JP6937013B2 - Method for producing benzene compound and catalyst for producing benzene compound - Google Patents

Description

The present invention relates to a method for producing a benzene compound and a catalyst for producing the benzene compound, which can design various benzene derivatives and can obtain a desired benzene compound in an environment-friendly reaction system.

Benzene compounds are still widely used because they can be used for various purposes such as various polymer raw materials and pharmaceutical intermediates by changing the substituent to a desired group.
The conventional method for producing a benzene compound is to obtain a desired benzene compound by substituting benzene or phenol obtained by petrochemically, but this method can be produced depending on the substituent of the desired benzene compound. There was a problem that it was difficult and that a lot of by-products and a lot of waste were generated.
Therefore, attempts have been made to obtain a desired benzene compound by an isocyclization reaction in which an alkyne having a desired substituent is cyclized.
For example, Patent Document 1 discloses that a Ni-based catalyst or a CoMo catalyst can be used in a method for producing benzenes by a cyclization reaction from a plastic solution containing alkenes.
Further, Non-Patent Document 1 discloses that an alkyne can be cyclized using a supported Au catalyst.

JP-A-2007-332345

A. Corma et al. ACS Catal. 2013, 3, 1865-1873.

However, the production method according to the above-mentioned proposal has a problem that a benzene compound can be obtained only with a limited raw material and a variety of benzene compounds cannot be obtained. Therefore, it is possible to produce a variety of benzene compounds. At present, there is a demand for the development of a method for producing a benzene compound.
Therefore, an object of the present invention is a method for producing a benzene compound, which does not generate waste as in the case of using benzene as a starting material, has a low environmental load, and can produce various benzene compounds. The purpose is to provide a catalyst used in a manufacturing method.

式中、Ｒ^１〜Ｒ^６は、それぞれ同一でも異なっていてもいい基であって、それぞれ水素原子、ヘテロアリール基、炭素数２〜６のアルキル基、炭素数２〜４の置換基を有するアリール基、炭素数２〜６の置換基を有するアルキル基を示す。また、Ｘは、酸素原子、硫黄原子、Ｒ^７Ｎ＜、Ｒ^１Ｒ^２Ｃ＜ を示す。Ｒ^７はＲ^１〜Ｒ^６と同一である。
３．アルキン類からベンゼン化合物を製造するための触媒であって、
担体にＰｄとＡｕとをモル比でＰｄ:Ａｕ＝１：１〜１０で担持させてなる担持ＰｄＡｕ触媒からなる、ベンゼン化合物製造用の触媒。 As a result of diligent studies to solve the above problems, the present inventors have found that a catalyst having both palladium and gold is effective among the heterogeneous catalysts, and further, the composition of palladium and gold. The present invention was completed by examining the ratio and the like.
That is, the present invention provides the following inventions.
1. 1. A production method for producing a benzene compound from alkynes in the presence of a catalyst.
A method for producing a benzene compound, wherein the catalyst is a supported PdAu catalyst in which Pd and Au are supported on a carrier at a molar ratio of Pd: Au = 1: 1 to 10.
2. 1. The alkynes are alkynes represented by the following general formulas (I), (I)'or (I)'', and the benzene compounds are compounds represented by the following general formula (II). Benzene compound production method.

In the formula, R ^{1 to} R ⁶ are groups which may be the same or different, and have a hydrogen atom, a heteroaryl group, an alkyl group having 2 to 6 carbon atoms, and a substituent having 2 to 4 carbon atoms, respectively. It shows an aryl group and an alkyl group having a substituent having 2 to 6 carbon atoms. Further, X represents an oxygen atom, a sulfur atom, R ⁷ N <, and R ¹ R ² C <. R ⁷ is the same as ^{R 1 to} R ^6.
3. 3. A catalyst for producing benzene compounds from alkynes
A catalyst for producing a benzene compound, which comprises a supported PdAu catalyst in which Pd and Au are supported on a carrier at a molar ratio of Pd: Au = 1: 1 to 10.

The catalyst for producing a benzene compound of the present invention is a catalyst that does not generate waste as in the case of using benzene as a starting material, has a low environmental load, and can produce various benzene compounds.
Further, according to the method for producing a benzene compound of the present invention, unlike the case where benzene is used as a starting material, no waste is generated, the environmental load is low, and various benzene compounds can be produced.
Specifically, it is as follows.
-Since it is a heterogeneous catalyst, it is easy to recover the catalyst.
-Since almost no metal is mixed in the product, the environmental load is small.
-The catalyst can be reused, which is more cost effective and advantageous than homogeneous catalysts.
-Easy to handle even in air, with little decrease in activity.
・ Various benzene compounds can be synthesized.
-The corresponding polysubstituted benzene derivative can be obtained in high yield.

FIG. 1 (a) is a transmission electron microscope (TEM) photograph (drawing substitute photograph) of the catalyst having a loading amount of 3% by weight obtained in the synthetic example, and FIG. 1 (b) is a bar graph showing the particle size distribution. be. FIG. 2A is a TEM photograph (drawing substitute photograph) of the catalyst having a loading amount of 1% by weight obtained in the synthetic example, and FIG. 2B is a bar graph showing the particle size distribution. FIG. 3 is a graph showing the results of Example 12. FIG. 4 is a graph showing the results of Example 13. FIG. 5 is a graph showing the results of Example 14. FIG. 6 is a graph showing the results of Example 15. FIG. 7 is a graph showing the results of Example 16.

Hereinafter, the present invention will be described in more detail. First, the catalyst of the present invention will be described.
<Catalyst>
The catalyst for producing a benzene compound of the present invention is a catalyst for producing a benzene compound from alkynes, and comprises supporting Pd and Au on a carrier at a molar ratio of Pd: Au = 1: 1-10. It is composed of a supported PdAu catalyst and will be described in detail below.

(Carrier)
As the carrier, activated carbon or metal oxide can be preferably used, and oxides of base metal elements, transition metal elements or lanthanoids are more preferable, and specifically, TiO ₂ , Al ₂ O ₃ , SiO ₂ , ZrO ₂ , Nb ₂ O _{5 and the} like. When used, they can be used alone or in combination of two or more.
The shape of the carrier is preferably powdery and classified into 100 mesh or less.
The average particle size of the carrier is preferably 10 nanometers to 1 micrometer. The particle size distribution preferably has an average diameter of 10 to 100 nanometers. Here, the average particle size and the particle size distribution can be measured by an SEM, a TEM, or a zeta electron measuring device.
The specific surface area of the carrier is 50 to 1000 m ² g ^-1.
Is preferable. Here, the specific surface area can be measured by a nitrogen adsorption / desorption measuring device.

(Pd and Au)
Atoms of Pd and Au are randomly accumulated to form a cluster in which Pd atoms and Au atoms are mixed on a carrier.
The shape of the cluster is not particularly limited as long as it is a shape formed by a normal crystallization state.
The loading ratio of Pd and Au is Pd: Au = 1: 1 to 10 in terms of molar ratio, and Pd: Au = 1: 2 to 5 is preferable. If it is out of the above range, the yield will be significantly low, and there is a problem in terms of reactivity.
Further, Pd and Au may be supported on the carrier in the above-mentioned loading ratio, and the supporting amounts thereof are not particularly limited, but from the viewpoint of reactivity, 1 to 10 with respect to 100 parts by weight of the total amount of the catalyst. It is preferably parts by weight, more preferably 1 to 4 parts by weight. Further, the number of clusters may be one or more.

(structure)
The catalyst of the present invention comprises Pd and Au supported on the above-mentioned carrier in the above-mentioned supported amounts.
The average particle size of the catalyst is preferably 2 to 5 nanometers. Further, the narrower the particle size distribution, the more preferable. Here, the average particle size and the particle size distribution can be measured by TEM.
The specific surface area of the catalyst is preferably ^{50 to 1000 m 2} g ^-1. Here, the specific surface area can be measured by a nitrogen adsorption / desorption measuring device.
Further, the shape of the entire catalyst is preferably powdery.

(Manufacturing method)
The catalyst can be produced as follows.
First, an aqueous polyvinylpyrrolidone solution (preferably having a polyvinylpyrrolidone concentration of 0.5 to 3.0 g / liter) as a binder is prepared. A gold compound (HAuCl4, etc.) and a palladium compound (PdCl2, etc.) are added to the obtained aqueous solution of polyvinylpyrrolidone in an amount such that the blending ratio of Au and Pd becomes a desired blending ratio in the obtained catalyst, and Au · Pd is contained. Prepare an aqueous solution of polyvinylpyrrolidone. Then, while cooling the Au / Pd-containing polyvinylpyrrolidone aqueous solution to a temperature below room temperature, preferably 0 to 10 degrees Celsius, the sodium borohydride aqueous solution (the sodium borohydride concentration is preferably 2 to 10 g / liter). Is mixed, and the mixture is stirred and mixed for 10 to 120 minutes.
Then, a predetermined amount of a predetermined carrier is added to the obtained aqueous solution, and an acid aqueous solution such as a hydrochloric acid aqueous solution (preferably an aqueous solution of 1 specified) is added dropwise while adjusting the pH to a zero charge point (PZC).
After completion of the dropping, the mixture is stirred for 1 day, then adjusted to pH 3 to 6 with purified water and methanol, and then separated and dried to obtain the catalyst of the present invention.

The catalyst of the present invention may be a catalyst in which the above-mentioned Pd and the above-mentioned Au are supported on the above-mentioned carrier at the above-mentioned carrying ratio, and other components may be supported in addition to these, and other components may be supported in use. It may be used in combination with an ingredient.

式中、Ｒ^１〜Ｒ^６は、それぞれ同一でも異なっていてもいい基であって、それぞれ水素原子、ヘテロアリール基、炭素数２〜６のアルキル基、炭素数２〜４の置換基を有するアリール基、炭素数２〜６の置換基を有するアルキル基を示す。また、Ｘは、酸素原子、硫黄原子、Ｒ^７Ｎ＜、Ｒ^１Ｒ^２Ｃ＜ を示す。Ｒ^７はＲ^１〜Ｒ^６と同一である。）
<Manufacturing method of benzene compound>
Next, the method for producing the benzene compound of the present invention will be described.
The method for producing a benzene compound of the present invention is a method for producing a benzene compound from alkynes in the presence of a catalyst.
The catalyst is a supported PdAu catalyst in which Pd and Au are supported on a carrier at a molar ratio of Pd: Au = 1: 1 to 10.
Specifically, the alkynes are alkynes represented by the following general formulas (I), (I)'or (I)'', and the benzene compounds are compounds represented by the following general formula (II). Is preferable.
It will be described in detail below.

In the formula, R ^{1 to} R ⁶ are groups which may be the same or different, and have a hydrogen atom, a heteroaryl group, an alkyl group having 2 to 6 carbon atoms, and a substituent having 2 to 4 carbon atoms, respectively. It shows an aryl group and an alkyl group having a substituent having 2 to 6 carbon atoms. Further, X represents an oxygen atom, a sulfur atom, R ⁷ N <, and R ¹ R ² C <. R ⁷ is the same as ^{R 1 to} R ^6. )

(Alkynes)
Specific examples of the alkynes include the following compounds. In the case of (I), all three molecules may be the same, two molecules may be the same, one molecule may be different, or all three molecules may be different.

(Benzene compound)
The benzene compound obtained by the production method of the present invention is determined by the above alkynes, and specific examples thereof include the following compounds.

(Production method)
In carrying out the production method of the present invention, a predetermined amount of catalyst is added to a solution of the above alkynes in a solvent, and the temperature is preferably room temperature to 200 ° C. in the air or in the presence of an inert gas such as argon. The reaction from alkynes to the benzene compound can be carried out by carrying out the reaction at a temperature of 30 to 100 ° C., preferably for 1 hour or longer, more preferably for 2 to 50 hours with stirring. After completion of the reaction, the catalyst is separated by filtration or the like, and the desired benzene compound can be obtained by isolating and purifying the desired benzene compound from the obtained solution according to a conventional method.
Examples of the solvent that can be used in this case are aromatic hydrocarbon solvents such as toluene and benzene; ether solvents such as tetrahydrofuran (THF) and 1,4-dioxane; dichloroethane; acetonitrile; ethanol; dichloromethane; xylene; hexane; Mesitylene; dimethylformamide (DMF), dimethyl sulfoxide (DMSO); and the like can be mentioned.
The concentration of the alkynes in the solution is preferably 0.02 to 10 mol / liter, more preferably 0.5 to 3 mol / liter, and most preferably 1 to 3 mol / liter. preferable.
The amount of the catalyst used is preferably such that the concentration of the catalyst in the solution is 0.1 to 10 mol% with respect to the entire solution, and particularly preferably 1 to 5 mol%. be.

<Effect>
The method for producing a benzene compound of the present invention carried out as described above can easily and easily obtain a desired benzene compound.
Specifically, unlike the case where benzene is used as a starting material, no waste is generated, the environmental load is low, and various benzene compounds can be produced. Moreover, since it is a heterogeneous catalyst, it is easy to recover the catalyst. Since almost no metal is mixed in the product, the environmental load is small. The catalyst can be reused, which is cost-effective and advantageous as compared with a homogeneous catalyst. Since the catalyst of the present invention is easy to handle even in air and the decrease in activity is small, the production method of the present invention is also superior in this respect. There are few restrictions on substituents, various benzene compounds can be synthesized, and high yields can be obtained.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

<Catalyst Examples>
[Example 1]
An aqueous solution of polyvinylpyrrolidone having a polyvinylpyrrolidone concentration of 0.9 g / liter was prepared, and a gold compound (HAuCl4, etc.) and a palladium compound (PdCl2, etc.) were added to the aqueous solution of polyvinylpyrrolidone. An Au · Pd-containing aqueous solution was prepared by adding an amount of 3.
Then, while cooling this aqueous solution, a sodium borohydride aqueous solution having a sodium borohydride concentration of 3.7 g / liter was mixed, and the mixture was stirred and mixed for about 30 minutes.
_{Then, titanium oxide (TiO 2} ) was added to the obtained aqueous solution as a carrier so as to be 3 parts by weight with respect to 100 parts by weight of the carrier, and 1 specified hydrochloric acid aqueous solution was further added to pH = 3, which is the PZC of titanium oxide. Dropped as in. After completion of the dropping, the mixture was stirred for 1 day, then adjusted to pH 5 with purified water and methanol, and then separated and dried to obtain a catalyst composed of _{a TiO 2 carrier carrying PdAu (Pd: Au = 1: 3).} The amount of PdAu supported on the obtained catalyst was 3 parts by weight with respect to 100 parts by weight of the carrier (this case is referred to as "3% by weight" in the following examples).
The obtained catalyst was observed with a scanning electron microscope (SEM). In addition, the particle size distribution and the average particle size according to the above-mentioned measurement method were measured. The result is shown in FIG.
[Example 2]
_{Further, a catalyst composed of a TiO 2} carrier carrying PdAu (Pd: Au = 1: 1) having a loading amount of 1% by weight was obtained in the same manner except that the loading amount was set to 1% by weight. The obtained catalyst was observed with a transmission electron microscope (TEM). In addition, the particle size distribution and the average particle size according to the above-mentioned measurement method were measured. The result is shown in FIG.
[Examples 3 to 6, Comparative Example]
The ratio of Pd to Au was 1; 2 (Example 3), 1: 4 (Example 4) 1; 5 (Example 5), 1:10 (Example 6), 3: 1 (Comparative Example 1). , 1: 0 (Comparative Example 2), 0: 1 (Comparative Example 3). _A catalyst composed of two carriers was obtained.
[Examples 7 to 10]
Same as Example 1 except that the carrier was changed from TiO ₂ to Al ₂ O ₃ (Example 7), SiO ₂ (Example 8), or ZrO ₂ (Example 9), Nb ₂ O _{5 (Example 10).} Then, a catalyst composed of each carrier on which PdAu (Pd: Au = 1: 3) with a loading amount of 3% by weight was supported was obtained.

<Example of manufacturing method>
[Example 12, Comparative Example 4]
The catalysts obtained in Examples 1 to 4, the catalysts of Comparative Examples 1 to 3, the catalysts of Pd and Pt for comparison (Pd: Pt = 1: 3), and the catalysts of Pt and Au (Pt). A benzene compound was produced for the catalyst of: Au = 1: 3).
As shown in the following chemical formula, 1.5 mmol of compound 1 is dissolved in 1 ml of toluene, each catalyst is added thereto so as to be 1 mol% in the whole solution, and the reaction is carried out at 75 ° C. for 3 hours in an argon atmosphere. To obtain the benzene compounds represented by compounds 2 and 3. The yield of each catalyst is shown in FIG. The yield and reaction rate (conv.) Were measured by gas chromatography (“GC-2014” manufactured by Shimadzu Corporation), respectively.
As is clear from the results shown in FIG. 3, it can be seen that the catalyst of the present invention exhibits excellent catalytic activity. On the other hand, when the ratio of Pd to Au is outside the range of the present invention, it can be seen that there is no catalytic activity or the ratio is extremely low.

[Example 13]
A benzene compound was produced in the same manner as in Example 12 for catalysts having different carriers obtained in Examples 1 and 7 to 10, and the yields thereof were measured. The result is shown in FIG.
As is clear from the results shown in FIG. 4, it can be seen that the catalyst of the present invention exhibits excellent catalytic activity.

[Example 14]
The reaction was carried out in the same manner as in Example 12 except that the solvent in the reaction system was changed to the solvent shown in FIG. 5, to obtain compounds 2 and 3, respectively. The yields of each are shown in FIG. From the results shown in FIG. 5, it can be seen that aromatic hydrocarbon solvents (toluene, benzene), ether solvents (THF, 1,4-dioxane), and dichloroethylene are particularly preferable.

[Example 15]
_{A catalyst composed of a TiO 2} carrier carrying 1% by weight of PdAu (Pd: Au = 1: 1) was obtained in the same manner except that the supported amount was 1% by weight (Example 15). catalyst). The obtained catalyst and the catalyst of Example 2 were reacted in the same manner as in Example 12 to obtain compounds 2 and 3. The yield at that time was measured and shown in FIG. 6 together with the result of Example 12.
As is clear from the results shown in FIG. 6, it can be seen that the catalysts of Examples 1 and 2 are preferable.

[Example 16]
Concentration 0.5 mmol / ml Al rk compound (Compound 1) at the time of the reaction, 0.75 mmol / ml, except that the 3 mmol / ml A reaction was conducted in the same manner as in Example 12, to give the compound 2 and 3 rice field. The yield of the obtained benzene compound was measured, and the result is shown in FIG. As is clear from the results shown in FIG. 7, it can be seen that the case of 1.5 mmol / ml and 3 mmol / ml is particularly preferable.

[Example 17]
1.5 mmol of the compound described in the following chemical formula was dissolved in 1 ml of toluene, the catalyst of Example 1 was added thereto so as to be 1 mol% in the whole solution, and the following was added for each compound under an argon atmosphere at 100 ° C. By carrying out the time reaction shown in (1), the benzene compounds shown in Compounds 2 and 3 were obtained.

[Example 18]
As described in the chemical formula below, the reaction conditions were the reaction temperature of 100 ° C., an argon atmosphere or an air atmosphere, and the reaction time was 2 hours. Got As is clear from the results shown below, it can be seen that the reaction proceeds sufficiently even in an air atmosphere and a benzene compound can be produced.

[Example 19]
The reaction was carried out in the same manner as in Example 12 except that the reaction temperature was 100 ° C. and the reaction time was 2 hours, and the catalyst taken out after the reaction was dried was reused. As shown below, the reuse reaction was carried out under the same conditions as the reaction of Example 12 except that the recovered catalyst was used and the reaction temperature was 100 ° C. and the reaction time was 2 hours. The results are shown below. It should be noted that the reuse was performed not only once but up to three times.
As is clear from the results shown below, high activity was obtained even after repeated use. It can also be seen that the amount of catalyst at the time of reuse does not decrease so much, and the catalyst can be recovered and reused with a high recovery rate.

[Example 20]
As shown in the following formula, using compound 5 (0.5 mmol) and compound 1 (0.6 mmol) as alkynes, the catalyst of Example 1 was added to the total solution in an argon atmosphere or an air atmosphere in an amount of 3 mol%. The benzene compound shown in Compound 6 was obtained by carrying out the reaction at a reaction temperature of 100 ° C. for 1.5 hours in 1 ml of toluene.
The yield of the obtained compound 6 is shown below. From this example, it can be seen that the catalyst is effective in various alkynes and that the reaction proceeds even in air to obtain a desired benzene compound.

[Example 21]
After completion of the reaction in the argon atmosphere in Example 20, the catalyst was recovered and the reaction was carried out in the same manner as in Example 20 except that it was reused in the same manner as in Example 19 to obtain the desired compound 6.

[Example 22]
Alkynes 5 0.3 mmol and alkynes 7 (R are as shown below) described in the following chemical formula are dissolved in 1 ml of toluene, and the catalyst of Example 1 is prepared therein so as to have a total solution of 6 mol%. Was added, and each compound was reacted for the time shown below in an argon atmosphere at 75 ° C. to obtain the benzene compound shown in Compound 8.

[Example 23]
Examples in which 0.3 mmol of the alkynes 9 (reactions were carried out for each of the five types 9a to 9e) and alkynes 1 described in the following chemical formula were dissolved in 1 ml of toluene, and the total amount of the solution was 6 mol%. By adding the catalyst of No. 1 and carrying out the time reaction shown below for each compound in an argon atmosphere at 75 ° C., the benzene compound represented by compound 10 (R in the formula corresponds to R of 9a to 9e, respectively) was obtained. Obtained.

[Example 24]
0.5 mmol of the alkynes described in the following chemical formula was dissolved in 2.5 ml of 0-xylene, the catalyst of Example 1 was added thereto so as to have a total solution of 3 mol%, and the temperature was 140 ° C. under an argon atmosphere. , The reaction was carried out for 24 hours to obtain the benzene compound represented by Compound 12 in a yield of 68%.
Further, 0.5 mmol of 13 0.5 mmol of the alkynes described in the following chemical formula was dissolved in 2.5 ml of 0-xylene, the catalyst of Example 1 was added thereto so as to have a total solution of 3 mol%, and argon was added at 140 ° C. By carrying out the reaction for 3 hours in an atmosphere, the benzene compound represented by compound 14 was obtained in a yield of 50%.

Claims (3)

A production method for producing a benzene compound from alkynes in the presence of a catalyst.
The catalyst is a supported PdAu catalyst in which Pd and Au are supported on a carrier at a molar ratio of Pd: Au = 1: 1 to 10.
The carrier is an oxide of a base metal element, a transition metal element or a lanthanoid.
A method for producing a benzene compound, wherein the amount of Pd and Au supported on the carrier is 1 to 4 parts by weight with respect to 100 parts by weight of the total amount of the catalyst. The claim that the alkynes are alkynes represented by the following general formula (I), (I)'or (I)'', and the benzene compound is a compound represented by the following general formula (II). 1. The method for producing a benzene compound according to 1.

In the formula, R ^{1 to} R ⁶ are groups that may be the same or different, respectively, and are a hydrogen atom, a heteroaryl group, an alkyl group having 2 to 6 carbon atoms, a phenyl group, a methylphenyl group, and a methoxy group, respectively. OCH ₃ ) and carboxymethyl group (CO ₂ CH ₃ ) are shown. Further, X represents an oxygen atom, a sulfur atom, R ⁷ N <, and R ¹ R ² C <. R ⁷ represents a tosyl group or the same group as R ^{1 to} R ⁶ . A catalyst composed of a supported PdAu catalyst in which Pd and Au are supported on a carrier at a molar ratio of Pd: Au = 1: 1 to 10 for producing a benzene compound from alkynes.
The carrier is an oxide of a base metal element, a transition metal element or a lanthanoid.
The amount of Pd and Au supported on the carrier is 1 to 4 parts by weight with respect to 100 parts by weight of the total amount of the catalyst. Production of benzene compound A catalyst for producing a benzene compound.

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