5 72.0 98.3 14 4.0 78.7 98.5

[0080] It can be seen from Table 2 that the pressure of synthesis gas can improve the conversion rate to a certain extent, but higher pressure will also increase production costs and safety considerations. Therefore, in some preferred embodiments, the synthesis gas pressure is 1.5-2.5 MPa.

[0081] [Example 7]

[0082] In this example, monophosphine ligand 1 and Rh(acac)(CO)2 were used as catalyst compositions to test the effects of different reaction temperatures on the hydroformylation reaction of diisobutylene.

[0083] In a 50mL high-pressure reactor, add 7.5mg Rh(acac)(CO)2, a certain amount of monophosphine ligand 1, so that the phosphine / rhodium molar ratio is 3, 30mL diisobutylene, then charge synthesis gas (CO:H2=1:1) into the reactor three times, charge synthesis gas again, keep the total pressure in the reactor at 2.5MPa, quickly heat to the temperature shown in Table 3 and start stirring, stop stirring after 3 hours of reaction, and quickly cool to room temperature, take out the reaction liquid for analysis. The experimental results are shown in Table 3:

[0084] Table 3:

[0085] Experimental Group Reaction temperature (℃) Conversion rate (%) Formaldehyde rate (%) 15 80 47.6 99.0 16 90 67.5 99.1 3 100 73.3 98.2 17 110 75.0 97.3 18 120 81.5 98.3

[0086] As shown in Table 3, when the temperature reaches 100°C, the conversion rate of diisobutylene hydroformylation reaction can reach 73.1%, and further increasing the temperature is conducive to increasing the conversion rate to 81.5%. Therefore, in some preferred embodiments, the reaction temperature is 100-120°C.

[0087] [Example 8]

[0088] In this example, the performance of different monophosphine ligands was tested by replacing different monophosphine ligands and Rh(acac)(CO)2 as the catalyst composition. The comparative example used the monophosphine ligand tris(2,4-di-tert-butylphenyl)phosphite commercialized by BASF.

[0089] In a 50mL high-pressure reactor, add 7.5mg Rh(acac)(CO)2, a certain amount of monophosphine ligand, so that the phosphine / rhodium molar ratio is 3, 30mL diisobutylene, then charge synthesis gas (CO:H2=1:1) to replace the reactor three times, charge synthesis gas again, keep the total pressure in the reactor at 2.5MPa, quickly heat to 100℃ and start stirring, stop stirring after 3 hours of reaction, and quickly cool to room temperature, take out the reaction liquid for analysis. The experimental results are shown in Table 4:

[0090] Table 4:

[0091]

[0092] As can be seen from Table 4, when the catalyst composition containing a monophosphine ligand is applied to the hydroformylation reaction of diisobutylene, it shows obvious performance advantages in terms of reaction activity and selectivity compared with the commercialized catalytic system, can significantly shorten the reaction time, improve the reaction efficiency, and the reaction conditions are milder, which is conducive to large-scale production.

[0093] [Example 9]

[0094] In this example, monophosphine ligand 1 and Rh(acac)(CO)2 were used as a catalyst composition to test the recycling of the catalyst composition for the hydroformylation reaction of diisobutylene.

[0095] In a 50mL high-pressure reactor, add 7.5mg Rh(acac)(CO)2, a certain amount of monophosphine ligand 1, so that the phosphine / rhodium molar ratio is 12, 30mL diisobutylene, then charge synthesis gas (CO:H2=1:1) into the reactor three times, charge synthesis gas again, keep the total pressure in the reactor at 2.5MPa, quickly heat to 100℃ and start stirring, stop stirring after 3 hours of reaction, and quickly cool to room temperature, take out the reaction liquid for analysis, distill and separate the reaction liquid and catalyst, and the catalyst is used for the next reaction. The experimental results are shown in Table 5:

[0096] Table 5:

[0097]

[0098]

[0099] It can be seen from Table 5 that the homogeneous catalyst composition containing the monophosphine ligand 1 can be recycled at least 5 times, and the conversion rate of the 5 times can reach more than 80%, indicating that this type of monophosphine ligand has excellent metal coordination ability, which makes the catalyst composition more stable, thereby helping to significantly reduce production costs and has wide promotion value.

[0100] [Example 10]

[0101] In this example, monophosphine ligand 1 and tris(2,4-di-tert-butylphenyl)phosphite were used as ligands and Rh(acac)(CO)2 was used as a catalyst composition to test the reaction rate of the catalyst for the hydroformylation of diisobutylene.

[0102] In a 50mL high-pressure reactor, add 7.5mg Rh(acac)(CO)2, a certain amount of phosphine ligand, so that the phosphine / rhodium molar ratio is 10, 30mL diisobutylene, then charge the reactor with synthesis gas (CO:H2=1:1) three times, charge the reactor with synthesis gas again, keep the total pressure in the reactor at 2.5MPa, quickly heat to 70-100℃ and start stirring, stop stirring after 3 hours of reaction, and quickly cool to room temperature, and calculate the reaction rate according to the consumption of synthesis gas. The experimental results are shown in Table 6:

[0103] Table 6:

[0104]

[0105] According to the obtained data, the reaction activation energy of the monophosphine ligand 1 is 66.46 KJ / mol, and the reaction activation energy of tris(2,4-di-tert-butylphenyl)phosphite is 89.65 KJ / mol. It can be seen that the reaction activation energy of the olefin hydroformylation reaction with the participation of the monophosphine ligand is lower and the reaction activity is stronger, which is conducive to further reducing the reaction cost and promoting the industrial application of the hydroformylation reaction.

[0106] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A monophosphine ligand, characterized in that The monophosphine ligand is a compound shown in Formula I: In formula I, ring X is a substituted or unsubstituted C6-C8 cycloalkyl group, wherein when ring X has a substituent, the substituent of ring X is a C1-C8 alkyl group; and the R group is H, a C1-C8 alkyl group, a C1-C6 alkoxy group, a halogen group or an aryl group.

2. A monophosphine ligand according to claim 1, characterized in that: When the ring X has a substituent, the ring X is monosubstituted or disubstituted, and the substituent is a C1-C4 alkyl group.

3. A monophosphine ligand according to claim 2, characterized in that: The monophosphine ligand has any of the following structural formulas:

4. A monophosphine ligand according to claim 1, characterized in that: The R group is selected from methyl, ethyl, propyl, isopropyl, n-butyl or tert-butyl.

5. A monophosphine ligand according to any one of claims 1 to 4, characterized in that: The monophosphine ligand has any of the following structural formulas:

6. A method for preparing a monophosphine ligand, characterized in that: For preparing the monophosphine ligand according to any one of claims 1 to 5, the preparation method comprises the following steps: Dissolving the compound represented by Formula II in a solvent to obtain a first solution; mixing phosphorus trichloride, a base, and a solvent to obtain a second solution; Under an inert atmosphere, slowly adding the second solution to the first solution to obtain the monophosphine ligand; Formula II:

7. A catalyst composition, characterized in that The invention comprises a rhodium complex and the monophosphine ligand according to any one of claims 1 to 5.

8. A catalyst composition according to claim 7, characterized in that: The molar ratio of phosphine to rhodium in the catalyst composition is 3-50.

9. Use of the catalyst composition according to claim 7 or 8 in a hydroformylation reaction, characterized in that: The method comprises the following steps: after the raw olefin is mixed with the catalyst composition, the air in the reaction system is replaced by synthesis gas, and then a hydroformylation reaction is carried out.

10. The use according to claim 9, characterized in that: The molar ratio of the raw olefin to the rhodium complex in the catalyst composition is 100 to 100,000.

Images