Bidentate phosphite ligand, preparation method thereof and application of bidentate phosphite ligand in hydroformylation of dicyclopentadiene

Abstract

The invention discloses a bidentate phosphite ligand, a preparation method thereof and an application of the bidentate phosphite ligand in dicyclopentadiene hydroformylation, the bidentate phosphite ligand has the following structure: in the formula, R1 is selected from substituted or non-substituted arylene. The bidentate phosphite ligand catalyst provided by the invention can regulate and control the hydroformylation reaction of dicyclopentadiene, and the yield of tricyclodecane dicarboxaldehyde reaches 95% or above under a milder condition.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis and relates to a bidentate phosphite ligand, its preparation method, and its application in the hydroformylation of dicyclopentadiene. Background Technology

[0002] Tricyclodecanediethanol (TCDDM) and tricyclodecanedimethylamine (TCDDMA) are important monomers for the preparation of high-performance polyesters and amides. High-performance specialty polyesters or polyamides synthesized using TCDDM or TCDDMA monomers exhibit high heat resistance, oxidation resistance, high transparency, and high mechanical strength, and are widely used in optical devices, liquid crystals, thin films, and sensor materials. One important method for synthesizing TCDDM and TCDDMA is to use dicyclopentadiene (DCPD) as a raw material, which undergoes a hydroformylation reaction to produce tricyclodecanedialdehyde (TCDDA). TCDDA is then further hydrogenated or catalytically aminationed to obtain TCDDM and TCDDMA.

[0003] Patent CN102795978B describes a two-step synthesis of dialdehydes using a heterogeneous catalyst: first, the hydroformylation of dicyclopentadiene is catalyzed at low temperature and pressure to synthesize tricyclodecane unsaturated monoaldehyde, ensuring a high yield; then, at relatively higher temperature and pressure, the tricyclodecane unsaturated monoaldehyde is catalyzed to synthesize tricyclodecanedialdehyde. Specifically, using cobalt-rhodium-triphenyloxyphosphine supported on iron oxide as a catalyst (with a triphenyloxyphosphine / rhodium molar ratio of 20 / 1), the reaction is first carried out at 110°C and 6 MPa for 1 hour to obtain tricyclodecane monoaldehyde; then, the reaction is carried out at 160°C and 8.5 MPa for 8 hours, ultimately achieving a DCPD conversion of 100% and a selectivity of 91% for tricyclodecanedialdehyde. This patent improves the experiment, obtaining tricyclodecanedialdehyde with higher selectivity, but the reaction conditions are more demanding, and the two-step reaction process is more complex.

[0004] Patent US6365782B1 uses rhodium (I) dicarbonylacetylacetone and tris(2,4-di-tert-butylphenyl) phosphite as catalysts (with a molar ratio of tris(2,4-di-tert-butylphenyl) phosphite / rhodium of 5 / 1), methylcyclohexane as solvent, at a reaction temperature of 130°C, a reaction pressure of 7 MPa, and a reaction time of 3 h. Dicyclopentadiene is continuously fed into a high-pressure reactor over 2 h. After the reaction, the reaction liquid separates into two phases: the upper layer is the methylcyclohexane phase, and the lower layer is the dialdehyde phase. The DCPD conversion rate is 100%. The yield of tricyclodecanedialdehyde is 97.6%, and the yield of monoaldehyde is 2.4%. This patent achieves a high dialdehyde yield and produces no other byproducts besides monoaldehyde, but the reaction conditions are relatively harsh, and the reaction process is relatively complex.

[0005] Dicyclopentadiene may undergo side reactions such as isomerization, excessive hydrogenation, and pyrolysis during hydroformylation. Isomerization can generate polymers such as tricyclopentadiene; excessive hydrogenation of the C=C double bond can produce the corresponding alkane; and pyrolysis can result in one molecule of dicyclopentadiene reacting to form two molecules of pentadiene at high temperatures. Furthermore, the stability of the ligand and the rhodium-based catalyst is crucial, as it involves catalyst recycling. Therefore, the key challenges in the hydroformylation of dicyclopentadiene are achieving high selectivity for tricyclodecanedialdehyde under milder reaction conditions and maintaining catalyst stability during recycling. Summary of the Invention

[0006] Compared with traditional heterogeneous catalysis, homogeneous catalysis can achieve highly selective conversion of dicyclopentadiene under milder conditions, and the structure of the ligand is particularly crucial in homogeneous catalysis. Based on the above issues, a bidentate phosphite ligand, its preparation method, and its applications are proposed. This bidentate phosphite ligand can regulate the hydroformylation reaction of dicyclopentadiene, obtaining tricyclodecanedialdehyde with higher selectivity under milder conditions. Furthermore, this ligand exhibits good stability and can be recycled multiple times.

[0007] A bidentate phosphite ligand structure is shown in the following formula:

[0008] R1 is selected from substituted or unsubstituted C6 to C1. 40 Alpha-aryl;

[0009] The substituents on the arylene group are one or more of C1-C6 alkyl or C1-C6 alkoxy groups.

[0010] The arylene group is a substituent formed after the loss of two H atoms from the aromatic ring.

[0011] Preferably, R1 is selected from substituted or unsubstituted biphenylene, binatylene, or naphthylene;

[0012] The substituents on the phenylene, naphthylene, or naphthylene group are one or more of C1-C6 alkyl or C1-C6 alkoxy groups, and are more preferably one or more of tert-butyl, methyl, or methoxy groups.

[0013] Preferably, R1 is one of the following structures.

[0014]

[0015] R2, R3, R4, R5, R6, and R7 are independently selected from one or more of H, C1-C6 alkyl, or C1-C6 alkoxy groups.

[0016] As a preferred option, R1 is selected from...

[0017] The present invention also provides a method for preparing the novel bidentate phosphite ligand compound as described above, comprising the following steps:

[0018] Step 1: Add 2,4-di-tert-butylphenol, oxidant, base and methanol to a three-necked flask, and react at 80-100℃ for 12-24 hours. After the reaction is completed, remove methanol by rotary evaporation of the reaction solution, and then wash and dry to obtain 3,3'-5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl.

[0019] Step 2: Under a protective atmosphere of N2 or Ar, add the corresponding bisphenol compound to a three-necked flask, followed by the solvent and catalyst. After complete dissolution, slowly add phosphorus trichloride dropwise to the solution. After the addition is complete, react at room temperature for 1-3 hours, then heat under reflux for 4-6 hours. After the reaction is complete, remove the solvent and excess phosphorus trichloride by vacuum distillation to obtain the corresponding chlorophosphite.

[0020] Step 3: Under a N2 or Ar protective atmosphere, add the 3,3'-5,5'-tetratert-butyl-2,2'-dihydroxybiphenyl obtained in Step 1 to a three-necked flask, then add solvent and catalyst. After complete dissolution, slowly add the chlorophosphite obtained in Step 2 at room temperature and react for 12-24 hours. After filtration and rotary evaporation to remove most of the solvent, purify the crude product by rapid column chromatography to obtain the corresponding bidentate phosphite ligand.

[0021] Preferably, the oxidant in step one is oxygen, potassium ferricyanide, hydrogen peroxide, or selenium dioxide; the base is potassium hydroxide, sodium hydroxide, calcium hydroxide, potassium carbonate, sodium carbonate, or tetramethylethylenediamine.

[0022] Preferably, the concentration of 2,4-di-tert-butylphenol in step one is 0.5 mol / L to 1.5 mol / L; the molar ratio of 2,4-di-tert-butylphenol to alkali is 0.5 to 5:1.

[0023] Preferably, the solvent in step two is toluene or tetrahydrofuran; the catalyst is pyridine or triethylamine.

[0024] Preferably, in step two, the molar ratio of phosphorus trichloride to the bisphenol compound is 1-3:1; the molar ratio of the catalyst to the bisphenol compound is 2-5:1; and the concentration of the bisphenol compound is 0.1 mol / L-1 mol / L.

[0025] Preferably, the solvent in step three is toluene, tetrahydrofuran, or dichloromethane; and the catalyst is pyridine or triethylamine.

[0026] Preferably, in step three, the molar ratio of chlorophosphite to 3,3'-5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl is 2-4:1; the molar ratio of catalyst to 3,3'-5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl is 3-5:1; and the concentration of 3,3'-5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl is 0.05 mol / L-0.5 mol / L.

[0027] The present invention also provides a catalyst composition for hydroformylation, comprising a rhodium precursor and the bidentate phosphite ligand described above.

[0028] Preferably, the rhodium precursor is rhodium dicarbonylacetylacetone (I).

[0029] Preferably, the mass ratio of the rhodium precursor to the ligand is 1:5-30.

[0030] This invention also provides a homogeneous catalytic method for the hydroformylation of dicyclopentadiene to tricyclodecanedicarboxaldehyde, comprising the following steps:

[0031] Under a nitrogen atmosphere, dicyclopentadiene, a rhodium catalyst, and a bidentate phosphite ligand prepared according to claim 3 are dissolved in an organic solvent and reacted at 70-90°C and 4-6 MPa syngas pressure for 4-6 hours to obtain tricyclodecanedialdehyde.

[0032] Preferably, the solvent is toluene, methylcyclohexane, diisopropylbenzene, isooctane, or cyclohexane; the rhodium precursor is rhodium dicarbonylacetylacetone (I).

[0033] Preferably, the mass ratio of dicyclopentadiene to ligand is 60-200:1; the mass ratio of rhodium precursor to ligand is 1:5-30; the concentration of dicyclopentadiene is 0.1g / g-0.5g / g; and the syngas is selected from a mixture of carbon monoxide and hydrogen in a volume ratio of 1:0.5-2.

[0034] The bidentate phosphite ligand structure described in this invention can better complex with rhodium-based catalysts through synergistic interactions between functional groups. By utilizing the interaction between the ligand and the substrate to form different transition states, tricyclodecanedialdehyde can be generated more quickly after the formation of tricyclodecane monoaldehyde. This allows for the regulation of dicyclopentadiene to undergo hydroformylation rather than side reactions such as polymerization, hydrogenation, and pyrolysis, and the reaction conditions are milder, demonstrating potential industrial application value. Detailed Implementation

[0035] Example 1

[0036] Step 1: Preparation of 3,3'-5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl: 2,4-di-tert-butylphenol (30 g, 145.65 mmol), hydrogen peroxide (0.50 g, 14.56 mmol), potassium carbonate (10.04 g, 72.83 mmol), and methanol (150 mL) were added to a three-necked flask. The mixture was reacted at 80 °C for 12 h. The reaction process was monitored by TLC. After the reaction was complete, the reaction solution was removed and the methanol was removed by rotary evaporation. The white solid obtained by filtration was washed four times with methanol (15 mL) and dried to obtain 28.20 g of 3,3',5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl white solid, with a yield of 94%.

[0037] Step 2: Preparation of 1,1'-biphenyl-2,2'-dioxyphosphine: Under a nitrogen atmosphere, 2,2'-biphenyl hydroquinone (11.17 g, 60 mmol), pyridine (14.24 g, 180 mmol), and toluene (150 ml) were added to a three-necked flask and completely dissolved. Phosphorus trichloride (8.25 g, 60 mmol) was then slowly added dropwise to the reaction solution. After the addition was complete, the mixture was brought back to room temperature and stirred for 1 h. After reflux for 4 h, the reaction solution was distilled under reduced pressure to remove the solvent and excess phosphorus trichloride, yielding 9.77 g of 1,1'-biphenyl-2,2'-dioxyphosphine, with a yield of 65%.

[0038] Step 3: 2,2'-Di[(1,1'-biphenyl-2,2'-diyl)phosphonite]-3,3',5,5'-tetratert-butyl-1,1'-biphenyl: Under a nitrogen atmosphere, 3,3',5,5'-tetratert-butyl-2,2'-dihydroxybiphenyl (4.1 g, 10 mmol), pyridine (3.16 g, 40 mmol), and toluene (100 mL) were added to a three-necked flask and completely dissolved. Then, the prepared 1,1'-biphenyl-2,2'-dioxyphosphine (5.01 g, 20 mmol) was slowly added dropwise to the reaction solution at room temperature. The reaction was allowed to proceed for 15 h. After the reaction was complete as determined by TLC, the reaction solution was filtered and evaporated to dryness to remove most of the solvent. The crude product was purified by rapid column chromatography to obtain 3.60 g of a white solid, with a yield of 43%.

[0039] The product obtained in this embodiment was subjected to nuclear magnetic resonance analysis, and the results are as follows:

[0040] (1) The hydrogen spectrum data is 1H-NMR (400MHz, Chloroform-d): δ (ppm) = 7.48 (s, 2H), 7.33 (d, 2H), 7.25-7.23 (m, 4H), 7. 19(t,2H),7.10(t,2H),7.04-7.01(m,4H),6.87(t,2H),6.62(d,2H),1.28-1.36(m,36H)

[0041] (2) Phosphorus spectrum data are 31 P-NMR (162MHz, Chloroform-d): δ (ppm) = 145.3

[0042]

[0043] Example 2

[0044] 3,3'-5,5'-tetratert-butyl-2,2'-dihydroxybiphenyl was prepared using the same method as step one in Example 1.

[0045] Step 2: Preparation of 1,1'-binaphthyl-2,2'-dioxyphosphine: Under a nitrogen atmosphere, 2,2'-binaphthol (14.32 g, 50 mmol), pyridine (11.87 g, 150 mmol), and toluene (200 mL) were added to a three-necked flask and completely dissolved. Phosphorus trichloride (6.88 g, 50 mmol) was then slowly added dropwise to the reaction solution. After the addition was complete, the mixture was brought back to room temperature and stirred for 2.1 h. After reflux for 5 h, the reaction solution was distilled under reduced pressure to remove the solvent and excess phosphorus trichloride, yielding 10.52 g of 1,1'-binaphthyl-2,2'-dioxyphosphine, with a yield of 60%.

[0046] Step 3: 2,2'-Bis[(1,1'-binaphthyl-2,2'-diyl)phosphonite]-3,3',5,5'-tetratert-butyl-1,1'-biphenyl: Under a nitrogen atmosphere, 3,3',5,5'-tetratert-butyl-2,2'-dihydroxybiphenyl (4.1 g, 10 mmol), pyridine (3.16 g, 40 mmol), and toluene (100 mL) were added to a three-necked flask and completely dissolved. Then, the prepared 1,1'-binaphthyl-2,2'-dioxyphosphine (7.01 g, 20 mmol) was slowly added dropwise to the reaction solution at room temperature. The reaction was allowed to proceed for 15 h. After the reaction was complete as determined by TLC, the reaction solution was filtered and evaporated to dryness to remove most of the solvent. The crude product was purified by column chromatography to obtain 4.23 g of a white solid, with a yield of 41%.

[0047] The product obtained in this embodiment was subjected to nuclear magnetic resonance analysis, and the results are as follows:

[0048] (1) The hydrogen spectrum data is 1H-NMR (400MHz, Chloroform-d): δ (ppm) = 7.82-7.87 (m, 5H), 7.74 (d, 1H), 7.68 (d, 1H), 7.59-7.62 (m, 2H),7.54(d,1H),7.30-7.39(m,8H),7.20-7.24(m,8H),7.11(d,1H),6.78(d,1H),1.54-1.16(m,36H)

[0049] (2) Phosphorus spectrum data are 31 P-NMR (162MHz, Benzene-d6): δ (ppm) = 159.6

[0050]

[0051] Example 3

[0052] 3,3'-5,5'-tetratert-butyl-2,2'-dihydroxybiphenyl was prepared using the same method as step one in Example 1.

[0053] Step 2: Preparation of 1,8-dioxychlorophosphine: Under a nitrogen atmosphere, 1,8-naphthol (9.61 g, 60 mmol), pyridine (14.24 g, 180 mmol), and tetrahydrofuran (120 mL) were added to a three-necked flask and completely dissolved. Then, phosphorus trichloride (8.25 g, 60 mmol) was slowly added dropwise to the reaction solution. After the addition was complete, the mixture was brought back to room temperature and stirred for 1 h. After reflux for 4 h, the reaction solution was distilled under reduced pressure to remove the solvent and excess phosphorus trichloride, yielding 9.02 g of 1,8-dioxychlorophosphine, with a yield of 67%.

[0054] Step 3: 2,2'-Di[(1,8-diylnaphthalene)phosphonite]-3,3',5,5'-tetra-tert-butyl-1,1'-biphenyl: Under a nitrogen atmosphere, 3,3',5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl (4.1 g, 10 mmol), pyridine (3.16 g, 40 mmol), and tetrahydrofuran (100 mL) were added to a three-necked flask and completely dissolved. Then, the prepared 1,8-dioxychlorophosphine (4.49 g, 20 mmol) was slowly added dropwise to the reaction solution at room temperature. The reaction was allowed to proceed for 12 h. After the reaction was complete as determined by TLC, the reaction solution was filtered and evaporated to dryness to remove most of the solvent. The crude product was purified by column chromatography to obtain 3.54 g of a white solid, with a yield of 45%.

[0055] The product obtained in this embodiment was subjected to nuclear magnetic resonance analysis, and the results are as follows:

[0056] (1) The hydrogen spectrum data is 1H-NMR (400MHz, Chloroform-d): δ (ppm) = 7.72 (d, 4H), 7.60 (d, 2H), 7.36-7.44 (m, 6H), 6.31 (dd, 4H), 1.44-1.35 (m, 36H)

[0057] (2) Phosphorus spectrum data are 31 P-NMR (162MHz, Benzene-d6): δ (ppm) = 151.2

[0058]

[0059] Example 4

[0060] 3,3'-5,5'-tetratert-butyl-2,2'-dihydroxybiphenyl was prepared using the same method as step one in Example 1.

[0061] Step 2: Preparation of 3,3'-5,5'-tetra-tert-butyl-1,1'-biphenyl-2,2'-dioxyphosphine: Under an N2 or Ar atmosphere, 16.42 g (40 mmol) of 3,3'-5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl, 12.14 g (120 mmol), and 180 ml of tetrahydrofuran obtained in Step 1 were added to a three-necked flask. After complete dissolution, 5.50 g (40 mmol) of phosphorus trichloride was slowly added dropwise to the reaction solution. After the addition was complete, the mixture was brought back to room temperature and stirred for 2 h. Then, it was refluxed for 6 h. The reaction solution was then distilled under reduced pressure to remove the solvent and excess phosphorus trichloride, yielding 10.818 g of 3,3'-5,5'-tetra-tert-butyl-1,1'-biphenyl-2,2'-dioxyphosphine, with a yield of 57%.

[0062] Step 3: 2,2'-Di[(3,3',5,5'-tetra-tert-butyl-1,1'-biphenyl-2,2'-diyl)phosphonite]-3,3',5,5'-tetra-tert-butyl-1,1'-biphenyl: Under a N2 or Ar atmosphere, add 3,3',5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl (4.1 g, 10 mmol) and triethylamine (4.05 g, 40 mmol) to a three-necked flask. After completely dissolving 100 mL of tetrahydrofuran, 9.49 g (20 mmol) of the prepared 3,3'-5,5'-tetratert-butyl-1,1'-biphenyl-2,2'-dioxyphosphine chloride (20 mmol) was slowly added dropwise to the reaction solution at room temperature. The reaction was allowed to proceed for 18 h. The reaction was then determined to be complete by TLC. The reaction solution was filtered and evaporated to dryness to remove most of the solvent. The crude product was purified by column chromatography to obtain 4.50 g of white solid, with a yield of 35%.

[0063] The product obtained in this embodiment was subjected to nuclear magnetic resonance analysis, and the results are as follows:

[0064] (1) The hydrogen spectrum data is 1 H-NMR (400MHz, Chloroform-d): δ (ppm) = 7.43-7.35 (m, 3H), 7.37-7.32 (m, 2H), 7.30-7.20 (m, 2H), 7.19-7.11 (m, 2H), 7.05 (d, 3H), 1.47-1.01 (m, 108H)

[0065] (2) Phosphorus spectrum data are 31 P-NMR (162MHz, Chloroform-d): δ (ppm) = 139.7

[0066]

[0067] Example 5

[0068] 3,3'-5,5'-tetratert-butyl-2,2'-dihydroxybiphenyl was prepared using the same method as step one in Example 1.

[0069] Step 2: Preparation of 5,5'-dimethyl-1,1'-biphenyl-2,2'-dioxyphosphine: Under a N2 or Ar atmosphere, 5,5'-dimethyl-2,2'-dihydroxybiphenyl (12.84 g, 60 mmol), triethylamine (18.21 g, 180 mmol), and tetrahydrofuran (150 mL) were added to a three-necked flask and completely dissolved. Then, phosphorus trichloride (8.25 g, 60 mmol) was slowly added dropwise to the reaction solution. After the addition was complete, the mixture was brought back to room temperature and stirred for 2 h. After reflux for 5 h, the reaction solution was distilled under reduced pressure to remove the solvent and excess phosphorus trichloride, yielding 10.19 g of 5,5'-dimethyl-1,1'-biphenyl-2,2'-dioxyphosphine, with a yield of 61%.

[0070] Step 3: 2,2'-Di[(5,5'-dimethyl-1,1'-biphenyl-2,2'-diyl)phosphonite]-3,3',5,5'-tetra-tert-butyl-1,1'-biphenyl: Under a nitrogen atmosphere, 3,3',5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl (4.1 g, 10 mmol), triethylamine (4.05 g, 40 mmol), and dichloromethane (100 mL) were added to a three-necked flask and completely dissolved. Then, the prepared 5,5'-dimethyl-1,1'-biphenyl-2,2'-dioxyphosphonochlorophosphine (5.57 g, 20 mmol) was slowly added dropwise to the reaction solution at room temperature. The reaction was allowed to proceed for 16 h. After the reaction was complete as determined by TLC, the reaction solution was filtered and evaporated to dryness to remove most of the solvent. The crude product was purified by column chromatography to obtain 3.31 g of a white solid, with a yield of 37%.

[0071] The product obtained in this embodiment was subjected to nuclear magnetic resonance analysis, and the results are as follows:

[0072] (1) The hydrogen spectrum data is 1 H-NMR (400MHz, Chloroform-d): δ (ppm) = 7.63 (d, 4H), 7.58 (d, 2H), 7.45 (d, 2H), 7.16 (dd, 4H), 6.92 (d, 4H), 2.44 (s, 12H), 1.28-1.36 (m, 36H)

[0073] (2) Phosphorus spectrum data are 31 P-NMR (162MHz, Benzene-d6): δ (ppm) = 156.8

[0074]

[0075] Example 6

[0076] 3,3'-5,5'-tetratert-butyl-2,2'-dihydroxybiphenyl was prepared using the same method as step one in Example 1.

[0077] Step 2: Preparation of 3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-dioxyphosphine chloride: Under a nitrogen atmosphere, 3,3'-di-tert-butyl-5,5'-dimethoxy-2,2'-dihydroxy-1,1'-biphenyl (14.32 g, 40 mmol), triethylamine (12.14 g, 120 mmol), and tetrahydrofuran (200 ml) were added to a three-necked flask and completely dissolved. Then, phosphorus trichloride (5.50 g, 40 mmol) was slowly added dropwise to the reaction solution. After the addition was complete, the mixture was brought back to room temperature and stirred for 2 h. After reflux for 6 h, the reaction solution was distilled under reduced pressure to remove the solvent and excess phosphorus trichloride, yielding 9.97 g of 3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-dioxyphosphine chloride, with a yield of 59%.

[0078] Step 3: 2,2'-Di[(3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)phosphonite]-3,3',5,5'-tetra-tert-butyl-1,1'-biphenyl: Under a nitrogen atmosphere, add 3,3',5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl (4.1 g, 10 mmol) and triethylamine (4.05 g, 40 mmol) to a three-necked flask. After completely dissolving 100 mL of dichloromethane, 8.45 g (20 mmol) of the prepared 3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-dioxyphosphine chloride was slowly added dropwise to the reaction at room temperature. The reaction was allowed to proceed for 18 h. The reaction was then determined to be complete by TLC. The reaction solution was filtered and evaporated to dryness to remove most of the solvent. The crude product was purified by column chromatography to obtain 3.78 g of white solid, with a yield of 32%.

[0079] The product obtained in this embodiment was subjected to nuclear magnetic resonance analysis, and the results are as follows:

[0080] (1) The hydrogen spectrum data is 1 H-NMR (400MHz, Chloroform-d): δ (ppm) = 7.52 (d, 2H), 7.48 (d, 2H), 6.95 (d, 4H), 6.26 (d, 4H), 3.83 (s, 12H), 1.33-1.45 (m, 36H)

[0081] (2) Phosphorus spectrum data are 31 P-NMR (162MHz, Benzene-d6): δ (ppm) = 142.3

[0082]

[0083] Comparative Example 1

[0084] The difference between Comparative Example 1 and Example 1 is that p-tert-butylphenol (21.88 g, 145.65 mmol) was used instead of 2,4-di-tert-butylphenol (30 g, 145.65 mmol) in step one.

[0085] The product structure is as follows:

[0086]

[0087] Comparative Example 2

[0088] The difference between Comparative Example 2 and Example 1 is that 2,4-dimethylphenol (18.35 g, 145.65 mmol) was used instead of 2,4-di-tert-butylphenol (30 g, 145.65 mmol) in step one.

[0089] The product structure is as follows:

[0090]

[0091] Application example:

[0092] Under room temperature and air atmosphere, 10g of dicyclopentadiene, 40g of toluene, 5mg of rhodium(I) dicarbonylacetylacetone, and the corresponding mass of bidentate phosphite ligand were weighed and added to a 200ml high-pressure reactor. The reactor was sealed, and the air inside was replaced with 1MPa N2 4-5 times, followed by purging with 1MPa syngas 4-5 times. The electric heating and stirring were turned on. When the temperature inside the reactor reached 70℃, the syngas pressure was increased to 4.5MPa, and the temperature was further increased to 80℃. The syngas pressure was then increased to 5MPa, and continuous aeration was maintained to keep the pressure inside the reactor at 5MPa. After reacting for 6 hours, the high-pressure reactor was rapidly cooled in a cold water bath, and samples were taken for analysis to determine the yields of tricyclodecanedialdehyde and tricyclodecane unsaturated monoaldehyde in the product. The reaction products were quantitatively analyzed using a Shimadzu gas chromatograph with an HP-5 capillary column and a flame ionization detector. The reaction results are shown in Table 1.

[0093] Table 1. Results of hydroformylation of dicyclopentadiene by different bidentate phosphite ligands

[0094] bidentate phosphite ligands Ligand mass (mg) Conversion rate Dialdehyde yield Monoaldehyde yield High-boiling-point impurities Example 1 80 100％ 91.2％ 3.1％ 5.7％ Example 2 100 100％ 93.3％ 2.1％ 4.6％ Example 3 75 100％ 90.5％ 2.7％ 6.8％ Example 4 125 100％ 95.6％ 2.6％ 1.8％ Example 5 85 100％ 94.8％ 2.3％ 2.9％ Example 6 115 100％ 92.6％ 3.3％ 4.1％ Comparative Example 1 70 100％ 83.4％ 6.3％ 10.3％ Comparative Example 2 65 100％ 85.8％ 5.7％ 8.5％

[0095] As shown in Table 1, the bisphosphite ligands provided by this invention can significantly improve the yield of tricyclodecanedialdehyde in the dicyclopentadiene hydroformylation reaction, and have high conversion efficiency, with a total aldehyde yield of up to 98.2%, which can meet the needs of industrialization.

[0096] Table 2 shows the results of recycling the catalyst composed of the ligand in Example 4 and rhodium dicarbonyl acetylacetone (I). No significant decrease in product yield was observed after five recycling cycles, indicating good catalyst activity and stability. After each reaction, the high-pressure reactor was rapidly cooled in a cold water bath, and samples were taken for analysis to determine the yield of the aldehyde in the product. Then, without separation, 10 g of dicyclopentadiene was added, and the above replacement, heating, and pressurization procedures were repeated, resulting in a total of five catalyst recycling cycles.

[0097] Table 2 Results of the ligand in Example 4 during dicyclopentadiene hydroformylation cycling

[0098] Catalyst usage times Conversion rate Dialdehyde yield Monoaldehyde yield High-boiling-point impurities first 100％ 95.6％ 2.6％ 1.8％ The second 100％ 95.1％ 2.6％ 2.3％ The third 100％ 94.8％ 2.5％ 2.7％ Fourth 100％ 93.9％ 3.2％ 2.9％ Fifth 100％ 93.0％ 3.9％ 3.1％

[0099] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A bidentate phosphite ligand, characterized in that, It has the following general formula: R1 is selected from substituted or unsubstituted C6 to C1. 40 Alpha-aryl; The substituents on the arylene group are one or more of C1-C6 alkyl or C1-C6 alkoxy groups.

2. The bidentate phosphite ligand according to claim 1, characterized in that, R1 is selected from substituted or unsubstituted biphenylene, binatylene, or naphthylene; The substituents on the phenylene, naphthylene, or naphthylene group are one or more of tert-butyl, methyl, or methoxy groups; Preferably, one of the following structures is selected: R2, R3, R4, R5, R6, and R7 are independently selected from one or more of H, C1-C6 alkyl, or C1-C6 alkoxy groups.

3. The bidentate phosphite ligand according to claim 2, characterized in that, R1 is selected from In this context, * indicates a replacement position.

4. A method for preparing a bidentate phosphite ligand as described in any one of claims 1 to 3, characterized in that, Includes the following steps: Step 1: 2,4-Di-tert-butylphenol, oxidant, base and methanol are reacted at 80-100℃ for 12-24 hours. After the reaction is completed, the methanol is removed by rotary evaporation of the reaction solution, and then washed and dried to obtain 3,3'-5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl. Step 2: Under a protective atmosphere of N2 or Ar, add solvent and catalyst to the diphenol compound. After complete dissolution, add phosphorus trichloride dropwise to the solution. After the addition is complete, react at 20-40℃ for 1-3 hours, then heat under reflux for 4-6 hours. After the reaction is complete, remove the solvent and excess phosphorus trichloride by vacuum distillation to obtain the corresponding chlorophosphite. Step 3: Under a N2 or Ar protective atmosphere, add solvent and catalyst to the 3,3'-5,5'-tetratert-butyl-2,2'-dihydroxybiphenyl obtained in Step 1. After complete dissolution, slowly add the chlorophosphite obtained in Step 2 at 20-40°C and react for 12-24 hours. After filtration and rotary evaporation to remove most of the solvent, purify the crude product by rapid column chromatography to obtain the corresponding bidentate phosphite ligand.

5. The method for preparing bidentate phosphite ligands according to claim 4, characterized in that: The oxidant in step one is oxygen, potassium ferricyanide, hydrogen peroxide, or selenium dioxide; the base is potassium hydroxide, sodium hydroxide, calcium hydroxide, potassium carbonate, sodium carbonate, or tetramethylethylenediamine. In step one, the concentration of 2,4-di-tert-butylphenol is 0.5 mol / L to 1.5 mol / L; the molar ratio of 2,4-di-tert-butylphenol to alkali is 0.5 to 5:

1.

6. The method for preparing bidentate phosphite ligands according to claim 4, characterized in that: The solvent in step two is toluene or tetrahydrofuran; the catalyst is pyridine or triethylamine. In step two, the molar ratio of phosphorus trichloride to the bisphenol compound is 1-3:1; the molar ratio of the catalyst to the bisphenol compound is 2-5:1; and the concentration of the bisphenol compound is 0.1 mol / L-1 mol / L.

7. The method for preparing bidentate phosphite ligands according to claim 4, characterized in that: The solvent in step three is toluene, tetrahydrofuran, or dichloromethane; the catalyst is pyridine or triethylamine. In step three, the molar ratio of chlorophosphite to 3,3'-5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl is 2-4:1; the molar ratio of catalyst to 3,3'-5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl is 3-5:1; and the concentration of 3,3'-5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl is 0.05 mol / L-0.5 mol / L.

8. A catalyst composition for hydroformylation, characterized in that, It consists of a rhodium precursor and a bidentate phosphite ligand as described in any one of claims 1 to 3 or a bidentate phosphite ligand obtained by the preparation method described in any one of claims 4 to 7.

9. A homogeneous catalytic method for the hydroformylation of dicyclopentadiene to tricyclodecanedicarboxaldehyde, characterized in that, include: Under a nitrogen atmosphere, dicyclopentadiene, a rhodium precursor, the bidentate phosphite ligand according to any one of claims 1 to 3, or the bidentate phosphite ligand obtained by the preparation method according to any one of claims 4 to 7 are dissolved in an organic solvent, and reacted at 70-90°C and 4-6 MPa syngas pressure for 4-6 h to obtain tricyclodecanedialdehyde.

10. The homogeneous catalytic method for the hydroformylation of dicyclopentadiene to tricyclodecanedialdehyde according to claim 9, characterized in that: The organic solvent is toluene, methylcyclohexane, diisopropylbenzene, isooctane, or cyclohexane; the rhodium precursor is rhodium dicarbonylacetylacetone (I); The mass ratio of dicyclopentadiene to bidentate phosphite ligand is 60-200:1; the mass ratio of rhodium precursor to bidentate phosphite ligand is 1:5-30; the concentration of dicyclopentadiene is 0.1 g / g-0.5 g / g; the synthesis gas is selected from a mixture of carbon monoxide and hydrogen in a volume ratio of 1:0.5-2.

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