A heterogeneous platinum catalyst and its application in the synthesis of γ-chloropropyltrichlorosilane

Abstract

The invention discloses a heterogeneous platinum catalyst and its application in the synthesis of γ-chloropropyltrichlorosilane (γ1). A ligand containing anthracene skeleton is introduced, a novel platinum metal catalyst is synthesized by coordination with platinum, and a heterogeneous platinum catalyst is prepared by loading the platinum metal catalyst into high vinyl polybutadiene using Diels-Alder (DA) reaction. This heterogeneous catalyst is used to catalyze the addition reaction of chloropropylene and trichlorosilane to prepare γ-chloropropyltrichlorosilane (γ1). Compared with the prior art, the novel heterogeneous platinum catalyst can effectively reduce the generation of by-products and improve product selectivity. The heterogeneous catalyst reported in the present invention has the characteristics of simple preparation, high catalytic efficiency, high selectivity, cyclic reuse, and continuous catalysis, and the purity of the obtained γ-chloropropyltrichlorosilane can reach 99.5%, and the product yield is as high as 95%.

Description

Technical Field

[0001] The invention relates to a heterogeneous platinum catalyst and application thereof in the synthesis of gamma-chloropropyltrichlorosilane (γ1). Background Art

[0002] Silane coupling agent, known as "industrial MSG", has unique temperature resistance, dielectric properties, physiological inertness and low surface tension. It is an indispensable functional additive in the rubber industry and the soul material of green tires. γ-Chloropropyltrichlorosilane (γ1) is the basic raw material for the preparation of silane coupling agent. Most of the industrial raw materials are made from allyl chloride and trichlorosilane through the silylation reaction. In this reaction process, the metal catalyst is the core technology of the silylation reaction.

[0003] Since Speier et al. proposed the use of hexahydrate chloroplatinic acid to catalyze the hydrosilylation reaction in 1957, many transition metal catalysts have been developed in recent years. However, platinum metal catalysts are still the most widely used catalysts, such as Speier catalyst and Karstedt catalyst. Most of these catalysts are homogeneous systems, and the reaction process is often accompanied by strong heat release, which causes the system to heat up rapidly, resulting in the generation of side reactions such as isomerization or secondary addition, leading to an increase in by-products. In addition, the residue of homogeneous platinum catalyst has a certain corrosive effect on the reactor, and the complex metal recovery process increases the production cost.

[0004] To solve the above problems, patent CN105964304B publicly reported the preparation of γ-chloropropyltrichlorosilane using polyacetylene polymer as carrier and nitrogen-containing heterocyclic platinum complex as catalyst, and the hydrosilylation reaction was carried out at 40-80°C. The advantage of this catalyst is that the catalytic system is heterogeneous, the catalyst is recyclable and the reaction conditions are mild. However, its disadvantage is that the catalyst selectivity is not high, and the yield is only 83.5%. Patent CN 113105494 A discloses a Wool-Pt heterogeneous catalyst synthesized with biopolymer wool as a ligand, and organic amines as auxiliary agents to prepare γ-chloropropyltrichlorosilane under normal pressure. Its advantage is that it can effectively reduce the generation of silicon tetrachloride and propyl trichlorosilane by-products and improve the selectivity of the target product. However, the yield of γ-chloropropyltrichlorosilane is only 85.6%.

[0005] In view of this, the present invention reports a heterogeneous platinum catalyst and applies it to the synthesis process of γ-chloropropyltrichlorosilane (γ1). The present invention introduces a ligand containing an anthracene skeleton, and synthesizes a new platinum metal catalyst by designing coordination with platinum. The platinum metal catalyst is loaded into high vinyl polybutadiene by Diels-Alder (DA) reaction to obtain a heterogeneous platinum catalyst. The heterogeneous catalyst reported in the present invention has the characteristics of simple preparation, high catalytic efficiency, cyclic reuse, and continuous catalysis. It is suitable for the preparation of γ-chloropropyltrichlorosilane by the reaction of allyl chloride and trichlorosilane, and the obtained γ-chloropropyltrichlorosilane has a high yield (up to 95%) and a high purity (99.5%).

[0006] Therefore, the heterogeneous platinum catalyst reported in the present invention is original and innovative, and has high economic and social benefits for the industrial production of γ-chloropropyltrichlorosilane. Summary of the invention

[0007] The purpose of the present invention is to provide a heterogeneous platinum catalyst and its application in the synthesis of γ-chloropropyltrichlorosilane (γ1).

[0008] The present invention provides platinum metal complexes shown in formula I-IV:

[0009]

[0010] The present invention provides a method for preparing the above metal complex, comprising the following steps:

[0011] (a) Under a nitrogen atmosphere, 1-aminoanthraquinone and Zn powder react in a NaOH solution, and after the reaction is completed, 1-aminoanthracene is obtained by filtering and removing the solvent;

[0012] (b) 1-aminoanthracene is dissolved in ethanol, and 6-methyl-2-pyridinecarboxaldehyde or 6-bromopyridine-2-carboxaldehyde and p-toluenesulfonic acid are added to start the reaction. After the reaction is completed, the ligand is obtained by filtering and recrystallization;

[0013] (c) dissolving the ligand and anhydrous sodium acetate in an organic solvent, adding potassium tetrachloroplatinate or potassium hexachloroplatinate to react, washing with water and methanol after the reaction, and recrystallizing to obtain the target complex;

[0014] (d) The metal complex and high-ethylene-content polybutadiene are dissolved in an organic solvent and heated to react. After the reaction is completed, the temperature is reduced and the solvent is removed to obtain the target heterogeneous platinum catalyst.

[0015] In the above preparation method, the concentration of the NaOH solution in the process (a) is 5-30wt%, preferably 10%wt%.

[0016] In the above preparation method, the reaction temperature of the process (a) is 60-100°C, preferably 80°C; the reaction time is 12-48 hours, preferably 24 hours.

[0017] In the above preparation method, the molar ratio of 6-methyl-2-pyridinecarboxaldehyde or 6-bromopyridine-2-carboxaldehyde to 1-aminoanthracene in the process (b) is 1.05-1.5:1, preferably 1.2:1.

[0018] In the above preparation method, the molar ratio of p-toluenesulfonic acid to 1-aminoanthracene in the process (b) is 0.5 to 4:100, preferably 1:100.

[0019] In the above preparation method, the reaction temperature of the process (b) is 0-40°C, preferably 25°C; the reaction time is 6-24 hours, preferably 12 hours.

[0020] In the above preparation method, in the process (c), the molar ratio of anhydrous sodium acetate to the ligand is 2.0 to 2.4:1, preferably 2.0:1.

[0021] In the above preparation method, in the process (c), the molar ratio of potassium tetrachloroplatinate or potassium hexachloroplatinate to the ligand is 1.0 to 1.2:1, preferably 1.05:1.

[0022] In the above preparation method, the reaction temperature of the process (c) is 80-140°C, preferably 110°C; the reaction time is 2-12 hours, preferably 6 hours.

[0023] In the above preparation method, the solvent used in the process (d) is toluene, xylene, acetonitrile, DMF, chloroform, tetrahydrofuran, preferably toluene.

[0024] In the above preparation method, in the process (d), the reaction temperature is 150-220°C, preferably 180°C; the reaction time is 2-48 hours, preferably 12 hours.

[0025] The present invention adopts the method for catalyzing the synthesis of γ-chloropropyltrichlorosilane by the heterogeneous catalyst, and the main steps are: premixing allyl chloride and the catalyst, adding trichlorosilane dropwise to carry out a hydrosilylation reaction, filtering and recovering the catalyst after the reaction is completed, and then purifying the reaction product by distillation to obtain γ-chloropropyltrichlorosilane.

[0026] In the above catalytic reaction, the ratio of allyl chloride to trichlorosilane is 1:1-1.5, preferably 1:1.05.

[0027] In the above catalytic reaction, the amount of the catalyst relative to allyl chloride is 100-10 ppm.

[0028] In the above catalytic reaction, the temperature of the hydrosilylation reaction is 50° C. to 80° C., and the reaction time is 1 to 6 hours, preferably the reaction temperature is 60° C., and the reaction time is 3 hours.

[0029] In the above catalytic reaction, the distillation collection temperature is 70-90°C.

[0030] The present invention provides the preparation of a heterogeneous platinum catalyst and the application of catalyzing the addition reaction of allyl chloride and trichlorosilane. The heterogeneous platinum catalyst reported in the present invention has the characteristics of simple preparation, high catalytic efficiency, cyclic reuse, and continuous catalysis, and the obtained γ-chloropropyltrichlorosilane (γ1) has a high yield (up to 95%) and a high purity (99.5%). BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is the synthetic route of catalyst I.

[0032] Figure 2 This is the NMR image of the anthracene ligand intermediate. DETAILED DESCRIPTION

[0033] The present invention is further described by way of examples, but the present invention is not limited thereto. The examples of the present invention can enable those skilled in the art to understand the present invention more comprehensively.

[0034] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. The content of 1,2 structure of high vinyl polybutadiene is greater than 80%.

[0035] The present invention is described below with reference to specific embodiments.

[0036] Example 1. Synthesis of anthracene ligands.

[0037] Weigh 3.34g / 15mmol of 1-aminoanthraquinone and place it in a 500mL single-mouth bottle, add 9.8g / 15mmol of Zn powder, add 10% NaOH solution under nitrogen atmosphere, stir at room temperature for 30min, reflux at 85℃ for 24h; then filter, add dichloromethane to dissolve the filter cake, and spin-dry the filtrate to obtain 1-aminoanthracene with a yield of 75%. Weigh 1g / 5mmol of 1-aminoanthracene, use ethanol as solvent, add 1.2 equivalents of 6-methyl-2-pyridinecarboxaldehyde 1.3g / 6mmol and 6mg of p-toluenesulfonic acid (1mol%), react for 12 hours, concentrate the filtrate and recrystallize it, and filter to obtain the ligand with a yield of 91%.

[0038] Example 2, Synthesis of Catalyst I.

[0039] Weigh 1.48g / 5mmol of ligand and 0.82mg / 10mmol of anhydrous sodium acetate, add 20mL of toluene, heat to 110°C, add 4.2g / 5mmol of potassium tetrachloroplatinate and react for 6 hours. Then add 10mL of distilled water and filter, wash the filter residue with 20mL of water 3 times and 20mL of methanol once. The residue is recrystallized in toluene to obtain 2.3g of platinum complex with a yield of 82%. Weigh 1.9g of platinum complex and 10g of high vinyl polybutadiene, add 20mL of toluene, heat to 180°C and react for 12 hours. After the reaction, filter at room temperature and vacuum dry to obtain catalyst I. The mass percentage of Pt measured by ICP is 5.3%.

[0040] Example 3. Synthesis of Catalyst II.

[0041] Weigh 1.48g / 5mmol of ligand and 0.82mg / 10mmol of anhydrous sodium acetate, add 20mL of toluene, heat to 110℃, add 4.9g / 5mmol of potassium chloroplatinate and react for 6 hours. Then add 10mL of distilled water and filter, wash the filter residue with 20mL of water 3 times and 20mL of methanol once. The residue is recrystallized in toluene to obtain 2.5g of platinum complex with a yield of 79%. Weigh 2.1g of platinum complex and 10g of high vinyl polybutadiene, add 20mL of toluene, heat to 180℃ and react for 12 hours. After the reaction, filter at room temperature and vacuum dry to obtain catalyst II. The mass percentage of Pt measured by ICP is 5.4%.

[0042] Example 4. Synthesis of Catalyst III.

[0043] Weigh 1.8g / 5mmol of ligand and 0.82mg / 10mmol of anhydrous sodium acetate, add 20mL of toluene, heat to 110°C, add 4.2g / 5mmol of potassium tetrachloroplatinate and react for 6 hours. Then add 10mL of distilled water and filter, wash the filter residue with 20mL of water 3 times and 20mL of methanol once. The residue is recrystallized in toluene to obtain 2.3g of platinum complex with a yield of 74%. Weigh 2.1g of platinum complex and 10g of high vinyl polybutadiene, add 20mL of toluene, heat to 180°C and react for 12 hours. After the reaction, filter at room temperature and vacuum dry to obtain catalyst I. The mass percentage of Pt measured by ICP is 5.3%.

[0044] Example 5. Synthesis of Catalyst IV.

[0045] Weigh 1.8g / 5mmol of ligand and 0.82mg / 10mmol of anhydrous sodium acetate, add 20mL of toluene, heat to 110℃, add 4.9g / 5mmol of potassium chloroplatinate and react for 6 hours. Then add 10mL of distilled water and filter, wash the filter residue with 20mL of water 3 times and 20mL of methanol once. The residue is recrystallized in toluene to obtain 2.6g of platinum complex with a yield of 75%. Weigh 2.3g of platinum complex and 10g of high vinyl polybutadiene, add 20mL of toluene, heat to 180℃ and react for 12 hours. After the reaction, filter at room temperature and vacuum dry to obtain catalyst IV. The mass percentage of Pt measured by ICP is 5.1%.

[0046] Example 6: Catalyst I catalyzes the reaction of allyl chloride and trichlorosilane.

[0047] Weigh 10g of allyl chloride and 3mg of catalyst I, heat to 50℃ for activation for 30 minutes; weigh 17.7g of trichlorosilane, add dropwise to the allyl chloride solution for about 1 hour. After reflux reaction at 60℃ for 3 hours, perform vacuum distillation and collect the fraction at 70-90℃. The obtained product is γ-chloropropyltrichlorosilane, and the reaction yield is 87%.

[0048] Example 7: Catalyst II catalyzes the reaction of allyl chloride and trichlorosilane.

[0049] Weigh 10g of allyl chloride and 3mg of catalyst II, heat to 50℃ for activation for 30 minutes; weigh 17.7g of trichlorosilane, add dropwise to the allyl chloride solution for about 1 hour. After reflux reaction at 60℃ for 3 hours, perform vacuum distillation and collect the fraction at 70-90℃. The obtained product is γ-chloropropyltrichlorosilane, and the reaction yield is 95%.

[0050] Example 8: Catalyst III catalyzes the reaction of allyl chloride and trichlorosilane.

[0051] Weigh 10g of allyl chloride and 3mg of catalyst III, heat to 50℃ for activation for 30 minutes; weigh 17.7g of trichlorosilane, add dropwise to the allyl chloride solution for about 1 hour. After reflux reaction at 60℃ for 3 hours, perform vacuum distillation and collect the fraction at 70-90℃. The obtained product is γ-chloropropyltrichlorosilane, and the reaction yield is 88%.

[0052] Example 9: Catalyst IV catalyzes the reaction of allyl chloride and trichlorosilane.

[0053] Weigh 10g of allyl chloride and 3mg of catalyst IV, heat to 50℃ for activation for 30 minutes; weigh 17.7g of trichlorosilane, add dropwise to the allyl chloride solution for about 1 hour. After reflux reaction at 60℃ for 3 hours, perform vacuum distillation and collect the fraction at 70-90℃. The obtained product is γ-chloropropyltrichlorosilane, and the reaction yield is 93%.

[0054] Example 10: The recovered catalyst II catalyzes the reaction of allyl chloride and trichlorosilane.

[0055] Cycle times Reaction temperature Reaction time Yield 1 60℃ 3 hours 95％ 2 60℃ 3 hours 94％ 3 60℃ 3 hours 94％ 4 60℃ 3 hours 93％ 5 60℃ 3 hours 92％

Claims

1. A heterogeneous platinum catalyst, characterized in that The structural formula of the heterogeneous platinum catalyst is one of the following:

2. The method for preparing the heterogeneous platinum catalyst according to claim 1, comprising the following steps: (a) Under a nitrogen atmosphere, 1-aminoanthraquinone and Zn powder react in a NaOH solution, and after the reaction is completed, 1-aminoanthracene is obtained by filtering and removing the solvent; (b) 1-aminoanthracene is dissolved in ethanol, and 6-methyl-2-pyridinecarboxaldehyde or 6-bromopyridine-2-carboxaldehyde and p-toluenesulfonic acid are added to start the reaction. After the reaction is completed, the ligand is obtained by filtering and recrystallization; (c) dissolving the ligand and anhydrous sodium acetate in an organic solvent, adding potassium tetrachloroplatinate or potassium hexachloroplatinate to react, washing with water and methanol after the reaction, and recrystallizing to obtain the target metal complex; (d) The target metal complex and high ethylene content polybutadiene are dissolved in an organic solvent and heated to react. After the reaction is completed, the temperature is reduced and the solvent is removed to obtain the target heterogeneous platinum catalyst.

3. The preparation method according to claim 2, characterized in that: The concentration of the NaOH solution in step (a) is 5 to 30 wt %; the reaction temperature in step (a) is 60 to 100° C., and the reaction time is 12 to 48 hours.

4. The preparation method according to claim 2, characterized in that: In the step (b), the molar ratio of 6-methyl-2-pyridinecarboxaldehyde or 6-bromopyridine-2-carboxaldehyde to 1-aminoanthracene is 1.05-1.5:1; the molar ratio of p-toluenesulfonic acid to 1-aminoanthracene is 0.5-4:100; the reaction temperature of the step (b) is 0-40°C, and the reaction time is 6-24 hours.

5. The preparation method according to claim 2, characterized in that: The molar ratio of anhydrous sodium acetate to the ligand in the step (c) is 2.0-2.4:1; the molar ratio of potassium tetrachloroplatinate or potassium hexachloroplatinate to the ligand in the step (c) is 1.0-1.2:1; the reaction temperature in the step (c) is 80-140° C., and the reaction time is 2-12 hours.

6. The preparation method according to claim 2, characterized in that: The solvent used in the step (d) is selected from any one of toluene, xylene, acetonitrile, DMF, chloroform and tetrahydrofuran; the reaction temperature of the step (d) is 150-220° C., and the reaction time is 2-48 hours.

7. A method for synthesizing γ-chloropropyltrichlorosilane (γ1) using a heterogeneous platinum catalyst, characterized in that: The following steps are involved: Allyl chloride and the heterogeneous platinum catalyst according to claim 1 are pre-mixed, trichlorosilane is added dropwise to carry out a hydrosilylation reaction, and after the reaction is completed, the catalyst is filtered and recovered, and then the reaction product is purified by distillation to obtain γ-chloropropyltrichlorosilane (γ1).

8. The method for synthesizing γ-chloropropyltrichlorosilane (γ1) according to claim 7, characterized in that: The ratio of allyl chloride to trichlorosilane is 1:1-1.5; the amount of the heterogeneous platinum catalyst relative to allyl chloride is 100-10 ppm; the temperature of the hydrosilylation reaction is 50°C-80°C, and the reaction time is 1-6 hours; the temperature of the distillation purification is 70-90°C.

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