JP2866936B2 - Method for producing oxygen-containing aromatic compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for efficiently producing useful oxygen-containing aromatic compounds such as aldehydes and alcohols by directly reacting aromatic hydrocarbons with carbon monoxide.

[0002]

2. Description of the Related Art It is known that it is possible in principle to convert aromatic hydrocarbons into oxygen-containing aromatic compounds such as aldehydes, alcohols and ketones via a carbonylation reaction. However, aromatic hydrocarbons generally have a large carbon-hydrogen bond energy, so that it is extremely difficult to activate the carbon-hydrogen bond to an extent sufficient to cause a carbonylation reaction. Accordingly, in order to convert aromatic hydrocarbons into useful oxygen-containing aromatic compounds such as aldehydes, alcohols, and ketones, generally, first, the compounds are converted to compounds activated by halogenation, oxidation, and the like, and then converted to a desired compound. Activating compounds of the structure must be separated and then the separated activating compounds must be sourced and reacted with carbon monoxide in the presence of a hydrogen source or a nucleophile by an indirect method. However, such an indirect method naturally requires more steps than the direct carbonylation method, and is not preferable in terms of resource saving and energy saving. In addition, a carbonylation method using a strong acid is known, but has practical problems in safety, corrosion of the apparatus, and the like.

On the other hand, in recent years, along with research on complex catalysts, attention has been paid to a method in which an activating means is combined with a complex catalyst, and research using this method on the reaction surface has been actively conducted.
In particular, research on a so-called photocatalytic reaction incorporating a means for activating by light is becoming active. In fact, based on a new activation method of carbon-hydrogen bond combining a transition metal complex catalyst and light irradiation, a method of reacting hydrocarbons and carbon monoxide under mild conditions near room temperature to obtain various useful compounds Has been proposed or reported [Japanese Patent No. 179
No. 1827, No. 1875550, No. 182594
No. 1986575, U.S. Pat. No. 4,900,41.
No. 3, No. 5,104,504, British Patent No. 2,195,117, French Patent No. 2,60
3,885, "American Chemical Society", No. 112
Vol., Page 7221 (1990)].

However, in this method for converting hydrocarbons in a photocatalytic reaction system, since a large amount of substrate is usually used in the form of a liquid phase reaction in which the raw material hydrocarbons also serve as a solvent. Need
There is a disadvantage that it is difficult to apply to hydrocarbons having a high melting point. Therefore, in such a case, it is desirable to use an appropriate solvent, but the solvent that can be usually considered is itself similar to the starting hydrocarbons by the light irradiation reaction in the presence of the complex catalyst. It undergoes various conversion reactions, generates many by-products, and inevitably inhibits the conversion reaction of target hydrocarbons.

[0005] As a solvent for the activation reaction of hydrocarbons by such a complex catalyst, a perfluoroalkane [Journal of the American Chemical Society, Vol.
7190 (1983)], liquefied xenon ["Journal of the American Chemical Society", Vol. 111, page 6841 (1989)], hydrocarbons having a plurality of tert-butyl groups ["The Bulletin of the Chemical Society of Japan", 1990, p. 585], trifluoroacetic acid [Journal of the Society of Synthetic Organic Chemistry, Vol. 52, p. 809 (1994)],
Water [“Journal of the American Chemical Society”, Vol. 118, p. 4574 (1996)] and the like are known.

However, these solvents have problems such as being expensive, complicated in handling, and insufficient in solubility of metal complexes and raw material hydrocarbons.
It was not industrially satisfactory. Therefore, the efficiency of the reaction can be increased and a wide range of raw materials can be applied.
And the development of an industrially advantageous solvent has been desired.

[0007]

SUMMARY OF THE INVENTION Under these circumstances, the present invention provides a method for producing useful oxygen-containing aromatic compounds such as aldehydes and alcohols by efficiently carbonylating aromatic hydrocarbons, and The purpose of the present invention is to provide a method for producing the present invention in an advantageous manner.

[0008]

The present inventors have conducted intensive studies on the direct carbonylation of aromatic hydrocarbons with carbon monoxide. As a result, the inventors have found that supercritical carbon dioxide or liquefied carbon dioxide can be used as a solvent. It was found that this compound formed a homogeneous phase with the complex catalyst, dissolved aromatic hydrocarbons and carbon monoxide as raw materials at a high concentration, and found that the above object could be achieved, and completed the present invention based on this finding. I came to.

That is, according to the present invention, in producing an oxygen-containing aromatic compound by reacting an aromatic hydrocarbon with carbon monoxide, supercritical carbon dioxide or liquefied carbon dioxide is used as a solvent, It is intended to provide a method for producing an oxygen-containing aromatic compound, which comprises irradiating light in the presence of a transition metal complex in which at least one is a phosphine compound.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the method of the present invention, the aromatic hydrocarbon used as a raw material preferably has 6 to 50 carbon atoms, particularly preferably 6 to 20 carbon atoms. This aromatic hydrocarbon is a group inert to the carbonylation reaction, for example, an alkoxy group, an aryloxy group, an acyl group, an acyloxy group,
It may be substituted with an alkoxycarbonyl group, a cyano group, a bis (hydrocarbyl) amino group, a bis (hydrocarbyl) aminocarbonyl group, a halogen atom, or the like.

Examples of such aromatic hydrocarbons include:
Benzene, toluene, o-, m- or p-xylene, ethylbenzene, propylbenzene, o-, m- or p-
Methylpropylbenzene, decylbenzene, naphthalene, α- or β-methylnaphthalene, 2,6-dimethylnaphthalene, α- or β-hexylnaphthalene, anthracene, 9,10-dihexylanthracene, tetralin, styrene, ethylphenyl ether, benzoic Ethyl acid and the like.

In the method of the present invention, a transition metal complex in which at least one of the ligands is a phosphine compound is used as a catalyst. As the transition metal component in the transition metal complex, rhodium, iridium, ruthenium,
Iron, nickel, cobalt and the like are preferably mentioned,
Of these, rhodium, iridium and ruthenium, particularly rhodium, are preferred.

In the transition metal complex, examples of the phosphine compound used as a ligand include a compound represented by the general formula R ¹ R ² R ³ P (I) (wherein R ¹ , R ² and R ³ are each an alkyl group) Group, an aryl group, an aralkyl group or a cycloalkyl group,
They may be the same or different, and may be a monophosphine compound represented by the general formula R ⁴ R ⁵ PA-PR ⁶ R ⁷ (II) (wherein R ⁴ , R ⁵ , R ⁶ and R ⁷ are each an alkyl group, an aryl group, an aralkyl group or a cycloalkyl group, which may be the same or different, and A represents an alkylene group, a cycloalkyl group or a cycloalkyl group; Which is an alkylene group, an arylene group, an aralkylene group or a ferrosenylene group).

In the general formulas (I) and (II), R
The carbon number of each group represented by ^{1 to} R ⁷ is not particularly limited, but is usually 20 or less. As for R ^{1 to} R ⁷ , an aliphatic hydrocarbon group such as an alkyl group or a cycloalkyl group is more preferable than an aromatic hydrocarbon group such as an aryl group or an aralkyl group from the viewpoint of catalytic performance.

Examples of the phosphine compounds represented by formulas (I) and (II) include trimethylphosphine, triethylphosphine, tributylphosphine, trioctylphosphine, tricyclohexylphosphine, tribenzylphosphine, triphenylphosphine, and diphenylmethyl. Phosphine, tri (p-tolyl)
Phosphine, tri (p-anisyl) phosphine, 1,2
-Bis (dimethylphosphino) ethane, 1,3-bis (dimethylphosphino) propane, 1,4-bis (dimethylphosphino) butane, 1,2-bis (dibutylphosphino) ethane, 1,2-bis (Dicyclohexylphosphino) ethane, α, α'-bis (dimethylphosphino) -o-xylene, 1,2-bis (dimethylphosphino) cyclohexane, 1,2-bis (diphenylphosphino) ethane, 1,4 -Bis (diphenylphosphino)
Butane, 1,1'-bis (dimethylphosphino) ferrocene, 1,2-bis (dimethylphosphino) benzene and the like.

In the method of the present invention, the transition metal complex used as a catalyst is not particularly limited as long as it has at least one phosphine compound as a ligand.

Examples of such transition metal complexes include RhX (R ¹ R ² R ³ P) ₃ and RhX (CO) (R ¹ R ² R ³
P) ₂ , HRh (CO) (R ¹ R ² R ³ P) ₃ , RhX (C
O) ₂ (R ¹ R ² R ³ P), [Rh (R ¹ R ² R ³ P) ₄ ] Y,
[Rh (R ¹ R ² R ³ P) ₂ (CNR) ₂ ] Y, RhX (C
O) R ⁴ R ⁵ PA-PR ⁶ R ⁷ ), IrX (R ¹ R ² R
³ P) ₃ , IrX (CO) (R ¹ R ² R ³ P) ₂ , IrH
₅ (R ¹ R ² R ³ P) ₂ , IrH ₃ (CO) (R ¹ R ² R
_{^{3 P) 2, IrX (CO}} ) (R 4 R 5 P-A-PR 6 R 7),
Cp'RhH ₂ (R ¹ R ² R ³ P), Cp'IrH ₂ (R ¹ R
² R ³ P), Co ₂ (CO) ₆ (R ¹ R ² R ³ P) ₂ , CpCo
X ₂ (R ¹ R ² R ³ P), CoX ₂ (R ¹ R ² R ³ P) ₂ , Co
X (R ¹ R ² R ³ P) ₃ , CoH (N ₂ ) (R ¹ R ² R
³ P) ₃ , CoH ₃ (R ¹ R ² R ³ P) ₃ , CpCo (R ¹ R ²
R ³ P) ₂ , AcCo (CO) ₃ (R ¹ R ² R ³ P), Fe
(CO) ₃ (R ¹ R ² R ³ P) ₂ , Ru (CO) ₃ (R ¹ R ² R
³ P) _{2 and the} like.

In the above formula, X is a hydrogen atom, a halogen atom, a hydroxyl group, a cyano group, an alkoxy group, a carboxylate group or a thiocyanato group, and Y is PF ₆ , B (C ₆ H
₅ ) ₄ , BF ₄ , ClO ₄ or X and CN are an isonitrile group, R is an alkyl group or an aryl group, Cp is a cyclopentadienyl group, Cp 'is a pentamethylcyclopentadienyl group, and Ac is an acetyl group. In the above, R ^{1 to} R ⁷ and A have the same meaning as described above.

In the method of the present invention, these transition metal complexes may be used alone or in combination of two or more. Further, the transition metal complex does not need to be prepared and used in advance, and the phosphine compound and an appropriate transition metal compound are allowed to coexist in a reaction system, and the in-situ (in situ)
In tu), a desired transition metal complex may be formed.

The transition metal compound used for such a purpose is not particularly limited. For example, when the transition metal is rhodium, RhX ₃ , Rh (acac)
(CO) ₂ , [RhX (CO) ₂ ] ₂ , [RhX (D
E)] ₂ , [RhX (EN) ₂ ] ₂ , RhX (CO) (R ¹
R ² R ³ P) _{2 and the} like. In the above formula, acac is an acetylacetonate group, DE is norbornadiene, 1,5-cyclooctadiene or 1,5-hexadiene, EN is ethylene or cyclooctene, and X and R ^{1 to} R ³ are as defined above. Has the same meaning.

In the method of the present invention, supercritical carbon dioxide or liquefied carbon dioxide is used as a solvent, and an aromatic hydrocarbon is reacted with carbon monoxide while irradiating light in the presence of the transition metal complex. , Is directly carbonylated. The light used for the light irradiation may have a wavelength range from ultraviolet to visible light, and the light source preferably includes, for example, a mercury lamp, a xenon lamp, and the sun. It is preferable that the irradiation light include a part or all of light in a region of 200 to 800 nm. For example, it is possible to control the wavelength range using a filter, a monochromator, or the like, or to use the light as monochromatic light.

In the method of the present invention, the amount of the transition metal complex to be used is not particularly limited and may be arbitrarily selected.
Advantageously, it is chosen to be in the range 1-5 mol%.
The raw material aromatic hydrocarbons may be initially charged all at once into the reaction system, or may be sequentially added to the reaction system. The reaction temperature and the reaction pressure are not particularly limited as long as they are in a supercritical region or a liquefaction region of carbon dioxide. Separation of the product after completion of the reaction can be easily carried out by subjecting the product to a usual separation operation such as distillation, recrystallization, chromatography and the like. In this way, the direct carbonylation of aromatic hydrocarbons results in oxygenated aromatics,
Mainly aldehydes and alcohols can be obtained efficiently. In this case, radicals generated in the middle may be combined with each other to form a dimer of hydrocarbon such as biphenyl and binaphthyl.

[0023]

According to the method of the present invention, aromatic hydrocarbons and carbon monoxide are reacted under mild conditions near room temperature using inexpensive and easily available carbon dioxide as a solvent. By directly carbonylating hydrogen, useful oxygen-containing aromatic compounds such as aldehydes and alcohols can be efficiently produced.

[0024]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The product was confirmed by the retention time of gas chromatography (GC) and the fragmentation pattern of GC-MS.

Example 1 10 mg of chlorocarbonylbis (trimethylphosphine) rhodium and 5 ml of benzene were charged into a stainless steel autoclave (window: quartz, diameter: 20 mm) with a window having a capacity of 30 ml, and heated at 35 ° C. to 5 atm of carbon monoxide ( Gauge pressure) and 90 atm of carbon dioxide (gauge pressure).
At this point, the carbon dioxide was in a supercritical state and formed a pale yellow homogeneous solution.

Next, this solution was externally irradiated with light using a 500 W high pressure mercury lamp at 35 ° C. for 24 hours. When the product was quantified by gas chromatography, the molar ratio of benzaldehyde, benzyl alcohol, biphenyl and benzophenone to the complex was 4.
2, 0.34, 0.10 and 0.007 were produced.

Comparative Example 1 The same procedure as in Example 1 was carried out except that 30 ml of benzene was used and the carbon dioxide pressure was changed to 0 atm (gauge pressure). It was 4. When this result is compared with Example 1, it is understood that almost the same yield can be obtained even when the amount of the substrate is reduced by using supercritical carbon dioxide as the solvent as in Example 1.

Example 2 In Example 1, except that the reaction temperature was changed to 15 ° C.
It carried out similarly to Example 1. In this case, the carbon dioxide was in a liquefied state and formed a pale yellow uniform solution. As a result, the amount of benzaldehyde produced was 8.2 in molar ratio to the complex.

Example 3 The procedure of Example 1 was repeated, except that 5 g of naphthalene was used in place of 5 ml of benzene, and the molar ratio of naphthaldehyde to the complex was 3.7.
Generated by

Comparative Example 2 The procedure of Comparative Example 1 was repeated except that 30 g of naphthalene was used instead of 30 ml of benzene and the reaction temperature was 90 ° C. (the melting point of naphthalene was 80 ° C.). , Naphthaldehyde was produced at a molar ratio of 0.2 to the complex. Comparing this result with Example 3, it can be seen that carbonylation proceeds more efficiently when supercritical carbon dioxide is used as a solvent than when naphthalene itself is used as a solvent.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ identification symbol FI // C07B 61/00 300 C07B 61/00 300 (58) Field surveyed (Int. Cl. ⁶ , DB name) C07C 47/50 -47/52 B01J 31/24 C07C 27/00 C07C 33/18 C07C 45/50 C07B 61/00 300 CA (STN)

Claims (5)

(57) [Claims] In producing an oxygen-containing aromatic compound by reacting an aromatic hydrocarbon with carbon monoxide, supercritical carbon dioxide or liquefied carbon dioxide is used as a solvent, and at least one of the ligands is used. A method for producing an oxygen-containing aromatic compound, which comprises irradiating light in the presence of a transition metal complex that is a phosphine compound. 2. The method according to claim 1, wherein the transition metal complex is rhodium, iridium,
The method according to claim 1, which is a complex of ruthenium, iron, nickel or cobalt. 3. The method according to claim 2, wherein the transition metal complex is a complex of rhodium, iridium or ruthenium. 4. The method according to claim 3, wherein the transition metal complex is rhodium.
The described method. 5. The method according to claim 1, wherein the oxygen-containing aromatic compound is an aromatic aldehyde or an aromatic alcohol.