An imine type phosphinimine ligand, a preparation method thereof and application thereof in a hydroformylation reaction of olefins

Abstract

The application provides an imine type phosphorus ligand, a preparation method thereof and application thereof in a hydroformylation reaction of olefins, and a structural general formula of the ligand is The imine type phosphorus ligand is obtained by reacting substituted dichlorophosphine and an alicyclic ketone to obtain 2,2'-carbonyl trisubstituted phosphine, and then reacting the 2,2'-carbonyl trisubstituted phosphine with an aliphatic amine. The obtained imine type phosphorus ligand can be used in the hydroformylation reaction of olefins, and has the characteristics of high normal / iso ratio, good selectivity and easy recovery of a metal catalyst.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis, specifically relating to an imine-type phosphine ligand, its preparation method, and its application in the hydroformylation reaction of olefins. Background Technology

[0002] Hydroformylation, as a highly atom-economical method for synthesizing alcohols, has a wide range of applications in industrial production. It is a synthetic method that uses olefins as raw materials to prepare alcohols with one more carbon atom. Currently, the main research direction in carbonyl synthesis is to obtain high-yield linear aldehydes / alcohols.

[0003] In CN1298859A, a water-soluble HRh(CO)(TPPTS)3 catalyst is generated in situ from sodium triphenylphosphine sulfonate and an aqueous solution of rhodium trichloride. Under conditions of 90°C and 2-3 MPa, ethylene gas is hydroformylated, and the total yield of propionaldehyde reaches 89.7%.

[0004] Patent CN1072691C proposes a method of adding organic amines and metal salts to improve the stability of phosphites, but organic amines can cause the aldehyde product in the hydroformylation reaction to undergo further polycondensation; Patent CN103702758A improves the stability of phosphites by adding epoxy compounds, but they may still be oxidized in actual operation.

[0005] Currently available technologies generally suffer from low selectivity for n-aldehydes, which puts pressure on production costs. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide an imine-type phosphine ligand and a preparation method. The ligand is used in the hydroformylation reaction of olefins and has the advantages of high conversion rate, high N / I ratio, good selectivity and easy recovery of metal catalyst.

[0007] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0008] This invention provides an imine-type phosphine ligand having a structure as shown in Formula I:

[0009]

[0010] In the formula, R 1 Selected from phenyl, substituted phenyl, pyridyl, thiophene, cyclohexyl, tert-butyl, preferably phenyl, cyclohexyl, or tert-butyl; R 2 Each is independently selected from n-butyl, tert-butyl, cyclohexyl, norbornel, and phenyl, with n-butyl, tert-butyl, and cyclohexyl being preferred; n takes the value of 1-4, preferably 1, 2, or 3, where n represents the number of carbon atoms in parentheses.

[0011] In this invention, the imine-type phosphine ligand has one of the following structures: L1-3.

[0012]

[0013] Another object of the present invention is to provide a method for preparing the imine-type phosphine ligand, comprising the following steps:

[0014] 1) The substituted phosphine dichloride reacts with alicyclic ketones under the action of a base catalyst to prepare a 2,2'-carbonyl trisubstituted phosphine intermediate;

[0015] 2) The 2,2'-carbonyl trisubstituted phosphine intermediate reacts with an aliphatic amine under the action of a catalyst to prepare the imine-type nitrogen phosphine ligand of Formula 1.

[0016] In this invention, the substituted phosphine dichloride described in step 1) has the structure shown in Formula 2.

[0017] In the formula, the substituent R 1 With R in Equation 1 1 Same, i.e., R 1 The components are selected from phenyl, substituted phenyl, pyridyl, thiophenyl, cyclohexyl, and tert-butyl, with phenyl, cyclohexyl, and tert-butyl being preferred;

[0018] Preferably, the substituted phosphine dichloride is selected from at least one of phenylphosphine dichloride, cyclohexylphosphine dichloride, and tert-butylphosphine dichloride.

[0019] In this invention, the alicyclic ketone in step 1) is selected from C5-C8 alicyclic ketones, preferably cyclopentanone or cyclohexanone, and more preferably cyclohexanone.

[0020] In this invention, the catalyst in step 1) is selected from organic bases, preferably alkyl lithium, and more preferably diisopropylamino lithium.

[0021] In this invention, the amount of alicyclic ketone added in step 1) is 2-2.5 times, preferably 2-2.2 times, the molar amount of the substituted phosphorus dichloride.

[0022] In this invention, the amount of catalyst added in step 1) is 2-3 times the molar amount of the substituted phosphorus dichloride, preferably 2-2.5 times.

[0023] In this invention, the reaction described in step 1) is carried out at a temperature of -100-30℃, preferably -78-25℃, for a time of 2-6 hours, preferably 3-5 hours (the reaction time does not include the catalyst feeding time mentioned above).

[0024] Preferably, the reaction is carried out in an inert gas atmosphere, preferably argon.

[0025] In this invention, the reaction in step 1) is carried out in a solvent environment, wherein the solvent is selected from non-polar organic solvents, preferably tetrahydrofuran (THF) or toluene, and more preferably tetrahydrofuran (THF);

[0026] The solvent dosage, calculated based on the mass of the alicyclic ketone raw material, is 2-10 ml / g, preferably 5-7 ml / g.

[0027] In this invention, after the reaction described in step 1) is completed, post-processing operations such as separation, extraction, washing, concentration, and drying are also included. These are conventional operations in the field. For example, adding saturated NH4Cl and saturated brine to separate the reaction solution into layers, using tetrahydrofuran for extraction, washing with saturated brine, concentration and drying, washing with ether, etc. This invention does not make specific limitations.

[0028] In this invention, the 2,2'-carbonyl trisubstituted phosphine intermediate described in step 1) has the structure shown in Formula 3.

[0029] (3), where the substituent R is in the formula 1 With R in Equation 1 1 Same, i.e., R 1 The components are selected from phenyl, substituted phenyl, pyridyl, thiophene, cyclohexyl, and tert-butyl, with phenyl, cyclohexyl, and tert-butyl being preferred; n takes the value of 1-4, preferably 1, 2, or 3.

[0030] In one embodiment, step 1) of the present invention specifically adopts the following process: in an inert gas atmosphere, the alicyclic ketone, catalyst, and solvent are mixed for 20-40 min at -78 to -72°C. Then, substituted phosphine dichloride is added to raise the temperature of the reaction system to 25°C. After reacting for 2-6 h, the mixture is stirred in air for 30 min, and then saturated NH4Cl and saturated brine are added to separate the reaction solution into layers. The aqueous phase is extracted twice with tetrahydrofuran, the organic phases are combined, and washed with saturated brine. The mixture is then concentrated and dried with anhydrous MgSO4, and then washed and dried with diethyl ether to obtain the 2,2'-carbonyl trisubstituted phosphine intermediate.

[0031] In this invention, the fatty amine described in step 2) has the structure shown in Formula 4.

[0032] R 2 -NH2(4), where the substituent R 2 With R in Equation 1 2 Same, i.e., R 2 Selected from n-butyl, tert-butyl, cyclohexyl, norbornel, and phenyl, with n-butyl, tert-butyl, and cyclohexyl being preferred;

[0033] Preferably, the fatty amine is selected from at least one of n-butylamine, tert-butylamine, and cyclohexylamine.

[0034] In this invention, the catalyst in step 2) is selected from acidic compounds, preferably TiCl4 and p-toluenesulfonic acid, more preferably TiCl4.

[0035] In this invention, the molar ratio of the 2,2'-carbonyl trisubstituted phosphine intermediate to the fatty amine in step 2) is 1:5-15, preferably 1:8-10.

[0036] In this invention, the amount of catalyst added in step 2) is 1-2 times the molar amount of the 2,2'-carbonyl trisubstituted phosphine intermediate, preferably 1.2-1.5 times.

[0037] In this invention, the catalyst in step 2) is fed continuously, preferably by drip feeding, and the feeding time is 20-60 min, preferably 20-40 min;

[0038] The catalyst is commercially available and can be in pure form or in solution form; the present invention does not make any particular limitation. For example, TiCl4 catalyst can be pure TiCl4 or a dichloromethane solution (1N) of TiCl4, preferably a dichloromethane solution (1N) of TiCl4.

[0039] In this invention, the reaction described in step 2) is carried out at a temperature of 0-30°C, preferably 0-25°C, for a time of 1-5 hours, preferably 1-3 hours (the reaction time does not include the catalyst feeding time mentioned above).

[0040] In this invention, the reaction in step 2) is carried out in a solvent environment, wherein the solvent is selected from diethyl ether and toluene, preferably diethyl ether;

[0041] The solvent dosage, calculated based on the mass of the 2,2'-carbonyl trisubstituted phosphine intermediate, is 5-10 ml / g, preferably 5-7 ml / g.

[0042] After the reaction is completed, the process further includes post-processing operations such as quenching the reaction with alkali, extraction, concentration, and drying. These are conventional operations in the field and are not specifically limited by this invention. In some specific examples of this invention, the quenching reaction with alkali is achieved by adding alkali solution to adjust the pH of the reaction solution to 5-7. The concentration of the alkali solution is preferably 0.3-0.5 mol / L, and preferably an aqueous solution of NaOH.

[0043] In one embodiment, step 2) of the present invention specifically adopts the following process: 2,2'-carbonyl trisubstituted phosphine intermediate, aliphatic amine and solvent are mixed, and then a catalyst solution is added dropwise over 20-60 min. The reaction system is reacted at 0-25℃ for 1-5 h. After the 2,2'-carbonyl trisubstituted phosphine reaction is complete as monitored by LC, the reaction is quenched with alkaline solution and extracted three times with diethyl ether. The organic phases are combined and dried with anhydrous Na2SO4. The mixture is then concentrated under reduced pressure and dried to obtain the imine-type nitrogen phosphine ligand.

[0044] Another object of the present invention is to provide the application of the imine-type phosphine ligand in the hydroformylation reaction of olefins;

[0045] The olefin is a C2-C10 monoolefin, preferably propylene, 1-butene, pentene, octene, or heptene.

[0046] This invention provides a method for the hydroformylation of olefins, wherein the method involves the catalytic hydroformylation of olefins with syngas in a solvent environment under the combined action of an imine-type phosphine ligand and a transition metal catalyst.

[0047] The reaction formula for the hydroformylation reaction described in this invention is as follows:

[0048]

[0049] Among them, the It is a C2-C10 monoolefin, preferably propylene, 1-butene, pentene, octene, or heptene.

[0050] In this invention, the transition metal catalyst is selected from one or more of rhodium acetate, rhodium octanoate, rhodium acetylacetonate, rhodium acetylacetonate carbonyl, rhodium dicarbonylacetylacetonate, rhodium triphenylphosphine acetylacetonate, cobalt acetate, cobalt octanoate, cobalt acetylacetonate, cobalt acetylacetonate carbonyl, and cobalt triphenylphosphine acetylacetonate.

[0051] In this invention, the amount of the transition metal catalyst is 0.0005-0.02 times the molar amount of the olefin, preferably 0.001-0.01 times, based on the metal atoms.

[0052] In this invention, the amount of the imine-type phosphine ligand is 20-100 times, preferably 50-80 times, the molar amount of metal atoms in the transition metal catalyst.

[0053] In this invention, the solvent is selected from at least one of tetrahydrofuran, dichloromethane, benzene, and toluene, preferably benzene or toluene;

[0054] The amount of solvent added is 5-50 times the molar amount of the olefin, preferably 10-20 times.

[0055] In this invention, the hydroformylation reaction is carried out at a temperature of 60-200℃, preferably 80-150℃, and for a time of 1.0-8.0h, preferably 2.0-5.0h.

[0056] In this invention, the hydroformylation reaction is carried out at a pressure of 1.0-20 MPaG, preferably 1.0-8.0 MPaG; the reaction pressure is controlled by the syngas, and the CO / H2 molar ratio in the syngas is 1:0.5-1.5, preferably 1:1.

[0057] In this invention, after the hydroformylation reaction is completed, the transition metal catalyst can be recovered. Specifically, the recovery of the transition metal catalyst can be achieved by adding a chelating agent to the reaction solution and then separating the phases.

[0058] The chelating agent is selected from carboxylic acid type, hydroxycarboxylic acid type, and hydroxyaminocarboxylic acid type, preferably at least one of ethylenediaminetetraacetic acid (EDTA), disodium ethylenediaminetetraacetic acid (EDTA-2Na), and hydroxyethyl ethylenediaminetriacetic acid (HEDTA), and more preferably ethylenediaminetetraacetic acid (EDTA).

[0059] The imine-type phosphine ligand described in this invention, in the presence of a transition metal catalyst, readily forms a two-five-membered ring coordination with the metal due to its three coordination active sites, thus stabilizing the metal. The substituents around the P and N groups in the ligand create significant steric hindrance, making it easier for the carbonyl group to add to the olefin terminal after coordination, resulting in high linear selectivity (95-97%), as illustrated below:

[0060]

[0061] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows:

[0062] (1) The imine-type phosphine ligand of the present invention has strong metal chelation ability in the presence of transition metal catalyst, and the large steric hindrance makes the linear selectivity high and the reaction efficient.

[0063] (2) The preparation of linear aldehydes by hydroformylation using the ligands of the present invention is simple, safe, low in production cost, and produces high-quality products. Detailed Implementation

[0064] The following embodiments will further illustrate the method provided by the present invention, but the present invention is not limited to the listed embodiments, and should also include any other known modifications within the scope of the claims of the present invention.

[0065] The main analytical methods used in the embodiments of this invention are as follows:

[0066] The reaction of alicyclic ketones and 2,2'-carbonyl trisubstituted phosphine intermediates was monitored by liquid chromatography: instrument model: Agilent 1260, column: Agilent ZORBAX SB-C18, acetonitrile / water gradient elution.

[0067] Characterization methods for imine-type phosphine ligands: 1 H NMR, instrument model: Bruker 500MHz nuclear magnetic resonance spectrometer.

[0068] The conversion of olefins and the selectivity of aldehydes were calculated by normalizing the gas chromatographic area: Gas chromatograph: Agilent 7890; Column: DB-5; Injector temperature: 280℃; Split ratio: 10:1; H2:Air:N2 = 40:400:30 (mL / min); Column flow rate: 5.0 mL / min; Temperature program: 50℃ for 2 min, then increased from 50℃ to 280℃ at a rate of 15℃ / min, and held at 280℃ for 5 min; FID detector temperature: 280℃.

[0069] Information on the main reagent sources used in the embodiments of this invention:

[0070] Phenylenol dichloride (AR), cyclohexylphosphine dichloride (AR), tert-butylphosphine dichloride (AR), cyclopentanone (AR), cyclohexanone (AR), cycloheptanone (AR), THF (AR), toluene (AR), diethyl ether (AR), TiCl4 (1N in DCM), lithium diisopropylaminopropyl LDA (2M in THF), tert-butylamine (AR), n-butylamine (AR), cyclohexylamine (AR), NH4Cl (AR), NaCl (AR): Inokai;

[0071] Unless otherwise specified, all other raw materials are commercially available products, and all reagents are of analytical grade.

[0072] Example 1

[0073] The steps for preparing the imine-type nitrogen-phosphorus ligand L1 are as follows:

[0074]

[0075] (1) Under an argon atmosphere, LDA (0.22 mol), cyclohexanone (0.2 mol, 19.63 g), and THF (100 mL) were mixed at -78 °C for 30 min. Then, phenylphosphine dichloride (0.1 mol, 17.90 g) was added, and the reaction system was heated from -78 °C to 25 °C and reacted for 4 h. After the reaction was completed, the mixture was stirred in air for 30 min, and then saturated NH4Cl and saturated brine were added to separate the reaction solution into layers. The aqueous phase was extracted twice with THF, the organic phases were combined, and washed with saturated brine. The product was concentrated and dried with anhydrous MgSO4, washed with diethyl ether, and dried to obtain 2,2'-carbonyl trisubstituted phosphine intermediate (III) (18.75 g, 0.062 mol).

[0076] The 1H NMR spectrum of intermediate (III) is as follows: 1H NMR (500MHz, CDCl3): δ=7.53-7.43(m,2H),7.37-7.28(m,3H),3.01-2.90(m,2H),2.39-2.29(m,2H),2.28(t, J=7.0Hz,2H),2.24-2.17(m,2H),2.08-1.98(m,2H),1.98-1.89(m,4H),1.89-1.82(m,2H),1.65-1.52(m,2H).

[0077] (2) 2,2'-carbonyl trisubstituted phosphine intermediate (III) (15.12 g, 0.05 mol) and tert-butylamine (36.57 g, 0.5 mol) were mixed in 100 mL of diethyl ether and cooled to 0 °C. 67 mL of TiCl4 (0.067 mol, 1 N in DCM) solution was added dropwise over 30 min. The reaction system was heated from 0 °C to 25 °C and reacted for 2 h until the reaction was complete. The reaction was quenched at room temperature with 0.5 mol / L NaOH aqueous solution and extracted three times with diethyl ether. The organic phases were combined and dried over anhydrous Na2SO4, concentrated under reduced pressure, and dried to obtain imine-type nitrogen phosphine ligand L1 (17.54 g, 0.043 mol).

[0078] The 1H NMR spectrum of imine-type nitrogen-phosphorus ligand L1 is as follows: 1 H NMR (500MHz, CDCl3): δ=7.50-7.36(m,2H), 7.36-7.20(m,5H), 2.39-2.19(m,4H), 1.88-1.66(m,4H), 1.52-1.22(m,6H), 1.13-0.79(m,20H).

[0079] The preparation of n-butyraldehyde by hydroformylation of propylene involves the following steps:

[0080] Propylene, triphenylphosphine acetylacetone cobalt catalyst, ligand L1, and toluene were added to a reactor. The molar amount of cobalt in the triphenylphosphine acetylacetone cobalt catalyst was 0.005 times that of propylene, the molar amount of ligand L1 was 60 times that of cobalt in the triphenylphosphine acetylacetone cobalt catalyst, and the molar amount of toluene was 15 times that of propylene. Syngas (CO / H2 molar ratio of 1:1) was then introduced, and the reaction was carried out at a pressure of 1 MPaG and a temperature of 80 °C for 2.0 hours. Gas chromatography analysis showed that the propylene conversion rate was 99.5%, and the linear product n-butyraldehyde had a selectivity of 95.8% and the 2-methylpropionaldehyde (isobutyraldehyde) selectivity was 0.8%.

[0081] EDTA-2Na and water were added to the reaction solution, mixed and allowed to stand. The aqueous phase and organic phase were separated. The content of metal Co in the organic phase was not detected. The aqueous phase was used to recover the metal catalyst.

[0082] Example 2

[0083] The steps for preparing the imine-type nitrogen-phosphorus ligand L2 are as follows:

[0084]

[0085] (1) Under an argon atmosphere, LDA (0.20 mol), cyclopentanone (0.21 mol, 17.67 g), and toluene (92.5 mL) were mixed at -78 °C for 40 min. Then, cyclohexylphosphine dichloride (0.1 mol, 18.50 g) was added to raise the reaction temperature from -78 °C to 25 °C and react for 3 h. After the reaction was completed, the mixture was stirred in air for 30 min, and then saturated NH4Cl and saturated brine were added to separate the reaction solution into layers. The aqueous phase was extracted twice with THF, the organic phases were combined, and washed with saturated brine. The product was concentrated and dried with anhydrous MgSO4, washed with diethyl ether, and dried to give 2,2'-carbonyl trisubstituted phosphine intermediate (III) (19.62 g, 0.07 mol).

[0086] The 1H NMR spectrum of intermediate (III) is as follows: 1 H NMR (500MHz, CDCl3): δ=2.40(s,2H),2.36-2.26(m,3H),2.19-2.08(m,2H), 2.07-1.87(m,6H),1.81-1.71(m,2H),1.71-1.63(m,3H),1.43-1.17(m,7H).

[0087] (2) 2,2'-carbonyl trisubstituted phosphine intermediate (III) (14.02 g, 0.05 mol) and n-butylamine (32.91 g, 0.45 mol) were mixed in 70.3 mL of diethyl ether and cooled to 0 °C. 60 mL of TiCl4 (0.06 mol, 1 N in DCM) solution was added dropwise over 20 min. The reaction system was heated from 0 °C to 25 °C and reacted for 3 h until the reaction was complete. The reaction was quenched at room temperature with 0.3 mol / L NaOH aqueous solution and extracted three times with diethyl ether. The organic phases were combined and dried over anhydrous Na2SO4, concentrated under reduced pressure, and dried to obtain imine-type nitrogen phosphine ligand L2 (16.01 g, 0.041 mol).

[0088] The 1H NMR data for the imine-type nitrogen-phosphorus ligand L2 are as follows: 1H NMR (500MHz, CDCl3): δ=3.63-3.54(m,2H),3.10-3.01(m,2H),2.69(s,2H),2.46-2.37(m,2H),2.29-2.20(m,2H) ),1.96-1.86(m,2H),1.72-1.60(m,4H),1.46-1.16(m,13H),1.16-0.95(m,6H),0.90(s,6H),0.75-0.64(m,2H).

[0089] The preparation of n-heptanal by hydroformylation of hexene involves the following steps:

[0090] Hexene, rhodium acetylacetone catalyst, ligand L2, and toluene were added to a reactor. The molar amount of rhodium in the rhodium acetylacetone catalyst was 0.001 times that of hexene, the molar amount of ligand L2 was 80 times that of rhodium in the rhodium acetylacetone catalyst, and the molar amount of toluene was 10 times that of hexene. Syngas (CO / H2 molar ratio of 1:1) was then introduced, and the reaction was carried out at a pressure of 5 MPaG and a temperature of 100 °C for 4.0 hours. Gas chromatography analysis showed that the hexene conversion rate was 98.7%, and the linear product n-heptaldehyde had a selectivity of 95.2% and the 2-methylhexanal had a selectivity of 0.7%.

[0091] HEDTA and water were added to the reaction solution, mixed and allowed to stand. The aqueous phase and organic phase were separated. The content of metal Rh in the organic phase was not detected. The aqueous phase was used to recover the metal catalyst.

[0092] Example 3

[0093] The steps for preparing the imine-type nitrogen-phosphorus ligand L3 are as follows:

[0094]

[0095] (1) Under an argon atmosphere, LDA (0.25 mol), cycloheptanone (0.22 mol, 24.68 g), and THF (110 mL) were mixed at -72 °C for 50 min. Then, tert-butylphosphine dichloride (0.1 mol, 15.90 g) was added to raise the reaction temperature from -72 °C to 25 °C and react for 5 h. After the reaction was completed, the mixture was stirred in air for 30 min, and then saturated NH4Cl and saturated brine were added to separate the reaction solution into layers. The aqueous phase was extracted twice with THF, the organic phases were combined, and washed with saturated brine. The mixture was concentrated and dried with anhydrous MgSO4. The product was washed with diethyl ether and dried to obtain 2,2'-carbonyl trisubstituted phosphine intermediate (III) (20.18 g, 0.065 mol).

[0096] The 1H NMR spectrum of intermediate (III) is as follows: 1H NMR (500MHz, CDCl3): δ=3.09(s,2H),2.92-2.83(m,2H),2.82-2.72(m,2H),2.25-2.14(m,2H) ),1.98-1.88(m,2H),1.76-1.63(m,2H),1.63-1.44(m,6H),1.43-1.24(m,4H),1.04(s,9H).

[0097] (2) 2,2'-carbonyl trisubstituted phosphine intermediate (III) (15.52 g, 0.05 mol) and cyclohexylamine (39.67 g, 0.40 mol) were mixed in 108.6 mL of diethyl ether and cooled to 0 °C. 75 mL of TiCl4 (0.075 mol, 1 N in DCM) solution was added dropwise over 40 min. The reaction system was heated from 0 °C to 25 °C and reacted for 1 h until the reaction was complete. The reaction was quenched at room temperature with 0.4 mol / L NaOH aqueous solution and extracted three times with diethyl ether. The organic phases were combined and dried with anhydrous Na2SO4. The mixture was concentrated under reduced pressure and dried to obtain imine-type nitrogen phosphine ligand L3 (20.80 g, 0.044 mol).

[0098] The 1H NMR data for the imine-type nitrogen-phosphorus ligand L3 are as follows: 1 H NMR (500MHz, CDCl3): δ=3.14-3.07(m,2H),2.80(d,J=17.9Hz,2H),2.69(s,2H),2.07(d,J=17.9Hz,2H),1.72-1.63(m, 4H), 1.61-1.55 (m, 4H), 1.54-1.42 (m, 8H), 1.41-1.27 (m, 10H), 1.24-1.12 (m, 6H), 1.05 (s, 9H), 0.96 (d, J = 12.9Hz, 4H).

[0099] The preparation of n-nonanal by octene hydroformylation involves the following steps:

[0100] Octene, a triphenylphosphine acetylacetone rhodium catalyst, ligand L3, and toluene were added to a reactor. The molar amount of rhodium in the triphenylphosphine acetylacetone rhodium catalyst was 0.01 times that of octene, the molar amount of ligand L3 was 50 times that of rhodium in the triphenylphosphine acetylacetone rhodium catalyst, and the molar amount of toluene was 20 times that of octene. Syngas (CO / H2 molar ratio of 1:1) was then introduced, and the reaction was carried out at a pressure of 8 MPaG and a temperature of 150 °C for 5.0 hours. Gas chromatography analysis showed that the octene conversion rate was 99.1%, and the linear product nonanal had a selectivity of 96.9% and 2-methyloctaldehyde had a selectivity of 0.4%.

[0101] EDTA and water were added to the reaction solution, mixed and allowed to stand. The aqueous phase and organic phase were separated. The content of metal Rh in the organic phase was not detected. The aqueous phase was used to recover the metal catalyst.

[0102] Comparative Example 1

[0103] The method of Example 2 was used to prepare n-heptaldehyde by hydroformylation of hexene, with the only difference being that ligand L2 was replaced with an equal amount of triphenylphosphine, while other operations and parameters remained unchanged. Gas chromatography analysis showed that the hexene conversion rate was 85.2%, the linear product n-heptaldehyde had a selectivity of 82.4%, and 2-methylhexanaldehyde had a selectivity of 9.7%.

[0104] HEDTA and water were added to the reaction solution, mixed and allowed to stand. The aqueous phase and organic phase were separated, and the Rh metal content in the organic phase was analyzed to be 856 ppm.

[0105] Comparative Example 2

[0106] The method of Example 2 was used to prepare n-heptaldehyde by hydroformylation of hexene, with the only difference being that ligand L2 was replaced with an equal amount of the 2,2'-carbonyl trisubstituted phosphine intermediate prepared in Example 2, while other operations and parameters remained unchanged. Gas chromatography analysis showed that the hexene conversion rate was 92.8%, the linear product n-heptaldehyde had a selectivity of 84.1%, and 2-methylhexaldehyde had a selectivity of 8.2%.

[0107] HEDTA and water were added to the reaction solution, mixed and allowed to stand. The aqueous phase and organic phase were separated, and the Rh metal content in the organic phase was analyzed to be 524 ppm.

[0108] Comparative Example 3

[0109] The method of Example 2 was used to prepare n-heptaldehyde by hydroformylation of hexene, with the only difference being that the ligand L2 was replaced with an equal amount of Xantphos, while other operations and parameters remained unchanged. Gas chromatography analysis showed that the hexene conversion rate was 93.5%, the linear product n-heptaldehyde had a selectivity of 85.3%, and 2-methylhexanal had a selectivity of 7.9%.

[0110] HEDTA and water were added to the reaction solution, mixed and allowed to stand. The aqueous phase and organic phase were separated, and the Rh content in the organic phase was analyzed to be 673 ppm.

Claims

1. An imine-type phosphine ligand, characterized in that, The ligand has a structure as shown in Formula I: （1） In the formula, R 1 Selected from phenyl, cyclohexyl, and tert-butyl; R 2 Each is independently selected from n-butyl, tert-butyl, cyclohexyl, and norbornel; n takes values ​​from 1 to 4.

2. The imine-type phosphine ligand according to claim 1, characterized in that, n can be 1, 2, or 3.

3. The imine-type phosphine ligand according to claim 1, characterized in that, The imine-type phosphine ligand has one of the following structures: L1-L3. (L1) (L2) (L3) 4. A method for preparing the imine-type phosphine ligand according to claim 2, characterized in that the step... include: 1) The substituted phosphine dichloride reacts with alicyclic ketones under the action of a base catalyst to prepare a 2,2'-carbonyl trisubstituted phosphine intermediate; 2) The 2,2'-carbonyl trisubstituted phosphine intermediate reacts with an aliphatic amine under the action of a catalyst to prepare the imine-type nitrogen phosphine ligand of Formula 1; Step 1) The substituted phosphine dichloride has the structure shown in Formula 2. (2), where the substituent R 1 With R in Equation 1 1 same; Step 1) The alicyclic ketone is selected from cyclopentanone, cyclohexanone, or cycloheptanone; The 2,2'-carbonyl trisubstituted phosphine intermediate described in step 1) has the structure shown in Formula 3. (3), where the substituent R1 is the same as R1 in Equation 1, and the value of n is the same as n in Equation 1; Step 2) The fatty amine has the structure shown in Formula 4. R 2 -NH2(4), where the substituent R 2 With R in Equation 1 2 same; Step 2) The catalyst is selected from acidic compounds.

5. The preparation method according to claim 4, characterized in that, Step 1) The substituted phosphine dichloride is selected from at least one of phenylphosphine dichloride, cyclohexylphosphine dichloride, and tert-butylphosphine dichloride; and / or Step 1) The alicyclic ketone is selected from cyclopentanone, cyclohexanone, or cycloheptanone; and / or Step 1) The base catalyst is selected from organic bases; and / or Step 1) The amount of the alicyclic ketone added is 2-2.5 times the molar amount of the substituted phosphorus dichloride; and / or Step 1) The amount of alkaline catalyst added is 2-3 times the molar amount of the substituted phosphorus dichloride.

6. The preparation method according to claim 5, characterized in that, The alkaline catalyst in step 1) is selected from alkyl lithium.

7. The preparation method according to claim 5, characterized in that, The alkaline catalyst in step 1) is lithium diisopropylamino.

8. The preparation method according to claim 5, characterized in that, Step 1) The amount of alicyclic ketone added is 2-2.2 times the molar amount of the substituted phosphorus dichloride.

9. The preparation method according to claim 5, characterized in that, In step 1), the amount of alkaline catalyst added is 2-2.5 times the molar amount of the substituted phosphorus dichloride.

10. The preparation method according to claim 4, characterized in that, The reaction described in step 1) is carried out at a temperature of -100 to 30°C for 2 to 6 hours; and / or Step 1) The reaction is carried out in a solvent environment, wherein the solvent is selected from nonpolar organic solvents.

11. The preparation method according to claim 10, characterized in that, The reaction is carried out at a temperature of -78 to 25°C for 3 to 5 hours.

12. The preparation method according to claim 10, characterized in that, The solvent is selected from tetrahydrofuran and toluene.

13. The preparation method according to claim 10, characterized in that, The solvent dosage, calculated based on the mass of the alicyclic ketone raw material, is 2-10 ml / g.

14. The preparation method according to claim 13, characterized in that, The solvent dosage, calculated based on the mass of the alicyclic ketone raw material, is 5-7 ml / g.

15. The preparation method according to claim 4, characterized in that, Step 1) The reaction is carried out in an inert gas atmosphere.

16. The preparation method according to claim 15, characterized in that, The inert gas atmosphere is argon.

17. The preparation method according to claim 4, characterized in that, Step 2) The fatty amine is selected from at least one of n-butylamine, tert-butylamine, and cyclohexylamine; and / or Step 2) The catalyst is selected from TiCl4, p-toluenesulfonic acid; and / or Step 2) The molar ratio of the 2,2'-carbonyl trisubstituted phosphine intermediate to the aliphatic amine is 1:5-15; and / or Step 2) The amount of catalyst added is 1-2 times the molar amount of the 2,2'-carbonyl trisubstituted phosphine intermediate; and / or Step 2) The catalyst is fed continuously.

18. The preparation method according to claim 17, characterized in that, The molar ratio of the 2,2'-carbonyl trisubstituted phosphine intermediate to the fatty amine is 1:8-10.

19. The preparation method according to claim 17, characterized in that, Step 2) The amount of catalyst added is 1.2-1.5 times the molar amount of the 2,2'-carbonyl trisubstituted phosphine intermediate.

20. The preparation method according to claim 17, characterized in that, Step 2) The catalyst is added by drip feeding.

21. The preparation method according to claim 17, characterized in that, Step 2) The catalyst feeding time is 20-60 min.

22. The preparation method according to claim 21, characterized in that, Step 2) The catalyst feeding time is 20-40 min.

23. The preparation method according to claim 4, characterized in that, The reaction described in step 2) is carried out at a temperature of 0-30°C for 1-5 hours; and / or Step 2) The reaction is carried out in a solvent environment, wherein the solvent is selected from diethyl ether or toluene; The solvent dosage, calculated based on the mass of the 2,2'-carbonyl trisubstituted phosphine intermediate, is 5-10 ml / g.

24. The preparation method according to claim 23, characterized in that, The reaction is carried out at a temperature of 0-25℃ for 1-3 hours.

25. The preparation method according to claim 23, characterized in that, The solvent dosage, calculated based on the mass of the 2,2'-carbonyl trisubstituted phosphine intermediate, is 5-7 ml / g.

26. The use of the imine-type phosphine ligand according to any one of claims 1-3 or the imine-type phosphine ligand prepared by the preparation method according to any one of claims 4-25 in the hydroformylation reaction of olefins, wherein the olefins are selected from C2-C10 monoolefins.

27. The application according to claim 26, characterized in that, The olefin is selected from propylene, 1-butene, pentene, octene, and heptene.

28. A method for the hydroformylation of an olefin, characterized in that, The method involves catalyzing the hydroformylation reaction of olefins with syngas in a solvent environment, using either the imine-type phosphine ligand described in any one of claims 1-3 or the imine-type phosphine ligand prepared by any one of claims 4-25, in conjunction with a transition metal catalyst. The olefins are selected from C2-C10 monoolefins.

29. The method for hydroformylation of olefins according to claim 28, characterized in that, The transition metal catalyst is selected from one or more of rhodium acetate, rhodium octanoate, rhodium acetylacetonate, rhodium acetylacetonate carbonyl, rhodium dicarbonyl acetylacetonate, rhodium triphenylphosphine acetylacetonate, cobalt acetate, cobalt octanoate, cobalt acetylacetonate, cobalt acetylacetonate carbonyl, and cobalt triphenylphosphine acetylacetonate.

30. The method for hydroformylation of olefins according to claim 28, characterized in that, The amount of the transition metal catalyst used is 0.0005-0.02 times the molar amount of the olefin, based on the metal atoms.

31. The method for hydroformylation of olefins according to claim 30, characterized in that, The amount of the transition metal catalyst used is 0.001-0.01 times the molar amount of the olefin, based on the metal atoms.

32. The method for hydroformylation of olefins according to claim 28, characterized in that, The amount of the imine-type phosphine ligand is 20-100 times the molar amount of metal atoms in the transition metal catalyst.

33. The method for hydroformylation of olefins according to claim 32, characterized in that, The amount of the imine-type phosphine ligand is 50-80 times the molar amount of metal atoms in the transition metal catalyst.

34. The method for hydroformylation of olefins according to claim 28, characterized in that, The solvent is selected from at least one of tetrahydrofuran, dichloromethane, benzene, and toluene.

35. The method for hydroformylation of olefins according to claim 28, characterized in that, The amount of solvent added is 5-50 times the molar amount of the olefin.

36. The method for hydroformylation of olefins according to claim 35, characterized in that, The amount of solvent added is 10-20 times the molar amount of the olefin.

37. The method for hydroformylation of olefins according to claim 28, characterized in that, The hydroformylation reaction is carried out at a temperature of 60-200℃ for a time of 1.0-8.0h.

38. The method for hydroformylation of olefins according to claim 37, characterized in that, The hydroformylation reaction is carried out at a temperature of 80-150℃ for a time of 2.0-5.0h.

39. The method for hydroformylation of olefins according to claim 28, characterized in that, The hydroformylation reaction is carried out at a pressure of 1.0-20 MPaG; the reaction pressure is controlled by the syngas, and the CO / H2 molar ratio in the syngas is 1:0.5-1.

5.

40. The method for hydroformylation of olefins according to claim 39, characterized in that, The hydroformylation reaction is carried out at a pressure of 1.0-8.0 MPaG.

41. The method for hydroformylation of olefins according to claim 39, characterized in that, The CO / H2 molar ratio in the synthesis gas is 1:

1.

42. The method for hydroformylation of olefins according to claim 28, characterized in that, After the hydroformylation reaction is completed, a chelating agent is added to the reaction solution, and then the transition metal catalyst is recovered by phase separation. The chelating agent is selected from the carboxylic acid type.

43. The method for hydroformylation of olefins according to claim 42, characterized in that, The chelating agent is selected from hydroxycarboxylic acid type.

44. The method for hydroformylation of olefins according to claim 42, characterized in that, The chelating agent is selected from the hydroxyaminocarboxylic acid type.

45. The method for hydroformylation of olefins according to claim 42, characterized in that, The chelating agent is selected from at least one of ethylenediaminetetraacetic acid, disodium ethylenediaminetetraacetic acid, and hydroxyethylethylenediaminetriacetic acid.

Images