A monophosphine ligand, a preparation method and application thereof

Abstract

The application relates to a monophosphine ligand, a preparation method and application thereof, wherein the monophosphine ligand exhibits a lower chemical shift in nuclear magnetic resonance phosphorus spectrum, reflects stronger power supply on P, has stronger metal coordination ability, can more effectively play a cocatalytic role, improves the conversion rate of hydroformylation reaction, and can achieve high conversion rate even for large steric olefins. Meanwhile, the stronger metal coordination ability makes the stability of the catalyst composition formed by the phosphine ligand stronger, thereby allowing the homogeneous catalyst composition to be recycled multiple times, and reducing the reaction cost. Moreover, according to a kinetic experiment, the olefin hydroformylation reaction participated by the monophosphine ligand has lower reaction activation energy and stronger reaction activity, which is beneficial to further reduce the reaction cost and promote the industrial application of the hydroformylation reaction.

Description

TECHNICAL FIELD

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

[0002] Hydroformylation reaction is a reaction process in which olefins react with synthesis gas under the action of a catalyst to generate an aldehyde with one more molecule than the original olefin. The generated aldehyde and its derivatives are widely used as plasticizers, fabric additives, surfactants, solvents and fragrances, etc. At present, hydroformylation reaction 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 researches on phosphine ligands have been carried out in recent years.

[0004] The tris(2,4-di-tert-butylphenyl) phosphite disclosed by BASF in patent CN115066429A has been commercialized, but this monophosphine ligand has low conversion rate and reaction activity when used in the hydroformylation reaction of large steric hindrance olefins, such as diisobutene, although a higher aldehyde yield can be obtained. In addition, increasing the reaction temperature and pressure can increase the conversion rate to a certain extent, but also increases the reaction cost, reduces the safety, and is not conducive to large-scale production and application. SUMMARY

[0005] An object of the present application is to provide a monophosphine ligand, which has a stronger electron-donating ability on the P atom through rational skeleton design, thereby having a stronger metal coordination ability. The catalytic system composed of the monophosphine ligand and rhodium complex can exhibit better conversion rate and reaction activity in the hydroformylation reaction of large steric hindrance olefins, thereby effectively reducing the reaction cost and making the reaction conditions more mild, which is conducive to industrial large-scale application.

[0006] The present application is realized by the following technical solutions:

[0007] A monophosphine ligand, which 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 group, the substituent group of ring X is a C1-C8 alkyl group; the R group is H, a C1-C8 alkyl group, a C1-C6 alkoxy group, a halogen or an aryl group.

[0010] In the technical solution, the monophosphine ligand has a structural formula shown in Formula I. Such structural formula exhibits a lower chemical shift in nuclear magnetic resonance phosphorus spectrum, reflecting a stronger power supply on P, and further having a stronger metal coordination ability, which can more effectively play a catalytic role and improve the conversion rate of hydroformylation reaction, and even high conversion rate can be achieved for large steric olefins. Meanwhile, the stronger metal coordination ability makes the stability of the catalyst composition formed by the phosphine ligand stronger, and further allows the homogeneous catalyst composition to be recycled multiple times, reducing the reaction cost. Moreover, according to the kinetic experiment, the olefin hydroformylation reaction involving the monophosphine ligand has a lower reaction activation energy and a stronger reaction activity, which is conducive to further reducing the reaction cost and promoting the industrial application of the hydroformylation reaction.

[0011] In the technical solution, ring X is a cycloalkyl group sharing a side with the furan ring, which can be cyclohexyl, cycloheptyl or cyclooctyl. In some embodiments, ring X can have a substituent or no substituent. In one or more embodiments, the substituent on ring X can be a C1-C8 linear alkyl group or a branched alkyl group. In some preferred embodiments, the substituent on ring X is preferably a C1-C8 linear alkyl group, more preferably a C1-C4 linear alkyl group. In some preferred embodiments, ring X is mono-substituted or di-substituted.

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

[0013]

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

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

[0016]

[0017] In the technical solution, the ring X is an unsubstituted or alkyl-substituted cyclohexyl or cycloctyl, and the R group is a tert-butyl group. The inventors have found through experiments that such a skeleton structure can further improve the power supply capability of P, enhance the conversion rate and reactivity of the hydroformylation reaction involving a monophosphine ligand, and in the hydroformylation of a highly hindered olefin, such as diisobutene, the conversion rate can reach more than 70%, which is significantly higher than that of the existing monophosphine ligand.

[0018] Another object of the present application is to provide a preparation method of any one of the monophosphine ligands described above, comprising the following steps:

[0019] dissolving a compound shown in 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] slowly adding the second solution to the first solution under an inert atmosphere to obtain the monophosphine ligand;

[0022] Formula II:

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

[0024]

[0025] In some embodiments, the solvent can 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 shown in Formula II is dissolved in tetrahydrofuran to form a first solution, and then phosphorus trichloride, triethylamine and tetrahydrofuran are mixed to obtain a second solution. Subsequently, the second solution is added dropwise to the first solution under an argon atmosphere at 0-5°C, and after the addition is completed, the reaction is carried out at room temperature for 1-3 hours. After the reaction is completed, the insoluble matter is removed by filtration, and the obtained solution is subjected to a low-pressure removal of 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 application also provides a catalyst composition based on any one of the aforementioned monophosphine ligands, which comprises a rhodium complex and the monophosphine ligand. The monophosphine ligand has excellent metal coordination ability, and can effectively catalyze the catalytic ability and stability of the system, improve the conversion rate of the hydroformylation reaction, and reduce the production cost.

[0030] Further, the molar ratio of phosphine to rhodium in the catalyst composition is 3-50. It has been found through experiments that, as the phosphine-to-rhodium ratio in the catalyst composition increases, the conversion rate of the hydroformylation reaction of the large steric hindrance olefin can be significantly increased, but when the phosphine-to-rhodium ratio reaches 6 or more, the conversion rate growth slows down significantly, and even decreases to a certain extent. In order to maintain a high conversion rate, reduce the amount of monophosphine ligand, and control the reaction cost, the phosphine-to-rhodium ratio is controlled to be 3-50 in the technical solution. In some preferred embodiments, the phosphine-to-rhodium ratio is 3-15, and more preferably, the phosphine-to-rhodium ratio is 6-12.

[0031] Further, the method comprises the following steps: after the raw material olefin is mixed with the catalyst composition, the air in the reaction system is replaced with synthesis gas, and then the hydroformylation reaction is performed.

[0032] In some embodiments, after the raw material olefin and the catalyst composition are mixed, the reaction kettle is filled with synthesis gas composed of hydrogen and carbon monoxide several times, and then the synthesis gas is filled again, so that the reaction kettle is under high pressure, and then the hydroformylation reaction is performed by heating until the reaction is completed.

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

[0034] In some preferred embodiments, the pressure of the synthesis gas is 1.0-4.0 MPa, and preferably, the pressure of the synthesis gas is 1.5-2.5 MPa in consideration of the production cost.

[0035] In some preferred embodiments, the reaction temperature is 90-120°C, and 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 embodiments, 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), 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 material olefin can be C2~C 18 olefin.

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

[0039] 1. The monophosphine ligand has stronger metal coordination ability, can more effectively play a catalytic role, and improve the conversion rate of the hydroformylation reaction, even for large steric olefins, a high conversion rate can be achieved.

[0040] 2. The monophosphine ligand has stronger metal coordination ability, so that the stability of the catalyst composition formed by the monophosphine ligand is stronger, and the homogeneous catalyst composition can be recycled multiple times, thereby reducing the reaction cost.

[0041] 3. The monophosphine ligand involved in the olefin hydroformylation reaction has lower reaction activation energy and stronger reaction activity, which is conducive to further reducing the reaction cost and promoting the industrial application of the hydroformylation reaction.

[0042] 4. By further selecting the R group as a tert-butyl group and the ring X as an unsubstituted or alkyl-substituted cyclohexyl or cyclooctyl group, the power supply capability of P can be further improved, and the conversion rate and reaction activity of the hydroformylation reaction involving the monophosphine ligand can be further improved.

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

[0044] 6. By setting the phosphine rhodium ratio in the catalyst composition to 3~50, the amount of monophosphine ligand can be reduced and the reaction cost can be controlled while maintaining a high conversion rate. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments, and the illustrative embodiments of the present application and their descriptions are only used to explain the present application, and not as a limitation on the present application.

[0046] The source of all raw materials of the present application is not particularly limited, and they can be purchased on the market or prepared according to conventional methods well known to those skilled in the art. The purity of all raw materials of the present application is not particularly limited, and the present application preferably uses analytical purity or the purity requirements conventional in the field of hydroformylation reaction catalysts. The grade and abbreviation of all raw materials of the present application are conventional in the art, and each grade and abbreviation is clear and explicit in the field of its relevant use, and those skilled in the art can purchase them on the market or prepare them by conventional methods according to the grade, abbreviation and corresponding use.

[0047] The expression of the substituent groups of the present application is not particularly limited, and the expression well known to those skilled in the art is used, and those skilled in the art can correctly understand the meaning thereof according to the expression based on common sense.

[0048] The "first", "second" and the like (e.g. first solution, second solution and the like) used herein are only used to distinguish the corresponding components for the sake of clarity, and are not intended to limit any order or emphasize importance. In addition, the term "connected" used herein can be directly connected or indirectly connected via other substituents without special description.

[0049] I. Preparation of monophosphine ligand

[0050] Example 1

[0051]

[0052] Under an argon atmosphere, 3-tert-butyl-6,7,8,9-tetrahydrodibenzo[b,d]furan-2-ol (18.6 mmol) and tetrahydrofuran (20 mL) were added into 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 dropwise addition was completed, the reaction was allowed to proceed at room temperature for 2 hours. The reaction was stopped, and the insoluble matter was removed by filtration. The obtained solution was subjected to removal of low-boiling compounds under reduced pressure to obtain an oily crude product, which was separated and purified by column chromatography to obtain a white solid, which was monophosphine ligand 1.

[0053] NMR Spectroscopy: 31 P NMR (162 MHz, chloroform-d) δ 121.67.

[0054] Example 2

[0055]

[0056] Into a 100 mL three-necked flask, 3-tert-butyl-8-methyl-6,7,8,9-tetrahydrodibenzo[b,d]furan-2-ol (18.6 mmol) and tetrahydrofuran (20 mL) were added under argon atmosphere. A mixture solution of phosphorous trichloride (5 mmol), triethylamine (20 mmol) and tetrahydrofuran (20 mL) was added dropwise at 0-5 °C. After the addition was completed, the reaction was allowed to proceed at room temperature for 2 hours. The reaction was stopped and the insoluble matter was removed by filtration. The resulting solution was subjected to removal of low-boiling compounds under reduced pressure to obtain an oily crude product. The white solid obtained by column chromatography was single phosphine ligand 2.

[0057] Structure characterization by nuclear magnetic resonance spectroscopy: 31 P NMR (162 MHz, chloroform-d) δ 127.51.

[0058]

Example 3

[0059]

[0060] Into a 100 mL three-necked flask, 3-tert-butyl-8-methyl-6,7,8,9-tetrahydrodibenzo[b,d]furan-2-ol (18.6 mmol) and tetrahydrofuran (20 mL) were added under argon atmosphere. A mixture solution of phosphorous trichloride (5 mmol), triethylamine (20 mmol) and tetrahydrofuran (20 mL) was added dropwise at 0-5 °C. After the addition was completed, the reaction was allowed to proceed at room temperature for 2 hours. The reaction was stopped and the insoluble matter was removed by filtration. The resulting solution was subjected to removal of low-boiling compounds under reduced pressure to obtain an oily crude product. The white solid obtained by column chromatography was single phosphine ligand 2.

[0061] Structure characterization by nuclear magnetic resonance spectroscopy: 31 P NMR (162 MHz, chloroform-d) δ 127.51.

[0062]

Example 4

[0063]

[0064] Into a 100 mL three-necked flask, 3-tert-butyl-8-methyl-6,7,8,9-tetrahydrodibenzo[b,d]furan-2-ol (18.6 mmol) and tetrahydrofuran (20 mL) were added under argon atmosphere. A mixture solution of phosphorous trichloride (5 mmol), triethylamine (20 mmol) and tetrahydrofuran (20 mL) was added dropwise at 0-5 °C. After the addition was completed, the reaction was allowed to proceed at room temperature for 2 hours. The reaction was stopped and the insoluble matter was removed by filtration. The resulting solution was subjected to removal of low-boiling compounds under reduced pressure to obtain an oily crude product. The white solid obtained by column chromatography was single phosphine ligand 2.

[0065] Structure characterization by nuclear magnetic resonance spectroscopy:31 P NMR (162 MHz, Chloroform-d) δ 128.12.

[0066] II. Test of monophosphine ligand

[0067] Diisobutene is a typical highly hindered olefin, therefore, the performance test involving monophosphine ligand is based on the hydroformylation reaction of diisobutene. The reaction path of diisobutene hydroformylation reaction is as follows:

[0068]

[0069]

Example 5

[0070] In this example, monophosphine ligand 1 and Rh(acac)(CO)2 are used as catalyst composition to test the effect of different phosphine-rhodium ratio on diisobutene hydroformylation reaction.

[0071] In a 50 mL high-pressure reactor, 7.5 mg of Rh(acac)(CO)2 and a certain amount of monophosphine ligand 1 are added, 30 mL of diisobutene is added, and then synthetic gas (CO:H2=1:1) is filled to replace the reactor three times, and then synthetic gas is filled again, the total pressure in the reactor is kept at 2.5 MPa, the temperature is quickly raised to 100°C and stirring is started, after 3 hours of reaction, the stirring is stopped, and the reaction solution is quickly cooled to room temperature and analyzed. The experimental results are shown in Table 1:

[0072] Table 1:

[0073] Experimental group Rhodium / phosphine ratio Conversion rate (%) Aldehyde formation 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 1-25, 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, and the conversion rate will not change significantly with the increase of the phosphine-rhodium ratio. Therefore, in some preferred embodiments, the phosphine-rhodium ratio of the reaction is determined to be 3-50, and in more preferred embodiments, the phosphine-rhodium ratio is determined to be 3-15.

[0075]

Example 6

[0076] In this example, monophosphine ligand 1 and Rh(acac)(CO)2 are used as catalyst composition to test the effect of different synthetic gas pressure on diisobutene hydroformylation reaction.

[0077] Into a 50 mL autoclave, 7.5 mg of Rh(acac)(CO)2, a certain amount of monophosphine ligand 1 to make the molar ratio of phosphine / rhodium 3, 30 mL of diisobutylene, then fill in the synthetic gas (CO:H2=1:1) to replace the reactor three times, fill in the synthetic gas again, keep the total pressure in the reactor as shown in Table 2, quickly heat to 100°C 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 Synthesis gas pressure (MPa) Conversion rate (%) Aldehyde formation 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] From Table 2, it can be seen that the pressure of the synthetic gas can increase the conversion rate to a certain extent, but higher pressure will also increase the production cost and safety considerations, therefore, in some preferred embodiments, the pressure of the synthetic gas is 1.5-2.5 MPa.

[0081]

Example 7

[0082] In this embodiment, monophosphine ligand 1 and Rh(acac)(CO)2 are used as the catalyst composition to test the effect of different reaction temperatures on the diisobutylene hydroformylation reaction.

[0083] Into a 50 mL autoclave, 7.5 mg of Rh(acac)(CO)2, a certain amount of monophosphine ligand 1 to make the molar ratio of phosphine / rhodium 3, 30 mL of diisobutylene, then fill in the synthetic gas (CO:H2=1:1) to replace the reactor three times, fill in the synthetic gas again, keep the total pressure in the reactor as 2.5 MPa, 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 (°C) Conversion rate (%) Aldehyde formation 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] From Table 3, it can be seen that when the temperature reaches 100°C, the conversion rate of diisobutylene hydroformylation reaction can reach 73.1%, and continuing to increase the temperature is beneficial to improve the conversion rate to 81.5%. Therefore, in some preferred embodiments, the reaction temperature is 100-120°C.

[0087]

Example 8

[0088] In this embodiment, different monophosphine ligands and Rh(acac)(CO)2 are used as the catalyst composition to test the performance of different monophosphine ligands, and the comparative example uses the monophosphine ligand tris(2,4-di-tert-butylphenyl) phosphite commercialized by BASF Company.

[0089] In a 50 mL autoclave, 7.5 mg of Rh(acac)(CO)2, a certain amount of monophosphine ligand, so that the molar ratio of phosphine / rhodium is 3, 30 mL of diisobutylene, followed by three times of replacement of the autoclave with synthetic gas (CO:H2=1:1), again filled with synthetic gas, keep the total pressure in the autoclave at 2.5 MPa, quickly heat to 100°C 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] From Table 4, it can be seen that the catalyst composition containing monophosphine ligand has obvious performance advantages in reaction activity and selectivity when applied to diisobutylene hydroformylation reaction compared with the commercialized catalyst system, which can significantly shorten the reaction time, improve the reaction efficiency, and the reaction conditions are more mild, which is conducive to large-scale production.

[0093] [Example 9]

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

[0095] In a 50 mL autoclave, 7.5 mg of Rh(acac)(CO)2, a certain amount of monophosphine ligand 1, so that the molar ratio of phosphine / rhodium is 12, 30 mL of diisobutylene, followed by three times of replacement of the autoclave with synthetic gas (CO:H2=1:1), again filled with synthetic gas, keep the total pressure in the autoclave at 2.5 MPa, quickly heat to 100°C and start stirring, stop stirring after 3 hours of reaction, and quickly cool to room temperature, take out the reaction liquid for analysis, distill 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] From Table 5, it can be seen that the homogeneous catalyst composition containing monophosphine ligand 1 can be recycled for at least 5 times, and the conversion rate of 5 times can reach more than 80%, which shows that this kind of monophosphine ligand has excellent metal coordination ability, so that the catalyst composition has stronger stability, thereby greatly reducing the production cost, and has wide popularization value.

[0100] [Example 10]

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

[0102] In a 50 mL high-pressure reactor, 7.5 mg of Rh(acac)(CO)2 and a certain amount of phosphine ligand were added to make the molar ratio of phosphine / rhodium 10, 30 mL of diisobutene, and then the reactor was filled with synthetic gas (CO:H2=1:1) three times, and then filled with synthetic gas again, keeping the total pressure in the reactor at 2.5 MPa, rapidly heating to 70-100°C and starting to stir, stopping stirring after 3 hours of reaction, and rapidly cooling to room temperature, and calculating the reaction rate according to the consumption of synthetic gas. The experimental results are shown in Table 6:

[0103] Table 6:

[0104]

[0105] According to the data obtained, the reaction activation energy under the participation of monophosphine ligand 1 is 66.46 KJ / mol, and the reaction activation energy under the participation of tris(2,4-di-tert-butylphenyl)phosphite is 89.65 KJ / mol. It can be seen that the reaction activation energy of olefin hydroformylation reaction under the participation of 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 hydroformylation reaction.

[0106] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application should be included in the protection scope of the present application.

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, wherein ring X has a substituent, and the substituent of ring X is a C1-C8 alkyl group; and R is H, a C1-C8 alkyl group, or a C1-C6 alkoxy group.

2. A monophosphine ligand according to claim 1, wherein When ring X has a substituent, ring X is mono-substituted or di-substituted, and the substituent is a C1-C4 alkyl group.

3. A monophosphine ligand according to claim 2, wherein The monophosphine ligand has any one of the following structural formulas:

4. The monophosphine ligand of claim 1, wherein, The R group is selected from a methyl group, an ethyl group, a propyl group, an isopropyl group, a n-butyl group, or a t-butyl group.

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

6. A process for the preparation of a monophosphine ligand, characterized in that, A method for preparing the monophosphine ligand of any one of claims 1-5, the method comprising the steps of: dissolving a compound shown in formula II in a solvent to obtain a first solution; mixing phosphorus trichloride, a base, and a solvent to obtain a second solution; slowly adding the second solution to the first solution under an inert atmosphere to obtain the monophosphine ligand; Formula II: wherein ring X and the R group in formula II correspond to the structure of the monophosphine ligand of any one of claims 1-5.

7. A catalyst composition characterized in that, A catalyst composition comprising a rhodium complex and a monophosphine ligand of any one of claims 1-5.

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

9. Use of a 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 with synthesis gas, and then a hydroformylation reaction is performed.

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

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