Phosphoramidite and preparation method and application thereof

Abstract

The invention discloses phosphoramidite and a preparation method and application thereof.The phosphoramidite has high stability and can catalyze a hydroformylation reaction of a raw material olefin under milder reaction conditions to obtain a high aldehyde forming rate, so that the phosphoramidite can be recycled for a longer time and more times in the hydroformylation reaction, and the yield of the olefin is increased. Therefore, the production cost is remarkably reduced, and the method is particularly suitable for the hydroformylation reaction of the raw material olefin, such as dicyclopentadiene, with low or no requirement on the normal / isomer ratio. Meanwhile, the phosphoramidite ligand is simple in preparation process and high in yield, and the cost of the phosphoramidite ligand can be reduced in large-scale production due to no participation of oxygen, so that the total cost of the hydroformylation reaction is further reduced.

Description

Technical Field

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

[0002] Hydroformylation occurs when olefins react with synthesis gas in the presence of a catalyst to produce an aldehyde with one additional molecule compared to the original olefin. The aldehydes and their derivatives produced by this reaction have a wide range of applications, including as plasticizers, textile additives, surfactants, solvents, and fragrances. Therefore, hydroformylation has become a crucial chemical reaction in industrial applications.

[0003] Phosphine ligands play an important role in hydroformylation catalyst systems, helping to improve reaction efficiency while also effectively reducing process costs. Consequently, extensive research on phosphine ligands has been conducted in recent years.

[0004] The inventor team discloses a single phosphorus ligand in patent CN119874773A, which, by reasonable skeleton design, makes P atom have strong power supply capability, can have excellent performance in large sterically hindered olefins, such as diisobutylene hydroformylation reaction. However, the single phosphorus ligand belongs to phosphite ligand, and phosphite ligand is inevitably more prone to decomposition when facing the weak acid environment in long-term reaction. In patent CN113583046B, the inventor team discloses a bidentate phosphine ligand, the ligand skeleton used by the bidentate phosphorus ligand not only has C2 symmetry and appropriate rigidity, and the phosphine ligand derived based on such skeleton can provide effectively steric hindrance around the catalyst center metal, so as to significantly improve the selectivity of the catalyst, in the hydroformylation reaction of 1-hexene, the ratio of normal aldehyde to isomeric aldehyde can be as high as 220. However, oxygen is needed to participate in the preparation process of this type of bidentate phosphorus ligand, there is certain safety risk, and therefore the cost of production is relatively higher.

[0005]

[0006] Furthermore, when the two existing phosphorus ligands are used in olefin hydroformylation reactions, higher temperatures and pressures are required. For example, the monophosphorus ligand of CN119874773A is more suitable for a temperature of 100-120°C and a reaction pressure of 1.5-2.5 MPa. When the diphosphorus ligand of CN113583046B is used, the reaction pressure needs to be 3 MPa and a temperature of 80°C to achieve a more ideal aldehyde formation rate and normal-to-iso ratio. Summary of the Invention

[0007] One object of the present invention is to provide a phosphoramidite having enhanced stability and being suitable for a longer hydroformylation reaction. Furthermore, the phosphoramidite can catalyze the hydroformylation of olefins at lower reaction temperatures and pressures to achieve a high aldehyde yield. The milder reaction conditions also enable the phosphoramidite to participate in a longer cyclic reaction, thereby significantly reducing production costs.

[0008] The present invention is achieved through the following technical solutions:

[0009] A phosphoramidite, wherein the phosphoramidite is a compound represented by formula I:

[0010]

[0011] In Formula I, R 1 The group is H, C1 to C8 alkyl, or C6 to C 12 Aryl; R 2 The group is selected from any one of the following groups:

[0012]

[0013] In the present technical solution, the phosphoramidite has a structure shown in Formula I. By introducing a nitrogen-substituted phosphoramidite on the PO bond, the problem of ligand decomposition caused by the weak acid environment during the hydroformylation process can be overcome from the root, thereby effectively improving the stability of the phosphoramidite in the cyclic reaction.

[0014] In this technical solution, R at the PO adjacent position of the phosphoramidite 1 The group may be H, i.e. unsubstituted. In some preferred embodiments, R 1 The group is a C1 to C8 alkyl group or a C6 to C 12 The aromatic group of the phosphoamidite is substituted to form a large steric hindrance substitution at the ortho position of the PO bond, so as to further improve the stability of the phosphoramidite in the cyclic reaction.

[0015] In some embodiments, R 1 The group can be a C1 to C8 alkyl group, which can be a chain alkyl group, such as ethyl, n-butyl, or a cyclic alkyl group, such as cyclohexyl. 1 The group may be a straight chain alkyl group or a branched chain alkyl group. 1 The group can be methyl, ethyl, propyl, isopropyl, butyl or tert-butyl. In some preferred embodiments, R 1 The group is a C1 to C6 straight chain alkyl group, for example, R 1 It can be methyl, ethyl, or n-hexyl; R 1 It can also be a C1-C6 branched alkyl group. In a preferred embodiment, R1 is a C3-C4 branched alkyl group, such as R 1 It can be isopropyl, tert-butyl, or isobutyl.

[0016] In some embodiments, R 1 The group can be C6~C 12 In one or more embodiments, the aryl group can be either a monocyclic aryl group or a condensed ring aryl group. In some embodiments, the aryl group is a phenyl group or a naphthyl group. In some preferred embodiments, R 1 In the present technical solution, the aryl group can be either an unsubstituted aryl group or a substituted aryl group, such as a monosubstituted or disubstituted aryl group. In some preferred embodiments, R 1 In one or more embodiments, the substituent of the phenyl group may be a C1-C4 alkyl group, for example, a monosubstituted or disubstituted methyl group, ethyl group, tert-butyl group, etc.

[0017] In this technical solution, R 2 The group is The skeletal structure of phosphoramidite and the nitrogen-substituted groups on P make the phosphoramidite exhibit a lower chemical shift in the nuclear magnetic resonance phosphorus spectrum, which means that the electron cloud density around the phosphine atom is relatively high. This shows that the skeletal structure and nitrogen-substituted groups can effectively enhance the power supply capacity of the P atom, making the metal coordination ability of the phosphoramidite stronger, so that it can catalyze the hydroformylation reaction at lower temperature and lower pressure, achieving excellent aldehyde formation rate. The milder reaction conditions also enable the phosphoramidite to participate in the cyclic reaction for a longer time, significantly reducing production costs.

[0018] It is worth noting that because the phosphoramidite itself lacks the C2 symmetry and greater rigidity of the bisphosphorus ligand of CN113583046B, it is difficult for the phosphoramidite to achieve the excellent iso-ratio of the bisphosphorus ligand of CN113583046B in the hydroformylation reaction. However, after sacrificing the iso-ratio, the phosphoramidite, on the one hand, relies on the addition of a large steric group at the ortho position of the P-O position and the introduction of an aza substituent on the P-position to increase its inherent stability. On the other hand, due to its strong metal coordination ability, it can participate in catalysis under milder reaction conditions and achieve an excellent aldehyde yield, significantly reducing the cost of the hydroformylation reaction. In addition, the synthesis process of the phosphoramidite does not require the participation of oxygen, which is conducive to further reducing the manufacturing cost of the phosphoramidite during industrial scale-up production, thereby reducing the overall cost of the hydroformylation reaction.

[0019] Therefore, this phosphoramidite is particularly suitable for hydroformylation reactions where a normal-to-isomer ratio is not required, such as in certain cases where both the normal- and iso-aldehydes are desired in the hydroformylation of 1-hexene. Alternatively, for feedstock olefins such as dicyclopentadiene, where there are no normal- or iso-aldehydes and the reaction product is a single product, phosphoramidite ligands can significantly reduce the cost of the hydroformylation reaction by extending the cycle time, providing a safer and more cost-effective option for industrial scale-up of hydroformylation.

[0020] Furthermore, the phosphoramidite has any of the following structures:

[0021]

[0022] Another object of the present invention is to provide a method for preparing any of the aforementioned phosphoramidites, specifically, the preparation method comprises the following steps:

[0023] Under an inert atmosphere, the compound of formula II is reacting to obtain the phosphoramidite;

[0024] Formula II:

[0025] In this technical solution, the inert atmosphere can be nitrogen or argon protection. In some embodiments, the compound of formula II, the base and the first solvent are mixed to obtain a first solution, and then After dissolving in a second solvent to obtain a second solution, the first solution and the second solution are slowly mixed and reacted at room temperature. After the reaction is complete, insoluble matter is filtered out, and the collected filtrate is subjected to vacuum distillation to obtain an oily substance, which is then recrystallized to obtain a phosphoramidite.

[0026] In this technical solution, the preparation process of phosphoramidite is simple, the reaction conditions are mild, and a high yield can be obtained. More importantly, the preparation process of phosphoramidite does not require the participation of oxygen. Therefore, the cost of considering relevant safety measures during scale-up production can be effectively reduced, which is conducive to reducing the manufacturing cost of phosphoramidite, thereby further reducing the overall cost of the hydroformylation reaction.

[0027] The present invention also provides a catalyst composition for olefin hydroformylation reaction, which comprises a rhodium catalyst and any one of the aforementioned phosphoramidites.

[0028] Furthermore, the phosphine to rhodium ratio of the catalyst composition is 10 to 30. In some preferred embodiments, the phosphine to rhodium ratio is 10 to 20, and more preferably, the phosphine to rhodium ratio is 15 to 20.

[0029] In some preferred embodiments, the rhodium catalyst is 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 and cod is 1,5-cyclooctadiene.

[0030] The present invention also provides an olefin hydroformylation reaction based on any of the aforementioned catalyst compositions, comprising the following steps:

[0031] The raw olefins and the catalyst composition are mixed, and the air in the reaction system is replaced by synthesis gas consisting of hydrogen and carbon monoxide, followed by a hydroformylation reaction.

[0032] In some preferred embodiments, a rhodium catalyst, phosphoramidite and raw olefin are added to a high-pressure reactor, and the raw olefin itself serves as a solvent. Synthesis gas is then introduced into the reaction system to replace oxygen. After the replacement, synthesis gas is added to the reaction pressure, and the hydroformylation reaction is carried out at the reaction temperature.

[0033] In this technical solution, by adopting a catalyst composition composed of phosphoramidite, an aldehyde formation rate of up to 99% can be obtained at a lower reaction temperature and reaction pressure. In some preferred embodiments, the reaction temperature of the hydroformylation reaction is 60-70°C, and the pressure of the synthesis gas is 1.0-2.0 MPa. Further preferably, the reaction temperature is 60°C and the synthesis gas pressure is 2.0 MPa. Compared with the existing technology, the reaction temperature and synthesis gas pressure can be greatly reduced, which is beneficial to maintaining the stability of the phosphoramidite and achieving a longer cycle reaction time.

[0034] In some preferred embodiments, after the hydroformylation reaction is completed, the catalyst composition is separated from the reaction liquid and used as the catalyst composition for the next hydroformylation reaction; the hydroformylation reaction can achieve an aldehyde formation rate of more than 99% when the same catalyst composition is used for the tenth time.

[0035] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0036] 1. The phosphoramidite of the present invention introduces an aza substituent on P to construct a phosphoramidite ligand, which can overcome the ligand decomposition problem caused by the weak acid environment during the hydroformylation process and effectively improve the stability of the phosphoramidite in the cyclic reaction. In addition, the large steric group introduced at the ortho position of the PO bond, such as a tert-butyl group, can further improve the stability of the phosphoramidite;

[0037] 2. The skeleton structure of the phosphoramidite of the present invention and the nitrogen-substituted groups on the P can effectively enhance the power supply capacity of the P atom, making the metal coordination ability of the phosphoramidite stronger, thereby being able to catalyze the hydroformylation reaction at lower temperatures and lower pressures, achieving excellent aldehyde yields. The milder reaction conditions also enable the phosphoramidite to participate in a longer cycle reaction, significantly reducing production costs.

[0038] 3. The preparation process of the phosphoramidite of the present invention is simple, the reaction conditions are mild, and a high yield can be obtained. More importantly, the preparation process of the phosphoramidite does not require the participation of oxygen, so the cost of considering relevant safety measures during scale-up production can be effectively reduced, which is conducive to reducing the manufacturing cost of the phosphoramidite, thereby further reducing the overall cost of the hydroformylation reaction;

[0039] 4. Although the phosphoramidite of the present invention sacrifices a high iso-to-normal ratio, it is applicable to hydroformylation reactions that do not require an iso-to-normal ratio, thereby significantly reducing the cost of the hydroformylation reaction with a longer cycle time, providing a safer and lower-cost option for industrial scale-up of hydroformylation. DETAILED DESCRIPTION

[0040] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples. The illustrative embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0041] 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. 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 unambiguous in the field of its related use. Those skilled in the art can purchase them from the market or prepare them by conventional methods based on the brand, abbreviation and corresponding use.

[0042] 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 meaning of the substituents according to the expressions.

[0043] The term "connected" used herein, unless otherwise specified, may refer to direct connection or indirect connection via other substituents.

[0044] 1. Preparation of phosphoramidites

[0045] [Example 1]

[0046]

[0047] Under an argon atmosphere, in a 50 mL three-necked flask, at 0°C, a mixed solution of indole (20 mmol), triethylamine (28.8 mol), and tetrahydrofuran (10 mL) was added dropwise to a mixed solution of phosphorus trichloride (10 mmol) and tetrahydrofuran (5 mL). After the addition was complete, the mixture was warmed to room temperature and reacted for 4 hours. The insoluble matter was removed by filtration, and the filtrate was collected and distilled under reduced pressure to obtain an oily product for use in the next reaction.

[0048] Under an argon atmosphere, a mixed solution of the compound of formula a (2 mmol), triethylamine (20 mmol), and tetrahydrofuran (15 mL) was added dropwise to a tetrahydrofuran solution (5 mL) of the product obtained in the previous step in a 100 mL three-necked flask at 0°C. After the addition was complete, the mixture was allowed to warm to room temperature and allowed to react for 4 hours. Insoluble matter was removed by filtration, and the filtrate was collected and distilled under reduced pressure to obtain an oily crude product. This was recrystallized from toluene and ethanol to obtain phosphoramidite 1 as a white solid in a 42% yield.

[0049] Structural characterization by NMR spectroscopy: 31 P NMR (162 MHz, deuterated chloroform) δ 64.44.

[0050] [Example 2]

[0051]

[0052] Under an argon atmosphere, in a 50 mL three-necked flask, at 0°C, a mixed solution of pyrrole (20 mmol), triethylamine (28.8 mol), and tetrahydrofuran (10 mL) was added dropwise to a mixed solution of phosphorus trichloride (10 mmol) and tetrahydrofuran (5 mL). After the addition was complete, the mixture was warmed to room temperature and reacted for 4 hours. The insoluble matter was removed by filtration, and the filtrate was collected and distilled under reduced pressure to obtain an oily product for use in the next reaction.

[0053] Under an argon atmosphere, a mixed solution of the compound of formula b (2 mmol), triethylamine (20 mmol), and tetrahydrofuran (15 mL) was added dropwise to a tetrahydrofuran solution (5 mL) of the product obtained in the previous step in a 100 mL three-necked flask at 0°C. After the addition was complete, the mixture was allowed to warm to room temperature and allowed to react for 4 hours. Insoluble matter was removed by filtration, and the filtrate was collected and distilled under reduced pressure to obtain an oily crude product. This was recrystallized from toluene and ethanol to obtain phosphoramidite 2 as a white solid in an 87% yield.

[0054] Structural characterization by NMR spectroscopy: 31 P NMR (162 MHz, deuterated chloroform) δ 63.26.

[0055] [Example 3]

[0056]

[0057] Under an argon atmosphere, in a 50 mL three-necked flask, at 0°C, a mixed solution of indole (20 mmol), triethylamine (28.8 mol), and tetrahydrofuran (10 mL) was added dropwise to a mixed solution of phosphorus trichloride (10 mmol) and tetrahydrofuran (5 mL). After the addition was complete, the mixture was warmed to room temperature and reacted for 4 hours. The insoluble matter was removed by filtration, and the filtrate was collected and distilled under reduced pressure to obtain an oily product for use in the next reaction.

[0058] Under an argon atmosphere, a mixed solution of the compound of formula b (2 mmol), triethylamine (20 mmol), and tetrahydrofuran (15 mL) was added dropwise to a tetrahydrofuran solution (5 mL) of the product obtained in the previous step in a 100 mL three-necked flask at 0°C. After the addition was complete, the mixture was allowed to warm to room temperature and allowed to react for 4 hours. Insoluble matter was removed by filtration, and the filtrate was collected and distilled under reduced pressure to obtain an oily crude product. This was recrystallized from toluene and ethanol to obtain phosphoramidite 3 as a white solid in a 92% yield.

[0059] Structural characterization by NMR spectroscopy: 31 P NMR (162 MHz, deuterated chloroform) δ 61.65.

[0060] [Example 4]

[0061]

[0062] Under an argon atmosphere, in a 50 mL three-necked flask, a mixed solution of carbazole (20 mmol), triethylamine (28.8 mol), and tetrahydrofuran (10 mL) was added dropwise to a mixed solution of phosphorus trichloride (10 mmol) and tetrahydrofuran (5 mL) at 0°C. After the addition was complete, the mixture was warmed to room temperature and reacted for 4 hours. The insoluble matter was removed by filtration, and the filtrate was collected and distilled under reduced pressure to obtain an oily product for use in the next reaction.

[0063] Under an argon atmosphere, a mixed solution of the compound of formula b (2 mmol), triethylamine (20 mmol), and tetrahydrofuran (15 mL) was added dropwise to a tetrahydrofuran solution (5 mL) of the product obtained in the previous step in a 100 mL three-necked flask at 0°C. After the addition was complete, the mixture was allowed to warm to room temperature and allowed to react for 4 hours. Insoluble matter was removed by filtration, and the filtrate was collected and distilled under reduced pressure to obtain an oily crude product. This was recrystallized from toluene and ethanol to obtain phosphoramidite 4 as a white solid in an 88% yield.

[0064] Structural characterization by NMR spectroscopy: 31 P NMR (162 MHz, deuterated chloroform) δ 61.73.

[0065] 2. Application of phosphoramidites in hydroformylation reactions

[0066] [Example 5]

[0067] In this example, the phosphoramidites prepared in Examples 1 to 4 were combined with Rh(acac)(CO)2 to form a catalyst composition, and the effects of phosphoramidites of different structures and dosages on the hydroformylation of 1-hexene were tested.

[0068]

[0069] Specifically, 7.5 mg of Rh(acac)(CO)2, a certain amount of phosphoramidite, and 30 mL of 1-hexene were added to a 50 mL high-pressure reactor. Synthesis gas (CO:H2=1:1) was then charged into the reactor to displace the reactor three times. Synthesis gas was then charged again, and the total pressure in the reactor was maintained at 2.0 MPa. The reactor was rapidly heated to 60°C and stirred. After reacting for 3 hours, stirring was stopped, and the reactor was rapidly cooled to room temperature. The reaction liquid was taken out for analysis. The experimental results are shown in Table 1.

[0070] Table 1:

[0071]

[0072]

[0073] As shown in Table 1, compared with the hydroformylation reaction without adding phosphoramidite as a phosphorus ligand, the 1-hexene hydroformylation reaction using a catalyst composition composed of phosphoramidite and Rh(acac)(CO)2 has a significantly higher aldehyde formation rate. At the same time, with the increase of the phosphine to rhodium ratio in the catalytic system, the conversion rate and aldehyde formation rate of the reaction both increase significantly. When the phosphine to rhodium ratio is between 10 and 30, the conversion rate of the reaction can be stabilized at more than 99%, and the aldehyde formation rate can also be as high as more than 99%, reflecting that the phosphoramidite can effectively enhance the metal coordination ability of the phosphoramidite by virtue of its skeleton structure and the nitrogen-substituted groups on the PO bond. At the same time, as can be seen from Table 1, the introduction of a large sterically hindered tert-butyl group at the ortho position of the PO bond on the benzene ring of the skeleton can further improve the aldehyde formation rate of the hydroformylation reaction.

[0074] Taking into account the aldehyde formation rate and production cost of the reaction, in some preferred embodiments, the phosphine to rhodium ratio in the catalytic system is 10-20, and more preferably, the phosphine to rhodium ratio is 15-20.

[0075] [Example 6]

[0076] In this example, phosphoramidite 3 and Rh(acac)(CO)2 were used as catalyst compositions to test the effects of different synthesis gas pressures on the hydroformylation reaction of 1-hexene.

[0077] In a 50 mL autoclave, 7.5 mg of Rh(acac)(CO)2, an amount of phosphoramidite 3 such that the phosphine / rhodium molar ratio of the catalyst system was 20, and 30 mL of 1-hexene were added. Synthesis gas (CO:H2 = 1:1) was then introduced into the autoclave three times to displace the reaction. Synthesis gas was then introduced again, maintaining the total pressure in the autoclave at 2.0 MPa. The autoclave was rapidly heated to the temperature shown in Table 2 and stirring was initiated. After 3 hours of reaction, stirring was stopped, the reaction mixture was rapidly cooled to room temperature, and the reaction liquid was collected for analysis. The experimental results are shown in Table 2.

[0078] Table 2:

[0079] Experimental group Reaction temperature (℃) Conversion rate (%) Formaldehyde rate (%) 21 50 79.8 96.5 14 60 99.3 99.2 23 70 99.9 98.8

[0080] As shown in Table 2, at a temperature of 50°C, the conversion rate of the 1-hexene hydroformylation reaction can reach 79.8%, and the aldehyde formation rate can reach 96.5%. After the temperature is raised to 60°C, the conversion rate and aldehyde formation rate of the reaction can both reach over 99%. Therefore, in some preferred embodiments, the reaction temperature is 50°C to 70°C, and in more preferred embodiments, the reaction temperature is 60°C. Compared with the bidentate phosphorus ligands and monophosphine ligands in the prior art, the reaction temperature is significantly reduced, which not only reduces production costs, but the milder reaction temperature also allows the phosphoramidite to circulate for a longer time.

[0081] [Example 7]

[0082] In this example, phosphoramidite 3 and Rh(acac)(CO)2 were used as catalyst compositions to test the effects of different reaction temperatures on the hydroformylation of 1-hexene.

[0083] In a 50 mL autoclave, 7.5 mg of Rh(acac)(CO)2, a certain amount of phosphoramidite 3 was added so that the phosphine / rhodium molar ratio of the catalyst system was 20, and 30 mL of 1-hexene was added. Synthesis gas (CO:H2=1:1) was then introduced into the autoclave three times to displace the reactor. Synthesis gas was then introduced again, and the total pressure in the autoclave was maintained at the pressure shown in Table 3. The reactor was rapidly heated to 60°C and stirred. After reacting for 3 hours, stirring was stopped, and the reaction mixture was rapidly cooled to room temperature. The reaction liquid was taken out for analysis. The experimental results are shown in Table 3:

[0084] Table 3:

[0085] Experimental group Syngas pressure (MPa) Conversion rate (%) Formaldehyde rate (%) 24 1.0 77.5 95.5 14 2.0 99.3 99.2 25 3.0 99.9 98.9

[0086] As shown in Table 3, at a syngas pressure of 1.0 MPa, the aldehyde yield in the 1-hexene hydroformylation reaction can reach over 96%. When the syngas pressure reaches 2.0 MPa, both the conversion rate and the aldehyde yield can reach over 99%. Therefore, in some preferred embodiments, the reaction pressure is 1.0 to 3.0 MPa, and in more preferred embodiments, the reaction pressure is 2.0 MPa. It can be seen that compared to bidentate phosphorus ligands and monophosphine ligands in the prior art, the reaction pressure can be further reduced, which is conducive to further reducing the cost of the hydroformylation reaction.

[0087] [Example 8]

[0088] In this example, phosphoramidite 3 and Rh(acac)(CO)2 were used as a catalyst composition to test the recycling of the catalyst composition for the hydroformylation reaction of 1-hexene.

[0089] In a 50 mL autoclave, 7.5 mg of Rh(acac)(CO)2, a certain amount of phosphoramidite 3 was added to make the phosphine / rhodium molar ratio 20, and 30 mL of 1-hexene. Synthesis gas (CO:H2=1:1) was then introduced into the autoclave to replace the reactor three times. Synthesis gas was then introduced again, and the total pressure in the autoclave was maintained at 2.0 MPa. The temperature was rapidly raised to 60°C and stirring was started. After reacting for 3 hours, stirring was stopped and the reactor was rapidly cooled to room temperature. The reaction liquid was taken out for analysis, and the reaction liquid and catalyst were separated by distillation. The catalyst was used for the next reaction. The experimental results are shown in Table 4:

[0090] Table 4:

[0091]

[0092]

[0093] As can be seen from Table 4, the catalytic system composed of phosphoramidite 3 and Rh(acac)(CO)2 can still maintain a conversion rate and aldehyde formation rate of more than 99% after being recycled 10 times. On the one hand, this is due to the structural stability brought by its skeleton structure. On the other hand, its strong metal coordination ability enables it to achieve excellent conversion rate and aldehyde formation rate at lower reaction temperature and reaction pressure, thereby enabling continuous recycling under milder reaction conditions, significantly reducing production costs, and having broad promotion value.

[0094] [Example 9]

[0095] Furthermore, this example uses phosphoramidite 3 and Rh(acac)(CO)2 as a catalyst composition to test the use of the catalyst composition in the hydroformylation reaction of different olefin substrates.

[0096] In a 50 mL autoclave, 7.5 mg of Rh(acac)(CO)2, a certain amount of phosphoramidite 3 was added to make the phosphine / rhodium molar ratio 20, and 30 mL of the raw olefin. Synthesis gas (CO:H2=1:1) was then introduced into the autoclave to displace the reactor three times. Synthesis gas was then introduced again, and the total pressure in the autoclave was maintained at 2.0 MPa. The reactor was rapidly heated to 60°C and stirred. After reacting for 3 hours, stirring was stopped, and the reactor was rapidly cooled to room temperature. The reaction liquid was taken out for analysis. The experimental results are shown in Table 5:

[0097] Table 5:

[0098] Experimental group Olefins Conversion rate (%) Formaldehyde rate (%) 14 1-Hexene 99.3 99.2 35 1-heptene 99.2 98.5 36 1-octene 99.7 98.6 37 Dicyclopentadiene 99.9 99.6

[0099] As shown in Table 5, phosphoramidite and Rh(acac)(CO)2 as catalyst compositions have a wide range of substrate adaptability for olefin hydroformylation reactions.

[0100] Simultaneously, as mentioned above, this phosphoramidite ligand is owing to not possessing the skeleton structure with C2 symmetry and suitable rigidity of diphosphorus ligand among the patent CN113583046B, so its positive iso-ratio is difficult to reach more than 90%.But the building-up process of this type of phosphoramidite ligand does not need oxygen to participate in, and production cost is lower, safety is higher, the cost of factor itself is lower, and it can under more gentle reaction conditions, long-term cyclic reaction and obtain excellent aldehyde yield, significantly reduced the cost of hydroformylation.Therefore, this type of phosphoramidite ligand is particularly useful in the hydroformylation that does not require positive iso-ratio, for example, in some cases, when the positive structural aldehyde and the iso-aldehyde of 1-hexene hydroformylation are all the products of expectation.Perhaps, for dicyclopentadiene this class does not have positive structural aldehyde, iso-aldehyde, the single raw material olefin of reaction product, this type of phosphoramidite ligand can significantly reduce the cost of hydroformylation with longer cycle time, for the selection that the hydroformylation industrialization amplifies production provides safer, low-cost.

[0101] 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 phosphoramidite, characterized in that The phosphoramidite is a compound represented by formula I: In Formula I, R 1 The group is H, C1 to C8 alkyl, or C6 to C 12 Aryl; R 2 The group is selected from any one of the following groups:

2. A phosphoramidite according to claim 1, characterized in that R 1 The group is H, a C1-C6 chain alkyl group, a C5-C6 cyclic alkyl group, or a phenyl group.

3. A phosphoramidite according to claim 2, characterized in that: The phosphoramidite has any of the following structures:

4. A method for preparing phosphoramidite, characterized in that: For preparing the phosphoramidite according to any one of claims 1 to 3, the preparation method comprises the following steps: Under an inert atmosphere, the compound of formula II is reacting to obtain the phosphoramidite; Formula II:

5. A catalyst composition for olefin hydroformylation reaction, characterized in that: The catalyst composition comprises a rhodium catalyst and the phosphoramidite according to any one of claims 1 to 3.

6. The catalyst composition according to claim 5, characterized in that The phosphine-rhodium ratio of the catalyst composition is 10-30.

7. The catalyst composition according to claim 5, characterized in that The rhodium catalyst is 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 and cod is 1,5-cyclooctadiene.

8. An olefin hydroformylation reaction, characterized in that: The following steps are involved: The raw olefin and the catalyst composition are mixed, and the air in the reaction system is replaced by synthesis gas consisting of hydrogen and carbon monoxide, followed by a hydroformylation reaction; Wherein, the catalyst composition is the catalyst composition according to any one of claims 5 to 7.

9. The olefin hydroformylation reaction according to claim 8, characterized in that: The reaction temperature of the hydroformylation reaction is 60-70° C., and the pressure of the synthesis gas is 1.0-2.0 MPa.

10. The olefin hydroformylation reaction according to claim 8, characterized in that: After the hydroformylation reaction is completed, the catalyst composition is separated from the reaction liquid and used as the catalyst composition for the next hydroformylation reaction. The hydroformylation reaction can achieve an aldehyde formation rate of more than 99% when the same catalyst composition is used for the tenth time.

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