Pillararene bisphosphite ligands, methods of making and using the same

Abstract

The present application provides a kind of formula I shows that the pillar aromatic double phosphite ligand and its preparation method and application, and the outer rim of pillar aromatic bonding phosphorus compound is prepared pillar aromatic double phosphite compound, can be used as novel ligand of homogeneous metal catalyst, for olefin hydrocyanation etc. Organic reaction. The catalyst prepared using the ligand of the present application is used for the preparation of nitrile, not only high catalytic activity, high yield, and the position selectivity of product is high, it is advantageous to obtain the product of anti-masashi linear addition.

Description

Technical Field

[0001] This invention relates to the field of phosphine ligand catalyst preparation technology, and in particular to a novel class of columnar aromatic bisphosphite ligands and their preparation methods, catalysts containing columnar aromatic bisphosphite ligands and their application in the hydrocyanation of olefins. Background Technology

[0002] The hydrocyanation of olefins has significant industrial applications. For example, the hydrocyanation of 1,3-butadiene to produce adiponitrile is fundamental to the production of nylon 66 in the chemical fiber industry. Currently, in the butadiene-based adiponitrile production technology, 1,3-butadiene undergoes a single hydrocyanation to produce 3-pentenonitrile (3PN), 2-methyl-3-butenonitrile (2M3BN), and a small amount of 4-pentenonitrile (4PN). Subsequently, 2M3BN isomerizes back to 3PN. During this process, the isomerization rate of 2M3BN is approximately 85%, accompanied by the formation of byproducts such as 2-pentenonitrile (2PN) and 2-methyl-2-butenonitrile (2M2BN). The presence of 2PN and 2M2BN can cause problems such as catalyst deactivation, precipitation of active components, and blockage of pipelines.

[0003] Therefore, improving the selectivity of linear products in the hydrocyanation of olefins and minimizing the formation of branched products remains an important issue. Summary of the Invention

[0004] To address the shortcomings and technical requirements of the existing technologies, a novel organophosphorus ligand—pillar aromatic bisphosphite ligand—was designed based on supramolecular chemistry catalyst systems. Catalysts using this ligand can improve the selectivity of linear products and increase the yield of target products.

[0005] One of the objectives of this invention is to provide a columnar aromatic bisphosphite ligand.

[0006] A second objective of this invention is to provide a method for preparing the aforementioned columnar aromatic bisphosphite ligand.

[0007] A third objective of this invention is to provide a catalyst comprising the aforementioned columnar aromatic bisphosphite ligand.

[0008] The fourth objective of this invention is to provide a method for preparing the catalyst.

[0009] The fifth objective of this invention is to provide an application of the catalyst in the hydrocyanation reaction of olefins.

[0010] In a first aspect, the present invention provides a columnar aromatic bisphosphite ligand of formula I.

[0011]

[0012] Wherein: R is selected from C1-C12 alkyl groups, preferably C1-C6 alkyl groups, and particularly methyl;

[0013] n can be 4, 5, 6, 7, 8, or 9, with 4 being the preferred value;

[0014] X1 and X2 are each independently selected from substituted or unsubstituted phenoxy, substituted or unsubstituted naphthoxy, C1-C6 alkoxy, and benzyloxy, wherein the substitution refers to being substituted by one or more substituents selected from C1-C4 alkyl and C1-C4 alkoxy; preferably X1 and X2 are each independently selected from phenoxy, o-tolyloxy, m-tolyloxy, p-tolyloxy, 2,4-dimethyltolyloxy, 2,4,6-trimethyltolyloxy, 4-tert-butylphenoxy, 2,4-di-tert-butylphenoxy, 2,4,6-tri-tert-butylphenoxy, methyl 1-naphthoxy, and methyl 2-naphthoxy, and preferably X1 and X2 are each independently selected from phenoxy, m-tolyloxy, and p-tolyloxy.

[0015] In some embodiments, n is 4 in the columnar aromatic bisphosphite ligand of Formula I, that is, Formula I has the structure shown in Formula I-1:

[0016]

[0017] The definitions of X1 and X2 are as described above.

[0018] The columnar aromatic bisphosphite ligand of the above formula I-1 is a columnar aromatic phosphite derivative obtained by further derivatization of all-methyl columnar[5] aromatics.

[0019] In some embodiments, in the columnar aromatic bisphosphite ligand of Formula I, n is 4, and X1 and X2 are m-tolyloxy, i.e., Formula I has the structure shown in Formulas P5-P:

[0020]

[0021] Secondly, the present invention provides a method for preparing the above-mentioned columnar aromatic bisphosphite ligand, comprising the following methods:

[0022]

[0023] The method includes the following steps:

[0024] Compound 3 undergoes a substitution reaction with phosphorous chloride X1X2PCl to obtain the columnar aromatic bisphosphite ligand of formula I; wherein, X1, X2, R, and n are defined as described above.

[0025] The substitution reaction can be carried out in an organic solvent in the presence of an acid-binding agent.

[0026] Preferably, the organic solvent is one or more selected from dichloromethane, chloroform, cyclohexane, n-hexane, petroleum ether, acetonitrile, tetrahydrofuran, methyltetrahydrofuran, etc., and is more preferably selected from n-hexane and cyclohexane.

[0027] Preferably, the acid-binding agent is one or more selected from triethylamine, diisopropylethylamine, N-methylmorpholine, potassium carbonate, sodium carbonate, etc., and triethylamine is preferred.

[0028] Preferably, the molar ratio of phosphorous chloride X1X2PCl to compound 3 is 2:1 to 10:1, and more preferably 2.5:1.

[0029] Preferably, the temperature of the substitution reaction is -5℃ to 0℃, and the reaction time is 2 to 3 hours.

[0030] There are no particular restrictions on the source of compound 3, which can be prepared by existing methods, for example, by oxidation and reduction of a permethyl columnar [n]arene.

[0031] In some embodiments, compound 3 is prepared by the following method,

[0032]

[0033] The method includes the following steps:

[0034] S1: Compound 1 undergoes an oxidation reaction to yield compound 2;

[0035] S2: Compound 2 undergoes a reduction reaction to give compound 3.

[0036] Step S1

[0037] Step S1 can be carried out in an organic solvent in the presence of an oxidizing agent.

[0038] Preferably, the organic solvent is an inert organic solvent, such as chloroform, dichloromethane, tetrahydrofuran, methyltetrahydrofuran, petroleum ether, cyclohexane, n-hexane, benzene, toluene, etc., and dichloromethane is preferred.

[0039] Preferably, the oxidant is one or more selected from sodium persulfate, sodium perchlorate, sodium periodate, ammonium pyrosulfate, hydrogen peroxide, ozone, cerium ammonium nitrate, pyridine-chromium trioxide, etc., and is preferably cerium ammonium nitrate.

[0040] Preferably, the mass ratio of compound 1 to organic solvent is 1:1 to 1:50, and more preferably 1:5.

[0041] Preferably, the molar ratio of the oxidant to compound 1 is 1:1 to 10:1, and more preferably 2:1.

[0042] Preferably, the reaction temperature is 0–60°C, more preferably 20–30°C; the reaction time is 1–100 minutes, more preferably 20–30 minutes.

[0043] Step S2

[0044] Step S2 can be carried out in an organic solvent in the presence of a reducing agent.

[0045] Preferably, the organic solvent is an inert organic solvent, such as chloroform, dichloromethane, tetrahydrofuran, methyltetrahydrofuran, petroleum ether, cyclohexane, n-hexane, benzene, toluene, etc., and dichloromethane is preferred.

[0046] Preferably, the reducing agent is one or more selected from sodium borohydride, lithium aluminum hydride, sodium sulfide, sodium hydrosulfide, sodium disulfide, sodium dithionite, formaldehyde solution, formic acid, hydroxylamine hydrochloride, hydroxylamine sulfate, DIBAL-H, etc., and is preferably sodium dithionite.

[0047] Preferably, the mass ratio of compound 2 to organic solvent is 1:1 to 1:50, and more preferably 1:5.

[0048] Preferably, the molar ratio of compound 2 to reducing agent is 1:2 to 1:10, and more preferably 1:5.

[0049] Preferably, the reaction temperature is 0–60°C, more preferably 20–30°C; the reaction time is 1–24 hours, more preferably 8–10 hours.

[0050] Thirdly, the present invention provides a catalyst comprising the columnar aromatic bisphosphite ligand and a Group VIII metal atom or ion thereof bonded to the columnar aromatic bisphosphite ligand.

[0051] Examples of Group VIII metals include, but are not limited to, cobalt, nickel, platinum, palladium, rhodium, ruthenium, iridium, etc.

[0052] Columnar aromatics, as novel macrocyclic compounds, exhibit many unique properties. For example, compared to the conical cavity of calixaranes, the cavity of columnar aromatics is a symmetrical column with uniform diameter, allowing them to interact with more small molecules. Furthermore, compared to cyclodextrins, columnar aromatics exhibit a pronounced aromaticity in their cavity. Therefore, in addition to hydrophobic interactions, host-guest interactions can achieve better selectivity through π-π and cation-π interactions. Moreover, from a technical perspective, the preparation methods of columnar aromatics and their derivatives are simple. Columnar aromatics can be obtained in high yields by reacting hydroquinone derivatives with paraformaldehyde, and the oxygen atoms uniformly distributed at the edges of columnar aromatics provide reaction sites for the preparation of phosphine ligands.

[0053] Through rational design, after a phosphorus-containing compound is bonded to the outer edge of the columnar aromatic hydrocarbon, the catalyst and substrate exhibit an enzyme-like interaction, thereby achieving high position selectivity. In this invention, the inner diameter of the ring portion of the columnar aromatic hydrocarbon bisphosphite ligand is approximately 0.54 nm, and the molecular length (height) of the cavity portion is approximately 0.4 nm. The molecular diameter of 1,3-butadiene is approximately 0.3 nm, and the molecular length is approximately 0.44 nm. Through molecular force field simulation, the interaction between the ligand and butadiene is as follows: Figure 1 As shown, a relatively stable state can be achieved. Furthermore, NMR studies revealed that, under the influence of the columnar aromatic bisphosphite ligand, the hydrogen atoms on butadiene underwent varying degrees of upward displacement, indicating that the protons on butadiene are in a vertical spatial orientation of the columnar aromatic ring. The protons are influenced by the π-electron circulation directly below them, further confirming the interaction mode between butadiene and columnar aromatics. Moreover, due to the limitations of the columnar aromatic cavity structure (length, inner diameter), this type of columnar aromatic ligand catalyst exhibits more specificity for certain types of molecules, similar to the "lock-and-key" model in enzyme catalysis, demonstrating good selectivity.

[0054] The catalyst prepared from the columnar aromatic bisphosphite ligand of this invention has the following unique properties:

[0055] 1. Compared with the traditional P(m-cresol)3 (tri-m-methoxyphosphite), the linear product is significantly increased, the formation of 2M3BN is significantly inhibited, and the selectivity of the reaction is improved;

[0056] 2. The system has good compatibility, and the catalyst activity does not decrease significantly after repeated use.

[0057] Fourthly, the present invention provides a method for preparing the above-mentioned catalyst, comprising the following steps:

[0058] The catalyst is obtained by reacting the columnar aromatic bisphosphite ligand as described above with a Group VIII metal or its salt under an anhydrous and oxygen-free environment.

[0059] The reaction can be carried out under solvent-free conditions or in the presence of an organic solvent.

[0060] Preferably, the organic solvent is one or more selected from benzene, toluene, xylene, acetonitrile, tetrahydrofuran, methyltetrahydrofuran, petroleum ether, n-hexane, cyclohexane, and petroleum ether.

[0061] Preferably, the mass of the organic solvent is 0.5 to 100.0 times the mass of the columnar aromatic bisphosphite ligand, and more preferably 2.0 to 4.0 times.

[0062] Preferably, the Group VIII metal or its salt is selected from one or more of cobalt and cobalt salts, nickel and nickel salts, platinum salts, palladium salts, rhodium salts, ruthenium salts, and iridium salts; nickel powder and nickel salts are preferred.

[0063] The metal or metal salt may be added in excess. Preferably, the molar amount of the Group VIII metal or its salt is 1.5 to 2.0 times the molar amount of the columnar aromatic bisphosphite ligand.

[0064] The reaction is carried out under heating. Preferably, the heating can be controlled by a water bath or oil bath, with the temperature ranging from room temperature to 200°C, more preferably 120-160°C; or, the heating can also be carried out in a microwave reactor.

[0065] After the reaction, the catalyst is stored at low temperature and kept in an anhydrous and oxygen-free state for later use.

[0066] Fifthly, the present invention provides the application of the above-described catalyst in the hydrocyanation reaction of olefins. Specifically, the present invention provides a method for the hydrocyanation of olefins, the method comprising the step of carrying out the hydrocyanation reaction of olefins in the presence of the catalyst described above.

[0067] In some embodiments, the application includes: hydrocyanation of olefins with hydrogen cyanide in the presence of the catalyst.

[0068] Examples of olefins include, but are not limited to, 1,3-butadiene, propylene, isoprene, 1,3-pentadiene, n-butene, C4 and C5 mixed olefins in the petroleum industry, and naturally occurring unsaturated fatty acids and their esters such as oleic acid and its methyl ester.

[0069] Specifically, hydrogen cyanide and olefins are added to a reactor, along with the catalyst, and the reaction is carried out at room temperature. After the reaction is complete, excess olefins can be removed through post-processing, and the composition and distribution of the products can be analyzed using gas chromatography.

[0070] Preferably, the molar ratio of hydrocyanic acid to olefins is 1:0.5-10, and more preferably 1:2.

[0071] The amount of catalyst used is 1% to 20% of the reactants, preferably 10% to 15%.

[0072] Beneficial effects:

[0073] The columnar aromatic bisphosphite compound of the present invention can be used as a novel ligand for homogeneous metal catalysts in organic reactions such as the hydrocyanation of olefins.

[0074] The catalysts prepared using the ligands of this invention exhibit high catalytic activity and yield in the preparation of nitrile compounds, and also demonstrate high position selectivity, favoring the acquisition of anti-Markovnikov linear addition products. Furthermore, the preparation process of the columnar aromatic bisphosphite ligands is simple and can be industrially used for the production of nitrile compounds.

[0075] The present invention has been described in detail above; however, the above embodiments are merely illustrative in nature and are not intended to limit the invention. Furthermore, this document is not limited to the foregoing prior art or the invention itself, or to any theory described in the following embodiments.

[0076] Unless otherwise expressly stated, numerical ranges throughout the application include any subranges therein and any numerical values ​​incremented by the smallest subunit of a given value. Unless otherwise expressly stated, numerical values ​​throughout the application represent approximate measures or limitations on the range of embodiments including minor deviations from a given value and having approximately the mentioned value as well as having the mentioned precise value. Except in the detailed description of the working embodiments provided at the end, all numerical values ​​of parameters (e.g., quantities or conditions) in this application (including the appended claims) should in all cases be understood to be modified by the term “approximately,” regardless of whether “approximately” actually precedes the numerical value. “Approximately” indicates that the stated numerical value allows for slight inaccuracies (some close to precision at that value; approximately or reasonably close to the value; approximate). If the inaccuracy provided by “approximately” is not understood in this common sense in the art, then “approximately” as used herein at least indicates a variation that can be produced by common methods of measuring and using these parameters. For example, “approximately” can include variations less than or equal to 10%, less than or equal to 5%, less than or equal to 4%, less than or equal to 3%, less than or equal to 2%, less than or equal to 1%, or less than or equal to 0.5%. Attached Figure Description

[0077] Figure 1 A molecular force field simulation diagram of the columnar aromatic bisphosphite ligand and 1,3-butadiene provided in one embodiment of the present invention. Detailed Implementation

[0078] The present invention will be further described below with reference to the embodiments. It should be noted that the following embodiments are provided for illustrative purposes only and do not constitute a limitation on the scope of protection of the present invention.

[0079] Unless otherwise specified, the raw materials, reagents, and methods used in the embodiments are all conventional raw materials, reagents, and methods in the art.

[0080] The phosphorus trichloride, n-hexane, triethylamine, p-phenylenedimethyl ether, boron trifluoride ethyl ether, etc. used in the examples were all purchased from companies such as Maclean's Reagent, Sinopharm Reagent, and Aladdin Reagent; trioxymethylene, methanol, etc. were respectively from Xuyang Group Xingtai Coal Chemical and Hebei Xuyang New Energy Co., Ltd.

[0081] Preparation Example 1: Preparation of all-methyl columnar aromatics [5]

[0082] In a 1000 mL round-bottom flask, 25.2 g of diphenyl ether (0.18 mol) and 400 mL of dichloromethane were added in sequence. The system was cooled to 0 °C and fully dissolved. Under N2 protection, 15.6 g of powdered trioxymethylene (0.54 mol) was slowly added. The system was kept at 0 °C and stirred for 60 min. Then, while keeping the temperature constant, 22.0 mL of boron trifluoride ether solution (0.18 mol) was slowly added dropwise to the system. After the addition was completed, stirring was continued and the solution turned dark green. Then, the system was quickly poured into 500 mL of methanol to quench the reaction. At room temperature, stirring produced a large amount of solid. After standing for 1-2 hours, the mixture was filtered. The filter cake was purified by column chromatography. After the product was desolventized, all-methyl columnar aromatic hydrocarbons were obtained. [5] The yield was about 25-35%.

[0083] Preparation Example 2: Preparation of bis(m-methoxyphosphine) chloride

[0084] In a 1000 mL round-bottom flask, a constant-pressure dropping funnel and a tail gas absorption device were set up. Phosphorus trichloride (13.7 g, 0.10 mol) and n-hexane (40 mL) were added sequentially. The system was cooled to 0 °C and, after complete dissolution, m-cresol (21.6 g, 0.20 mol) was slowly added dropwise under N2 protection and moisture-free conditions. The system was maintained at 0 °C, and stirring was continued for 60 min. Subsequently, the system was slowly heated to 65-70 °C, and the reaction was continued for 2-3 hours. The tail gas generated during the process was completely absorbed by passing it through a drying tube and then through a 30% sodium hydroxide solution. The solvent and the generated hydrogen chloride were removed by vacuum distillation. An oily liquid was obtained, which was used directly in the next reaction without purification.

[0085] Example 1 Preparation of column [5] aromatic bisphosphite (compound P5-P)

[0086]

[0087] Step 1: In a 1000 mL round-bottom flask, place a magnetic stir bar, add 400 mL of dichloromethane, and add the permethyl columnar [5] aromatic hydrocarbon (15.0 g, 20.0 mmol) obtained in Preparation Example 1. Stir thoroughly until completely dissolved. Then add cerium ammonium nitrate (22 g, 40.0 mmol) and add 10 mL of water to promote the dissolution of cerium ammonium nitrate and ensure full contact with the permethyl columnar [5] aromatic hydrocarbon. Stir the mixture at room temperature for 20-40 minutes. Quench the reaction by adding 200 mL of water. Separate the organic layer, wash the organic phase three times with saturated brine and deionized water, and then concentrate and desolvent to obtain a dark red solid (12.0 g). The crude product can be used directly in the next step of the reaction without purification.

[0088] Step 2: In a 1000mL round-bottom flask, place a magnetic stir bar, a constant-pressure dropping funnel, and a nitrogen protection device. Dissolve the crude product obtained in the previous step in 200mL of dichloromethane and add it to the reaction flask. Add a solution of sodium hyposulfite (20g, 115mmol) in 200mL of water to the constant-pressure dropping funnel. Purge with nitrogen, then slowly add sodium hyposulfite dropwise to the reaction flask, carefully controlling the reaction temperature and maintaining it at room temperature until the addition is complete. After the addition is finished, observe that the red solution turns colorless. Continue stirring at room temperature for 2 hours. Separate the liquid and wash the organic phase three times with water. After solvent removal from the organic phase, freeze-dry to remove water, yielding a pale yellow solid (12.0g). The crude product can be used directly in the next reaction without purification.

[0089] Step 3: In a 1000 mL round-bottom flask, place a magnetic stir bar, a thermometer, a constant-pressure dropping funnel, and a nitrogen protection device. Set up an ice bath. Add the crude product obtained in the previous step to the reaction flask, along with 200 mL of anhydrous cyclohexane and 4 g of freshly distilled triethylamine. Stir thoroughly until dispersed. Add 50 mL of a cyclohexane solution of 14 g of bis(m-methoxyphosphoryl chloride) obtained in Preparation Example 2 to the constant-pressure dropping funnel. Replace with nitrogen and cool the system to -5 °C. Then, slowly add the bis(m-methoxyphosphoryl chloride) dropwise to the reaction flask, carefully controlling the reaction temperature and maintaining it at -5 °C. After the addition is complete, slowly raise the temperature to room temperature. Filter the salt generated in the reaction. Wash the filter cake three times with cyclohexane. Combine the filtrates, concentrate, and remove solvent to obtain a light yellow amorphous solid (10.0 g), namely compound P5-P. ESI-MS: 1211.4 ([M+H)). + ), 1H-NMR (400MHz, CDCl3, 298K) δ (ppm): 6.97 (s, 4H), 6.87 (s, 2H), 6.80 (d, 4H), 6.74 (s, 2H), 6.70 (s, 2H), 6.67-6.63 (m, 8H),6.55(s,2H),5.92(s,2H),3.92–3.71(m,10H),3.69(d,6H),3.57(s,6H),3.38(s,6H),3.30(s,6H),2.26(s,12H).

[0090] Other multi-substituted byproducts are insoluble in cyclohexane. Filtration has already removed the byproducts generated in the reaction. Therefore, the product does not require further purification and can be used directly to prepare catalysts.

[0091] Example 2: Preparation of a catalyst containing columnar[5] aromatic bisphosphite (compound P5-P)

[0092] In a 10 mL microwave-safe reaction tube, a magnetic stir bar was placed, and 3.0 g of compound P5-P obtained in Example 1, 0.22 g of nickel powder, and 3 g of 3PN were added as a solvent. The mixture was purged with nitrogen and placed in a microwave reactor. The reactor was heated at 800 W for 30 min, or stirred in an oil bath at 140-150 °C for 12 hours. After cooling to room temperature, the upper oily liquid was removed, which is the catalyst. Unreacted, excess Ni powder precipitated at the bottom of the reaction tube.

[0093] Application Example 1: A catalyst containing columnar[5] aromatic bisphosphite (compound P5-P) was used for the hydrocyanation of butadiene.

[0094] In a 100 mL reactor of 316 L capacity, equipped with a pressure gauge, thermometer, stirrer, nitrogen purging, and hydrogen cyanide inlet, 3.0 g of the catalyst obtained in Example 2 was added. After nitrogen purging, liquid 1,3-butadiene (30 g) and hydrogen cyanide (7.5 g) were introduced at low temperature. The reactor was sealed, and the system was heated to 90 °C. The reaction was carried out for 1-2 hours. After the reaction was complete, the hydrogen cyanide content in the nitrogen gas was checked and found to be below 200 ppm. The reactor was then cooled and opened. GC analysis was performed on the product. The conversion rate of 1,3-butadiene was 51%, the combined conversion rate of 3PN and 4PN was 93%, the proportion of 2M3BN was approximately 4%, the proportion of adiponitrile was 1.6%, and the proportion of other impurities was 1.4%.

[0095] Application Example 2: A catalyst containing columnar[5] aromatic bisphosphite (compound P5-P) was used for the hydrocyanation of 1-hepten.

[0096] In a 100 mL reaction vessel of 316 L, 54.4 g of 1-heptene and 7.5 g of hydrogen cyanide were added, following the same procedure as in Application Example 1. The product was analyzed by GC. The conversion rate of 1-heptene was 42%, and the ratio of 1-octanilide to 1-methyl-1-heptanilide was 93:7.

[0097] Application Example 3: A catalyst containing columnar[5] aromatic bisphosphite (compound P5-P) was used for the hydrocyanation of methyl 10-undecenoate.

[0098] In a 100 mL reactor of 316 L capacity, 1.0 g of the catalyst obtained in Example 2, methyl 10-undecenoate (36.7 g), and hydrogen cyanide (2.5 g) were added, and the procedure was the same as in Application Example 1. The products were analyzed by GC. The conversion rate of methyl 10-undecenoate was 50%, the linear product methyl 11-cyano-undecenoate accounted for 96%, the branched product methyl 10-cyano-undecenoate accounted for 2.5%, and the remainder were other byproducts.

[0099] Comparative Application Example 1: Catalysts containing tri-m-methoxyphosphite ligands for the hydrocyanation of butadiene

[0100] In this comparative example, the preparation of tri-methoxyphosphite was carried out in accordance with the method of GM Kosolapoff, "Organophosphorus Compounds," John Wiley and Sons, Inc., New York, NY, 1950, p184.

[0101] The catalyst was prepared in the same way as in Example 2, except that 3g of 3PN, 1.75g ​​of tri-m-methoxyphosphite, and 0.20g of Ni powder were added. After the reaction was completed, the excess nickel powder was filtered off to obtain the catalyst liquid (NiL4, where L is tri-m-methoxyphosphite).

[0102] In a 100 mL reactor of 316 L capacity, equipped with a pressure gauge, thermometer, stirrer, nitrogen purging system, and hydrogen cyanide inlet, 3.0 g of the catalyst prepared in the previous step was added. After nitrogen purging, liquid 1,3-butadiene (30 g) and hydrogen cyanide (7.5 g) were introduced at low temperature. The reactor was then sealed, and the system was heated to 90 °C. The reaction was carried out for 1-2 hours. After the reaction was completed, the hydrogen cyanide content in the nitrogen gas was measured to be below 200 ppm. The reactor was then cooled, opened, and the product was analyzed by GC. The conversion rate of 1,3-butadiene was 50%, the combined conversion rate of 4PN and 3PN was 77%, the proportion of 2M3BN was approximately 20%, and the proportion of other impurities was 3.0%.

[0103] Comparative Application Example 2: A catalyst containing a tetra-tert-butylcalix[4] aromatic modified phosphite ligand C4-P for the hydrocyanation of butadiene.

[0104]

[0105] The preparation method of C4-P is the same as in Example 1. The difference is in the third step. In a 1000 mL round-bottom flask, a magnetic flask is placed, along with a thermometer, a constant pressure dropping funnel and a nitrogen protection device. An ice bath is set up. 11 g (17 mmol) of tetra-tert-butylcalix[4] aromatic hydrocarbon (purchased from Aladdin Reagent Co., Ltd.) is added to the reaction flask, along with 200 mL of anhydrous cyclohexane and 4.0 g of freshly distilled triethylamine. The mixture is stirred thoroughly until dispersed. 50 mL of cyclohexane solution of 14 g of bis(m-methoxyphosphoryl chloride) is added to the constant pressure dropping funnel. Nitrogen purging was performed, and the system was cooled to -5°C. Then, bis(m-methoxyphosphoryl chloride) was slowly added dropwise to the reaction flask, carefully controlling the reaction temperature and maintaining it at -5°C. After the addition was complete, the temperature was slowly raised to room temperature. The resulting salt was filtered, and the filter cake was washed three times with cyclohexane. The filtrates were combined, concentrated, and dissolved to obtain a pale yellow amorphous solid (10.0 g), namely compound C4-P. ESI-MS: 1137.3 ([M+H)). + ), 1159.3([M+Na] + ); 1 H-NMR (400MHz, CDCl3, 298K) δ (ppm): 7.91 (2H, s), 6.98 (4H, m), 6.85-6.65 (20H, m), 4 .42(4H,d,J=13.1),3.38(4H,d,J=13.1),2.25(12H,s),1.41(18H,s),1.26(18H,s).

[0106] The catalyst was prepared in the same way as in Example 2, except that 3g of 3PN, 3.0g of C4-P, and 0.22g of Ni powder were added. After the reaction was completed, the excess nickel powder was filtered off to obtain the catalyst liquid.

[0107] In a 100 mL reactor of 316 L capacity, equipped with a pressure gauge, thermometer, stirrer, nitrogen purging system, and hydrogen cyanide inlet, 3.0 g of the catalyst prepared in the previous step was added. After nitrogen purging, liquid 1,3-butadiene (30 g) and hydrogen cyanide (7.5 g) were introduced at low temperature. The reactor was sealed, and the system was heated to 90 °C. The reaction was allowed to proceed for 3-4 hours. Monitoring showed that the hydrogen cyanide had not reacted completely, so the reaction was terminated. The reactor was cooled, and nitrogen was purged until the hydrogen cyanide content in the tail gas was below 200 ppm. The reactor was then opened, and the product was analyzed using GC. The conversion rate of 1,3-butadiene was 22.0%, the combined percentage of 4PN and 3PN was 38.7%, the proportion of 2M3BN was approximately 35.0%, and the proportion of other impurities was 26.3%.

[0108] As can be seen from the above, the columnar aromatic hydrocarbon-phosphite derivatives used in this invention and the catalysts prepared therefrom can efficiently catalyze the linear addition of butadiene to obtain 3PN and 4PN. Compared with the catalyst system currently widely reported in Comparative Application Example 1 and the catalyst with calixar aromatic hydrocarbon-modified phosphite ligands in Comparative Application Example 2, the selectivity and product distribution are significantly improved.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A columnar aromatic bisphosphite ligand of formula I, （I）， in: R is selected from C1-C12 alkyl groups; n is 4, 5, 6, 7, 8, 9; X1 and X2 are each independently selected from substituted or unsubstituted phenoxy, substituted or unsubstituted naphthoxy, C1-C6 alkoxy, benzyloxy, wherein the substitution means being substituted by one or more substituents selected from C1-C4 alkyl, C1-C4 alkoxy.

2. The columnar aromatic bisphosphite ligand according to claim 1, characterized in that, R is a C1-C6 alkyl group.

3. The columnar aromatic bisphosphite ligand according to claim 1, characterized in that, R stands for methyl.

4. The columnar aromatic bisphosphite ligand according to claim 1, characterized in that, X1 and X2 are each independently selected from phenoxy, o-tolyloxy, m-tolyloxy, p-tolyloxy, 2,4-dimethyltolyloxy, 2,4,6-trimethyltolyloxy, 4-tert-butylphenoxy, 2,4-di-tert-butylphenoxy, 2,4,6-tri-tert-butylphenoxy, 1-naphthylmethoxy, and 2-naphthylmethoxy.

5. The columnar aromatic bisphosphite ligand according to claim 1, characterized in that, X1 and X2 are each independently selected from phenoxy, m-tolyloxy, and p-tolyloxy.

6. The columnar aromatic bisphosphite ligand according to any one of claims 1-5, characterized in that, n is 4.

7. The columnar aromatic bisphosphite ligand according to claim 1, characterized in that, n is 4, and X1 and X2 are m-tolyloxy groups.

8. A method for preparing the columnar aromatic bisphosphite ligand according to any one of claims 1-7, characterized in that, The method includes the following steps: Compound 3 undergoes a substitution reaction with phosphorous chloride X1X2PCl to obtain the columnar aromatic bisphosphite ligand of formula I; wherein X1, X2, R, and n are defined as in the corresponding claims.

9. The preparation method according to claim 8, characterized in that, The substitution reaction is carried out in an organic solvent in the presence of an acid-binding agent.

10. The preparation method according to claim 9, characterized in that, The organic solvent is selected from one or more of dichloromethane, chloroform, cyclohexane, n-hexane, petroleum ether, acetonitrile, tetrahydrofuran, and methyltetrahydrofuran.

11. The preparation method according to claim 9, characterized in that, The organic solvent is selected from n-hexane and cyclohexane.

12. The preparation method according to claim 9, characterized in that, The acid-binding agent is selected from one or more of triethylamine, diisopropylethylamine, N-methylmorpholine, potassium carbonate, and sodium carbonate.

13. The preparation method according to claim 9, characterized in that, The acid-binding agent is triethylamine.

14. The preparation method according to claim 8, characterized in that, The molar ratio of phosphorous chloride X1X2PCl to compound 3 is 2:1 to 10:

1.

15. The preparation method according to claim 8, characterized in that, The molar ratio of phosphorous chloride X1X2PCl to compound 3 is 2.5:

1.

16. The preparation method according to claim 8, characterized in that, The temperature for the substitution reaction is -5℃ to 0℃, and the reaction time is 2 to 3 hours.

17. The preparation method according to claim 8, characterized in that, Compound 3 was prepared by the following method, The method includes the following steps: S1: Compound 1 undergoes an oxidation reaction to yield compound 2; S2: Compound 2 undergoes a reduction reaction to give compound 3.

18. The preparation method according to claim 17, characterized in that, Step S1 is carried out in an organic solvent in the presence of an oxidizing agent.

19. The preparation method according to claim 18, characterized in that, The organic solvent is selected from one or more of chloroform, dichloromethane, tetrahydrofuran, methyltetrahydrofuran, petroleum ether, cyclohexane, n-hexane, benzene, and toluene.

20. The preparation method according to claim 18, characterized in that, The organic solvent is dichloromethane.

21. The preparation method according to claim 18, characterized in that, The oxidant is selected from one or more of sodium persulfate, sodium perchlorate, sodium periodate, ammonium pyrosulfate, hydrogen peroxide, ozone, cerium ammonium nitrate, and pyridine-chromium trioxide.

22. The preparation method according to claim 18, characterized in that, The oxidant is cerium ammonium nitrate.

23. The preparation method according to claim 18, characterized in that, The mass ratio of compound 1 to organic solvent is 1:1 to 1:

50.

24. The preparation method according to claim 18, characterized in that, The mass ratio of compound 1 to the organic solvent is 1:

5.

25. The preparation method according to claim 18, characterized in that, The molar ratio of oxidant to compound 1 is 1:1 to 10:

1.

26. The preparation method according to claim 18, characterized in that, The molar ratio of oxidant to compound 1 is 2:

1.

27. The preparation method according to claim 18, characterized in that, The oxidation reaction temperature is 0~60 ℃; the oxidation reaction time is 1~100 minutes.

28. The preparation method according to claim 18, characterized in that, The oxidation reaction temperature is 20~30 ℃; the oxidation reaction time is 20~30 minutes.

29. The preparation method according to claim 17, characterized in that, Step S2 is carried out in an organic solvent in the presence of a reducing agent.

30. The preparation method according to claim 29, characterized in that, The organic solvent is selected from one or more of chloroform, dichloromethane, tetrahydrofuran, methyltetrahydrofuran, petroleum ether, cyclohexane, n-hexane, benzene, and toluene.

31. The preparation method according to claim 29, characterized in that, The organic solvent is dichloromethane.

32. The preparation method according to claim 29, characterized in that, The reducing agent is selected from one or more of sodium borohydride, lithium aluminum hydride, sodium sulfide, sodium hydrosulfide, sodium disulfide, sodium dithionite, formaldehyde solution, formic acid, hydroxylamine hydrochloride, hydroxylamine sulfate, and DIBAL-H.

33. The preparation method according to claim 29, characterized in that, The reducing agent is sodium dithionite.

34. The preparation method according to claim 29, characterized in that, The mass ratio of compound 2 to organic solvent is 1:1 to 1:

50.

35. The preparation method according to claim 29, characterized in that, The mass ratio of compound 2 to the organic solvent is 1:

5.

36. The preparation method according to claim 29, characterized in that, The molar ratio of compound 2 to reducing agent is 1:2 to 1:

10.

37. The preparation method according to claim 29, characterized in that, The molar ratio of compound 2 to the reducing agent is 1:

5.

38. The preparation method according to claim 17, characterized in that, The reduction reaction temperature is 0~60 ℃; the reduction reaction time is 1~24 hours.

39. The preparation method according to claim 17, characterized in that, The reduction reaction temperature is 20~30 ℃; the reduction reaction time is 8~10 hours.

40. A catalyst, characterized in that, The catalyst comprises the columnar aromatic bisphosphite ligand as described in any one of claims 1-7 and nickel atoms bonded to the columnar aromatic bisphosphite ligand.

41. A method for preparing a catalyst, characterized in that, Includes the following steps: The catalyst is obtained by reacting the columnar aromatic bisphosphite ligand according to any one of claims 1-3 with nickel under anhydrous and oxygen-free conditions.

42. The preparation method according to claim 41, characterized in that, The molar amount of nickel is 1.5 to 2.0 times that of the columnar aromatic bisphosphite ligand.

43. The use of the catalyst according to claim 40 in the hydrocyanation reaction of olefins.

44. The application according to claim 43, characterized in that, The application includes: hydrocyanation of olefins with hydrogen cyanide in the presence of the catalyst.

45. The application according to claim 44, characterized in that, The olefins are selected from one or more of 1,3-butadiene, propylene, isoprene, 1,3-pentadiene, n-butene, C4 and C5 mixed olefins, oleic acid and its methyl esters.

46. ​​The application according to claim 44, characterized in that, The molar ratio of hydrocyanic acid to alkenes is 1:0.5-10.

47. The application according to claim 44, characterized in that, The molar ratio of hydrocyanic acid to alkenes is 1:

2.

48. The application according to claim 44, characterized in that, The amount of catalyst used is 1% to 20% of the reactants.

49. The application according to claim 44, characterized in that, The amount of catalyst used is 10% to 15% of the reactants.

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