JPH06262086A - Catalyst for aldehyde synthesis and preparation of aldehyde - Google Patents

Abstract

PURPOSE:To obtain a catalyst for aldehyde synthesis with high catalytic activity and stability capable of producing branched chain aldehyde. CONSTITUTION:The subject catalyst for aldehyde synthesis uses hydroformylation reaction of olefin and synthesizes aldehyde containing rhodium complex which has a multidentate ligand with at least. one nitrogen atom. The multidentate ligand has a nitrogen atom such as imidazole or hexamethylphosphorustriamide, and at least, one atom selected from nitrogen atom, phosphorus atom and oxygen atom. The branched chain aldehyde can be obtained at high selectivity by subjecting olefin, carbon monoxide and hydrogen to a chemical reaction in the presence of the catalyst for aldehyde synthesis, under conditions such as the sum of partial pressures of carbon monoxide and hydrogen of about 10 to 150kg/cm<2> and the reaction temperature of about 50 to 160 deg.C.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a catalyst for aldehyde synthesis, and a method for producing an aldehyde by reacting an olefin with carbon monoxide and hydrogen in a liquid phase.

[0002]

2. Description of the Related Art Cobalt-carbonyl complex catalysts, cobalt-tertiary alkylphosphine complex catalysts, rhodium-carbonyl complex catalysts, and rhodium-triarylphosphine complex catalysts are used as a method for producing aldehydes by hydroformylation of olefins. Each method using a catalyst is known.

Of these, the method using a rhodium-triarylphosphine complex catalyst has extremely high catalytic activity and reaction selectivity, and the reaction can be carried out at a lower pressure than other catalyst systems, so that the equipment cost is low. It has the advantage that aldehydes can be produced. According to this method, a linear aldehyde can be obtained from α-olefin with high selectivity,
It is used for industrial production of n-butyraldehyde and the like.

However, in the method using the above rhodium-triarylphosphine complex catalyst, it is necessary to allow a large excess of phosphine ligand to exist in the system in order to avoid deactivation of the catalyst. For example, in JP-B-57-61336 and JP-B-58-57413, a phosphine ligand is used in an amount of 200 moles or more relative to rhodium.
Therefore, in the above method, the recovery of the phosphine ligand becomes very complicated. Further, if the phosphine concentration in the reaction solution is high, the reaction rate tends to decrease.

On the other hand, in recent years, due to the demand for conversion of the methyl methacrylate production method, the usefulness of isobutyraldehyde as a synthetic intermediate for methacrylic acid has increased, and branched aldehydes have been selected in the hydroformylation reaction of olefins. The development of technology for manufacturing with good performance has been desired.

However, in the above method, under low pressure conditions,
It is not possible to obtain a branched aldehyde with a high selectivity while maintaining the stability of the catalyst. For example, in the hydroformylation reaction of 1-octene using the rhodium-triarylphosphine-based catalyst, it is known that when the reaction pressure is lowered, the production ratio of branched aldehydes is reduced [Catalysis Reviews, 6 , 72 (1972)
]. Further, in JP-A-50-123611, in a hydroformylation reaction of propylene with a rhodium-triarylphosphine-based catalyst, when the concentration of triarylphosphine in the reaction solution is low, the reaction pressure is lowered below a specific pressure. The higher the selectivity of the branched chain aldehyde, the poorer the stability of the catalyst,
It is described that when the concentration of the triarylphosphine is increased to improve the stability of the catalyst, the selectivity of the branched chain aldehyde decreases.

[0007]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a catalyst for aldehyde synthesis which has high catalytic activity and stability and which produces a branched aldehyde with high selectivity.

Another object of the present invention is to provide a method for producing an aldehyde which is capable of producing a branched chain aldehyde efficiently with high selectivity and stably.

[0009]

The present inventors have conducted extensive studies in order to achieve the above object, and as a result, have found that a rhodium complex having a polydentate ligand having at least one nitrogen atom, olefin, carbon monoxide, and hydrogen. When reacted in the presence of a catalyst containing
The inventors have found that a branched aldehyde can be produced with a high selectivity in a high yield and stably for a long period of time, and completed the present invention.

That is, the present invention is a catalyst for aldehyde synthesis by olefin hydroformylation reaction,
Provided is a catalyst for aldehyde synthesis, which comprises a rhodium complex having a polydentate ligand having at least one nitrogen atom.

The present invention also provides a catalyst for branched aldehyde synthesis, which comprises a rhodium complex having a polydentate ligand having at least one nitrogen atom.

The present invention further provides a method for producing an aldehyde, which comprises reacting an olefin with carbon monoxide and hydrogen in the presence of the above-mentioned catalyst for aldehyde synthesis.

In the present specification, the polydentate ligand means an atomic group containing two or more coordinating atoms capable of coordinating with the central atom of the complex. The atomic group includes a neutral molecule and an anion.

The catalyst of the present invention is not particularly limited as long as it contains a rhodium complex having a polydentate ligand having at least one nitrogen atom. The polydentate ligand is a bidentate ligand,
It may be any ligand having two or more coordination atoms such as a tridentate ligand, a tetradentate ligand, a pentadentate ligand, and a hexadentate ligand. Among these ligands, polydentate ligands having 2 to 12 coordinating atoms, particularly polydentate ligands having 2 to 8 coordinating atoms are frequently used.

The coordinating atom of the polydentate ligand may be any atom capable of coordinating with the rhodium atom, and in addition to the nitrogen atom, for example, atoms such as oxygen, sulfur, selenium, tellurium and phosphorus. Is mentioned. Each coordinating atom of the multidentate ligand may be the same or different. Further, in the rhodium complex, the polydentate ligand and a rhodium atom may form a chelate. It is not necessary that all the coordination atoms of the polydentate ligand be bonded to the rhodium atom.

As the polydentate ligand, a polydentate ligand having a nitrogen atom and at least one atom selected from a nitrogen atom, a phosphorus atom and an oxygen atom is particularly preferable. Such polydentate ligands include (1) a polydentate ligand containing at least two nitrogen atoms, (2) a polydentate ligand containing at least one nitrogen atom and at least one phosphorus atom, (3) A polydentate ligand containing at least one nitrogen atom and at least one oxygen atom is included.

Examples of the polydentate ligand (1) containing at least two nitrogen atoms include, for example, imidazole, 1-methylimidazole, imidazolidine, pyrazole, pyrazolidine, 1H-1,2,3-triazole, 2H-1. , 2,
3-triazole, 1H-1,2,4-triazole,
4H-1,2,4-triazole, 1H-tetrazole, 1,2,5-oxadiazole, 1,3-dimethyl-2-phenyl-1,3,2-diazaphosphoridine (DMADPP), 1 Compounds having a nitrogen-containing 5-membered heterocycle such as pyrrolepropionitrile; pyridazine, pyrimidine, pyrazine, piperazine, 1,3,5-triazine, 1,2,4,5-tetrazine, 2-cyanopyridine, 2- Dimethylaminopyridine, 4-dimethylaminopyridine, 1-piperidine propionitrile, 2,
Compounds having a nitrogen-containing 6-membered heterocycle such as 2 ′, 2 ″ -terpyridyl; 1H-indazole, 2H-indazole, benzimidazole, 5,6-dimethylbenzimidazole, benzotriazole, purine, adenine, quinazoline, 1,8 -Naphthyridine, 1,10-phenanthroline, 1,4-diazabicyclo [2.2.2] octane (DABCO), 1,5-diazabicyclo [5.
4.0] undecene-5 (DBU), 1,5-diazabicyclo [4.3.0] nonene-5 (DBN), porphyrin, 5,10,15,20-tetraphenyl-21.
H, 23H-porphyrin (TPP), phthalocyanine, 4,4 ′, 4 ″, 4 ″ ″-tetraaza-29H,
31H-phthalocyanine, 3-cyanoindole, 5-
Nitrogen-containing polycyclic compounds such as cyanoindole; ethylenediamine, N, N, N ', N'-tetramethylethylenediamine, ethylenediaminetetraacetic acid, propylenediamine, diamines and polyamines such as diethylenetriamine; hexamethylphosphoramide (HMPA), Examples thereof include amides such as hexamethylphosphorus triamide (HMPT).

(2) As the polydentate ligand containing at least one nitrogen atom and at least one phosphorus atom, phosphorus-containing amines such as tris (diphenylphosphinoethyl) amine and bis (diphenylphosphinoethyl) amine; ，
A nitrogen-containing phosphorus-containing heterocyclic compound such as 3-dimethyl-2-phenyl-1,3,2-diazaphosphoridine (DMADPP); the hexamethylphosphoramide (HMP
A), the hexamethylphosphorus triamide (HMP
Examples thereof include phosphorus-containing amides such as T).

As the polydentate ligand (3) containing at least one nitrogen atom and at least one oxygen atom, oxazole,
Oxygen-containing nitrogen-containing heterocyclic compounds such as isoxazole, 4H-1,4-oxazine, morpholine, 1-methylmorpholine and benzoxazole; amino alcohols such as ethanolamine, diethanolamine and triethanolamine.

Most of the polydentate ligands are water-soluble, such as imidazole and triethanolamine. Such a water-soluble polydentate ligand is preferably used as the polydentate ligand in the catalyst of the present invention. When a water-soluble polydentate ligand is used as the polydentate ligand, the following advantages occur. That is, in the conventional method using a rhodium-triarylphosphine complex-based catalyst, an excess amount of the triarylphosphine ligand is usually present in the reaction system to stabilize the catalyst. Since both of the high boiling point compound produced as a by-product in the reaction and are lipophilic, they cannot be easily separated. Therefore, it is difficult to efficiently recover the triarylphosphine ligand. On the other hand, in the method of the present invention, when the water-soluble ligand is used as the polydentate ligand of the rhodium complex, for example, water is allowed to exist in the reaction system to cause a reaction in a bilayer system, By adding water after the reaction is completed, the ligand used in excess is distributed to the water layer, and the high-boiling compound by-produced is distributed to the organic layer, so that the ligand is efficiently recovered from the water layer. In addition, the high boiling point compound can be easily separated and removed.

The rhodium complex may have a plurality of the polydentate ligands.

The catalyst of the present invention can be prepared by a conventional method. For example, it can be easily prepared by reacting an appropriate rhodium compound with the polydentate ligand. More specifically, for example, hydrocarbonyl tris (triphenylphosphine) rhodium [HRh (CO)]
A desired catalyst can be prepared by reacting a rhodium complex such as (PPh ₃ ) ₃ ] with the polydentate ligand in a suitable solvent, if necessary, and exchanging the ligand. The prepared catalyst may be used as it is, or may be separated and purified before use.

The catalyst of the present invention thus obtained is preferably used as a catalyst for aldehyde synthesis by hydroformylation reaction of olefins and as a catalyst for synthesis of branched aldehydes. For example, in the presence of the catalyst of the present invention,
When an olefin is reacted with carbon monoxide and hydrogen, the hydroformylation reaction proceeds rapidly, and a branched aldehyde having one more carbon number than the starting olefin is produced with high selectivity.

The olefin in the production method of the present invention is not particularly limited, and includes a wide range of compounds having a carbon double bond in the molecule. The olefin may have a substituent as long as the reaction is not hindered. Examples of the olefin include propene, 1-butene,
2-butene, 1,3-butadiene, 2-methylpropene, 1-pentene, 2-pentene, 1-hexene, 2-
C2-C1 such as hexene, 3-hexene, 1-heptene, 1-octene, 1-decene, 1-pentadecene
Examples thereof include linear or branched olefins of No. 5, and the like. Among them, propene, 1-butene, 1-pentene,
C3-C15 α-olefins such as 1-hexene, 1-heptene and 1-pentadecene, especially propene, 1
-C3-C4 α-olefins such as butene are preferably used.

The reaction may be carried out without using a solvent, but it may also be carried out in the presence of a solvent which does not adversely influence the reaction. Examples of the solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane and dodecane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; benzene, toluene, xylene, ethylbenzene, cumene and cymene. Aromatic hydrocarbons such as; carbon tetrachloride, chloroform, dichloromethane, halogenated hydrocarbons such as 1,2-dichloroethane; carboxylic acids such as acetic acid and propionic acid; methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, etc. Amyl acetate, cellosolve acetate, ethyl propionate and other esters; diethyl ether, dibutyl ether, dimethoxyethane, anisole, dioxane, tetrahydrofuran and other ethers; acetone, methyl ethyl ketone, cyclohexanone and other ketones Aldehydes such as benzaldehyde; emissions such acetonitrile, N,
An aprotic polar solvent such as N-dimethylformamide or dimethyl sulfoxide is included. Preferred solvents include aliphatic hydrocarbons such as decane, aromatic hydrocarbons such as toluene, ethers such as anisole, carboxylic acids such as acetic acid, and the like. Further, when the reaction product is separated by distillation after the completion of the reaction, the boiling point of the solvent is preferably higher than that of the target compound, aldehyde, so that the solvent can be recycled to the reaction system without distilling the solvent.

The reaction can also be carried out in a two-layer system by allowing water to exist in the system. When the reaction is carried out in a two-layer system, as described above, the recovery of the ligand and the separation and removal of the high boiling point compound are easy, so that it is particularly advantageous when the reaction is carried out in a continuous system.

The catalyst used in the reaction may be any of the above-mentioned catalysts, but it is particularly preferable to use a catalyst which produces 0.3 mol or more of a branched aldehyde with respect to 1 mol of a linear aldehyde. .

The concentration of the catalyst can be appropriately selected in consideration of the reaction rate and the economical efficiency, but usually, as rhodium, it is 0.
01-100 mmol / L, preferably 0.05-50
It is about mmol / L. If the catalyst concentration is too low, the reaction rate tends to decrease, and conversely, if it is too high, it is economically undesirable.

The active species when the catalyst of the present invention is used in the hydroformylation reaction is not known in detail, but the polydentate ligand, the starting olefin, carbon monoxide and hydrogen are coordinated with rhodium. Presumed to be a complex. It is considered that such a complex is not a single complex, but a plurality of complexes having different ligands produced by the competitive coordination between the respective ligands exist in an equilibrium state.

In the production method of the present invention, the polydentate ligand may be present in excess in the reaction system. The amount of the polydentate ligand used is, for example, 1 to 300 mol, preferably 5 to 100 mol, per 1 gram atom of rhodium. When the polydentate ligand is present in excess in the system, not only the stability of the catalyst is improved but also the selectivity of the branched chain aldehyde may be improved. Further, unlike the case of the conventional triarylphosphine ligand, the decrease in the reaction rate due to the excessive amount of the polydentate ligand is not observed.

The reaction temperature is, for example, 20 to 200 ° C, preferably 50 to 160 ° C, more preferably 90 to 130 ° C.
It is about ℃. If the reaction temperature is lower than 20 ° C., the reaction rate is slow, and if it exceeds 200 ° C., the produced aldehyde is likely to condense or the catalyst is easily deactivated.

The amounts of carbon monoxide and hydrogen used are usually 1 to 1000 per mol of the raw material olefin.
Mol, preferably 1 to 100 mol, more preferably 1
It is about 10 mol. The ratio of carbon monoxide to hydrogen is not particularly limited, but usually 1 to 10 mol of carbon monoxide is used with respect to 1 mol of hydrogen. The gas supplied to the reaction system is
If necessary, it may be diluted with a gas inert to the reaction, such as nitrogen, helium, argon or carbon dioxide.

The reaction pressure is usually from atmospheric pressure to 200 Kg / c.
m ² , preferably about ²⁰ to 150 Kg / cm ² . The sum of the partial pressures of carbon monoxide and hydrogen is, for example, 10 to 15
It is about 0 Kg / cm ² .

The reaction can be carried out in any of a batch system, a semi-batch system and a continuous system. ． The aldehyde produced by the reaction can be separated and purified by a conventional method such as concentration, distillation,
It can be easily obtained by extraction, crystallization, recrystallization, column chromatography or the like, or a combination thereof.

[0035]

EFFECTS OF THE INVENTION Since the catalyst of the present invention contains a rhodium complex having a polydentate ligand having at least one nitrogen atom, it has high catalytic activity and stability, and at the same time produces a branched chain aldehyde with high selectivity. Let

According to the production method of the present invention, since the catalyst having the above-mentioned excellent properties is used, a branched chain aldehyde can be produced efficiently with high selectivity and stably.

[0037]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited by these examples.

Examples 1 to 16 and Comparative Example In an electromagnetic stirring type autoclave having an internal volume of 300 ml, 5
Solvent 60 containing 50 ppm (however, 1650 ppm in Example 2) of hydrocarbonyl tris (triphenylphosphine) rhodium [HRh (CO) (PPh ₃ ) ₃ ]
A predetermined amount of ml and a predetermined ligand (L) were charged, the gas phase was replaced with nitrogen gas, and the mixture was stirred at 110 ° C. for 2 hours. In Example 10, the ligand was prepared by dissolving it in 0.6 ml of water.

Next, 0.06 mol of propylene gas was charged, and 40% of a mixed gas of carbon monoxide and hydrogen in a predetermined ratio was charged.
The mixture was pressed into a pressure of Kg / cm ² and reacted at a predetermined temperature for 2 hours.

After completion of the reaction, each component was qualitatively and quantitatively analyzed by gas chromatography. Table 1 shows the reaction conditions and reaction results of each Example and Comparative Example.

In Table 1, "DMADPP" is 1,3-dimethyl-2-phenyl-1,3,2-diazaphosphoridine, and "TPP" is 5,10,15,20-.
Tetraphenyl-21H, 23H-porphyrin, "H
"MPT" is hexamethylphosphorus triamide, "HM
“PA” is hexamethylphosphoramide, “production ratio (i /
"n)" is a production molar ratio of isobutyraldehyde and n-butyraldehyde (isobutyraldehyde / n-butyraldehyde), and "reaction selectivity" is when the "production ratio (i / n)" in Comparative Example is 1. The value of the "generation ratio (i / n)" of each example is shown.

[0042]

[Table 1]

Claims (5)

[Claims] 1. A catalyst for aldehyde synthesis by olefin hydroformylation reaction, which comprises a rhodium complex having a polydentate ligand having at least one nitrogen atom. 2. A catalyst for the synthesis of branched aldehydes, which comprises a rhodium complex having a polydentate ligand having at least one nitrogen atom. 3. The polydentate ligand comprises a nitrogen atom, a nitrogen atom,
The aldehyde synthesis catalyst according to claim 1 or 2, which has at least one atom selected from a phosphorus atom and an oxygen atom. 4. A method for producing an aldehyde, which comprises reacting an olefin, carbon monoxide, and hydrogen in the presence of the catalyst for aldehyde synthesis according to any one of claims 1 to 3. 5. The method for producing an aldehyde according to claim 4, wherein the reaction is carried out in the presence of a catalyst for aldehyde synthesis which produces 0.3 mol or more of a branched aldehyde with respect to 1 mol of the linear aldehyde.