Preparation and application of bisphosphine ligands based on a ferrocene framework

Abstract

This invention discloses the preparation and application of a bisphosphine ligand based on a ferrocene framework, belonging to the field of organometallic catalysis technology. The invention utilizes a chemical synthesis method, using N,N-dimethylaminomethylferrocene as the starting material, and through a series of reactions including aldehyde introduction, reduction, acetylation, and nucleophilic attack by a phosphine hydrogen reagent, to obtain the novel bisphosphine ligand based on the ferrocene framework. The catalytic complex of this bisphosphine ligand and palladium exhibits excellent catalytic activity and selectivity in the alkoxycarbonylation reactions of terminal alkenes, internal alkenes, and polysubstituted alkenes.

Description

Technical Field

[0001] This invention belongs to the field of organometallic catalysis technology, and in particular relates to the preparation and application of bisphosphine ligands based on a ferrocene framework. Background Technology

[0002] Carbonylation refers to the reaction of an unsaturated or halogenated substrate with carbon monoxide and a nucleophile (NuH = H2, ROH, H2O, NHR1R2) under the catalysis of a carbonyl complex of a noble metal (such as Rh, Ir, or Pd) or a complex with a phosphine ligand. The reaction involves CO insertion, nucleophilic attack, and reductive elimination, producing an ester, carboxylic acid, amide, or acyl chloride with one more carbon atom than the initial carbon. This reaction has extremely high atom economy and ease of operation among many methods for synthesizing organic carboxylic acid esters. Alkoxycarbonylation, also known as carbonyl esterification, specifically refers to the reaction of alkenes or alkynes with carbon monoxide and alcohols in a metal-phosphine ligand catalytic system to produce the corresponding esters. Palladium (II) or palladium (O) is usually used as the metal precursor, and an organophosphine compound as the ligand. The following schematic diagram shows the general reaction equation for alkoxycarbonylation:

[0003] Organic carboxylic acid esters are an important class of oxygen-containing compounds, widely used in fine chemicals, pharmaceuticals, pesticides, food additives, fragrances, coatings, and paints. For example, Lucite's alpha process refers to the reaction of ethylene with a phosphine-ligand-modified palladium catalyst at a specific temperature and in a carbon monoxide atmosphere, using methanol as a solvent to produce 3-methylpropionate (MP). MP is then condensed with formaldehyde to obtain MMA. MMA, as a chemical raw material, is mainly used in high-transmittance acrylic glass and is widely used in the automotive, furniture, and construction industries. It can also be used as a chemical product in surface coatings, leather, textiles, papermaking, and plastics additives. Furthermore, diisobutylene, with a phosphine-ligand-modified palladium catalyst at a specific temperature and in a carbon monoxide atmosphere, uses methanol as a solvent to produce 3,5,5-trimethylhexanoic acid. Isonononate, as a solvent and additive, is widely used in the cosmetics and animal feed industries. Furthermore, it is an important chemical intermediate and a key raw material for the production of isononanoic acid. Isononanoic acid can be esterified with polyols to produce synthetic refrigeration oils, which can replace the currently widely used and obsolete mineral-based refrigeration oils. Therefore, developing efficient synthetic methods for organic carboxylic acid esters is of great significance.

[0004] Currently reported catalyst systems mainly consist of a central metal, related phosphine ligands, and acid additives. The central metal is typically a group III or X transition metal such as Rh, Pd, Ni, Co, and Cu, with Pd being the most studied. Research on related phosphine ligands, such as alkylphosphine, cycloalkylphosphine, and bidentate phosphine, has been described in numerous patents, including EPA04489472, EPA0499329, EPA0495547, US2005085671A1, US6284919B1, US2001051745A1, and US6476255B1. In particular, Lucite disclosed a group of bidentate phosphides with substituted aryl bridges, 1,2-bis(di-tert-butylphosphinomethyl)benzene (dtbpx), which can provide significantly higher reaction rates and produce few or no impurities than previously disclosed catalysts, and has high conversion (Chem. Commun., 1999, 1877-1878; WO96 / 19434; WO2004 / 014552A1). Based on dtbpx, Butler et al. developed the ferrocene-based bisphosphine ligand butphos (i.e., 1,2-bis(di-tert-butylphosphinomethyl)ferrocene) Inorg. Chem. Commun., 2004, 7(9):1049-1052). Butphos has high conversion number and selectivity in the catalytic alkoxycarbonylation of ethylene (Inorganics, 2021, 9, 57.). In particular, Evonik-Degusa has disclosed 1,1'-bis(tert-butyl-2-pyridylphosphino)-ferrocene ligands, which exhibit high catalytic performance for the alkoxycarbonylation of olefins (Angew. Chem. Int. Ed., 2017, 56(19), 5267-5271; US2017 / 0022234Al). These ligands are currently the most efficient ligands for olefin carbonyl esterification reactions. These examples indicate that a key factor in their high activity stems from the tert-carbon alkylphosphine ligand structure.

[0005] The purpose of this invention is to provide novel ligands for alkoxy carbonylation reactions, enabling catalyst recycling, better ester selectivity, higher ester yield, and milder reaction conditions. In particular, the ligands of this invention should also be applicable to hydroformylation, hydroamine methylation, or hydrocarboxylation reactions of compounds containing unsaturated double or triple bonds. It is also applicable to alkenes with other functional groups. Summary of the Invention

[0006] The purpose of this invention is to develop a method for preparing novel bisphosphine ligands based on a ferrocene framework and its application, thereby improving the yield and selectivity of target products in carbonylation reactions (including but not limited to hydroformylation, alkoxycarbonylation, hydrocarboxylation, and hydroaminocarbonylation).

[0007] This invention utilizes a chemical synthesis method, employing N,N-dimethylaminomethylferrocene as the starting material. Following a series of reactions including n-BuLi / DMF introduction of an aldehyde group, reduction, acetylation, and nucleophilic attack by a phosphine hydrogen reagent, a novel 1,2-substituted, sterically hindered bisphosphine ligand is obtained. The catalytic complex of this ligand and palladium exhibits excellent catalytic activity and selectivity in the alkoxycarbonylation of terminal alkenes, internal alkenes, and polysubstituted alkenes.

[0008] Therefore, the above-mentioned objective of the present invention is achieved through the following technical solution: In a first aspect, the present invention provides a bisphosphine ligand based on a ferrocene framework, the structural formula of which is shown below: ; R1, R2, R3, and R4 are each independently selected from C1 to C10 alkyl groups, C3 to C15 cycloalkyl groups, C5 to C20 aryl groups, and heterocyclic aryl groups.

[0009] Furthermore, in the ferrocene-based bisphosphine ligand, R1, R2, R3, and R4 are each independently selected from phenyl, naphthyl, methylpyrazolyl, methylimidazolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-quinyl, 8-quinyl, 2-isoquinyl, 8-isoquinyl, 2-bromoquinolinyl, 3-bromoquinolinyl, isopropyl, tert-butyl, cyclopentyl, cyclohexyl, adamantyl, and phosphonocyclohexanone.

[0010] Furthermore, the bisphosphine ligand based on the ferrocene framework is one of the following compounds: .

[0011] Secondly, the present invention provides a method for preparing the aforementioned bisphosphine ligands based on a ferrocene framework. The aforementioned bisphosphine ligands based on a ferrocene framework can be prepared using any one of the following three methods.

[0012] Furthermore, the preparation method includes the following steps: ; S1: Compound 1 reacts with HPR1R2 in the presence of acetic acid to give compound 2; S2: Compound 2 reacts in the presence of n-butyllithium and DMF to give compound 3; S3: Compound 3 reacts with HPR3R4 in the presence of acetic acid to give compound I.

[0013] Furthermore, the preparation method includes the following steps: ; S1: Compound 1 was reacted with sodium borohydride and acetic anhydride in the presence of n-butyllithium and DMF, and then in the presence of sodium hydroxide to give compound 4; S2: Compound 4 reacts with SOCl2 to give compound 5; S3: Compound 5 reacts in the presence of Na1O4 and RuO4 to give compound 6; S4: Compound 6 reacts first with LiPR1R2, then with LiPR3R4, to prepare compound I.

[0014] Furthermore, the preparation method includes the following steps: ; S1: Compound 1 was given by adding sodium borohydride in the presence of n-butyllithium and DMF to obtain compound 7; S2: Compound 7 reacts with HPR1R2 and HBF4 to give compound 8; S3: Compound 8 reacts in the presence of HPtBu2 and acetic acid to give compound I.

[0015] Thirdly, the present invention also provides a bisphosphine ligand transition metal complex catalyst based on a ferrocene framework, wherein the transition metal is ruthenium, rhodium, palladium, or cobalt, preferably a palladium salt, and may be one of Pd(OAc)2, PdCl2, Pd(MeCN)2Cl2, Pd(COD)2Cl2, Pd(acac)2, Pd(dba)2, or Pd2(dba)3. The acid additive may be a Brønsted acid or a Lewis acid, such as HCl, H2SO4, MeSO3H, CF3SO3H, etc. p One of -TsOH, Al(OTf)3, Sc(OTf)3, Yb(OTf)3, and La(OTf)3.

[0016] Fourthly, this invention provides a bisphosphine ligand transition metal complex based on a ferrocene framework as described above. This catalyst is mainly used in carbonyl synthesis reactions, and is most suitable for olefin alkoxycarbonylation or hydrogen esterification reactions. The general reaction formula is as follows:

[0017] The olefin can be a terminal olefin, such as at least one of ethylene, acetylene, propylene, butene, and C5-C18 olefins; or a mixed olefin (containing an inner olefin or a mixture of alkanes), such as at least one of mixed butene, mixed octene, and C5-C18 olefins and mixtures thereof; more preferably, a polysubstituted olefin or a halogenated hydrocarbon, wherein the polysubstituted olefin or halogenated hydrocarbon is preferably at least one of 2-methyl-1-butene, a mixture of 2,4,4-trimethylpentene (diisobutene), and 2,3-dimethyl-2-butene. Furthermore, the nucleophile (NuH) can be at least one of hydrogen (H2), lower to higher aliphatic alcohols (R'OH, R' = C1-C20) or aryl alcohols or heterocyclic aryl alcohols, water (H2O), aliphatic amines containing at least one hydrogen atom, aryl amines or heterocyclic aryl amines (NHR'R'"), aliphatic thiols, aromatic thiols or heterocyclic thiols (R'SH).

[0018] The steps of the catalytic reaction are as follows: (1) Depending on the type of olefin substrate, a catalyst solution is prepared in a solvent under a nitrogen atmosphere at a ratio of Pd / ligand L1-L7 / acid = 1:2:4 to 1:6:12; (2) The prepared catalyst and olefin substrate are transferred to the reactor under a nitrogen atmosphere, fully purged, and then CO is introduced to a pressure of 1 to 50 bar, preferably 10 bar; depending on the substrate activity, the reaction temperature is raised to 25-100℃ and the reaction is carried out for 15-120 min. (3) After the reaction is completed, the olefin conversion (TON, TOF), byproduct ratio, and selectivity of ester, carboxylic acid or amide in the sample are tested using a non-polar chromatographic column; the olefin conversion is between 90-99%, the positive-to-iso ratio is between 50-99.9:1, the proportion of byproduct isomerized olefin is less than 5%, and the proportion of byproduct ether / alcohol or amine is less than 0.5%.

[0019] Compared with the prior art, the technical solution of the present invention has the following positive effects: This invention provides a method for preparing bisphosphine ligands based on a ferrocene framework. The raw materials are readily available, the operation is simple, the reaction conditions are mild (low pressure and low temperature), and the process flow is straightforward. This significantly reduces production costs, improves production efficiency, and is beneficial for industrial-scale production. The palladium complex with the novel bisphosphine ligand exhibits excellent performance in the alkoxycarbonylation of olefins. Attached Figure Description

[0020] Figure 1 This is a magnified experimental result diagram from Example 13.

[0021] Figure 2 The 1H NMR spectrum of ligand L2 1 H NMR.

[0022] Figure 3 This is the NMR spectrum of phosphine ligand L2. 31 P NMR.

[0023] Figure 4 The NMR spectrum of phosphine with oxidized ligand L2 1 H NMR.

[0024] Figure 5 The NMR spectrum of phosphine with oxidized ligand L2 31 P NMR.

[0025] Figure 6 It is a liquid chromatography-mass spectrometry (LCMS) (ESI) of the oxidized ligand L2.

[0026] Figure 7 This is a gas chromatogram of diisobutylene raw material.

[0027] Figure 8 This is a gas chromatogram of diisobutylene under Pd / L2 / Al(OTf)3 catalysis, with a methyl isononanoate yield of 99.62%. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments and accompanying drawings, but the present invention is not limited thereto.

[0029] Experimental methods not specified in the examples are generally performed under standard conditions and as described in the manual, or as recommended by the manufacturer; materials and reagents used are commercially available unless otherwise specified.

[0030] Example 1: Preparation of 2-pyridyltert-butylphosphine methylferrocene (compound 1-1)

[0031] Under an anhydrous and oxygen-free atmosphere, compound 1 (10 g) and 50 mL of glacial acetic acid were added to a 500 mL round-bottom flask until completely dissolved. Then, 7.8 g of 2-pyridine tert-butylphosphine hydrogen was added, and the reaction mixture was allowed to react overnight at room temperature. The reaction solution was concentrated under a nitrogen atmosphere and rapidly purified by column chromatography to give 9.46 g of a pale yellow solid, in 63% yield.

[0032] Example 2 Preparation of 1-hydroxymethyl-2-(2-pyridyltert-butylphosphinemethyl)ferrocene (compounds 1-2)

[0033] Under an anhydrous and oxygen-free atmosphere, compound 1-1 (8.5 g) and 50 mL of diethyl ether were added to a 200 mL round-bottom flask until completely dissolved. The reaction flask was stirred at -20 °C, and 48 mL of n-butyllithium (2.5 M) was slowly added dropwise. After the addition was complete, the reaction flask was placed at room temperature. Subsequently, 10 mL of N,N-dimethylformamide (DMF) was added, and the reaction flask was refluxed overnight. The reaction solution was concentrated under a nitrogen atmosphere, and rapid column chromatography yielded 8.42 g of intermediate 1-2, with a yield of 92%.

[0034] Under nitrogen protection, compounds 1-2 (6.0 g) and 20 mL of THF were added to a 200 mL reaction flask until completely dissolved. The reaction flask was stirred at 0 °C, and a total of 490 mg of sodium borohydride solid powder (1.02 eq.) was added in batches. After returning to room temperature, the reaction was carried out for 2 h. After quenching with water under nitrogen atmosphere, the mixture was extracted several times with ethyl acetate, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. Rapid column chromatography yielded 4.87 g of solid (compounds 1-3), with a yield of 97%.

[0035] Example 3 Preparation of 1,2-bis(2-pyridyltert-butylphosphinemethyl)ferrocene (ligand L2)

[0036] Under an anhydrous and oxygen-free atmosphere, compound 1-3 (1.5 g) and 10 mL of glacial acetic acid were added to a 100 mL round-bottom flask until completely dissolved. The reaction flask was stirred at room temperature, and 2.1 g of 2-pyridyltert-butylphosphine hydrogen was slowly added dropwise. After the addition was complete, the reaction flask was placed at room temperature and allowed to react overnight. The reaction solution was concentrated under a nitrogen atmosphere, and rapid column chromatography was performed to give 1.55 g of ligand L2, with a yield of 75%.

[0037] Example 4 Preparation of 1,2-bis(hydroxymethyl)ferrocene (compound 2-2)

[0038] Under an anhydrous and oxygen-free atmosphere, compound 1 (15 g) and 80 mL of THF were added to a 500 mL round-bottom flask until completely dissolved. The reaction flask was stirred at -20 °C, and 25 mL of n-butyllithium (2.5 M, 1.02 eq.) was slowly added dropwise. After the addition was complete, the reaction flask was placed at room temperature. Subsequently, 20 mL of N,N-dimethylformamide (DMF) was added, and the reaction flask was refluxed overnight. After quenching, the water and oil phases separated. The oil phase product was concentrated to obtain 14.89 g of crude product, which was directly used for the next reduction step without purification.

[0039] The crude product from the previous step and 80 ml of THF were added to the reaction flask and stirred at 0°C. A total of 2.14 g of sodium borohydride solid powder (1.03 eq.) was added in batches, and the reaction was allowed to return to room temperature for 2 h. The reaction solution was concentrated, quenched with water, extracted several times with ethyl acetate, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. Rapid column chromatography yielded 14.4 g of solid (compound 2-1), with an overall yield of 85%.

[0040] In a 500 mL single-necked flask, 14 g of intermediate 2-1 was added, followed by 35 g of acetic anhydride under ice bath conditions. The mixture was stirred at room temperature for 2 h, then 100 mL of NaOH solution was added, and the reaction was carried out at room temperature for 5 h. The mixture was extracted several times with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, the solvent was removed by rotary evaporation, and the compound 2-2 was obtained as a solid powder of 11.4 g after rapid column chromatography, with a yield of 90%.

[0041] Example 5 Preparation of cyclopentadienedioxane-heptanediene-ferrocene (compounds 2-4)

[0042] In a 500 mL single-necked flask, 10 g of intermediate 2-2 and 50 mL of DCM were added until completely dissolved. Then, 4.93 g of thionyl chloride (SOCl2) was added under ice bath conditions, and the mixture was stirred at room temperature for 2 h. The solvent was then removed by rotary evaporation to obtain approximately 11.0 g of brown oily intermediate 2-3, with a yield of 93%.

[0043] The resulting oily substance was dissolved in a mixed solvent of DCM (50 mL), MeCN (50 mL), and water (75 mL) at 0 °C. RuCl3·nH2O ruthenium chloride hydrate (55 mg) and sodium periodate (NaIO4, 16 g) were added sequentially. The reaction mixture was stirred overnight at room temperature. The mixture was extracted several times with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, the solvent was removed by rotary evaporation, and the ruthenium salt was rapidly removed with diatomaceous earth. The crude product was dissolved in methanol / n-hexane to give 9.5 g of solid, with a yield of 82%.

[0044] Example 6 Preparation of 1-di-tert-butylphosphinemethyl-2-(2-pyridyl-tert-butylphosphinemethyl)ferrocene (ligand L5)

[0045] Under inert gas protection, 2.0 g of intermediate 2-4 and 10 ml of THF were added sequentially to a 100 ml Schlenk flask, stirred thoroughly, and cooled to 0 °C. In another dry and nitrogen-purged Schlenk flask, 1.04 g (1.1 eq.) of a 2-pyridyl-tert-butylphosphine hydrogen THF solution (5 ml) was added at -40 °C, followed by the slow addition of 2.5 M n-butyllithium solution (3.0 ml). After the addition was complete, the mixture was allowed to return to room temperature and reacted for 1.5 h. The reaction solution was concentrated under a nitrogen atmosphere and rapidly column chromatography was performed to obtain 2.14 g of ligand L5, with a yield of 63%.

[0046] Example 7 Preparation of 1-dimethylamino-2-(2-pyridyltert-butylphosphinemethyl)ferrocene (compound 3-1)

[0047] Under an anhydrous and oxygen-free atmosphere, compound 2-1 (2.0 g) and 20 mL of 50 wt% tetrafluoroborate ether solution were added to a 100 mL round-bottom flask until completely dissolved. The reaction flask was stirred at room temperature, and 1.47 g of 2-pyridyltert-butylphosphine hydrogen was slowly added dropwise. After the addition was complete, the reaction flask was placed at room temperature and reacted overnight. The reaction solution was concentrated under a nitrogen atmosphere, and rapid column chromatography was performed to give approximately 2.1 g of intermediate 3-1, with a yield of 68%.

[0048] Example 8 Preparation of 1,2-bis(2-pyridyltert-butylphosphinemethyl)ferrocene (ligand L2)

[0049] The reaction steps and post-processing operations were the same as in Example 3. 1.0 g of intermediate 3-1 was fed to obtain approximately 920 mg of ligand L2, with a yield of 71%.

[0050] Example 9 Preparation of 1,2-bis(2-pyridyltert-butylphosphomethyl)ferrocene (oxidized ligand L2)

[0051] In a 50 mL flask, 500 mg of L2 ligand and 10 mL of THF were added until completely dissolved. Then, 10 wt% hydrogen peroxide solution was added, and the mixture was stirred at room temperature for 1 h. The solution was quenched with sodium sulfite, and the peroxide was detected using starch-potassium iodide reagent. The mixture was extracted three times with ethyl acetate, and the organic phase was collected, dried over anhydrous sodium sulfate, and crystallized in methanol to obtain approximately 519 mg of solid, with a yield of 98%. Because trivalent phosphine ligand L2 and other ligands L1-L7 are readily oxidized, the oxide needs to be prepared for detection by liquid chromatography-mass spectrometry.

[0052] Example 10 Preparation of ligands L1, L3-L7 Ligands L1, L3-L7 were prepared according to the preparation method of 1,2-bis(2-pyridyltert-butylphosphinemethyl)ferrocene (ligand L2) in Example 3. Specifically, the 2-pyridinetert-butylphosphine hydrogen used in the preparation of ligand L2 was replaced with 2-phenyltert-butylphosphine hydrogen, 2-quinolinetert-butylphosphine hydrogen, and 2-methylimidazoliumtert-butylphosphine hydrogen, respectively, to prepare ligands L1, L6, and L7. Similarly, the 2-pyridinetert-butylphosphine hydrogen used in the preparation of ligand L2 was replaced with 2-pyridineadamantylphosphine hydrogen, 2-pyridineisopropylphosphine hydrogen, and 2-pyridinecyclohexylphosphine hydrogen, respectively, to prepare ligands L3, L4, and L5.

[0053] Example 11 (Preparation of palladium / phosphine ligand complex and diisobutylene catalytic experiment) Under an argon atmosphere, 5 μmol of Pd(acac)₂, 10 μmol of ligands L1-L7, and 20 μmol of Al(OTf)₃ were added to a 150 mL stainless steel high-pressure reactor equipped with a pressure sensor, temperature probe, online sampling port, and safety relief valve. 5 mL of methanol was then added and stirred until the solids were completely dissolved, generating palladium / phosphine ligands and anionic OTf. -- The reaction was catalyzed by palladium hydrogen (Pd-H) or palladium methoxy (Pd-OMe) complexes. Subsequently, 25 mmol of a diisobutylene mixture (2,4,4-trimethyl-1-pentene: 2,4,4-trimethyl-2-pentene = 76:24) with a purity ≥99.5% was added to the reactor. After connecting the gas line and fully purging with CO, the reactor pressure was increased to 20 MPa and the reactor temperature was raised to 110 °C. During the reaction, a pressure-controlled reaction was employed, with CO continuously supplied to the reactor using a mass flow meter, flow controller, and back pressure valve. Instantaneous and cumulative flow rates were recorded using a Coriolis flow meter (to calculate the reaction conversion frequency, TOF). After 2 h of reaction, the reactor was cooled to room temperature, and the reaction solution was sampled. Gas chromatography (GC) was used to calculate the conversion, the ratio of normal to isomeric esters, ester selectivity (the proportion of normal / isomeric esters in all products), and TOF. The results are shown in Table 1.

[0054]

[0055] Table 1

[0056] a: The structural formula of the contrast ligand used is as follows: .

[0057] Example 12 (Preparation of palladium / ligand L2 complex and catalytic experiments with different terminal and internal olefins) The preparation of palladium / ligand L2 complexes and the catalytic experiments for the alkoxycarbonylation of different terminal and internal olefins were performed using the same procedures as in Example 10, and the results are shown in Table 2.

[0058]

[0059] Table 2

[0060] Example 13: Scale-up Experiment of Diisobutylene Intermittent Application in a 5 L Reactor Following the preparation method of the palladium / ligand L2 complex in Example 12, this catalyst was applied to a batch-scale experiment of alkoxycarbonylation of diisobutylene. Nineteen trials were conducted using a 5 L reactor under the following conditions: Pd = 0.0167 mol%, Pd / L2 / LA = 1:4:8, T = 110℃, P = 1.6 MPa, t = 2 h, VL MeOH V DIB =0.8:1, V 反应液 = 3.0 L, TON (cumulative) = 96942; the results are shown in the table below.

[0061] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A bisphosphine ligand based on a ferrocene framework, characterized in that: The ferrocene-based skeleton The structural formula of the bisphosphine ligand is shown below: ; R1, R2, R3, and R4 are each independently selected from C1 to C10 alkyl groups, C3 to C15 cycloalkyl groups, C5 to C20 aryl groups, and heterocyclic aryl groups.

2. The bisphosphine ligand based on a ferrocene framework according to claim 1, characterized in that, R1, R2, R3, and R4 are each independently selected from phenyl, naphthyl, methylpyrazolyl, methylimidazolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-quinyl, 8-quinyl, 2-isoquinyl, 8-isoquinyl, isopropyl, tert-butyl, cyclopentyl, cyclohexyl, adamantyl, and phosphonocyclohexanone.

3. The bisphosphine ligand based on a ferrocene framework according to any one of claims 1-2, characterized in that, The bisphosphine ligand based on the ferrocene framework is one of the following compounds: 。 4. The method for preparing bisphosphine ligands based on a ferrocene framework according to any one of claims 1-3, characterized in that, Includes the following steps: ； S1: Compound 1 reacts with HPR1R2 in the presence of acetic acid to give compound 2; S2: Compound 2 reacts in the presence of n-butyllithium and DMF to give compound 3; S3: Compound 3 reacts with HPR3R4 in the presence of acetic acid to give compound I; Wherein, R1, R2, R3, and R4 are the same as those described in claim 1.

5. The method for preparing bisphosphine ligands based on a ferrocene framework according to any one of claims 1-3, characterized in that, Includes the following steps: ； S1: Compound 1 was reacted with sodium borohydride and acetic anhydride in the presence of n-butyllithium and DMF, and then reacted in the presence of sodium hydroxide to obtain compound 4; S2: Compound 4 reacts with SOCl2 to give compound 5; S3: Compound 5 reacts in the presence of Na1O4 and RuO4 to give compound 6; S4: Compound 6 reacts first with LiPR1R2, then with LiPR3R4, to prepare compound I; Wherein, R1, R2, R3, and R4 are the same as those described in claim 1.

6. The method for preparing bisphosphine ligands based on a ferrocene framework according to any one of claims 1-3, characterized in that, Includes the following steps: ； S1: Compound 1 was reacted with sodium borohydride in the presence of n-butyllithium and DMF to obtain compound 7; S2: Compound 7 reacts with HPR1R2 and HBF4 to give compound 8; S3: Compound 8 reacts in the presence of HPR3R4 and acetic acid to give compound I; Wherein, R1, R2, R3, and R4 are the same as those described in claim 1.

7. The bisphosphine ligand transition metal complex catalyst based on a ferrocene framework according to any one of claims 1-3, characterized in that, The transition metal is ruthenium, rhodium, palladium, or cobalt; palladium is preferred; more preferably, one of Pd(OAc)₂, PdCl₂, Pd(MeCN)₂Cl₂, Pd(COD)₂Cl₂, Pd(acac)₂, Pd(dba)₂, or Pd₂(dba)₃ is selected; the acid additive is selected from Brønsted acids or Lewis acids, preferably HCl, H₂SO₄, MeSO₃H, CF₃SO₃H, etc. p -At least one of TsOH, Al(OTf)3, Sc(OTf)3, Yb(OTf)3, and La(OTf)3.

8. The bisphosphine ligand transition metal complex catalyst based on a ferrocene framework according to claim 7, characterized in that, The catalyst is mainly used in carbonyl synthesis reactions; preferably, the carbonyl synthesis reaction is selected from olefin alkoxycarbonylation or hydrogen esterification reactions, and its general reaction formula is as follows: 。 9. The olefin alkoxycarbonylation or hydrogen esterification reaction according to claim 8, characterized in that, In the general reaction formula, the olefin can be a terminal olefin or a mixed olefin, preferably containing an inner olefin or a mixture of alkanes or a functionalized substituted olefin, wherein the functionalized substituted olefin is preferably at least one of ethylene, acetylene, propylene, propyne, mixed butene, mixed octene, C5-C18 olefins and mixtures thereof; further preferably a polysubstituted olefin or a halogenated hydrocarbon, wherein the polysubstituted olefin or halogenated hydrocarbon is preferably at least one of 2-methyl-1-butene, a mixture of 2,4,4-trimethylpentene (diisobutene), 2,3-dimethyl-2-butene, chloroethane, and 2-chloroethylbenzene; Preferably, the nucleophile (NuH) can be at least one of hydrogen (H2), lower to higher aliphatic alcohols (R'OH, R' = C1-C20) or aryl alcohols or heterocyclic aryl alcohols, water (H2O), aliphatic amines containing at least one hydrogen atom, aryl amines or heterocyclic aryl amines (NHR'R"), aliphatic thiols, aromatic thiols or heterocyclic thiols (R'SH).

10. The olefin alkoxycarbonylation or hydrogen esterification reaction according to claim 9, characterized in that, The steps of the catalytic reaction are as follows: (1) A catalyst solution prepared in a solvent under a nitrogen atmosphere according to a ratio of Pd: ligand: acid = 1: 2: 4 to 1: 6: 12, depending on the type of olefin substrate; the amount of the combined catalyst is based on the amount of Pd relative to the olefin: the molar amount of Pd is 0.005 to 0.01% of the molar amount of the olefin, preferably 0.01%; (2) The prepared catalyst and olefin substrate are transferred to the reactor under a nitrogen atmosphere, fully purged, and then CO is introduced to a pressure of 1 to 50 bar, preferably 10 bar; depending on the substrate activity, the reaction temperature is raised to 25-100℃ and the reaction is carried out for 15-120 min. (3) After the reaction is complete, the olefin conversion (TON, TOF) in the sample is tested using a non-polar chromatographic column. The proportion of byproducts and the selectivity of esters, carboxylic acids or amides; the conversion rate of olefins is between 90-99%, the positive-to-iso ratio is between 50-99.9:1, the proportion of byproduct isomerized olefins is less than 5%, and the proportion of byproduct ethers / alcohols or amines is less than 0.5%.

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