CN116969821A - Method for photo-thermal catalysis of hydration carbonylation reaction of 4-tert-butyl phenylacetylene by using carbon nano tube - Google Patents

Abstract

The invention relates to a method for catalyzing aryl acetylene hydration carbonylation reaction by utilizing photo-thermal effect of carbon nano tubes, belonging to the technical field of catalysts. The method utilizes a photochemistry synthesis method, uses a xenon lamp as a light source, uses Carbon Nanotubes (CNTs) as a photo-thermal material, uses tetrabutylammonium bromide and a selective fluorine reagent Selectfluor as additives, and realizes hydration carbonylation of aryl alkyne under the action of Al, and when the reaction is carried out for 6 hours, the separation yield of carbonyl products is up to 81 percent. The method utilizes photocatalysis to efficiently realize alkyne carbonylation under the mild conditions of no acid and strong oxidant.

Description

A photothermal catalytic hydration carbonylation reaction of 4-tert-butylphenylacetylene using carbon nanotubes Methods

Technical field

The invention relates to a green chemical synthesis method, in particular utilizing the photothermal effect of carbon nanotubes to achieve catalysis of the hydration and carbonylation reaction of aryl acetylene under relatively mild conditions, and belongs to the technical field.

Background technique

As a method to form carbon-oxygen bonds, carbonylation reaction has high application value in the total synthesis of natural products. Aryl carboxylic acids, aryl amino acids, aryl esters and their derivatives can be prepared from carbonyl chemical precursors such as aryl ethyl ketones and aryl acetaldehyde. These chemicals are also used to synthesize many natural products and drugs. Very important intermediate. In 1860 Berthelot discovered the hydration of acetylene in sulfuric acid. At the same time, M. Kutscheroff discovered that the hydration reaction of alkynes catalyzed by mercury salts can generate propyne gas, and the concept of alkyne hydration began to appear. Beginning in 1916, Germany's industrial production of acetic acid was based on the hydration of acetylene to produce acetaldehyde, which was then oxidized by manganese-catalyzed air. Acetylene was initially produced from water and calcium carbide, but after 1940, the thermal cracking of CH ₄ gradually replaced the energy-intensive decomposition of carbides as the source of acetylene. The method of hydrated acetylene has been used to produce a variety of industrial chemicals on a large scale. The hydration carbonylation reaction of terminal alkynes in organic media was discovered in 1938, and until 1970, acetylene remained an important organic raw material for the production of vinyl derivatives, acrylates, and alkyne chemicals.

Among the various traditional synthesis methods of carbonyl compounds, the catalytic addition reaction of water and alkynes is also called hydration reaction. It is a synthesis method using unsaturated hydrocarbon precursors as raw materials and has the advantage of simplicity and efficiency. However, most of the reported catalysts for alkyne hydration reactions are based on toxic or expensive transition metals. For example, the classic Kucherov reaction is a nucleophilic addition reaction between alkynes and water to form aldehydes or ketones under the catalysis of HgSO ₄ -H ₂ SO _4. Although the reaction is relatively easy, the use of mercury salts is harmful to humans and the environment. Very harmful. With the rapid development of global economy and technology, however, the disposal of seriously polluting and toxic mercury waste has been an inherent problem of hydration reactions. For many years, other metal-based alkyne hydration methods besides mercury have been studied to develop new , a more efficient alkyne hydration process. Therefore, scientists have been working hard to develop safer and easier-to-operate alkynes carbonylation reactions.

With the rapid development of global economy and science and technology, humans are increasingly aware of the importance of sustainable development. Many synthetic chemists focus on the research direction of green chemistry. With the emergence and rapid development of photocatalytic free radical reactions, people have begun to think about replacing traditional organic reactions with greener and more environmentally friendly photochemical methods.

Contents of the invention

The technical problem solved by the present invention is to propose a photothermal catalytic hydration carbonylation reaction of 4-tert-butylphenylacetylene. This method does not use strong acid or alkali, has mild conditions, can be carried out at normal temperature and pressure, and is a green and efficient synthesis of carbonyl. chemical products.

In order to solve the above technical problems, the technical solution proposed by the present invention is: a method for utilizing the photothermal effect of carbon nanotubes to catalyze the hydration carbonylation reaction of 4-tert-butylphenylacetylene. The specific steps include:

Weigh tetrabutylammonium bromide and aluminum flakes into the container, then add 4-tert-butylphenylacetylene and acetonitrile, dissolve, take the fluorine reagent Selectfluor and dissolve it in water, then add it to the above mixed solution and add carbon nanotubes. The reaction is stirred under the irradiation of a xenon lamp to obtain the target product. The reaction route is as follows:

Preferably, weigh tetrabutylammonium bromide and an aluminum piece and add them into a glass bottle, then add 4-tert-butylphenylacetylene and acetonitrile to dissolve, take the fluorine reagent Selectfluor and dissolve it in water, then add it to the above mixed solution and mix Add the carbon nanotubes, stir the reaction under the irradiation of a xenon lamp, and use a TLC plate to detect the reaction progress. After the reaction is completed, the acetonitrile is removed by rotary evaporation, and then ethyl acetate is added for extraction, and the organic phase is washed three times with water. After drying over anhydrous sodium sulfate, the organic phase was collected and concentrated on a rotary evaporator. The obtained crude product was separated and purified using a silica gel chromatography column, using ethyl acetate/n-hexane as the eluent to obtain the pure target product.

Preferably, the volume ratio of acetonitrile to water is 1:1.

Preferably, under normal temperature and pressure, the conversion of the reaction substrate can be completed in 6 hours of light reaction.

Preferably, after the reaction is completed, the temperature of the reaction system can reach 40°C.

Preferably, the molar ratio of 4-tert-butylphenylacetylene, tetrabutylammonium bromide and Selectfluor is: 1:5:3. The mass ratio of carbon nanotubes to Selectfluor is: 5:2.

Preferably, weigh 2 mmol of tetrabutylammonium bromide in the glove box, add it to a glass bottle together with a piece of 1 cm × 1 cm aluminum sheet, and then add 52.5 μL of 0.4 mmol of 4-tert-butylphenylacetylene and 8 mL of acetonitrile. , dissolve, take 0.425g1.2mmol Selectfluor and dissolve it in 8mL of aqueous solution, then add it to the above mixed solution and add 1g of 8-15nm carbon nanotubes, stir the reaction under the irradiation of a xenon lamp, and use a TLC plate to detect the reaction progress , after the reaction is completed, acetonitrile is removed by rotary evaporation, and then ethyl acetate is added for extraction, and the organic phase is washed three times with water, and after drying with anhydrous sodium sulfate, the organic phase is collected and concentrated on a rotary evaporator, and the obtained crude The product was separated and purified using a silica gel chromatography column, using ethyl acetate/n-hexane as the eluent, to obtain the pure target product, with an isolation yield of 81% and an HPLC yield of 96.5%.

Beneficial effects of the present invention:

(1) A research method that uses the photothermal effect of carbon nanotubes to catalyze the hydration reaction of aryl alkynes. Carbon nanotubes can absorb light of almost all wavelengths and have good heat transfer properties. CNTs have a very large long diameter. Therefore, its heat exchange performance along the length direction is very high, while its heat exchange performance in the vertical direction is relatively low. Through appropriate orientation, carbon nanotubes can synthesize highly anisotropic thermal conductivity materials. In addition, carbon nanotubes have high thermal conductivity. As long as a trace amount of carbon nanotubes is doped in the composite material, the thermal conductivity of the composite material will be greatly improved.

(2) The method of the present invention is simple and easy to operate. It directly uses carbon nanotubes as photothermal materials to catalyze the hydration carbonylation reaction of 4-tert-butylphenylacetylene under normal temperature and pressure. This method can obtain an isolation yield of 81% of the target ketone product in a short period of time.

(3) The method of the present invention can directly use sunlight as a light source, and also has a good yield under gram-level reaction, which provides the possibility for the method to be applied to large-scale production in the future.

(4) Using copper, zinc and other metals to replace the aluminum of the present invention, the catalytic hydration carbonylation reaction of 4-tert-butylphenylacetylene has a very low conversion rate, or tetrabutylammonium iodide or tetrabutylammonium tetrafluoroborate can be used When replacing the tetrabutylammonium bromide of the present invention, the conversion rate of the catalytic hydrated carbonylation reaction of 4-tert-butylphenylacetylene is also extremely low. The combination of the present invention has the ability to catalyze the hydrated carbonylation reaction of 4-tert-butylphenylacetylene with high The isolated yield of the target ketone product was 81%. For example, in the implementation of 2, the yield of 4-methylformate phenylacetylene is only 71%.

Description of the drawings

The present invention will be further described below in conjunction with the accompanying drawings.

Figure 1 shows the applied NMR image (A) and high-performance liquid phase image (B) of the hydrated carbonylation reaction of 4-tert-butylphenylacetylene catalyzed by carbon nanotubes.

Figure 2 shows the application of carbon nanotube photothermal catalytic hydration carbonylation reaction of 4-methyl formate phenyl acetylene (A), NMR image (B) and high performance liquid phase image (C).

Figure 3 shows the application of carbon nanotube photothermal catalytic hydration carbonylation reaction of 4-tert-butylphenylacetylene.

Detailed ways

Example 1

Weigh 2 mmol of tetrabutylammonium bromide in the glove box, add it to the glass bottle together with a piece of 1 cm × 1 cm aluminum piece, then add 52.5 μL (0.4 mmol) of 4-tert-butylphenylacetylene and 8 mL of acetonitrile. Dissolve. Dissolve 0.425g (1.2mmol, 3equiv) of Selectfluor in 8mL of aqueous solution, then add it to the above mixed solution and add 1g of carbon nanotubes (Xianfeng Nano, 8-15nm). The reaction was stirred under the irradiation of a xenon lamp, and the reaction progress was monitored using a TLC plate. Under normal temperature and pressure, the conversion of the reaction substrate can be completed in 6 hours of light reaction. After the reaction is completed, the temperature of the reaction system can reach 40°C.

After the reaction is completed, the acetonitrile is removed by rotary evaporation, and then ethyl acetate is added for extraction, and the organic phase is washed three times with water. After drying with anhydrous sodium sulfate, the organic phase was collected and concentrated on a rotary evaporator to obtain a crude product. Separate and purify using silica gel chromatography column (using ethyl acetate/n-hexane as eluent) to obtain the pure target product, with an isolation yield of 81% and an HPLC yield of 96.5%.

Figure 1 shows the applied NMR image (A) and high-performance liquid phase image (B) of the hydrated carbonylation reaction of 4-tert-butylphenylacetylene catalyzed by carbon nanotubes, respectively proving the structure of the product and the conversion rate of the product.

Example 2

Weigh 2 mmol of tetrabutylammonium bromide in the glove box, add it to a glass bottle together with a piece of 1 cm × 1 cm aluminum sheet, then add 64 mmg (0.4 mmol) of 4-methylformate phenylacetylene and 8 mL of acetonitrile, and dissolve . Dissolve 0.425g (1.2mmol, 3equiv) of Selectfluor in 8mL of water, add 1g of carbon nanotubes, and then add it to the above mixed solution. The reaction was stirred under the irradiation of a xenon lamp, and the reaction progress was monitored using a TLC plate. After the reaction is completed, the acetonitrile is removed by rotary evaporation, and then ethyl acetate is added for extraction, and the organic phase is washed three times with water. After drying with anhydrous sodium sulfate, the organic phase was collected and concentrated on a rotary evaporator to obtain a crude product. Separate and purify using silica gel chromatography column (using ethyl acetate/n-hexane as eluent) to obtain the pure target product, with an isolation yield of 71% and an HPLC yield of 83%.

Figure 2 shows the application of carbon nanotube photothermal catalytic hydration and carbonylation reaction of 4-methyl formate phenyl acetylene (A), nuclear magnetic spectrum (B) and high performance liquid phase diagram (C), respectively proving the structure of the product and the conversion rate of the product. .

Comparative ratio

1. Weigh 0.644g (2mmol, 5equiv) of tetrabutylammonium bromide in the glove box, add it to a glass bottle together with a 1cm×1cm aluminum piece, then add 52.5μL of 4-tert-butylphenylacetylene and 8 mL of acetonitrile, dissolved. Dissolve 0.425g (1.2mmol, 3equiv) of Selectfluor in 8mL of water and add 0.5g and 1.5g of carbon nanotubes respectively, and then add them to the above mixed solution. The reaction was stirred under the irradiation of a xenon lamp, and the reaction progress was monitored using a TLC plate. Through testing, it was found that too many or too few carbon nanotubes will affect the conversion efficiency of the reaction, resulting in a reduction in conversion efficiency. When 0.5g of carbon nanotubes is used, it takes 8h to achieve complete conversion of the substrate, and when 1.5g is used, it takes 6.5h to achieve complete conversion of the substrate.

2. Weigh 0.644g (2mmol, 5equiv) of tetrabutylammonium bromide in the glove box, add it to the glass bottle together with a piece of 1cm×1cm aluminum sheet, then add 46.8mmg of 4-aminophenylacetylene and 8mL of Acetonitrile, dissolved. Dissolve 0.425g (1.2mmol, 3equiv) of Selectfluor in 8mL of water, add 1g of carbon nanotubes, and then add it to the above mixed solution. The reaction was stirred under the irradiation of a xenon lamp, and the reaction progress was monitored using a TLC plate. Through detection, it was found that the reaction did not occur and the target product was not detected.

3. Weigh 0.644g (2mmol, 5equiv) of tetrabutylammonium bromide in the glove box, add it to the glass bottle together with a piece of 1cm×1cm aluminum sheet, then add 41.2mmg of 2-ethynylpyridine and 8mL of Acetonitrile, dissolved. Dissolve 0.425g (1.2mmol, 3equiv) of Selectfluor in 8mL of water, add 1g of carbon nanotubes, and then add it to the above mixed solution. The reaction was stirred under the irradiation of a xenon lamp, and the reaction progress was monitored using a TLC plate. Through detection, it was found that the reaction did not occur, the target product was not detected, and the reaction system was not suitable for nitrogen-containing heterocyclic alkynes.

4. Weigh 0.644g (2mmol, 5equiv) of tetrabutylammonium bromide in the glove box, add it to the glass bottle together with a 1cm×1cm aluminum piece, and then add 52mmg of 1-phenyl-1-butyne. and 8 mL of acetonitrile to dissolve. Dissolve 0.425g (1.2mmol, 3equiv) of Selectfluor in 8mL of water, add 1g of carbon nanotubes, and then add it to the above mixed solution. The reaction was stirred under the irradiation of a xenon lamp, and the reaction progress was monitored using a TLC plate. Through detection, it was found that the reaction did not occur, the target product was not detected, and the reaction system was not suitable for non-terminal alkynes.

5. Weigh 0.644g (2mmol, 5equiv) of tetrabutylammonium bromide in the glove box, add it to the glass bottle together with a 1cm×1cm aluminum piece, then add 71.22mmg of 4-ethynylbiphenyl and 8mL of Acetonitrile, dissolved. Dissolve 0.425g (1.2mmol, 3equiv) of Selectfluor in 8mL of water, add 1g of carbon nanotubes, and then add it to the above mixed solution. The reaction was stirred under the irradiation of a xenon lamp, and the reaction progress was monitored using a TLC plate. After the reaction is completed, the product is separated and purified, and the yield of the target product is only 39%.

6. Weigh 2 mmol of tetrabutylammonium bromide in the glove box, add it to the glass bottle together with a 1 cm × 1 cm copper piece, then add 52.5 μL (0.4 mmol) of 4-tert-butylphenylacetylene and 8 mL of Acetonitrile, dissolved. Dissolve 0.425g (1.2mmol, 3equiv) of Selectfluor in 8mL of aqueous solution, then add it to the above mixed solution and add 1g of carbon nanotubes (Xianfeng Nano, 8-15nm). The reaction was stirred under the irradiation of a xenon lamp, and the reaction progress was monitored using a TLC plate. It was found that no reaction occurred.

7. Weigh 2 mmol of tetrabutylammonium bromide in the glove box, add it to the glass bottle together with a 1 cm × 1 cm zinc piece, then add 52.5 μL (0.4 mmol) of 4-tert-butylphenylacetylene and 8 mL of Acetonitrile, dissolved. Dissolve 0.425g (1.2mmol, 3equiv) of Selectfluor in 8mL of aqueous solution, then add it to the above mixed solution and add 1g of carbon nanotubes (Xianfeng Nano, 8-15nm). The reaction was stirred under the irradiation of a xenon lamp, and the reaction progress was monitored using a TLC plate. It was found that the formation of the target product was not detected.

9. Weigh 0.738g (2mmol, 5equiv) of tetrabutylammonium iodide in the glove box, add it to the glass bottle together with a 1cm×1cm aluminum piece, then add 52.5μL of 4-tert-butylphenylacetylene and 8 mL of acetonitrile, dissolved. Dissolve 0.425g (1.2mmol, 3equiv) of Selectfluor in 8mL of water, add 1g of carbon nanotubes, and then add it to the above mixed solution. The reaction was stirred under the irradiation of a xenon lamp, and the reaction progress was monitored using a TLC plate. After the reaction, the conversion rate of the target product was only 37.5%.

10. Weigh 0.658g (2mmol, 5equiv) of tetrabutyl ammonium tetrafluoroborate in the glove box, add it to the glass bottle together with a piece of 1cm×1cm aluminum sheet, and then add 52.5μL of 4-tert-butylphenylacetylene. and 8 mL of acetonitrile to dissolve. Dissolve 0.425g (1.2mmol, 3equiv) of Selectfluor in 8mL of water, add 1g of carbon nanotubes, and then add it to the above mixed solution. The reaction was stirred under the irradiation of a xenon lamp, and the reaction progress was monitored using a TLC plate. After the reaction, the conversion rate of the target product was only 19.6%.

Claims (7)

1. A method for utilizing the photothermal effect of carbon nanotubes to catalyze the hydration carbonylation reaction of 4-tert-butylphenylacetylene, characterized in that: specific steps include: Weigh tetrabutylammonium bromide and aluminum flakes into the container, then add 4-tert-butylphenylacetylene and acetonitrile, dissolve, take the fluorine reagent Selectfluor and dissolve it in water, then add it to the above mixed solution and add carbon nanotubes. The reaction is stirred under the irradiation of a xenon lamp to obtain the target product. The reaction route is as follows: 2. The method for utilizing the photothermal effect of carbon nanotubes to catalyze the hydration carbonylation reaction of 4-tert-butylphenylacetylene according to claim 1, characterized in that: weighing tetrabutylammonium bromide and an aluminum sheet are added to the glass together bottle, then add 4-tert-butylphenylacetylene and acetonitrile, dissolve, take the fluorine reagent Selectfluor and dissolve it in water, then add the above mixed solution and the added carbon nanotubes, stir the reaction under the irradiation of a xenon lamp, and use TLC Check the reaction progress with a plate. After the reaction is completed, remove the acetonitrile by rotary evaporation, then add ethyl acetate for extraction, wash the organic phase three times with water, dry it with anhydrous sodium sulfate, collect the organic phase and concentrate on the rotary evaporator. The obtained crude product was separated and purified using a silica gel chromatography column using ethyl acetate/n-hexane as the eluent to obtain the pure target product. 3. The method of utilizing the photothermal effect of carbon nanotubes to catalyze the hydration carbonylation reaction of 4-tert-butylphenylacetylene according to claim 2, characterized in that: the volume ratio of acetonitrile to water is 1:1. 4. The method for utilizing the photothermal effect of carbon nanotubes to catalyze the hydration carbonylation reaction of 4-tert-butylphenylacetylene according to claim 2, characterized in that: under normal temperature and pressure, the reaction substrate can be completed by illumination reaction for 6 hours. Transformation. 5. The method of utilizing the photothermal effect of carbon nanotubes to catalyze the hydration carbonylation reaction of 4-tert-butylphenylacetylene according to claim 2, characterized in that after the reaction is completed, the temperature of the reaction system can reach 40°C. 6. The method for utilizing the photothermal effect of carbon nanotubes to catalyze the hydrated carbonylation reaction of 4-tert-butylphenylacetylene according to claim 1, characterized in that: 4-tert-butylphenylacetylene, tetrabutylammonium bromide, The molar ratio of Selectfluor is: 1:5:3, and the mass ratio of carbon nanotubes to Selectfluor is 5:2. 7. The method of utilizing the photothermal effect of carbon nanotubes to catalyze the hydration carbonylation reaction of 4-tert-butylphenylacetylene according to claim 1, characterized in that: weighing 2 mmol of tetrabutylammonium bromide in a glove box, Add a piece of 1cm×1cm aluminum piece into the glass bottle, then add 52.5μL 0.4mmol 4-tert-butylphenylacetylene and 8mL acetonitrile, dissolve, take 0.425g1.2mmol Selectfluor and dissolve it in 8mL aqueous solution, then Add 1g of 8-15nm carbon nanotubes to the above mixed solution, stir the reaction under the irradiation of a xenon lamp, and use a TLC plate to detect the reaction progress. After the reaction is completed, remove the acetonitrile by rotary evaporation, and then add ethyl acetate for extraction. , and wash the organic phase with water three times, dry it with anhydrous sodium sulfate, collect the organic phase and concentrate it on a rotary evaporator, and separate and purify the obtained crude product with a silica gel chromatography column, washing with ethyl acetate/n-hexane. After removing the agent, the pure target product was obtained with an isolation yield of 81% and an HPLC yield of 96.5%.