CN114854005B - A kind of method of synthesizing polyamide by carbonylation of olefin hydroamine - Google Patents

Abstract

The invention discloses a method for synthesizing polyamide by olefin hydroamine carbonylation, which realizes the diversity synthesis of polyamide in one step through olefin relay hydroamine carbonylation process under the combined action of palladium catalyst, ligand and alkali. The invention provides a novel method for preparing polyamide, which has the advantages of simple and easily obtained raw materials, low price, simple operation and wide application, and can simultaneously realize the preparation of aromatic polyamide and aliphatic polyamide.

Description

A kind of method that polyamide is synthesized by carbonylation of olefin hydroamine

technical field

The invention belongs to the technical field of polyamide, and relates to a novel catalytic synthesis method for preparing polyamide.

Background technique

As a kind of polymer compound with wide range of uses, polyamide has good comprehensive properties, including mechanical properties, heat resistance, wear resistance, chemical resistance and self-lubrication, and has low friction coefficient and certain flame retardancy. Non-toxic, easy to process, suitable for glass fiber and other filler filling reinforcement modification, improving performance and expanding application range. Therefore, it is of great significance to develop a novel and efficient catalytic method to realize the synthesis of different types of polyamides.

At present, polyamides are mainly synthesized by polycondensation, ring-opening polymerization of lactams, carbonylation of amines, and catalytic dehydrogenation of alcohols. Wherein, the monomers of the polycondensation reaction can be amino acids, diamines, dicarboxylic acids and derivatives thereof (CN112920400A, CN114349956A, CN114349956A, CN114369238A, etc.). It is worth noting that in this type of reaction, carboxylic acids usually need to be pre-activated to form acid chlorides or esters. The reaction conditions are harsh and accompanied by the production of stoichiometric toxic waste, which is not friendly to the environment.

Amino Acid Polycondensation:

Polycondensation of diamine and dicarboxylic acid:

Lactams are also commonly used as monomers to prepare polyamides through ring-opening polymerization. The industry mainly includes hydrolysis ring-opening polymerization (CN103772643A, CN104327266A, CN104629044A, etc.) The hydrolytic ring-opening polymerization method uses water as an initiator, and the relative molecular weight distribution of the obtained product is relatively narrow, so it is widely used, but this method requires a higher polymerization temperature and a longer reaction time. The anionic ring-opening polymerization method needs to add a strong base as an initiator. The temperature required for this reaction is relatively low and the reaction speed is fast. The distribution fluctuates greatly and produces more by-products.

Lactam ring-opening polymerization:

In addition, palladium-catalyzed amine carbonylation of aromatic dihalides as an amide synthesis method can also be used to prepare polyamides. Since the 1980s, palladium-catalyzed carbonylation polycondensation of aromatic dihalides, aromatic diamines, and carbon monoxide to synthesize polyamides has been extensively studied (Macromolecules 1988,21,1908–1911; Polymer Chemistry 1989,27, 1985-1992; Polymer Chemistry 1994, 32, 2065-2071; Polymer Bulletin 2020, 77, 1951–1968). The method uses carbon monoxide as a cheap and easy-to-obtain carbon source, and the raw materials are simple and easy to obtain, the reaction conditions are mild, and the environment is hardly polluted. However, this type of reaction usually requires the addition of a large amount of ligands to inhibit the formation of palladium black, and the scope of substrate application is relatively small, so only aromatic polyamides can be synthesized.

Palladium-catalyzed amine carbonylation polycondensation of aromatic dihalides:

Recently, Guan and Milstein et al. reported a new method for the direct synthesis of polyamides by catalytic dehydrogenation using Milstein catalysts (J.Am.Chem.Soc. 2011, 133, 1159–1161; Polymer Chemistry 2012, 50, 1755–1765) . The method uses diols and diamines as raw materials, and not only aromatic polyamides but also aliphatic polyamides can be synthesized. However, this type of catalyst is sensitive to oxygen and the reaction conditions are relatively harsh.

Catalytic dehydrogenation of diols and diamines:

In the previous research work, our research group developed a palladium-catalyzed hydrogenoamine carbonylation reaction of simple alkenes and hydroxylamine hydrochloride. This reaction system has high atom utilization, good selectivity, strong substrate adaptability, and can realize a series of secondary amides Efficient synthesis of (Communications Chemistry 2019,2,14). On this basis, we assume that if starting from a symmetrical diene, the efficient synthesis of polyamides can be achieved through the relay hydrogenoamine carbonylation process. However, in order to achieve the above process, three key scientific issues must be solved: 1. The alkylpalladium intermediate produced by the insertion of olefins into palladium hydrogen species will continue to react with olefins and form polyolefin by-products through the migration insertion process; 2. The acyl palladium species produced by the insertion of carbon monoxide into the alkyl palladium intermediate will also continue to undergo migration and insertion with the olefin to form a by-product of polyketide; 3. Can the activity of the catalyst support the symmetrical diene substrate to complete the continuous relay hydrogen amine carbonylation process to achieve high-efficiency synthesis of polymer products. Therefore, how to regulate the catalytic reaction system to realize the specific and efficient preparation of polyamide is the key of the prior art.

Contents of the invention

The purpose of the present invention is to provide a novel synthetic method with simple process and low cost to prepare polyamide, using diene monomer, hydroxylamine hydrochloride and carbon monoxide as raw materials, under the joint action of palladium catalyst, ligand and alkali, through olefin Relay hydrogen amine carbonylation process, one-step realization of polyamide diversity synthesis. The method has simple and easy-to-obtain raw materials and low price, can realize the preparation of aromatic polyamide and aliphatic polyamide at the same time, and adopts a one-pot process, and has the advantages of simple operation and wide application.

The reaction scheme of the present invention is as follows:

Route 1:

Route 2:

In the formula, the substituent ^R1 is independently selected from H, straight or branched C1-C40 aliphatic groups, C4-C12 aromatic groups or heterocyclic groups.

In Route 1:

The palladium catalyst is selected from palladium chloride, palladium bromide, palladium iodide, palladium acetate, palladium trifluoroacetate, palladium acetylacetonate, diacetonitrile palladium chloride, bis-tri-tert-butylphosphine palladium, allyl palladium chloride One or more of the palladium catalysts such as; preferably bisacetonitrile palladium chloride is the catalyst.

The ligand is selected from triphenylphosphine, benzyldiadamantylphosphine, dicyclohexyl-(2,6-diisopropylphenyl)phosphine, 2-(di-tert-butylphosphine)biphenyl, 2 -(Dicyclohexylphosphino)biphenyl, 2-dicyclohexylphosphine-2'6'-bis(N,N-dimethylamino)-1,1'-biphenyl, 2-dicyclohexylphosphine- One of the monophosphine ligands such as 2',6'-diisopropoxy-1,1'-biphenyl and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl One or more; preferably 2-dicyclohexylphosphine-2',6'-diisopropoxy-1,1'-biphenyl is the ligand.

In route 2:

The palladium catalyst is selected from palladium chloride, palladium bromide, palladium iodide, palladium acetate, palladium trifluoroacetate, palladium acetylacetonate, diacetonitrile palladium chloride, bis-tri-tert-butylphosphine palladium, allyl palladium chloride One or more of palladium catalysts such as; preferably allyl palladium chloride is a catalyst.

The ligand is selected from 4,5-bisdiphenylphosphine-9,9-dimethylxanthene, 1,1'-bis(diphenylphosphino)ferrocene, bis(2-diphenyl Phosphophenyl) ether, 1,2-bis(di-tert-butylphosphinomethyl)benzene, 1,3-bis(dimethylcyclopentaphosphino)benzene, 4,6-bis(diphenylphosphine)phen One or more of bisphosphine ligands such as oxazine, bisdiphenylphosphinemethane, 1,4-bis(diphenylphosphine)butane; preferably 4,5-bisdiphenylphosphine-9,9- Dimethylxanthene as a ligand.

Specifically include the following steps:

Add diene monomer, hydroxylamine hydrochloride, palladium catalyst, ligand, alkali additive and solvent to the reaction kettle in sequence, then replace the air in the kettle with carbon monoxide three times and fill it with carbon monoxide at a certain pressure, heat it to the set temperature and react for a certain period of time After the reaction, the carbon monoxide in the autoclave is slowly released after the autoclave is cooled, the reaction solution is poured into methanol, the mixture is centrifuged to obtain a crude product, and then washed with methanol and water in sequence, and vacuum-dried to obtain a polyamide product.

The diene monomer is selected from at least one of the following structural compounds:

The substituents R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are independently selected from H, straight-chain or branched C1-C40 aliphatic groups, C4-C12 aromatic groups or heterocyclic groups; m ¹ , m ² , m ³ , and m ⁴ represent chain lengths, each independently taking a value from 1 to 20.

The base is selected from sodium acetate, sodium phosphate, sodium benzoate, potassium acetate, potassium phosphate, triethylamine, N,N-diisopropylethylamine, 1,8-diazobispiro[5.4.0 ] one or more of undec-7-ene, triethylenediamine, pyridine, 4-dimethylaminopyridine, 2-cyano-6-picoline, etc. 2-Cyano-6-picoline is preferred as the base.

The solvent is selected from one or more of anisole, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and the like. Anisole or N-methylpyrrolidone is preferred as the solvent.

In the preparation process of the present invention, the reaction temperature is generally controlled at 100-200°C, preferably 120°C; the reaction time is generally controlled at 12-72 hours, preferably 24 hours.

During the preparation process of the present invention, the carbon monoxide pressure is generally controlled at 10-60 atm, preferably 20 atm.

In the preparation process of the present invention, the molar ratio of the diene monomer to the hydroxylamine hydrochloride is 1.5:1-1:1.5. Preferably 1.2:1.

Compared with the prior art, the beneficial effects of the present invention are reflected in:

1. The present invention directly utilizes diene, hydroxylamine hydrochloride and carbon monoxide as reactants, and the raw materials are simple, cheap and readily available.

2. The present invention adopts a one-pot process, which can convert dienes into corresponding polyamide compounds in one step, without additional steps such as preactivation, and the steps are economical and environmentally friendly.

3. The present invention is not only capable of preparing aromatic polyamides, but is also applicable to the synthesis of aliphatic polyamides. The substrate has a wide range of applications and strong practicability.

Description of drawings

Figure 1 is the infrared characteristic absorption peak of polyamide.

Detailed ways

The present invention will be further described by the given examples below. It should be noted that the present invention is not limited to these examples.

Embodiment 1: do not add alkali as additive

Aryldiene (213.1 mg), hydroxylamine hydrochloride (55.6 mg), bisacetonitrile palladium(II) chloride (10.4 mg), 2-dicyclohexylphosphine-2',6' were sequentially added to a strictly dried ampoule - Diisopropoxy-1,1'-biphenyl (41.1 mg) and anisole (2.0 mL). Put the ampoule bottle into the autoclave, replace the air in the autoclave with carbon monoxide three times and fill with 20atm carbon monoxide, heat to 120°C for 24 hours. After the autoclave was cooled, the carbon monoxide in the autoclave was slowly released. The reaction solution was poured into methanol, and the mixture was centrifuged to obtain a crude product, followed by washing with methanol and water in sequence, and vacuum drying to obtain a polyamide product with a yield of 11%.

Example 2: 2-cyano-6-picoline as base

Aryldiene (213.1 mg), hydroxylamine hydrochloride (55.6 mg), bisacetonitrile palladium(II) chloride (10.4 mg), 2-dicyclohexylphosphine-2',6' were sequentially added to a strictly dried ampoule - Diisopropoxy-1,1'-biphenyl (41.1 mg), 6-methyl-2-pyridinecarbonitrile (18.9 mg) and anisole (2.0 mL). Put the ampoule bottle into the autoclave, replace the air in the autoclave with carbon monoxide three times and fill with 20atm carbon monoxide, heat to 120°C for 24 hours. After the autoclave was cooled, the carbon monoxide in the autoclave was slowly released. The reaction solution was poured into methanol, and the mixture was centrifuged to obtain a crude product, which was washed successively with methanol and water, and vacuum-dried to obtain a polyamide product with a yield of 62%, a number-average molecular weight of 3.1×10 ⁴ , and a polymer dispersion of The index was 1.84.

Example 3: Preparation of polyamide from aryl diene

Aryldiene (240.1 mg), hydroxylamine hydrochloride (34.7 mg), bisacetonitrile palladium(II) chloride (6.5 mg), 2-dicyclohexylphosphine-2',6' were sequentially added to a strictly dried ampoule - Diisopropoxy-1,1'-biphenyl (25.7 mg) and N-methylpyrrolidone (4.0 mL). Put the ampoule bottle into the autoclave, replace the air in the autoclave with carbon monoxide three times and fill with 20atm carbon monoxide, heat to 120°C for 12 hours. After the autoclave was cooled, the carbon monoxide in the autoclave was slowly released. The reaction solution was poured into methanol, and the mixture was centrifuged to obtain a crude product, which was washed successively with methanol and water, and vacuum-dried to obtain a polyamide product with a yield of 73%, a number-average molecular weight of 9×10 ³ , and a polymer dispersion of The index was 3.79.

Example 4: Preparation of polyamide from triaryl dienes

Aryldiene (410.6 mg), hydroxylamine hydrochloride (34.7 mg), bisacetonitrile palladium(II) chloride (6.5 mg), 2-dicyclohexylphosphine-2',6' were sequentially added to a strictly dried ampoule - Diisopropoxy-1,1'-biphenyl (25.7 mg) and N-methylpyrrolidone (4.0 mL). Put the ampoule bottle into the autoclave, replace the air in the autoclave with carbon monoxide three times and fill with 20atm carbon monoxide, heat to 120°C for 12 hours. After the autoclave was cooled, the carbon monoxide in the autoclave was slowly released. The reaction solution was poured into methanol, and the mixture was centrifuged to obtain a crude product, which was washed successively with methanol and water, and vacuum-dried to obtain a polyamide product with a yield of 80%, a number-average molecular weight of 1.8×10 ⁴ , and a polymer dispersion of The index was 4.40.

Example 5: Preparation of polyamide from aryl diene

Aryldiene (405.8 mg), hydroxylamine hydrochloride (34.7 mg), bisacetonitrile palladium(II) chloride (6.5 mg), 2-dicyclohexylphosphine-2',6' were sequentially added to a strictly dried ampoule - Diisopropoxy-1,1'-biphenyl (25.7 mg) and N-methylpyrrolidone (4.0 mL). Put the ampoule bottle into the autoclave, replace the air in the autoclave with carbon monoxide three times and fill with 20atm carbon monoxide, heat to 120°C for 12 hours. After the autoclave was cooled, the carbon monoxide in the autoclave was slowly released. The reaction solution was poured into methanol, and the mixture was centrifuged to obtain a crude product, which was washed successively with methanol and water, and vacuum-dried to obtain a polyamide product with a yield of 78%, a number average molecular weight of 8.4×10 ⁴ , and a polymer dispersion of The index is 2.58.

Example 6: Preparation of polyamide from aryl fluorene diene

Aryldiene (424.7 mg), hydroxylamine hydrochloride (55.6 mg), diacetonitrile palladium(II) chloride (10.4 mg), 2-dicyclohexylphosphine-2',6' were sequentially added to a strictly dried ampoule - Diisopropoxy-1,1'-biphenyl (41.1 mg), 6-methyl-2-pyridinecarbonitrile (18.9 mg) and anisole (2.0 mL). Put the ampoule bottle into the autoclave, replace the air in the autoclave with carbon monoxide three times and fill with 20atm carbon monoxide, heat to 120°C for 24 hours. After the autoclave was cooled, the carbon monoxide in the autoclave was slowly released. The reaction solution was poured into methanol, and the mixture was centrifuged to obtain a crude product, which was washed successively with methanol and water, and vacuum-dried to obtain a polyamide product with a yield of 76%, a number-average molecular weight of 6.4×10 ³ , and a polymer dispersion of The index was 3.06.

Embodiment 7: Norbornene prepares polyamide

Add allylpalladium(II) chloride (4.6mg), 4,5-bisdiphenylphosphine-9,9-dimethylxanthene (17.4mg), hydroxylamine hydrochloride successively to a strictly dry ampoule (34.7mg), norbornene (184.1mg) and anisole (4.0mL), put the ampoule bottle into the autoclave, replace the air in the autoclave with carbon monoxide three times and fill with 20atm carbon monoxide, heat to 140°C for 24 hours. After the autoclave was cooled, the carbon monoxide in the autoclave was slowly released. The reaction solution was poured into methanol, and the mixture was centrifuged to obtain a crude product, which was washed successively with methanol and water, and vacuum-dried to obtain a polyamide product with a yield of 54%, a number-average molecular weight of 6.2×10 ³ , and a polymer dispersion of The index was 5.23.

Example 8: Preparation of polyamides from quaternary carbon-linked alkyl dienes

Add allylpalladium(II) chloride (4.6mg), 4,5-bisdiphenylphosphine-9,9-dimethylxanthene (17.4mg), hydroxylamine hydrochloride successively to a strictly dry ampoule (34.7mg), alkyl diene (336.4mg), 6-methyl-2-pyridinenitrile (11.8mg) and anisole (4.0mL), put the ampoule in the autoclave, and replace the air in the autoclave with carbon monoxide Three times and filled with 20atm carbon monoxide, heated to 120°C for 24 hours. After the autoclave was cooled, the carbon monoxide in the autoclave was slowly released. The reaction solution was poured into methanol, and the mixture was centrifuged to obtain a crude product, which was washed successively with methanol and water, and vacuum-dried to obtain a polyamide product with a yield of 58%, a number-average molecular weight of 1.3×10 ³ , and a polymer dispersion of The index was 1.64.

Example 9: Preparation of polyamide from 1,7-octadiene

Add allylpalladium(II) chloride (4.6mg), 4,5-bisdiphenylphosphine-9,9-dimethylxanthene (17.4mg), hydroxylamine hydrochloride successively to a strictly dry ampoule (34.7mg), 1,7-octadiene (220.2mg), 6-methyl-2-pyridinecarbonitrile (11.8mg) and anisole (4.0mL), put the ampoule in the autoclave, and replace with carbon monoxide The kettle was aired three times and filled with 20atm carbon monoxide, heated to 120°C for 24 hours. After the autoclave was cooled, the carbon monoxide in the autoclave was slowly released. The reaction solution was poured into methanol, and the mixture was centrifuged to obtain a crude product, which was washed successively with methanol and water, and vacuum-dried to obtain a polyamide product with a yield of 66%, a number-average molecular weight of 2.4×10 ³ , and a polymer dispersion of The index is 1.00.

Example 10: Preparation of polyamide from 1,3-butadiene

Add allylpalladium(II) chloride (7.3mg), 4,5-bisdiphenylphosphine-9,9-dimethylxanthene (27.8mg), hydroxylamine hydrochloride in sequence to a strictly dry ampoule (55.6mg), 1,3-butadiene (1.0mL, 2.8mol/Linanisole), 6-methyl-2-pyridinecarbonitrile (11.8mg) and anisole (2.0mL), put the ampoule into high pressure In the kettle, carbon monoxide replaced the air in the kettle three times and filled with 20atm carbon monoxide, heated to 140°C for 24 hours. After the autoclave was cooled, the carbon monoxide in the autoclave was slowly released. The reaction solution was poured into methanol, and the mixture was centrifuged to obtain a crude product, which was washed successively with methanol and water, and vacuum-dried to obtain a polyamide product with a yield of 61%, a number-average molecular weight of 3.1×10 ³ , and a polymer dispersion of The index is 2.16.

It can be seen from the above examples that the catalytic synthesis method for preparing polyamide provided by the present invention has cheap and easy-to-obtain raw materials, simple synthesis process, and can simultaneously realize the preparation of aromatic polyamide and aliphatic polyamide. The invention not only provides new ideas and techniques for the preparation of polyamides, but also promotes the diversity synthesis of functionalized polyamides.

The descriptions of the above examples are only used to help understand the method and core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (5)

1. A method for synthesizing polyamide by olefin hydroamine carbonylation is characterized in that:

taking a diene monomer, hydroxylamine hydrochloride and carbon monoxide as raw materials, and under the combined action of a palladium catalyst, a ligand and alkali, realizing the diversity synthesis of polyamide in one step through an alkene relay hydroamine carbonylation process, wherein the synthetic route is shown as a route 1 or a route 2;

route 1:

route 2:

in the formula (II) wherein R is a substituent ¹ Independently selected from H, straight chain or branched chain C1-C40 aliphatic group, C4-C12 aromatic group or heterocyclic group;

in the synthesis process, the pressure of the carbon monoxide is controlled to be 10-60 atm;

in scheme 1:

the palladium catalyst is selected from one or more of palladium chloride, palladium bromide, palladium iodide, palladium acetate, palladium trifluoroacetate, palladium acetylacetonate, bis-acetonitrile palladium chloride, bis-tri-tert-butylphosphine palladium and allyl palladium chloride;

the ligand is selected from one or more of triphenylphosphine, benzyldiadamantylphosphine, dicyclohexyl- (2, 6-diisopropylphenyl) phosphine, 2- (di-tert-butylphosphino) biphenyl, 2- (dicyclohexylphosphino) biphenyl, 2-dicyclohexylphosphine-2 '6' -bis (N, N-dimethylamino) -1,1' -biphenyl, 2-dicyclohexylphosphine-2 ',6' -diisopropoxy-1, 1' -biphenyl, and 2-dicyclohexylphosphine-2 ',4',6' -triisopropylbiphenyl monophosphine ligand;

in route 2:

the palladium catalyst is selected from one or more of palladium chloride, palladium bromide, palladium iodide, palladium acetate, palladium trifluoroacetate, palladium acetylacetonate, bis-acetonitrile palladium chloride, bis-tri-tert-butylphosphine palladium and allyl palladium chloride;

the ligand is selected from one or more of 4, 5-bis (diphenylphosphino) -9, 9-dimethyl xanthene, 1' -bis (diphenylphosphino) ferrocene, bis (2-diphenylphosphino) ether, 1, 2-bis (di-tert-butylphosphinomethyl) benzene, 1, 3-bis (dimethylcyclopentylphosphino) benzene, 4, 6-bis (diphenylphosphino) phenazine, bis (diphenylphosphinomethane) and 1, 4-bis (diphenylphosphino) butane diphosphine ligand;

the alkali is selected from one or more of sodium acetate, sodium phosphate, sodium benzoate, potassium acetate, potassium phosphate, triethylamine, N-diisopropylethylamine, 1, 8-diazohetero-bis-spiro [5.4.0] undec-7-ene, triethylene diamine, pyridine, 4-dimethylamino pyridine and 2-cyano-6-methyl pyridine;

the molar ratio of the diene monomer to the hydroxylamine hydrochloride is 1.5.

2. The method of claim 1, wherein:

the diene monomer is selected from at least one of the following structural compounds:

substituent R ² 、R ³ 、R ⁴ 、R ⁵ 、R ⁶ Independently selected from H, straight chain or branched chain C1-C40 aliphatic group, C4-C12 aromatic group or heterocyclic group; m is ¹ 、m ² 、m ³ 、m ⁴ Represents the chain length and independently takes a value of 1-20.

3. A method according to claim 1 or 2, characterized by comprising the steps of:

adding a diene monomer, hydroxylamine hydrochloride, a palladium catalyst, a ligand, an alkali additive and a solvent into a reaction kettle in sequence, replacing air in the kettle with carbon monoxide for three times, filling carbon monoxide with a certain pressure, and heating to a set temperature for reacting for a certain time; after the reaction is finished, slowly releasing carbon monoxide in the autoclave after the autoclave is cooled, pouring the reaction liquid into methanol, centrifugally separating the mixture to obtain a crude product, then washing the crude product with methanol and water in sequence, and drying the crude product in vacuum to obtain the polyamide product.

4. The method of claim 3, wherein:

the solvent is one or more selected from anisole, tetrahydrofuran, N-dimethylformamide, N-dimethylacetamide and N-methylpyrrolidone.

5. The method of claim 3, wherein:

the reaction temperature is controlled between 100 and 200 ℃, and the reaction time is controlled between 12 and 72 hours.

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