A modified platinum catalyst for hydrosilylation reactions and a continuous flow hydrosilylation process

Abstract

The present application belongs to the technical field of organic synthesis, and particularly relates to a modified platinum catalyst for hydrosilylation and a continuous flow hydrosilylation method. The modified platinum catalyst is prepared by mixing and concentrating the following raw materials in parts by weight: isopropyl alcohol 95-103 parts, H2PtCl6.6H2O 0.9-1.2 parts, polyhydric alcohol 3.5-5 parts, and nitrogen-containing heterocyclic compound 0.8-1.3 parts. The modified platinum catalyst is used, and the process steps and process conditions are further optimized, so that the continuous flow synthesis reaction of hydrosilylation is realized, the yield and product purity are high, the method is suitable for the needs of industrial production, and has a good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a modified platinum catalyst for hydrosilylation reactions and a continuous flow hydrosilylation method. Background Technology

[0002] Hydrosilylation is an addition reaction between a silane compound containing silane and an unsaturated compound under certain conditions. It has wide applications and a significant role in organosilicon chemistry. Since its discovery in 1947, the reaction has undergone several rapid development stages, from initially using only high temperatures to later incorporating common catalysts such as ultraviolet light, peroxides, and azo compounds. In 1957, Speier discovered that dissolving chloroplatinic acid in isopropanol could effectively catalyze hydrosilylation, marking the first introduction of platinum into the reaction. In 1966, Willing, building on Speier's method, reacted chloroplatinic acid with unsaturated siloxane compounds, using the resulting compound in hydrosilylation reactions to further improve the efficiency. In 1973, Karstedt further improved Willing's method by heating chloroplatinic acid or chloroplatinate with sodium bicarbonate and vinylsiloxane in ethanol to form a platinum vinylsiloxane complex. This halogen-free catalyst has a significantly improved catalytic efficiency compared to the previous chloroplatinic acid vinylsiloxane complex and is now widely used.

[0003] Continuous flow reactions, compared to traditional batch reactions, offer advantages such as smaller reactor volume, larger specific surface area, better sealing, higher heat exchange efficiency, easier and more precise control of reaction temperature and material ratios, and greater safety and environmental friendliness. Therefore, continuous flow reactions for hydrosilylation have significant industrial application value. However, there are substantial differences in the thermodynamics and kinetics between batch and continuous flow reactions, and the performance of existing platinum catalysts under continuous flow conditions still needs improvement. Furthermore, how to rationally set reaction conditions to achieve high-yield continuous flow reactions is also a pressing issue that needs to be addressed. Summary of the Invention

[0004] To address the problems of existing technologies, this invention provides a modified platinum catalyst and a continuous flow hydrosilylation method for hydrosilylation reactions, aiming to achieve a continuous flow hydrosilylation reaction with high yield and high product purity.

[0005] A modified platinum catalyst for hydrosilylation reactions is prepared by mixing and concentrating the following raw materials in parts by weight:

[0006] 95-103 parts of isopropanol

[0007] H2PtCl6·6H2O 0.9~1.2 parts

[0008] 3.5 to 5 parts of polyols

[0009] 0.8 to 1.3 parts of nitrogen-containing heterocyclic compounds.

[0010] Preferably, it is made by mixing and concentrating the following raw materials in parts by weight:

[0011] 100 parts of isopropanol

[0012] 1 part of H2PtCl6·6H2O

[0013] 4 parts of polyols

[0014] One part of a nitrogen-containing heterocyclic compound.

[0015] Preferably, the modified platinum catalyst obtained after concentration is 5 parts by weight.

[0016] Preferably, the polyol is selected from at least one of ethylene glycol, diethylene glycol, or triethylene glycol.

[0017] Preferably, the nitrogen-containing heterocyclic compound is selected from at least one of morpholine or N-methylmorpholine.

[0018] The present invention also provides the use of the above-mentioned modified platinum catalyst for catalyzing hydrosilylation reactions.

[0019] The present invention also provides a continuous flow hydrosilylation method using the above-mentioned modified platinum catalyst, comprising the following steps:

[0020] Step 1: Use hydrogen-containing silane as raw material A, mix the modified platinum catalyst with a portion of olefins as raw material B, and use the remaining olefins as raw material C;

[0021] Step 2: Feed raw material A and raw material B into a continuous flow mixer respectively. After mixing in the continuous flow mixer, reaction solution A is obtained.

[0022] Step 3: Feed reaction solution A and raw material C into continuous flow reactor A respectively to react and obtain reaction solution B;

[0023] Step 4: The reaction solution B, raw material A and raw material C are respectively fed into at least one continuous flow reactor device connected in series to carry out the reaction and obtain the hydrosilylation product.

[0024] Preferably, the hydrogen-containing silane is selected from at least one of the following compounds:

[0025] The olefin is selected from at least one of the following compounds:

[0026] Preferably, in step 2, raw material A and raw material B are preheated and then fed into a continuous flow mixer. The preheating temperature of raw material A is 30℃~70℃, the preheating temperature of raw material B is 30℃~70℃, and the temperature of the continuous flow mixer is controlled at 40℃~70℃.

[0027] And / or, in step 2, the flow rate of raw material A is 3-200 ml / min, the flow rate of raw material B is 3-200 ml / min, the preheating time of raw material A is 5-50 min, the preheating time of raw material B is 5-50 min, and the residence time of raw material A and raw material B in the continuous flow mixer is 2.73-15 min.

[0028] And / or, in step 3, the flow rate of raw material C is 2-145 ml / min, the residence time of reaction solution A and raw material C in the continuous flow reactor A is 6.76-25 min, and the reaction temperature is 50℃~90℃;

[0029] And / or, in step 4, the flow rate of raw material A is 2-145 ml / min, the flow rate of raw material C is 2-145 ml / min, and the reaction solution B, raw material A and raw material C react in a series of continuous flow reactors B and C. The residence time of the reaction in the continuous flow reactor B is 5.6-13 min, the residence time of the reaction in the continuous flow reactor C is 5.6-13 min, and the reaction temperature is 50℃~90℃.

[0030] Preferably, in step 2, the preheating temperature of raw material A is 40℃~50℃, the preheating temperature of raw material B is 50℃~60℃, and the temperature control of the continuous flow mixer is 60℃~70℃.

[0031] In step 3, the reaction temperature is 70℃~80℃;

[0032] In step 4, the reaction temperature is 70℃~80℃.

[0033] This invention provides a modified platinum catalyst that exhibits excellent catalytic activity for hydrosilylation reactions. In particular, the modified platinum catalyst of this invention is highly suitable for continuous-flow synthesis of hydrosilylation reactions, which is beneficial for improving the yield and purity of the product. Furthermore, this invention optimizes the process steps and conditions of the hydrosilylation reaction, employing a unique continuous gradient feed method to make the induction of hydrosilylation controllable, achieving intrinsically safe continuous-flow hydrosilylation production. The atom economy reaches over 99%, and the environmental factor is close to the theoretical value, as low as below 1.05. Therefore, this invention has excellent application prospects.

[0034] Obviously, based on the above description of the present invention, and according to common technical knowledge and conventional methods in the field, various other modifications, substitutions or alterations can be made without departing from the basic technical concept of the present invention.

[0035] The following detailed embodiments further illustrate the above-described content of the present invention. However, this should not be construed as limiting the scope of the present invention to the following examples. All technologies implemented based on the above-described content of the present invention fall within the scope of the present invention. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the continuous flow reaction apparatus used in this invention. Detailed Implementation

[0037] In the following examples, reagents and raw materials not specifically described are all commercially available products.

[0038] Example 1: Modified platinum catalyst ATC-P01

[0039] In this embodiment, the modified platinum catalyst is prepared by adding an auxiliary agent to the isopropanol solvent of chloroplatinic acid, reacting at a certain temperature, removing the isopropanol by evaporation, and then adding the raw material olefin for complexation.

[0040] Specifically, it is prepared according to the following method:

[0041] Add 100g isopropanol to a 500ml glass reaction flask, then add 1g chloroplatinic acid (H2PtCl6·6H2O), 4g ethylene glycol, and 1g N-methylmorpholine. Heat to 80℃ and stir for 2-4 hours. Concentrate under reduced pressure to 5g to obtain the modified platinum catalyst ATC-P01.

[0042] Example 2: Modified platinum catalyst ATC-PO2

[0043] The modified platinum catalyst in this embodiment was prepared as follows:

[0044] Add 100g isopropanol to a 500ml glass reaction flask, then add 1g chloroplatinic acid (H2PtCl6·6H2O), 4g diethylene glycol, and 1g N-methylmorpholine. Heat to 80℃ and stir for 2-4 hours. Concentrate under reduced pressure to 5g to obtain the modified platinum catalyst ATC-PO2.

[0045] Example 3 Modified platinum catalyst ATC-PO3

[0046] The modified platinum catalyst in this embodiment was prepared as follows:

[0047] Add 100g isopropanol to a 500ml glass reaction flask, then add 1g chloroplatinic acid (H2PtCl6·6H2O), 4g triethylene glycol, and 1g morpholine. Heat to 80℃ and stir for 2-4 hours. Concentrate under reduced pressure to 5g to obtain the modified platinum catalyst ATC-PO3.

[0048] Example 4: Modified platinum catalyst ATC-PO4

[0049] The modified platinum catalyst in this embodiment was prepared as follows:

[0050] Add 100g isopropanol to a 500ml glass reaction flask, then add 1g chloroplatinic acid (H2PtCl6·6H2O), 4g ethylene glycol, and 1g N-methylmorpholine. Heat to 80℃ and stir for 2-4 hours. Concentrate under reduced pressure to 5g to obtain the modified platinum catalyst ATC-PO4.

[0051] Example 5: Continuous flow synthesis of hydrosilylation reaction

[0052] 1. Continuous flow reactor

[0053] The continuous flow reactor used in this embodiment is as follows: Figure 1 As shown, the system includes three raw material tanks for storing raw material A, raw material B, and raw material C, respectively. The raw material tank storing raw material A is connected to a continuous flow mixer (90 mL volume) via metering pump A and continuous flow preheater A (150 mL volume). The raw material tank storing raw material B is connected to the continuous flow mixer via metering pump B and continuous flow preheater B (150 mL volume). The downstream end of the continuous flow mixer is connected to continuous flow reactor A. The raw material tank storing raw material C is connected to continuous flow reactor A via metering pump C. The downstream end of continuous flow reactor A is connected to continuous flow reactor B. The raw material tank storing raw material A is connected to continuous flow reactor B via metering pump D. The raw material tank storing raw material C is connected to continuous flow reactor B via metering pump E. The downstream end of continuous flow reactor B is connected to continuous flow reactor C. An online density detector is installed at the downstream end of continuous flow reactor C. The downstream end of the online density detector is connected to a non-conforming product tank and a conforming product tank. A product packaging machine is installed at the downstream end of the conforming product tank. The total volume of continuous flow reactors A, B, and C is 750 mL.

[0054] 2. Continuous flow synthesis steps of hydrosilylation reaction

[0055] The synthesis reaction in this embodiment is as follows:

[0056]

[0057] Step 1: Hydrogen-containing silane (compound Y1) is used as raw material A (884g), 0.2g of the modified platinum catalyst (the modified platinum catalyst ATC-PO1 prepared in Example 1) is mixed with 200g of olefin (compound X1) as raw material B, and the remaining olefin (compound X1) is used as raw material C (200g).

[0058] Step 2: Feed raw material A and raw material B into a continuous flow mixer respectively. After mixing in the continuous flow mixer, reaction solution A is obtained.

[0059] In step 2, raw material A is controlled to flow at a rate of 7 ml / min by metering pump A, the preheating temperature of continuous flow preheater A is 30℃~35℃, and the residence time for preheating in continuous flow preheater A is 21.4 min; raw material B is controlled to flow at a rate of 7 ml / min by metering pump B, the preheating temperature of continuous flow preheater B is 30℃~35℃, and the residence time for preheating in continuous flow preheater B is 21.4 min.

[0060] The temperature in the continuous flow mixer is controlled at 40℃~50℃, and the residence time in the continuous flow mixer is 6.43min;

[0061] Step 3: Feed reaction solution A and raw material C into continuous flow reactor A respectively to react and obtain reaction solution B;

[0062] In step 3, the flow rate of raw material C is controlled at 5 mL / min by metering pump C, the reaction temperature in continuous flow reactor A is 50℃~60℃, and the residence time in continuous flow reactor A is 13.16 min;

[0063] Step 4: Feed reaction solution B, raw material A and raw material C into at least one continuous flow reactor connected in series to carry out the reaction and obtain hydrosilylation product.

[0064] In step 4, the flow rate of raw material A is controlled at 5 mL / min by metering pump D, and the flow rate of raw material C is controlled at 5 mL / min by metering pump E. The reaction temperature in both continuous flow reactors B and C is set to 50℃~60℃, and the residence time in both continuous flow reactors B and C is 8.62 min.

[0065] In this embodiment, the product yield was 94.7% and the purity was GC-96.4%.

[0066] Example 6-14 Continuous flow synthesis of hydrosilylation reaction

[0067] In the following examples, the continuous flow reactor and synthesis steps are the same as in Example 5, except that the reactants, modified platinum catalysts and process conditions are different, as shown in Table 1 (for ease of comparison, the relevant conditions of Example 5 are also listed).

[0068] Among them, the modified platinum catalyst ATC-P01 was prepared according to the method of Example 1, the modified platinum catalyst ATC-P02 was prepared according to the method of Example 2, the modified platinum catalyst ATC-P03 was prepared according to the method of Example 3, and the modified platinum catalyst ATC-P04 was prepared according to the method of Example 4.

[0069] Combination 1 in the raw materials refers to the raw materials for the following synthesis reaction:

[0070]

[0071] Combination 2 in the raw materials refers to the raw materials for the following synthetic reaction:

[0072]

[0073] Combination 3 in the raw materials refers to the raw materials for the following synthetic reaction:

[0074]

[0075] Combination 4 in the raw materials refers to the raw materials for the following synthetic reaction:

[0076]

[0077]

[0078]

[0079] As can be seen from the table above, the modified platinum catalyst provided by this invention can achieve ideal yield and product purity. Furthermore, conducting a continuous flow reaction under the temperature conditions set in Examples 12-14 can increase the yield to 99% and the product purity to over 96%, making it suitable for industrial production.

[0080] Catalytic effect of modified platinum catalysts (Comparative Examples 1-4) and Speier catalysts on the continuous flow synthesis of hydrosilylation reactions

[0081] The continuous flow reaction apparatus and synthesis steps used in the following comparative examples are the same as those in Example 5, except that the reactants, modified platinum catalysts and process conditions are different, as shown in Table 2.

[0082] The preparation method of the Speier catalyst is as follows:

[0083] Add 100g of isopropanol to a 500ml glass reaction flask, then add 1g of chloroplatinic acid (H2PtCl6·6H2O) and 100g of substrate olefin (dimethylvinylchlorosilane), stir to dissolve and set aside.

[0084] Combination 1 in the raw materials refers to the raw materials for the following synthesis reaction:

[0085]

[0086] Combination 2 in the raw materials refers to the raw materials for the following synthetic reaction:

[0087]

[0088] Combination 3 in the raw materials refers to the raw materials for the following synthetic reaction:

[0089]

[0090] Combination 4 in the raw materials refers to the raw materials for the following synthetic reaction:

[0091]

[0092]

[0093] As can be seen from the data in the table above, when the modified platinum catalyst is used with the Speier catalyst, the continuous flow synthesis yield and product purity of the hydrosilylation reaction are relatively low.

[0094] As can be seen from the above embodiments, the present invention achieves a continuous flow synthesis reaction of hydrosilylation reaction by modifying the catalyst, optimizing the process steps and process conditions, with high yield and product purity, which is suitable for the needs of industrial production and has good application prospects.

Claims

1. A continuous flow hydrosilylation process employing a modified platinum catalyst characterized in that, comprising the following steps: Step 1, hydrogen-containing silane as raw material A, mixing the modified platinum catalyst with part of the olefin as raw material B, and the remaining olefin as raw material C; Step 2, raw material A and raw material B are respectively sent into a continuous flow mixer, and after mixing in the continuous flow mixer, reaction liquid A is obtained; Step 3, reaction liquid A and raw material C are respectively sent into continuous flow reactor A to react, and reaction liquid B is obtained; Step 4, reaction liquid B, raw material A and raw material C are respectively sent into at least one continuous flow reactor device in series to react, and a hydrosilylation product is obtained; The hydrogen-containing silane is selected from the following compounds: ; The olefin is selected from the group consisting of: ; The modified platinum catalyst is prepared by mixing and concentrating the following raw materials by weight: Isopropyl alcohol 95~103 parts, H2PtCl6•6H2O 0.9~1.2 parts, Polyhydric alcohol 3.5~5 parts, Nitrogen-containing heterocyclic compound 0.8~1.3 parts; The polyhydric alcohol is selected from ethylene glycol, diethylene glycol or triethylene glycol; The nitrogen-containing heterocyclic compound is selected from morpholine or N-methyl morpholine.

2. The continuous flow hydrosilylation method according to claim 1, wherein: The modified platinum catalyst is prepared by mixing and concentrating the following raw materials by weight: Isopropyl alcohol 100 parts, H2PtCl6•6H2O 1 part, Polyhydric alcohol 4 parts, Nitrogen-containing heterocyclic compound 1 part.

3. Continuous flow hydrosilylation process according to claim 1 or 2, characterized in that: The weight of the modified platinum catalyst obtained after concentration is 5 parts.

4. The continuous flow hydrosilylation method according to claim 1, wherein: In step 2, raw material A and raw material B are respectively preheated and then sent into a continuous flow mixer, the preheating temperature of raw material A is 30~70℃, the preheating temperature of raw material B is 30~70℃, and the temperature of the continuous flow mixer is controlled at 40~70℃; And / or, in step 2, the flow rate of raw material A is 3-200 ml / min, the flow rate of raw material B is 3-200 ml / min, the preheating time of raw material A is 5-50 min, the preheating time of raw material B is 5-50 min, and the residence time of raw material A and raw material B in the continuous flow mixer is 2.73-15 min; And / or, in step 3, the flow rate of raw material C is 2-145 ml / min, the residence time of reaction liquid A and raw material C in the continuous flow reactor A is 6.76-25 min, and the reaction temperature is 50~90℃; And / or, in step 4, the flow rate of raw material A is 2-145 ml / min, the flow rate of raw material C is 2-145 ml / min, reaction liquid B, raw material A and raw material C are reacted in the continuous flow reactor B and the continuous flow reactor C in series, the residence time of the reaction in the continuous flow reactor B is 5.6-13 min, the residence time of the reaction in the continuous flow reactor C is 5.6-13 min, and the reaction temperature is 50~90℃.

5. The continuous flow hydrosilylation method according to claim 4, wherein: In step 2, the preheating temperature of the raw material A is 40-50°C, the preheating temperature of the raw material B is 50-60°C, and the temperature control of the continuous flow mixer is 60-70°C; In step 3, the reaction temperature is 70-80°C; In step 4, the reaction temperature is 70-80°C.

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