A method for preparing straight-chain aldehydes by hydroformylation of aqueous long-chain olefins catalyzed by Rh / porous polymers.

Abstract

A synthetic method for the hydroformylation of long-chain olefins in aqueous phase using Rh / porous polymer catalysis to prepare straight-chain aldehydes. The catalyst has the following general formula: [formula omitted]. The catalyst is obtained by reacting a compound with compounds [compounds omitted], [compounds omitted], and [compounds omitted]. The amphiphilic porous organic copolymer-supported rhodium metal catalyst provided by this invention can catalyze the hydroformylation of long-chain olefins in the aqueous phase to prepare straight-chain aldehyde products, exhibiting high activity, good yield, and recyclability, and has practical value.

Description

Technical Field

[0001] This invention relates to a method for the hydroformylation of long-chain olefins in aqueous phase using Rh / porous polymer catalysis to prepare straight-chain aldehydes. Specifically, it relates to the preparation and application of a class of Rh / porous polymer catalysts. This heterogeneous catalyst can efficiently catalyze the hydroformylation reaction of olefins in an aqueous phase, belonging to the field of organic chemistry technology. Technical Background

[0002] Hydroformylation of long-chain olefins is an important reaction for preparing fine chemical intermediates such as high-carbon aldehydes and high-carbon alcohols. Traditional homogeneous catalytic systems suffer from problems such as difficulty in separating and recovering rhodium catalysts and serious loss of precious metals. Aqueous / two-phase catalytic systems, using water-soluble rhodium-phosphine complexes as catalysts, have advantages such as easy separation of products and catalysts, environmental friendliness, and controllable costs, and have become the mainstream direction for green transformation. Currently, to address the bottlenecks of poor water solubility and high mass transfer resistance of long-chain olefins, strategies such as adding surfactants, designing amphiphilic phosphine ligands, introducing co-solvents, or constructing supported aqueous catalytic systems are mainly used to improve reaction efficiency. However, this technology still suffers from problems such as limited mass transfer at the phase interface, low reaction rate, easy aggregation and deactivation of rhodium active centers during cycling, easy oxidative degradation of ligands, and easy emulsification during phase separation, which restrict its industrial scale-up and long-term stable operation. Therefore, based on the above problems, this patent has successfully developed a rhodium / porous polymer catalyst. The unit structure of this support has both hydrophilic and lipophilic properties, so it can not only be dispersed in water, but also improve the solubility of long-chain olefins in water, thereby improving catalytic activity. Furthermore, by altering the ratio of the three monomers in the polymer, the hydrophilicity and lipophilicity of the polymer can be adjusted, avoiding emulsification problems during phase separation. Simultaneously, the high concentration of phosphine ligands in the polymer can suppress the loss and deactivation of the rhodium catalyst. Therefore, this catalyst exhibits high activity, good yield, and recyclability in the hydroformylation of long-chain olefins in the aqueous phase, demonstrating practical value. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing and applying a class of amphiphilic Rh / porous polymer catalysts, adding a new type of catalyst to the aqueous-phase catalytic hydroformylation reaction of long-chain olefins to prepare straight-chain aldehydes.

[0004] A synthetic method for preparing straight-chain aldehydes by hydroformylation of aqueous long-chain olefins catalyzed by Rh / porous polymers, characterized in that the catalytic method is as follows: (1) Take monomer L1 (0.1-5 mmol), monomer L2 (0.1-500 mmol), monomer L3 (0.1-500 mmol) and AIBN (5-100 mg) and dissolve them in tetrahydrofuran (1-100 mL); after reacting the mixture at 100 °C for 24 hours, remove the solvent under reduced pressure to obtain a porous polymer support; (2) Take the prepared porous polymer support (0.1-100 g) and Rh salt (0.1-100 mg) and add them to tetrahydrofuran (5-200 mL). Stir at room temperature for 24 hours, remove the solvent, and then dry under vacuum to obtain the Rh / porous polymer catalyst; (3) Under nitrogen atmosphere, take the prepared Rh / porous polymer catalyst (10-100 mg), olefin and water (1-10 mL) and add them to the reactor; then add CO and H2 to the reactor and carry out hydroformylation reaction at 20-200 °C to prepare straight-chain aldehyde product; The polymer monomer L1 in step (1) has the following characteristics: ; In step (1), the polymer monomer L2 is selected from: , , , One of them; The polymerizable monomer L3 in step (1) has the following characteristics: ; In the above general formula: R 1 R 2 R 3 R 4 Each group is independently selected from hydrogen, sulfonic acid group, vinyl group, C1-C4 alkane group, and C1-C4 alkoxy group; As a further preferred embodiment, the polymer has the following structure: , , , , As a further preferred embodiment, the mass ratio of the porous polymer to the metal salt is 1:1 to 50:1.

[0005] As a further preferred option, the x:y:z ratio is 1:1:1 to 1:100:100. As a further preferred option, the rhodium salt is Rh(acac)(CO)2, RhCl(PPh3)3, or RhH(CO)(PPh3)3.

[0006] As a further preferred embodiment, the molar ratio of the olefin substrate to the Rh salt in the catalyst is 100:1 to 100000:1.

[0007] Compared with the prior art, the present invention has the following significant effects: 1. The Rh / porous polymer catalyst provided by this invention can efficiently catalyze the hydroformylation reaction of long-chain olefins in an aqueous phase, with a TON value as high as 30,000 and a straight-chain aldehyde / branched-chain aldehyde ratio of 22.6-40.5.

[0008] 2. The porous polymer support provided by this invention allows for the regulation of hydrophilic and lipophilic polymerization units, resulting in catalysts with broad substrate compatibility and recyclability. Furthermore, the catalyst preparation method is simple, yields high results, and is suitable for large-scale production, thus possessing practical value. Detailed Implementation

[0009] The present invention will be further described in detail and completely below with reference to the embodiments.

[0010] Example 1 Preparation of L1 monomer: Under nitrogen protection and an ice-water bath, 4,6-bis(diphenylphosphine)phenazine (110 mg, 0.2 mmol) and NaH (30 mg, 1.25 mmol) were added to a Shrek flask containing DMF (6 mL). During the addition of the raw materials, 4,6-bis(diphenylphosphine)phenazine was first added to the Shrek flask containing the DMF solution, followed by small, multiple additions of NaH to the Shrek flask. After all the raw materials were added, the gas inside the Shrek flask was replaced with N2, and the flask was tightened to prevent leakage. The Shrek flask containing the mixture was then stirred and reacted in a 70 °C oil bath for 1.5 hours. After the first step of the reaction was completed, the Shrek flask was cooled to room temperature. Then, 4-vinylbenzyl chloride (61 mg, 0.4 mmol) was added to the flask, and N2 was used for protection. The Shrek flask was then stirred and reacted in an oil bath at 60 °C for 18 hours. After the reaction was complete, the solid-liquid mixture in the Shrek flask was transferred to a round-bottom flask. 6 mL of deionized water was added to the round-bottom flask, and a white solid precipitated. The solid was separated by centrifugation and allowed to air dry. The dried crude product was ultrasonically vibrated with petroleum ether. Some impurities dissolved in the petroleum ether. The petroleum ether was then separated. This ultrasonic treatment was repeated three times, followed by rotary evaporation to remove any remaining trace amounts of petroleum ether, yielding the final crude product. The product was then dried and weighed to obtain a light green solid (153 mg).

[0011]

[0012] Example 2 POP-1 Synthesis: L1 (35 mg, 0.05 mmol), styrene (5.1 mg, 0.05 mmol), sodium 4-vinylbenzenesulfonate (11 mg, 0.05 mmol), and AIBN (5.0 mg, 0.03 mmol) were dissolved in a Shrek flask containing THF (3 mL) and subjected to N2 displacement. The Shrek flask containing the mixture was stirred at room temperature for 10 minutes and then transferred to an oil bath at 100 °C for 24 hours with continued stirring and heating to obtain a light white solid product. After the reaction was completed, the solid-liquid mixture was transferred to a centrifuge tube and collected by centrifugation to remove the solvent. The solid obtained by centrifugation was washed with THF three times, and the THF solution was removed by rotary evaporation to obtain a porous organic polymer, the product being a white solid (45 mg).

[0013]

[0014] Example 3 POP-2 Synthesis: L1 (35 mg, 0.05 mmol), divinylbenzene (6.51 mg, 0.05 mmol), sodium 4-vinylbenzenesulfonate (11 mg, 0.05 mmol), and AIBN (5.0 mg, 0.03 mmol) were dissolved in a Shrek flask containing THF (3 mL) and subjected to N2 displacement. The Shrek flask containing the mixture was stirred at room temperature for 10 minutes and then transferred to an oil bath at 100 °C for further stirring and heating for 24 hours, yielding a light white solid product. After the reaction was complete, the solid-liquid mixture was transferred to a centrifuge tube and collected by centrifugation to remove the solvent. The solid obtained by centrifugation was washed with THF three times, and the THF solution was removed by rotary evaporation to obtain a porous organic polymer, the product being a white solid (44 mg).

[0015]

[0016] Example 4 POPs-3 Synthesis: L1 (35 mg, 0.05 mmol), m-divinylbenzene (6.51 mg, 0.05 mmol), sodium 4-vinylbenzenesulfonate (11 mg, 0.05 mmol), and AIBN (5.0 mg, 0.03 mmol) were dissolved in a Shrek flask containing THF (3 mL) and subjected to N2 displacement. The Shrek flask containing the mixture was stirred at room temperature for 10 minutes and then transferred to an oil bath at 100 °C for further stirring and heating for 24 hours, yielding a light white solid product. After the reaction was complete, the solid-liquid mixture was transferred to a centrifuge tube and collected by centrifugation to remove the solvent. The solid obtained by centrifugation was washed with THF three times, and the THF solution was removed by rotary evaporation to obtain a porous organic polymer, the product being a white solid (45 mg).

[0017]

[0018] Example 5 POPs-4 Synthesis: L1 (35 mg, 0.05 mmol), o-vinylbenzene (6.51 mg, 0.05 mmol), sodium 4-vinylbenzenesulfonate (11 mg, 0.05 mmol), and AIBN (5.0 mg, 0.03 mmol) were dissolved in a Shrek flask containing THF (3 mL) and subjected to N2 displacement. The Shrek flask containing the mixture was stirred at room temperature for 10 minutes and then transferred to an oil bath at 100 °C for 24 hours with continued stirring and heating to obtain a light white solid product. After the reaction was completed, the solid-liquid mixture was transferred to a centrifuge tube and collected by centrifugation to remove the solvent. The solid obtained by centrifugation was washed with THF three times, and the THF solution was removed by rotary evaporation to obtain a porous organic polymer, the product being a white solid (46 mg).

[0019]

[0020] Example 6 Synthesis of Rh / POPs catalysts: Under a nitrogen atmosphere, polymer 1 (100 mg), Rh(acac)(CO)2 (1 mg), and THF (5 mL) were added to a 100 mL Schlenk tube. The reaction was carried out at 100 °C for 24 h. After the reaction was completed, the solid product was separated by centrifugation, washed three times with petroleum ether by sonication, and the petroleum ether was removed by rotary evaporation to obtain the catalyst Rh / POPs (101 mg).

[0021] Example 7 The hydroformylation of 1-butene catalyzed by Rh / POP-1: Under a nitrogen atmosphere, Rh / POPs-1 (10 mg) and H2O (1 mL) were added to the reactor. The reactor was then placed in a -30°C cold trap and purged with 0.5 g of 1-butene, followed by the introduction of CO (10 bar) and H2 (10 bar). The reaction was carried out in an oil bath at 100°C. o The reaction was stirred at C for 10 h. After the reaction was completed, the yield was 95% and the L / B ratio was 40.5, as analyzed by gas chromatography.

[0022] Example 8 Hydroformylation of 1-hexene catalyzed by Rh / POP-2: Under a nitrogen atmosphere, Rh / POPs-2 (10 mg), H2O (1 mL), and 1-hexene (0.5 mL) were added to the reactor. Then, H2 was introduced to replace the nitrogen in the reactor three times, followed by purging with H2 (10 bar), CO (10 bar), and an oil bath at 100°C. o The reaction was stirred at C for 5 h. After the reaction was complete, gas chromatography analysis showed a yield of 96% and an L / B ratio of 32.8.

[0023] Example 9 Hydroformylation of 1-nonene catalyzed by Rh / POP-1: Under a nitrogen atmosphere, Rh / POPs-1 (10 mg), H2O (1 mL), and 1-nonene (0.5 mL) were added to the reactor. The nitrogen in the reactor was then replaced three times with H2, followed by purging with H2 (10 bar), CO (10 bar), and an oil bath at 100°C. o The reaction was stirred at C for 5 h. After the reaction was complete, the yield was 90% and the L / B ratio was 31.5, as analyzed by gas chromatography.

[0024] Example 10 The hydroformylation of 1-octene catalyzed by Rh / POP-1: Under a nitrogen atmosphere, Rh / POPs-1 (10 mg), H2O (1 mL), and 1-octene (0.5 mL) were added to the reactor. Then, H2 was introduced to replace the nitrogen in the reactor three times, followed by purging with H2 (10 bar), CO (10 bar), and an oil bath at 100°C. o The reaction was stirred at C for 5 h. After the reaction was complete, gas chromatography analysis showed a yield of 92% and an L / B ratio of 22.6.

[0025] Example 11 The hydroformylation of 1-pentene catalyzed by Rh / POP-3: Under a nitrogen atmosphere, Rh / POPs-3 (10 mg), H2O (1 mL), and 1-pentene (0.5 mL) were added to the reactor. Then, H2 was introduced to replace the nitrogen in the reactor three times, followed by the introduction of H2 (10 bar), CO (10 bar), and an oil bath at 100°C. o The reaction was stirred at C for 5 h. After the reaction was complete, gas chromatography analysis showed a yield of 93% and an L / B ratio of 33.5.

[0026] Example 12 The hydroformylation of 1-decene catalyzed by Rh / POP-1: Under a nitrogen atmosphere, Rh / POPs-1 (10 mg), H2O (1 mL), and 1-decene (0.5 mL) were added to the reactor. Then, H2 was introduced to replace the nitrogen in the reactor three times, followed by purging with H2 (10 bar), CO (10 bar), and an oil bath at 100°C. o The reaction was stirred at C for 10 h. After the reaction was complete, the yield was 92% and the L / B ratio was 25.2, as analyzed by gas chromatography.

[0027] Example 13 The hydroformylation of 1-heptene catalyzed by Rh / POP-1: Under a nitrogen atmosphere, Rh / POPs-1 (10 mg), H2O (1 mL), and 1-heptene (0.5 mL) were added to the reactor. Then, H2 was introduced to replace the nitrogen in the reactor three times, followed by purging with H2 (10 bar), CO (10 bar), and an oil bath at 100°C. o The reaction was stirred at C for 5 h. After the reaction was complete, the yield was 95% and the L / B ratio was 36.1, as analyzed by gas chromatography.

[0028] Example 14 The hydroformylation of undecene catalyzed by Rh / POP-1: Under a nitrogen atmosphere, Rh / POPs-1 (10 mg), H2O (1 mL), and undecene (0.7 mL) were added to the reactor. Then, H2 was introduced to replace the nitrogen in the reactor three times, followed by purging with H2 (10 bar), CO (10 bar), and an oil bath at 100°C. o The reaction was stirred at C for 24 h. After the reaction was complete, the yield was 89% and the L / B ratio was 28.5, as analyzed by gas chromatography.

[0029] Example 15 Rh / POP-1 catalyzes the hydroformylation of 1-hexene. Under a nitrogen atmosphere, catalyst Rh / POP-1 (10 mg), H2O (1 mL), and 1-hexene (0.5 mL) were added to the reactor. Then, H2 was introduced to replace the nitrogen in the Shrek tube three times, followed by the introduction of H2 (10 bar) and CO (10 bar). The reactor was then heated in an oil bath at 100°C. o The reaction was stirred at C for 5 h. After the reaction was complete, the catalyst and solvent were recovered and reused, and the yield of the product was calculated by gas chromatography. After phase separation, the catalyst and solvent were added to the reactor under a nitrogen atmosphere and the reaction was repeated 5 times under the same conditions. Specific test data are as follows:

[0030] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions claimed by the present invention.

Claims

1. A method for synthesizing straight-chain aldehydes by Rh / porous polymer-catalyzed hydroformylation of aqueous long-chain olefins, characterized in that, The catalytic method is as follows: (1) Take monomer L1 (0.1-5 mmol), monomer L2 (0.1-500 mmol), monomer L3 (0.1-500 mmol) and AIBN (5-100 mg) and dissolve them in tetrahydrofuran (1-100 mL); after reacting the mixture at 100 °C for 24 hours, remove the solvent under reduced pressure to obtain a porous polymer support; (2) Take the prepared porous polymer support (0.1-100 g) and Rh salt (0.1-100 mg) and add them to tetrahydrofuran (5-200 mL). Stir at room temperature for 24 hours, remove the solvent, and then dry under vacuum to obtain the Rh / porous polymer catalyst; (3) Under nitrogen atmosphere, the prepared Rh / porous polymer catalyst (10-100 mg), olefin and water (1-10 mL) are added to the reactor; CO and H2 are then introduced into the reactor, and hydroformylation reaction is carried out at 20-200 °C to prepare straight-chain aldehyde products; The polymer monomer L1 in step (1) has the following characteristics: ; In step (1), the polymer monomer L2 is selected from: , , , One of them; The polymerizable monomer L3 in step (1) has the following characteristics: ; In the above general formula: R 1 R 2 R 3 R 4 Each group is independently selected from hydrogen, sulfonic acid group, vinyl group, C1-C4 alkane group, and C1-C4 alkoxy group.

2. The method for synthesizing straight-chain aldehydes by Rh / porous polymer-catalyzed hydroformylation of aqueous long-chain olefins according to claim 1, characterized in that, The porous polymer support synthesized in step (1) has the following general structural formula: ， ， General structural formula 1, General structural formula 2 ， ， General structural formula 3, General structural formula 4 In the above general formula: R 1 R 2 R 3 R 4 Each group is independently selected from hydrogen, sulfonic acid group, vinyl group, C1-C4 alkane group, and C1-C4 alkoxy group; The x:y:z ratio is 1:1:1 to 1:100:

100.

3. The method for synthesizing straight-chain aldehydes by Rh / porous polymer-catalyzed hydroformylation of aqueous long-chain olefins according to claim 1, characterized in that, In step (2), the rhodium salt is selected from one of Rh(acac)(CO)2, RhCl(PPh3)3, [Rh(COD)Cl]2, Rh2(OAc)4, Rh(acac)3 and RhH(CO)(PPh3)3; acac represents acetylacetone and COD represents cyclooctadiene.

4. The method for synthesizing straight-chain aldehydes by Rh / porous polymer-catalyzed hydroformylation of aqueous long-chain olefins according to claim 1, characterized in that, The olefin substrate in step (3) is a terminal olefin or an internal olefin; the molar ratio of the olefin substrate to the Rh salt in the catalyst is 100:1 to 100000:1.

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