Method for synergistically catalyzing hydroformylation reaction of 1, 3-butadiene by adopting mixed phosphine ligand

Abstract

The invention provides a method for synergistically catalyzing 1, 3-butadiene hydroformylation reaction by adopting a mixed phosphine ligand, the mixed phosphine ligand is composed of a phosphine ligand La with a cyclosiloxane skeleton and phosphine hydrogen Lb, and the butadiene hydroformylation reaction method comprises the following steps: under the protection of an inert atmosphere, adding active metal rhodium, a solvent, butadiene and the mixed phosphine ligand La and Lb into a reaction bottle, and stirring at a constant temperature; the method comprises the following steps: putting a reaction bottle into a high-pressure kettle, sealing the high-pressure kettle, filling H2 and CO, stirring and reacting at 25-100 DEG C for 1-24 hours, cooling to room temperature after the reaction is completed, releasing unreacted gas, and separating a product by a conventional method, such as a column chromatography method, a distillation method, a rectification method or a reduced pressure distillation method. The mixed phosphine ligand provided by the invention can synergistically catalyze the hydroformylation reaction of 1, 3-butadiene, synchronously realizes efficient regulation and control of branched-chain dialdehyde regioselectivity, and is widely applied to the fields of organic silicon industry, coating industry, material science and the like.

Description

Technical Field

[0001] The invention belongs to the fields of catalysis and fine chemicals, and in particular relates to a method for synergistically catalyzing the hydroformylation reaction of 1,3-butadiene by using mixed phosphine ligands. Background Art

[0002] Hydroformylation, also known as oxo synthesis, involves the transition-metal-catalyzed reaction of olefins with synthesis gas to produce aldehydes containing an additional carbon. Due to its high atom economy, hydroformylation not only allows for carbon chain growth, but its products can also be further converted into higher-value fine chemicals such as alcohols, carboxylic acids, amines, and esters. Consequently, hydroformylation has become one of the largest-scale catalytic processes.

[0003] The most mature research is the hydroformylation of monoolefins. The research on the hydroformylation of polyolefins, especially conjugated olefins, is still immature. The main reasons are the large number of reaction by-products and poor regioselectivity. Taking the simplest conjugated olefin 1,3-butadiene as an example, the hydroformylation reaction of 1,3-butadiene can produce 1,4-addition carbonyl.

[0004] The process involves multiple reaction pathways, including hydroformylation, 1,2-addition carbonylation, C=C double bond isomerization, reductive hydrogenation, and isomerized reductive hydrogenation. These pathways are characterized by slow reaction rates and poor regioselectivity, with nearly 20 isomerized products and by-products generated simultaneously. To date, olefin substrates used in industrial production have primarily focused on non-conjugated terminal or internal olefins, while the hydroformylation of molecularly conjugated olefins, such as butadiene, remains extremely challenging due to the lack of regioselectivity and the formation of complex product mixtures.

[0005] The key to the breakthrough of 1,3-butadiene hydroformylation technology lies in the development of catalysts. The structure of the phosphine ligand plays a decisive role in the activity of the catalytic reaction and the selectivity of the product. The research on the synthesis of adipaldehyde by the hydroformylation of butadiene has been carried out for more than 60 years, but it is still in the laboratory research and exploration stage, and there is no industrial report. In the early days (between 1960 and 1980), different alkyl or aryl monodentate or bidentate phosphine ligands-rhodium-based catalysts were used.

[0006] The system's butadiene hydroformylation to produce adipaldehyde has the disadvantages of harsh reaction conditions and adipaldehyde product selectivity of less than 10%. The reaction needs to be carried out under a syngas pressure of >750 bar. See:

[0007] Tetrahedron Lett., 1969, 32, 2721-2723; J. Mol. Catal., 1977, 2, 211-218; J. Mol. Catal., 1980, 8, 329-337; J. Mol. Catal., 1985, 31, 345-353; U.S. Patents 4,507,508; 3,947,503, etc. In 1994, the Union Carbide Chemical & Plastics Technology Corporation of the United States developed a class of phosphite bidentate ligands-rhodium catalysts.

[0008] The targeted conversion of butadiene to adipaldehyde under relatively mild reaction conditions achieved a 30% selectivity for adipaldehyde. This groundbreaking result has led to the development of a series of novel phosphite ligands for use in the hydroformylation of butadiene. However, the hydroformylation of 1,3-butadiene is currently primarily used to produce adipaldehyde and adipic acid. Because most phosphine ligands only promote the formation of linear aldehydes in the hydroformylation of butadiene, further research is needed to achieve high-yield synthesis of other products. Summary of the Invention

[0009] The object of the present invention is to address the deficiencies of the prior art and provide a method for the synergistic catalysis of 1,3-butadiene hydroformylation reaction using mixed phosphine ligands, wherein the method has high conversion rate and product selectivity.

[0010] The present invention is achieved through the following technical solutions:

[0011] Under inert atmosphere protection, 1,3-butadiene, active metal rhodium precursor, phosphine ligand La of cyclosiloxane skeleton, phosphine hydrogen Lb and solvent are mixed, wherein the molar ratio of phosphine ligand La of cyclosiloxane skeleton to phosphine hydrogen Lb is 1:3-12, and hydrogen and carbon monoxide mixed gas is introduced to carry out hydroformylation reaction to obtain branched dialdehyde; reaction

[0012] The formula is as follows:

[0013]

[0014] wherein R, R1, and R2 are each independently selected from hydrogen, C1-C 12 Alkyl, C3-C 12 Cycloalkyl, C1-C 10 Halogenated alkyl, C4-C 10 Aryl, C4-C 10 One of heteroaryl and substituted phenyl, wherein n is an integer selected from 3-8.

[0015] Further, the structure of the phosphine ligand La of the cyclic siloxane skeleton may be selected from but not limited to the following structures:

[0016]

[0017] The ligand L b may be selected from but not limited to the following structures:

[0018]

[0019] Specifically, the above method includes the following steps:

[0020] Under the protection of an inert atmosphere, an active metal rhodium precursor, a solvent, 1,3-butadiene, the phosphine ligand La of the cyclic siloxane skeleton, and the phosphine hydride Lb are added to a reaction flask. The reaction flask is placed in an autoclave, the autoclave is sealed, and the high-pressure reactor is flushed 3 times with N2 at 0.1 MPa, and then flushed 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reactor is replaced by hydrogen. Charge 0.1 MPa - 3 MPa of H2, and then slowly inject high-pressure CO into the autoclave until 0.1 MPa - 3 MPa of CO is charged. Stir and react at 25 - 100 °C for 1 hour - 24 hours. After the reaction is completed, cool to room temperature and release the unreacted gas. The product can be separated by conventional methods, such as column chromatography, distillation, rectification, or vacuum distillation, etc.

[0021] The reaction route is shown in the following figure:

[0022]

[0023] Preferably, the active metal rhodium precursor is selected from one or more of Rh(CO)2(acac), Rh(AcO)2, RhCl3, Rh(NO3)3, RhH(CO)(PPh3)3, [Rh(CO)2Cl]2, RhH(CO)(PPh3)3, [Rh2(m-Cl)2(cod)2], [Rh(cod)2]BF4, and preferably Rh(CO)2(acac).

[0024] Preferably, the solvent is selected from one or more of alcohols, alkanes, ethers, ketones, aromatic hydrocarbons, and halogenated hydrocarbons. The solvent is further preferably one or more of n-hexane, cyclohexane, benzene, toluene, xylene, tetrahydrofuran, and dioxane.

[0025] Preferably, the molar ratio of 1,3-butadiene to rhodium in the active metal rhodium precursor is 100:0.01 - 0.3, preferably

[0026] 100:0.05 - 2, and most preferably 100:1.

[0027] Preferably, n(La):n(Lb) = 1:10.

[0028] Preferably, the stirring speed is 500 rpm to 1500 rpm, preferably 1000 rpm.

[0029] Preferably, the reaction temperature is 50 - 80 °C.

[0030] Preferably, the reaction time is 5 - 15 h.

[0031] The pressure of the mixed gas of H2 and CO is 1 - 10 MPa, and the volume ratio of H2 and CO is (1:10) - (10:1). The pressure of the mixed gas is further preferably 2 - 5 Mpa, and the volume ratio of H2 and CO is (1:5) - (1:1).

[0032] The above reaction using the mixed phosphine ligand has wide applications in the fields of silicone industry, coating industry or material science.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention innovatively develops a process method for the synergistic catalytic conversion of 1,3 - butadiene into branched - chain dialdehyde through hydroformylation reaction by a novel mixed phosphine ligand. At the same time, the conversion rate of 1,3 - butadiene is high, and the by - products generated are few, which is convenient for industrial separation. The method has mild conditions, simple operation and is convenient for industrial application. The main product of this reaction is 2 - ethylbutyraldehyde, which has good reaction activity and can undergo various chemical reactions with other organic compounds, such as hydrogenation, oxidation, amination, condensation, polymerization, etc. It can also be used as an intermediate for many reactions, helping to synthesize more complex molecular structures. And due to the unique aroma of the branched - chain dialdehyde, it can be used in the synthesis of various fragrances and can be widely used in the production fields of cosmetics, perfumes, washing products, etc., with great potential application value and broad development prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 1H NMR spectrum of the organophosphorus ligand compound La2 (R = Ph) in Example 1.

[0036] Figure 2 13C NMR spectrum of the organophosphorus ligand compound La2 (R = Ph) in Example 1.

[0037] Figure 3 31P NMR spectrum of the organophosphorus ligand compound La2 (R = Ph) in Example 1.

[0038] Figure 4 1H NMR spectrum of 2 - ethylbutanediol obtained from the conversion of 2 - ethylbutyraldehyde in Example 1.

[0039] Figure 5 13C NMR spectrum of 2-ethyl-1,4-butanediol obtained from the conversion of 2-ethylbutanedial in Example 1.

[0040] Figure 6 1H NMR spectrum of 2-methylglutaric acid obtained from the conversion of 2-methylglutaraldehyde in Example 1.

[0041] Figure 7 1H NMR spectrum of 2-methylglutaric acid obtained from the conversion of 2-methylglutaraldehyde in Example 1. Detailed implementation manners

[0042] The present invention will be further described below in conjunction with examples and drawings.

[0043] In the present invention, the terms "comprising", "including", "having", "containing" or any other similar terms are all open conjunctions, which are intended to cover non-exclusive inclusions. For example, a composition or article containing plural elements is not limited to only these elements listed in the present invention, but may also include other elements that are not explicitly listed but are usually inherent in the composition or article. In addition, unless there is a clear contrary statement, the term "or" refers to an inclusive "or" rather than an exclusive "or". For example, any of the following situations satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), A and B are both true (or exist). In addition, in the present invention, the interpretations of the terms "comprising", "including", "having", "containing" should be regarded as having been specifically disclosed and simultaneously covering closed or semi-closed conjunctions such as "consisting of" and "substantially consisting of".

[0044] In the present invention, all features or conditions defined in the form of numerical ranges or percentage ranges are only for the sake of brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be regarded as having covered and specifically disclosed all possible sub-ranges and individual values within the range, especially integer values. For example, the description of the range "1 to 8" should be regarded as having specifically disclosed all sub-ranges such as 1 to 7, 2 to 8, 2 to 6, 3 to 6, 4 to 8, 3 to 8, etc., especially the sub-ranges defined by all integer values, and should be regarded as having specifically disclosed individual values such as 1, 2, 3, 4, 5, 6, 7, 8 within the range. Unless otherwise specified, the foregoing interpretation method applies to all contents of the present invention, regardless of the breadth of the range.

[0045] If a quantity, or other numerical value or parameter, is expressed as a range, a preferred range, or a series of upper and lower limits, it should be understood that all ranges formed by any pair of the upper or preferred values of the range and the lower or preferred values of the range are specifically disclosed in the present invention, whether or not these ranges are separately disclosed. In addition, when a range of numerical values is mentioned in the present invention, unless otherwise specified, the range should include its endpoints and all integers and fractions within the range.

[0046] According to the method of the present invention, rhodium is used as the catalyst active center, and two ligands act synergistically to convert 1,3-butadiene into 2-ethylbutyraldehyde and 2-methylvaleraldehyde with high yield, thereby improving the selectivity of the hydroformylation reaction of 1,3-butadiene based on the overall reaction.

[0047] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with embodiments. The following embodiments are only partial examples of the implementation schemes of the present invention and do not constitute any limitation to the present invention. Those skilled in the art can understand that modifications within the scope not deviating from the essence and concept of the present invention fall within the protection scope of the present invention.

[0048] Unless otherwise specified, various starting materials, reagents, solvents, instruments, etc. used in the following embodiments can generally be obtained through commercial channels.

[0049] The ligand L a The structure of may be selected from, but not limited to, the following structures:

[0050]

[0051] wherein R may be selected from one of hydrogen, a monosubstituted halogen atom, a C1-C 12 alkyl group, a C3-C 12 cycloalkyl group, a C1-C 10 haloalkyl group, a C1-C5 alkoxy group, a C4-C 10 aryl group or a substituted phenyl group. In the embodiments of the present invention, the phenyl group is taken as an example.

[0052] Existing literature studies have shown that when such ligands are used in the hydroformylation reaction of butadiene, the formation of linear aldehydes will be promoted. However, if the strategy of synergistic catalysis with the mixed ligands provided by the present invention is used, the hydroformylation of butadiene can be highly selectively converted into branched-chain dialdehydes.

[0053] The ligand L b The structure of may be selected from, but not limited to, the following structures, and can be selected according to actual needs, and no special limitation is made here:

[0054]

[0055] The following will be further described with specific examples.

[0056] Example 1:

[0057] General method for preparing La2(R = Ph) ligand:

[0058]

[0059] Under nitrogen protection, at room temperature, 17.28 g (88 mmol) of diphenylphosphine hydride, 6.96 g (20 mmol) of 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 10 g of toluene, and 0.15 g (0.9 mmol) of AIBN were added to a three-necked flask respectively; the mixture was stirred and reacted at 80 °C for 10 days. After the reaction was completed, it was cooled to room temperature, washed with 30 ml of methanol, and the solvent was removed by rotary evaporation. The residue was purified by silica gel column chromatography to obtain a colorless viscous substance, namely the multidentate phosphine ligand La2 containing a cyclosiloxane skeleton. Its 1H NMR spectrum is as shown in Figure 1 shown, and its 13C NMR spectrum is as shown in Figure 2 shown, and its 31P NMR spectrum is as shown in Figure 3 shown.

[0060] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La2(R = Ph) were added to a reaction flask, then 2 ml of toluene, 1 mmol of butadiene, and 0.1 mmol of PPh2H were added. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa, and then flushed 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 0.7 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 0.7 MPa of CO was charged. It was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature, and the product could be separated by conventional methods, such as column chromatography, distillation, rectification, or vacuum distillation, etc.

[0061] The analysis method is as follows:

[0062] After the reaction was completed, it was cooled to room temperature, the gas was fully released, n-decane was added as an internal standard, and gas chromatography analysis was carried out using a SHIMADZU GC-2010Pro system equipped with a SH-5 chromatographic column of 30 m * 250 μm * 0.25 μm. The nitrogen flow rate was maintained at 0.8 mL / min. The column temperature was initially maintained at 35 °C for 8 min, then heated to 90 °C at a rate of 20 °C / min and maintained for 3 min. Then it was heated to 200 °C at a rate of 30 °C / min and the temperature was maintained for 5 min. The gas phase results are as follows: the conversion rate of 1,3-butadiene is 100%, the selectivity of 2-ethylbutanedial is 46%, the selectivity of 2-methylglutaraldehyde is 20%, and the selectivity of adipaldehyde is 18%.

[0063] Due to the high activity of branched-chain aldehydes, they can be converted into other substances within the silica gel column, so branched-chain aldehydes cannot be directly obtained by column chromatography. Based on this, a conversion method was adopted to efficiently convert the branched-chain aldehydes in the reaction into branched-chain diols and branched-chain dibasic acids to obtain pure products, as shown in the following formula:

[0064]

[0065] The nuclear magnetic resonance hydrogen spectrum of 2-ethylbutanediol obtained by the conversion of 2-ethylbutanedial is as shown in Figure 4 and the nuclear magnetic resonance carbon spectrum is as shown in Figure 5 ; the nuclear magnetic resonance hydrogen spectrum of 2-methylglutaric acid obtained by the conversion of 2-methylglutaraldehyde is as shown in Figure 6 and the nuclear magnetic resonance carbon spectrum is as shown in Figure 7 .

[0066] Example 2:

[0067] According to the method of Example 1, the structure of the reactants was changed, and ligand La1 was prepared under the same conditions.

[0068] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La1 (R = Ph) were added to the reaction flask, then 2 ml of toluene, 1 mmol of butadiene and 0.1 mmol of PPh2H were added. The reaction flask was placed in an autoclave, the autoclave was sealed, and the high-pressure reaction autoclave was flushed 3 times with 0.1 MPa of N2, and then flushed 3 times with 0.1 MPa of H2 to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 0.7 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 0.7 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature, and the product could be separated by conventional methods, such as column chromatography, distillation, rectification or vacuum distillation, etc. The gas-phase results are as follows: the conversion rate of 1,3-butadiene is 100%, the selectivity of 2-ethylbutanedial is 35%, the selectivity of 2-methylglutaraldehyde is 32%, and the selectivity of adipaldehyde is 7%.

[0069] Example 3:

[0070] According to the method of Example 1, the structure of the reactants was changed, and ligand La3 was prepared under the same conditions.

[0071] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La3 (R = Ph) were added to a reaction flask, followed by 2 ml of toluene, 1 mmol of butadiene and 0.1 mmol of PPh2H. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa and then 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 0.7 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 0.7 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature, and the product could be separated by conventional methods, such as column chromatography, distillation, rectification or vacuum distillation, etc. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 100%, the selectivity of 2-ethylbutanedial was 47%, the selectivity of 2-methylglutaraldehyde was 23%, and the selectivity of adipaldehyde was 11%.

[0072] Example 4:

[0073] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La3 (R = Ph) were added to a reaction flask, followed by 2 ml of 1,4-dioxane, 1 mmol of butadiene and 0.1 mmol of PPh2H. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa and then 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 0.7 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 0.7 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature, and the product could be separated by conventional methods, such as column chromatography, distillation, rectification or vacuum distillation, etc. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 100%, the selectivity of 2-ethylbutanedial was 35%, the selectivity of 2-methylglutaraldehyde was 25%, and the selectivity of adipaldehyde was 5%.

[0074] Example 5:

[0075] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La3 (R = Ph) were added into a reaction flask, then 2 ml of acetonitrile, 1 mmol of butadiene and 0.1 mmol of PPh2H were added. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa, and then flushed 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 0.7 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 0.7 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature. The product could be separated by conventional methods, such as column chromatography, distillation, rectification or vacuum distillation, etc. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 100%, the selectivity of 2-ethylbutanedial was 48%, the selectivity of 2-methylglutaraldehyde was 17%, and the selectivity of adipaldehyde was 5%.

[0076] Example 6:

[0077] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La3 (R = Ph) were added into a reaction flask, then 2 ml of N-methylpyrrolidone, 1 mmol of butadiene and 0.1 mmol of PPh2H were added. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa, and then flushed 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 0.7 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 0.7 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature. The product could be separated by conventional methods, such as column chromatography, distillation, rectification or vacuum distillation, etc. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 100%, the selectivity of 2-ethylbutanedial was 41%, the selectivity of 2-methylglutaraldehyde was 9%, and the selectivity of adipaldehyde was 8%.

[0078] Example 7:

[0079] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La3 (R = Ph) were added to a reaction flask, followed by the addition of 2 ml of isopropanol, 1 mmol of butadiene, and 0.1 mmol of PPh2H. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa and then 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 0.7 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 0.7 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature, and the product could be separated by conventional methods, such as column chromatography, distillation, rectification, or vacuum distillation. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 100%, the selectivity for 2-ethylbutanedial was 30%, the selectivity for 2-methylglutaraldehyde was 24%, and the selectivity for adipic dialdehyde was 3%.

[0080] Example 8:

[0081] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La3 (R = Ph) were added to a reaction flask, followed by the addition of 2 ml of dimethyl sulfoxide, 1 mmol of butadiene, and 0.1 mmol of PPh2H. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa and then 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 0.7 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 0.7 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature, and the product could be separated by conventional methods, such as column chromatography, distillation, rectification, or vacuum distillation. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 100%, the selectivity for 2-ethylbutanedial was 41%, the selectivity for 2-methylglutaraldehyde was 14%, and the selectivity for adipic dialdehyde was 7%.

[0082] Example 9:

[0083] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La2 (R = Ph) were added to a reaction flask, followed by 2 ml of toluene, 1 mmol of butadiene and 0.1 mmol of PPh2H. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa and then 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 1.0 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 1.0 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature, and the product could be separated by conventional methods such as column chromatography, distillation, rectification or vacuum distillation. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 100%, the selectivity for 2-ethylbutanedial was 46%, the selectivity for 2-methylglutaraldehyde was 12%, and the selectivity for adipic dialdehyde was 16%.

[0084] Example 10:

[0085] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La2 (R = Ph) were added to a reaction flask, followed by 2 ml of toluene, 1 mmol of butadiene and 0.1 mmol of PPh2H. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa and then 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 1.5 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 1.5 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature, and the product could be separated by conventional methods such as column chromatography, distillation, rectification or vacuum distillation. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 100%, the selectivity for 2-ethylbutanedial was 44%, the selectivity for 2-methylglutaraldehyde was 15%, and the selectivity for adipic dialdehyde was 16%.

[0086] Example 11:

[0087] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La2 (R = Ph) were added to a reaction flask, then 2 ml of toluene, 1 mmol of butadiene and 0.1 mmol of PPh2H were added. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa, and then flushed 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 2.0 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 2.0 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature. The product could be separated by conventional methods such as column chromatography, distillation, rectification or vacuum distillation, etc. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 100%, the selectivity of 2-ethylbutanedial was 47%, the selectivity of 2-methylglutaraldehyde was 12%, and the selectivity of adipic dialdehyde was 17%.

[0088] Example 12:

[0089] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La2 (R = Ph) were added to a reaction flask, then 2 ml of toluene, 1 mmol of butadiene and 0.1 mmol of PPh2H were added. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa, and then flushed 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 2.5 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 2.5 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature. The product could be separated by conventional methods such as column chromatography, distillation, rectification or vacuum distillation, etc. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 100%, the selectivity of 2-ethylbutanedial was 33%, the selectivity of 2-methylglutaraldehyde was 11%, and the selectivity of adipic dialdehyde was 17%.

[0090] Example 13:

[0091] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La2 (R = Ph) were added to a reaction flask. Then, 2 ml of toluene, 1 mmol of butadiene, and 0.1 mmol of PPh2H were added. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa and then 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 3.0 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 3.0 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature, and the product could be separated by conventional methods such as column chromatography, distillation, rectification, or vacuum distillation. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 100%, the selectivity for 2-ethylbutanedial was 32%, the selectivity for 2-methylglutaraldehyde was 11%, and the selectivity for adipaldehyde was 17%.

[0092] Example 14:

[0093] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La2 (R = Ph) were added to a reaction flask. Then, 2 ml of toluene, 1 mmol of butadiene, and 0.03 mmol of PPh2H were added. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa and then 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 2.0 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 2.0 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature, and the product could be separated by conventional methods such as column chromatography, distillation, rectification, or vacuum distillation. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 86%, the selectivity for 2-ethylbutanedial was 6%, the selectivity for 2-methylglutaraldehyde was 9%, and the selectivity for adipaldehyde was 4%.

[0094] Example 15:

[0095] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La2 (R = Ph) were added into a reaction flask, then 2 ml of toluene, 1 mmol of butadiene and 0.06 mmol of PPh2H were added. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa, and then flushed 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 2.0 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 2.0 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature, and the product could be separated by conventional methods, such as column chromatography, distillation, rectification or vacuum distillation, etc. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 90%, the selectivity of 2-ethylbutanedial was 12%, the selectivity of 2-methylglutaraldehyde was 38%, and the selectivity of adipic dialdehyde was 3%.

[0096] Example 16:

[0097] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La2 (R = Ph) were added into a reaction flask, then 2 ml of toluene, 1 mmol of butadiene and 0.09 mmol of PPh2H were added. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa, and then flushed 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 2.0 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 2.0 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature, and the product could be separated by conventional methods, such as column chromatography, distillation, rectification or vacuum distillation, etc. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 91%, the selectivity of 2-ethylbutanedial was 8%, the selectivity of 2-methylglutaraldehyde was 51%, and the selectivity of adipic dialdehyde was 4%.

[0098] Example 17:

[0099] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La2 (R = Ph) were added to a reaction flask, followed by the addition of 2 ml of toluene, 1 mmol of butadiene and 0.12 mmol of PPh2H. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa and then 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 2.0 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 2.0 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature, and the product could be separated by conventional methods such as column chromatography, distillation, rectification or vacuum distillation. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 100%, the selectivity of 2-ethylbutanedial was 17%, the selectivity of 2-methylglutaraldehyde was 32%, and the selectivity of adipic dialdehyde was 5%.

[0100] Example 18:

[0101] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La2 (R = Ph) were added to a reaction flask, followed by the addition of 2 ml of toluene, 1 mmol of butadiene and 0.1 mmol of PCy2H. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa and then 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 2.0 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 2.0 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature, and the product could be separated by conventional methods such as column chromatography, distillation, rectification or vacuum distillation. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 100%, the selectivity of 2-ethylbutanedial was 22%, the selectivity of 2-methylglutaraldehyde was 11%, and the selectivity of adipic dialdehyde was 17%.

[0102] Example 19:

[0103] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La2 (R = Ph) were added to a reaction flask, followed by the addition of 2 ml of toluene, 1 mmol of butadiene and 0.1 mmol of P tBu2H. Place the reaction flask in an autoclave, seal the autoclave, and flush the autoclave with N2 at 0.1 MPa three times, then flush it with H2 at 0.1 MPa three times to ensure that all the nitrogen in the autoclave is replaced by hydrogen. Charge 2.0 MPa of H2, and then slowly inject high-pressure CO into the autoclave until 2.0 MPa of CO is charged. Stir at 80 °C for 12 hours. After the reaction is completed, cool to room temperature. The product can be separated by conventional methods, such as column chromatography, distillation, rectification, or vacuum distillation, etc. The gas-phase results are as follows: the conversion rate of 1,3-butadiene is 100%, the selectivity of 2-ethylbutanedial is 3%, the selectivity of 2-methylglutaraldehyde is 9%, and the selectivity of adipic dialdehyde is 22%.

[0104] Example 20:

[0105] Under nitrogen protection, take 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La2 (R = Ph) and add them to the reaction flask, then add 2 ml of toluene, 1 mmol of butadiene and 0.1 mmol of PPh3. Place the reaction flask in an autoclave, seal the autoclave, and flush the autoclave with N2 at 0.1 MPa three times, then flush it with H2 at 0.1 MPa three times to ensure that all the nitrogen in the autoclave is replaced by hydrogen. Charge 2.0 MPa of H2, and then slowly inject high-pressure CO into the autoclave until 2.0 MPa of CO is charged. Stir at 80 °C for 12 hours. After the reaction is completed, cool to room temperature. The product can be separated by conventional methods, such as column chromatography, distillation, rectification, or vacuum distillation, etc. The gas-phase results are as follows: the conversion rate of 1,3-butadiene is 100%, the selectivity of 2-ethylbutanedial is 2%, the selectivity of 2-methylglutaraldehyde is 7%, and the selectivity of adipic dialdehyde is 25%.

[0106] Example 21:

[0107] Under nitrogen protection, 0.01 mmol of Rh(CO)2(acac) and 0.01 mmol of ligand La2 (R = Ph) were added into a reaction flask, then 2 ml of toluene, 1 mmol of butadiene and 0.1 mmol of PPh2Me were added. The reaction flask was placed in an autoclave, and the autoclave was sealed. The high-pressure reaction autoclave was flushed 3 times with N2 at 0.1 MPa, and then flushed 3 times with H2 at 0.1 MPa to ensure that all the nitrogen in the high-pressure reaction autoclave was replaced by hydrogen. 2.0 MPa of H2 was charged, and then high-pressure CO was slowly injected into the autoclave until 2.0 MPa of CO was charged. The mixture was stirred at 80 °C for 12 hours. After the reaction was completed, it was cooled to room temperature. The product could be separated by conventional methods, such as column chromatography, distillation, rectification or vacuum distillation, etc. The gas-phase results were as follows: the conversion rate of 1,3-butadiene was 100%, the selectivity of 2-ethylbutanedial was 5%, the selectivity of 2-methylglutaraldehyde was 7%, and the selectivity of adipaldehyde was 22%.

[0108] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, and all should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for the co - catalytic hydroformylation of 1,3 - butadiene using a mixed phosphine ligand, characterized in that, The method comprises the following steps: Under the protection of an inert atmosphere, 1,3-butadiene, an active metal rhodium precursor, a phosphine ligand La with a cyclic siloxane backbone, a phosphine hydride Lb, and a solvent are mixed, and a hydrogen carbon monoxide mixture is introduced for hydroformylation reaction to obtain a branched dialdehyde, wherein the molar ratio of the phosphine ligand La with a cyclic siloxane backbone to the phosphine hydride Lb is 1:3 - 12; the reaction route is as follows: Wherein, R, R1, and R2 are each independently selected from hydrogen, C1-C 12 alkyl, C3-C 12 cycloalkyl, C1-C 10 haloalkyl, C4-C 10 aryl, C4-C 10 heteroaryl, or a substituted phenyl, and n is an integer selected from 3 to 8.

2. The method according to claim 1, characterized in that, The phosphine ligand La with a cyclic siloxane backbone is selected from one of the following structures: The ligand L b is selected from one of the following structures:

3. The method according to claim 2, characterized in that, The molar ratio of the phosphine ligand La with a cyclic siloxane backbone to the phosphine hydride Lb is 1:

10.

4. The method according to claim 1, wherein The active metal rhodium precursor is selected from one or more of Rh(CO)2(acac), Rh(AcO)2, RhCl3, Rh(NO3)3, RhH(CO)(PPh3)3, [Rh(CO)2Cl]2, RhH(CO)(PPh3)3, [Rh2(m-Cl)2(cod)2], [Rh(cod)2]BF4.

5. The method according to claim 1, characterized in that, The solvent is selected from one or more of alcohols, alkanes, ethers, ketones, aromatic hydrocarbons, halogenated hydrocarbons.

6. The method according to claim 1, wherein The molar ratio of 1,3-butadiene to rhodium in the active metal rhodium precursor is 100:0.01 - 0.

3.

7. The method according to claim 1, wherein The hydroformylation reaction is carried out under stirring conditions, and the stirring speed is 500 - 1500 rpm.

8. The method according to claim 1, wherein The reaction temperature of the hydroformylation reaction is 25 - 100 °C.

9. The method according to claim 8, wherein The reaction time of the hydroformylation reaction is 1 - 24 h.

10. The method according to claim 1, wherein The pressure of the hydrogen carbon monoxide mixture is 1 - 10 MPa, and the volume ratio of hydrogen to carbon monoxide is 1:10 - 10:1.

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