JPS60181032A - Synthesis of organic compound using oxygen complex - Google Patents

Abstract

PURPOSE:In oxidizing an organic compound by the use of an oxygen compound, to obtain advantageously an oxygen-containing organic compound under mild conditions, by using a complex as a catalyst capable of forming a stable oxygen complex, consisting of a transition metal compound and an organic phosphorous compound as a ligand. CONSTITUTION:In synthesizing an oxygen-containing organic compound by oxidizing an organic compound in the presence of a catalyst which activates oxygen by formation of an oxygen catalyst, a complex shown by the formula MmXn.Le [M is transition metal belonging to I group, IV-VII group or iron group of VIII group of periodic table; X is anion such as halogen (especially Cl<->, Br<->, or I<->); L is ligand, preferably amide derivative of phosphorous acid or phosphoric acid, etc.; m-l are number to be determined by charge of M, X, and L, preferably 1-4], consisting of a transistion metal compound (MmXn) and an organic phosphorous compound (L) as a ligand, is used as the catalyst, and the desired compound is obtained under mild conditions selectively in high yield.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to a method for synthesizing an organic compound using an oxygen complex, and particularly to a method for producing a new oxygen-containing organic compound using an oxygen complex.

(Background of the Invention) Acetic acid and aldehyde, which are basic chemicals in the petrochemical industry, are synthesized by oxidation reactions using appropriate organic substrates as raw materials. Such an oxidation reaction is a reaction that occupies an important position in the reaction processes used in the petrochemical industry. However, these oxidation reactions have conventionally been carried out at high temperatures and pressures, and by-products are simultaneously produced, making it important to improve reaction selectivity and yield. For example, in the synthesis of carboxylic acids from aldehydes, C0lM
An oxygen oxidation method using transition metal ions such as n as a catalyst has been put into practical use. The reaction mechanism is that metal ions are first oxidized to a high valence state by oxygen, and Go (3
) or Mn(3), but it takes a complicated route that involves the generation of radicals in the intermediate stage, and the reaction temperature is, for example, around 50 to 70°C, so the oxidation reaction progresses further. Formic acid and CO□ are said to be produced as by-products. For this reason, high yields cannot be expected, and furthermore, complex separation steps are required to purify the product.

On the other hand, various studies have been conducted on oxygen complexes that act as effective oxidizing agents for the oxidation reaction of organic substances as a model for the respiratory reaction of living organisms. For example, iron in mammals
There are proteins or copper-proteins in molluscs. These are complex compounds of low valence ions such as divalent iron and monovalent copper and proteins.

Among metal ions that can have various valences, low-valence ions become oxidized by oxygen when they come into contact with oxygen, and become high-valence metal ions as shown in the following formula.

However, in hemoglobin and hemocyanin, in which Fe (2) or Cu (1) reacts with protein to form a protein complex (G), a direct oxidation reaction of metal ions does not occur even when they come into contact with oxygen, and the metal ions are oxidized as oxygen molecules. It is known that metal ions in complexes coordinate with G in a complex (that is, form an oxygen complex) as follows (Ogaki and Yamanaka, eds. Chemistry of Metal Tanno-Crystals, Kodansha (1983)).

P-Fe (2)-02-Fe (2)-P.

P Cu (1) 02 Cu (1) P (3) (P means protein) The oxygen molecules bound in this way are activated by coordination to metal ions, and the It has the ability to oxidize many organic substances at low temperatures, and the heat of reaction serves as an energy source for living organisms. However, such protein complexes become unstable once they leave the living body, and the metal ions are easily oxidized with oxygen, making them unsuitable as practical oxidation catalysts).

Therefore, finding a complex that can form a stable oxygen complex by using an artificial compound as a complexing agent and combining it with an appropriate transition metal has become a major challenge in terms of application to industrial oxidation reactions. There is.

(Objective of the Invention) The object of the present invention is to solve these problems, perform an oxidation reaction of organic substances under mild conditions, and selectively synthesize the target oxygen-containing compound in high yield. An object of the present invention is to provide a method for synthesizing organic compounds.

(Summary of the Invention) In short, the present invention aims to oxidize an organic compound as a substrate with the bound oxygen of the oxygen complex using a transition metal complex capable of forming an oxygen complex by coordinate bonding of oxygen molecules as a catalyst. This method synthesizes oxygen-containing compounds under mild conditions. That is, the present invention provides a method for synthesizing an oxygen-containing organic compound by oxidizing an organic compound in the presence of a catalyst that activates oxygen by forming an oxygen complex, in which a transition metal compound (M m X n ) and a transition metal compound (M m Using a complex (MmXn-L4) consisting of an organophosphorus compound (L) as a ligand (where M is a transition metal belonging to Group 1, Groups ■ to ■ of the Periodic Table, or Iron group of Group ■); X is an anion such as a halogen, a ligand is an organic phosphorus compound, and m and n11 are numbers determined by the charges of the transition metal and the ligand.

In the complex of the present invention, the X is C1-1Br-1■
- or BF4-1PF≦-1co, 2
The organic phosphorus compound containing anions and ligands such as -1CH, COO'''' is preferably a compound represented by an alkoxy, alkyl or amide derivative of phosphorous acid or phosphoric acid, and m, n'' Lt generally means the number of elements, and l means the number of ligands, each preferably from 1 to 4.

As mentioned above, the present inventors have studied various compounds that can form stable oxygen complexes in combination with appropriate transition metals in the oxygen oxidation of organic compounds. 1 Copper Cu (1) Hexamethylphosphoramide (also known as tris(dimethylamino)phosphine oxide, hereinafter h), which is a derivative of CA' and leonic acid
We have found that a complex of (referred to as mpa) can form a stable oxygen complex, and also confirmed that the bound oxygen is an effective oxidizing agent for organic substrates.

Cu (1) C4 in liquid h m p a! When added, a 1:111 complex is formed as shown below, but when such a complex is expressed by the general formula MmXn-Ll, m
=l, n-1, z-1. Note that Ti (3) or v (3) is the central metal and the anion is, for example, CI! −
In this case, m=l, n=3, i-1.

Cu (1) Cl +hmpa2-Cu (1)',
(J ・hmpla' (4) The formed complex is the liquid ligand h m p a itself (m, p, 7°C, b, 9.2
33°C/760mHg) is present in excess;
Toluene, cyclohexane, methyl isobutyl ketone,
cyclohexanone, ethanol, ethylene glycol,
Butyl acetate, propylene carbonate, chloroform,
Also soluble in chlorobenzene, triethylamine, pyridine, ethylmethyl sulfoxide, diphenyl sulfone, sulfolane, fluorinated toluene, pencitrifluoride, furan, tetrahydrofuran, etc.

Cu (1) Cn ・hmp a&! An ethyl alcohol solution of the body exhibits a pale yellow color, and its absorption spectrum has a maximum absorption at 260 nm, as shown at 1 in Figure 1. When oxygen or air is aerated into this, the absorbance increases and 2
Maximum absorption appears at 65 nm (2 in Figure 1), giving a green color. This was initially thought to be a complex of Cu(2) formed by oxidation of Cu(1) with oxygen. but,
As a result of synthesizing a complex solution of cupric chloride (Cu (2) Cl 2 ) and hmpa and measuring its spectrum, it was found that C
u (1) It shows a remarkable difference from the Cl・hmpa and its oxygen absorption liquid P spectrum, and as shown in 3 in Figure 1, the 290 nm
It had a maximum absorption at , and was reddish-brown in color. This Cu(1)C
The contrasting color difference with respect to the 1l-hmpa solution is thought to be due to the formation of so-called oxygen complexes in which oxygen molecules are coordinated in the former.

By the way, at a constant concentration of Cu (1)C1t -hmpa
As a result of measuring the oxygen absorption amount of body solution, Cu
The molar ratio of o2Vk yield to (1) is 2:l,
Therefore, it was found that the compound having maximum absorption at 265 nm and exhibiting a green color is a new oxygen complex having the following structure, similar to the oxygen complex of Cu(1)-hemocyanin.

hmp a-Cj! Cu(1), -O□-Cu(1)
Cl・, hmp aThe special feature of this oxygen complex is that the coordinated 0
2 is not desorbed from the complex even by heating or degassing under reduced pressure. Therefore, if the free oxygen/element in the liquid is removed in advance, there will be no free 02 in the catalyst liquid, thereby avoiding the risk of explosion due to direct mixing of the organic matter and the 02 gas. In addition, it is more stable than copper protein, and boiling at 100° C. is required to oxidize Cu (1) to Cu (2) with bound oxygen. Furthermore, it was found that this oxygen complex selectively oxidizes organic substances with bound oxygen under mild conditions, giving the desired new oxygen-containing compound in high yield.

For example, this oxygen complex can be converted into acetaldehyde (CH3CHO).
The reaction when applied to the oxidation of the ligand h m p a
is written as L, it is shown by the following formula, and acetic acid (CH3'C00
H) is generated.

2CH3CHO+L-Cu(1)C1! -02-Cu(
1) CIl-L-2CH3COOH+2LCu(1)C
m! Since this reaction proceeds at a low temperature of around 40° C. as described in the examples below, acetic acid can be obtained in high yield with few by-products. Oxygen activated by coordination bonds acts as an oxidizing agent, and there is no change in the valence of the central transition metal ion, and the oxygen complex is similar to the original Cu (1).
Since it becomes a CIl .hmpa complex, if oxygen is absorbed, it becomes an effective oxygen complex again. Cu (1) C1・hm
Since the oxygen absorption of p a is selective, it has the characteristic that an oxygen complex can be easily formed again if air is aerated as an oxygen source. That is, Cu (1) CI −
The hmpa complex acts as an oxygen activation catalyst. In addition, since oxygen is selectively absorbed using air,
The effect is exactly the same as when using pure oxygen, and this is advantageous in terms of cost.

The present invention can be applied to various oxidation reactions in which an organic compound as a substrate is oxidized with oxygen to obtain an oxygen-containing organic compound. Preferred common examples include reactions from aldehydes to corresponding organic acids, such as acetaldehyde to acetic acid, propionaldehyde to propionic acid, acrolein to acrylic acid, benzaldehyde to benzoic acid, etc.
Examples include reactions from primary alcohols such as ethyl alcohol to aldehydes such as acetaldehyde, secondary alcohols such as isopropyl alcohol to ketones such as acetone, and reactions from cumene etc. to phenol and acetone. In addition, the present invention can also be used in combination with other complex catalysts if necessary, from olefins such as ethylene and propylene, to aldehydes such as acetaldehyde and acrolein, to LPG,
Butane, naphtha, etc. to acetic acid, propylene and ammonia to acrylonitrile, ethylene and hydrogen chloride to vinyl chloride, ethylene and acetic acid to vinyl acetate, benzene to maleic anhydride, toluene to benzoic acid, naphthalene to phthalic anhydride, 0-xylene to anhydride It can be applied to various synthetic reactions such as phthalic acid, p-xylene to terephthalic acid, cyclohexane to cyclohexanol, etc.

In the present invention, a transition metal compound (Mm
The metal M in Xn) is Cu, Ag, which belongs to Group 1 of the periodic table.
, Tl5Z of group ■, rs V of group V, Nb, Cr of group ■% Mo, W1 Mn of group ■1 Fe of group ■,
Co, Ni, etc. are preferred, especially Cu(1), Ti
(3) and V (3) are preferred. Further, X of the transition metal compound is halogen or BF+-1PF<-150
Examples include anions such as 42-1CH3COO-,
Particularly preferred are halogens (1-1, Br-11-).

Ligands include mono-, di-, or triesters, phenylphosphinic acid esters, and phenylphosphinic acid esters produced from the reaction of phosphorous acid, which is a phosphorous acid derivative, with methanol, ethanol, etc.
Reaction of dimethylphosphinate, triethylphosphine, triphenylphosphine, etc., phosphoric acid derivatives such as triphenylphosphine oxyto, hexamethylphosphoramide, hexaethylphosphoramide, and phosphoric acid with methanol, ethanol, etc. Preferred are mono-, di-, and triester formed from organic phosphorus, as well as organic phosphorus compounds typified by dimethyl methylphosphonate and methyl dimethylphosphinate, with hexaethylphosphoramide being particularly preferred.

In addition, when carrying out the reaction in a solution state, it is preferable to use a solvent that can dissolve the complex and easily separate it from the produced oxygen-containing organic compound, including aliphatic, aromatic and alicyclic hydrocarbons. At least one compound selected from compounds, alcohols, ethers, ketones, glycols, carbonates, sulfones, and nitriles is used, or if the ligand is liquid, it also serves as the solvent. You can also do that.

The oxidation reaction can also be carried out by supporting a complex that absorbs oxygen to form an oxygen complex on a porous carrier such as activated carbon, silicate, porous glass, or a polymer having a giant network structure.

The novel complexes that form oxygen complexes, their properties, and examples of synthetic reactions using them have been described above. Next, examples of the present invention will be described. Note that the gas volumes in the examples are values under standard conditions.

(Embodiments of the invention) Example 1 5 g (50 mmol) of Cu (1) CI and 515 g of hmpa were charged into a reaction tube with an internal volume of 11, and 0.1
m o 1 / j! 500 ml of a Cu(1)C1·hmpa complex melt was prepared. When 3.3 liters of air and 1 O.sub.1 were bubbled through this, 0.55 Il (24.5 mmol) of oxygen was absorbed. The t&n2 gas was vented, but
The oxygen that had been physically dissolved in the liquid phase of the reactor was only removed, and no desorption of oxygen from the bound oxygen in the oxygen complex was observed, indicating that the oxygen absorption reaction was irreversible. This is a major feature in terms of process safety. 10 g (227 mmol) of acetaldehyde was added to this solution, and the mixture was heated to 40° C. under normal pressure. After reacting for 2 hours, the reaction solution was analyzed by gas chromatography. As a result, 2-8 g <41 mmol) of acetic acid was produced.

The reaction between acetaldehyde and the oxygen complex is zero according to the above-mentioned equation (5), and since acetaldehyde is present in excess in this example, the amount of acetic acid produced is regulated by the oxygen complex concentration. Therefore, the conversion rate of acetaldehyde to acetic acid was 96% based on the concentration of bond 02 in the oxygen complex, indicating that the oxidation reaction proceeded almost quantitatively.

Example 2 A reaction was carried out in the same manner as in Example 1 except that the reaction temperature was 60° C. and the reaction was allowed to proceed for 1 hour. As a result, acetic acid was 2.9
g (48 mmol) was produced, and by increasing the reaction temperature from 40°C to 60°C, the reaction rate increased,
It was found that the yield reached 98% in a short time.

Example 3 Acetaldehyde 0.9 g (2
0° C. rimole) was added thereto, and the reaction was carried out at a reaction temperature of 60° C. for 1 hour. In this case, since the oxygen complex is present in excess,
The yield of acetic acid is regulated by the acetaldehyp concentration. In this example, the acetic acid yield based on acetaldehyde was 98%.
It was found that the reaction proceeded almost quantitatively as in the previous example.

Example 4 In Example 2, acetaldehyde was pre-coated with Cu.
(1) An oxidation experiment was conducted under the same reaction conditions as in Example 2 by adding it to the Cjl-hmpa solution and then aerating air, and the reaction rate was 96%. Furthermore, if air and acetaldehyde are simultaneously mixed within the explosion limit, Cu(1)C1!
-Amount of reaction liquid in hmpa solution/Gas aeration rate = 60h-
When aerated at a rate of 1:1, 86% of the acetaldehyde was oxidized to acetic acid.

Example 5 In Example 1, the amount of hmpa added was 17.3 g, and Cu (1) C'j! - form a hmp a complex,
By adding toluene to this, Cu(1)Cjl
The toluene solution of the -hmpa complex was cleaved. after that,
The reaction was carried out under the same conditions as in Example 2, but the yield was 97%, and there was no change in the acetic acid yield even when toluene was used as the solvent.

Example 6 Under the same conditions as Example 2, 10 g of propionaldehyde
(172 mmol) was added to carry out the reaction. As a result, 3.4 g (46 mmol) of propionic acid was produced, and the yield based on the acid S complex was 94%. That is, it was confirmed that propionaldehyde was oxidized at a rate and selectivity comparable to that of acetaldehyde.

Example 7 Vanadium trichloride V(3)C was placed in the same reaction tube as in Example 1.
Z37.9g (50 mmol) and hmpa515
Prepare 0.1 m o 1/j! ■(3)C
m! 3. 500 ml of hmpa complex solution was prepared.

When I vented 1.5J of air into this, it was 0.45I! (2
0 mmol) of oxygen was absorbed, but the color rendering changed from the original red-purple to yellow-green. V(4)OC12-h of the complex of vanadyl chloride, which is a tetravalent vanadium complex, and hmpa
The color rendering of mpa is dark green, and from the difference between the two, V (3)
It is estimated that an oxygen complex of C13-hmpa is generated. Acetaldehyde 10 is added to the complex solution after oxygen absorption.
g (227 mmol) was added thereto, and the mixture was heated to 60 t'' under normal pressure.

After reacting for 1.5 hours, the amount of acetic acid produced was calculated.
The amount was 1.1 g (18 mmol), and the yield based on the bound oxygen in the oxygen complex was 43%.

Example 8 Titanium trichloride Ti(3)Cm was placed in the same reaction tube as in Example 1.
! 3 7.7g (50 mmol) and hmp a
Prepare 270 g and 230 g of sulfolane and prepare 0゜lm
o I/j! T'i (3)'Cj! 3 ・hm
500ml of pa complex solution was prepared. When air was aerated into this complex solution in the same manner as in Example 8, 0.284' (1
i, 5 mmol) of oxygen was absorbed. The original blue color changed to orange-red. Incidentally, when titanium tetrachloride Ti(4)C14, which is a high valence tetravalent titanium compound, is added to the same solution as above, a yellow precipitate is formed. From this, it is considered that an oxygen complex was generated also in the Ti(3)CJ:h .hmpali body solution. 10 g (172<lmol) of propionaldehyde was added to this solution, and the mixture was heated to 40° C. under normal pressure. When the complex solution was analyzed by gas chromatography after 1 hour, it was found that 1.0 g (14 mmol) of propionic acid had been produced, and the yield based on the oxygen complex was 56%.

Example 9 In Example 1, Cu (1) CJ is replaced by Cu (1) B
The same operation was performed except for r. As a result, there was no significant difference in the amount of oxygen absorbed, and the acetic acid yield was 94%.

Example 1O Giant reticulated styrene-divinylbenzene copolymer beads (particle size IBφ, specific surface area 700-800 nr/g
A catalyst solution containing an oxygen complex having the composition shown in Example 1 was impregnated into 50 ml of Amberlite This inner diameter is 20
A wφ hard glass reaction tube was filled, and acetaldehyde gas was aerated at a rate of 117 min.
It was heated to C. When the product in the outlet gas was analyzed using a gas chromatograph, it was found that the only product was acetic acid, and the yield based on acetaldehyde was 5% for 2 hours from the start of the reaction.
%Met. Thereafter, the outlet gas was recycled and the acetaldehyde yield on the basis of oxygen complexes reached 85%. Furthermore, the supply of acetaldehyde was temporarily stopped6.
After cooling to 0° C., air was aerated to regenerate the combined oxygen consumed in the reaction, and the oxidation experiment was performed again under the above conditions, but similar results were obtained.

From the above, it has become clear that even if the complex of the present invention is supported on a porous carrier, the reaction due to the bound oxygen in the oxygen complex proceeds.

Note that porous carriers such as silicates, activated carbon, and porous glass can be used as carriers, and as treatment methods after impregnation, various methods such as heated gas ventilation and low-temperature calcination can be used in addition to suction filtration. It was available for use.

(Effects of the Invention) According to the present invention, air is aerated into a complex consisting of a salt of a specific transition metal and an organic phosphorus compound to form a rilI elementary complex, and the combined oxygen activated thereby is used to form an organic compound. By oxidizing the organic compound, the oxygen oxidation reaction of the organic compound becomes possible at a temperature and under pressure, so the desired oxygen-containing organic compound can be selectively synthesized with high efficiency. In addition, since there are few by-products in the product, the manufacturing process including subsequent purification is simplified, and since oxygen is selectively absorbed using air as an oxygen source, it is completely comparable to products using pure oxygen gas. You can get the same effect. Furthermore, since oxygen absorption is irreversible, excess free oxygen can be easily removed after forming an oxygen complex, which is extremely advantageous in terms of safety.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the absorption spectrum of the complex used in the present invention. Agent Patent Attorney Takenaga Kawakita Figure 1 Moxibustion (nm)

Claims (1)

[Scope of Claims] (1) A method for synthesizing an oxygen-containing organic compound by oxidizing an organic compound in the presence of a catalyst that activates oxygen by forming an oxygen complex, in which a transition metal compound (Mm
Xn) and an organophosphorus compound (L) as a ligand (Mm X is an anion such as a halogen, a ligand is an organic phosphorus compound, and m, n, l are numbers determined by the charges of the transition metal and the ligand. Synthesis method of organic compound to be used. (2. In claim 1, the X is Cj!
Halogen such as -1Br-1■- or BF4-1PB
Anionic and ligand-based organic phosphorus compounds such as F4-1PF''-1CH and Coo- are characterized by being compounds represented by alkoxy, alkyl, or amide derivatives of phosphorous acid or phosphoric acid. A method for synthesizing an organic compound using an oxygen complex. (3) In claim 1 or 2, m
5nSl is a method of synthesizing organic compounds using oxygen complexes each having a value of 1 to 4. (4) In any one of claims 1 to 3, the solvent for the complex is an aliphatic, aromatic, or alicyclic hydrocarbon, an oxygen-containing organic compound, an organic halide,
An oxygen complex characterized by using at least one compound selected from a nitrogen-containing compound, an organic sulfur compound, an organic fluorine compound, and a heterocyclic compound, or by using the ligand itself as a solvent when the ligand is a liquid. A method of synthesizing organic compounds using (5) In any one of claims 1 to 4, oxygen is aerated into the solution of the complex to form an oxygen complex, and a substrate which is an organic compound is introduced into the solution to form an oxygen complex. A method for synthesizing organic compounds using an oxygen complex, which is characterized by oxidizing the complex with bound oxygen to synthesize an oxygen-containing organic compound. (6) In any one of claims 1 to 5, the complex is dissolved in a solvent, impregnated and supported on a porous carrier, and brought into contact with oxygen or air and an organic substance to form an oxygen complex. A method for synthesizing an organic compound using an oxygen complex, characterized by oxidizing the organic substance with bound oxygen to synthesize an oxygen-containing organic compound.