JPS5817732B2 - Method for producing aldehydes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the production of aldehydes by hydroformylation of olefins.

More specifically, the present invention utilizes a complex consisting of platinum and a dicarboxylic ligand as a catalyst to catalytically hydroformylate olefins, such as propylene and 1-pentene, with hydrogen and carbon monoxide to produce the respective corresponding This invention relates to a method for selectively synthesizing aldehyde products such as butyraldehyde and hexylaldehyde.

It is conventionally known to hydroformylate olefins by reacting them with hydrogen and carbon monoxide.

Conventionally, the catalysts used in this hydroformylation reaction include cobalt carbonyl complexes (first group catalysts) such as dicobalt octacarbonyl, tetracarbonyl cobalt hydride, organophosphine-substituted cobalt carbonyl, Rh4(CO)12, RhCI( CO)(PPh3
)2, rhodium carbonyl complexes (second group catalysts) such as HRh (CO)(PPh3)3, platinum phosphine complexes -
Tin chloride-based catalysts (third group catalysts) are known, but the first group catalysts have relatively low activity (unusable if exposed to extremely high temperatures, and the second group catalysts have relatively high activity. Although it is known to exhibit activity, in reactions using olefins such as 1-pentene as raw materials, (linear isomer/branched isomer)
A mixture of aldehydes with a small production ratio is produced, and in order to obtain an industrially important linear isomer, it is necessary to coexist a large amount of phosphine ligand in the reaction system.

In addition, although the third group of catalysts are expensive, they only exhibit an activity intermediate between that of rhodium and cobalt, and the possibility of their being put to practical use as industrial catalysts was not considered at all.

Furthermore, it is also known that when a divalent ligand such as Ph2P(CH2)2PPh2 is used as a ligand, the aldehyde production activity is significantly reduced and the reaction virtually does not proceed.

Therefore, the present inventors aimed to provide a catalyst for the hydroformylation of olefins that has higher activity than conventional rhodium catalysts and also provides a product with a large ratio of linear to branched isomers. As a result of extensive research, it was surprisingly discovered that even with dicarboxylic ligands, which had been thought to be unsuitable as cocatalysts for platinum catalysts, when a ligand with a specific steric structure is used, platinum catalysts can be activated. , RhCI(CO)(PPh3)2 and HRh(CO)(P
Ph3).

It has significantly higher activity than rhodium carbonyl complexes such as (
We also discovered that an aldehyde mixture product with a very large proportion of linear isomers/branched isomers can be obtained at °C.
Two patent applications were filed (Japanese Patent Application Laid-open No. 54-119407 and Japanese Patent Application Laid-open No. 55-100331.).

However, the crown ligand used in the above invention has a stereochemical restriction that the configuration of the saturated carbocyclic ring must be trans, so that the synthesis of these two-carbohydrate ligands requires a long reaction step. There is a problem.

The present inventors have conducted intensive studies on disorientating ligands for platinum complexes that are easy to synthesize and exhibit greater activity than hydrorodium complexes.
The inventors have also discovered that the expected activity can be achieved by using a royal ligand having a phosphino group, an aldino group, or a stibino group at the 1-position together with a platinum complex, and have completed the present invention.

These royal ligands can be easily synthesized in two steps by lithiation of easily synthesized fecho7ine and reacting with diarylchlorobosphine or dialkylchlorophosphine, also arsine, or the same (stivine, etc.). Since it can be synthesized, it is extremely advantageous industrially.

The basic purpose of the present invention is to produce aldehydes in which the activity of the catalyst used is high, the reaction rate is good, and an aldehyde mixture product with a high proportion of linear isomers/branched isomers can be obtained. The purpose is to provide a method.

The details of the implementation of the invention will become apparent from the description below.

The object of the present invention is to provide a method for the hydroformylation of olefins by reacting them with hydrogen and carbon monoxide in the presence of a platinum catalyst and cocatalyst at heat and pressure with or without the use of a solvent. This can be achieved by using a tin halide as the cocatalyst and coexisting in the reaction system a royal ligand represented by the general formula or arsenic (R is a phenyl group).

The present invention will be explained in more detail below.

The olefins used in the present invention include alkenes such as 1-alkenes, 2-alkenes, alkadienes or derivatives thereof, alkyl alkenoates such as acrylic esters or methacrylic esters, alkenyl alkanoates such as fatty acid vinyls or fatty acid allyl esters. ates, alkenyl alkyl ethers such as alkyl vinyl ethers, alkenols such as allyl alcohol, and olefins having 2 to 20 carbon atoms are preferably used.

More specifically, the olefins include, for example, ethylene, propylene, 1-butene, ■-pentene, 1-hexene, 1-heftene, ■-dodecene, ■-vinyl-3-
Examples include cyclohexene, 2-ethyl-1-hexene, styrene, methyl acrylate, methyl methacrylate, vinyl acetate, vinyl methyl ether, and allyl alcohol.

As the platinum catalyst in the present invention, it is preferable to prepare and use a platinum-two-chain ligand complex such as Pt (two-chain ligand) C12 in advance, but it is not limited to this. Any platinum compound that can form a platinum carbonyl complex under the reaction conditions with a separately added divalent ligand can be used as the precursor.

These precursors include, for example, Pt(PhCN)
2C12 has 2PtC1 Pt (PPh3) 2C12, P
Examples include organic platinum complex compounds and platinum inorganic salts such as t(1.5-COD)C12 and PtCl2 (in the above, COD means 1.5-cyclooctadiene).

Next, the co-catalyst used in the present invention is a tin chloride.

Further, halogens are fluorine, chlorine, bromine, and iodine.

Specifically, such promoters include 5nC12, SnBr2, S
Examples include nF2 and SbI3.

These may contain water of crystallization.

In addition, 2 as a reaction accelerator that coexists with this promoter
The pendant is represented by the above-mentioned general formula, and a phenyl group is selected as R in the general formula.

Examples of compounds represented by the general formula include 1,1'-his(diphenylphosphino)ferrocene, 1,1'-bis(di-P-tolylphosphino)ferrocene, 1,1'
-bis(diphenylardino)ferrocene and the like.

To carry out the present invention, a complex consisting of a platinum catalyst bidentate ligand or both, a tin cocatalyst and an olefin are placed in a pressurized container, and a mixed gas (synthesis gas) consisting of carbon monoxide and hydrogen is placed under pressure. react with.

In this case, it is not necessary to use a solvent, but aliphatic saturated hydrocarbons such as hexane and heptane, alicyclic hydrocarbons such as cyclohexane and decalin, aromatic hydrocarbons such as benzene, toluene and tetralin, diethyl ether, tetrahydrofuran, etc. The use of ethers such as methylene chloride, chlorobenzene, logenated hydrocarbons, ketones such as acetone and methyl ethyl ketone, and alcohols such as methanol and ethanol as solvents is effective in keeping the catalyst system homogeneous and stable. It is.

In particular, the presence of a high boiling point solvent that allows the catalyst to remain as a solution after distilling off the product is convenient for recovering and reclosing the catalyst and is industrially desirable.

There is no clear limit to the amount of solvent used, but if it is too large, the reaction rate will decrease, so there is a limit.

It is usually used in an amount of 10 volumes or less per volume of olefin.

In the present invention, a small amount of platinum catalyst may be used (the amount to be used is determined depending on the reaction conditions, reaction substrate, and desired reaction rate; 1.0×10-5 to 1.0×10”
Used in molar range.

Furthermore, the amount of the two-chain ligand to be allowed to coexist in the reaction system with the platinum catalyst is determined by its coordination power and reaction conditions;
Generally, the number of moles of ligand per platinum atom is 20 or less, particularly preferably in the range of 0.5 to 10.

The amount of tin halide used as a cocatalyst is generally 50 or less per platinum atom, particularly preferably 0.5 to
The range is 20.

Further, the method of the present invention is carried out at a mixing molar ratio of carbon monoxide and hydrogen between 0.1 and 10, and more preferably the ratio is 0.1 to 10.
．． Between 5 and 3.0.

- 1 carbon oxide and hydrogen oxide each per mole of olefin
Consumed in molar proportions.

Total pressure of mixed gas of carbon monoxide and hydrogen, 5 to 500 B
It can be selected within the range of arr, but preferably 50
~200Barr.

Furthermore, the lower the reaction temperature, the higher the selectivity to aldehyde, but in consideration of the preferred reaction rate, the method of the present invention is usually
It is carried out between -200 degreeC, more preferably between 50-150 degreeC.

Thus, according to the method of the invention, propylaldehyde, n-
Butyraldehyde, n-pentylaldehyde, n-hexylaldehyde, n-octylaldehyde, 3-cyclohexenyl-propionaldehyde, 2-phenylpropylaldehyde, 3-phenylpropylaldehyde, 3
Various aldehydes such as methyl -formylpropionate, methyl 3-formyl-2-methylpropionate, 3-acetoxypropylaldehyde, 3-methoxyglobilaldehyde, and 4-hydroxybutyraldehyde are obtained.

These aldehydes are used as they are, or after being derived into various alcohols or organic acids through hydrogenation or oxidation reactions, as final products or industrial raw materials.

According to the method of the invention, under the corresponding reaction conditions:
It is useful in the plasticizer industry in that it is possible to obtain a product containing a significant amount of linear aldehyde from a compound having a vinyl group at the end in a significantly shorter time than with any conventionally known hydroformylation reaction catalyst. It is extremely meaningful in the surfactant industry, synthetic fiber industry, and other industries.

Below, some examples will be given and the results of using conventional monodentate ligands (comparative examples) will be illustrated to illustrate how superior the catalyst system of the present invention is. is not limited to these examples.

Example 1 Platinum complex PtC12 (PhCN) 215.1 m9 (3.2 x 10
-5 mol), stannous chloride dihydrate 36.1 m9 (1,
6 x 10-4 mol) and 17.7 mg (3,2 x 10
After purging with nitrogen, 18+nl of benzene was added as a solvent, 3 ml of 1-pentene (2,7 x 10' mol) was added, and a 1:1 mixed gas of carbon monoxide and hydrogen was added at 0°C. , the pressure was injected to 100 atm (pcO=pH2=50 atm).

Immerse this reactor in an oil solution at 100°C and start stirring.

After 5 hours of holding, the pressure drop stopped.

The reaction rate was obtained by plotting the pressure inside the reactor as a function of time, and the slope in Comparative Example 2 was adjusted to 10
Relative speed was expressed as 0.

Once the reaction was complete, the reactor was cooled and the contents analyzed by gas chromatography.

At a relative velocity of 720, the conversion of 1 = pentene is 100%, and the product distribution is 59.9% for aldehydes (such as capronaldehyde) with a linear content of 97%, and hydrides (n-hentane).
13.3%, and isomerized product (2-pentene) 10.9%.

Comparative example: 1,4-bis(diphenylphosphino) as a locating ligand
The reaction was carried out in the same manner as in Example 1 except that butane was used. As a result, the pressure drop stopped after 15 hours, but the equivalent rate was 40
0 product distribution + 1 aldehyde with linear content 92% 73
7%, hydride 125 isomerate 13.8%.

Comparative Example 2 Twice the mole of triphenylphosphine (6,
The reaction was carried out in the same manner as in Example 1, except that 1-pentene (4, The percentage of aldehyde was 75.7%, hydride was 4.1%, and isomerization was 9.9%.

The relative reaction rates of other examples are shown with the gas pressure drop rate of this reaction set as 100.

Example 2 The reaction was carried out in the same manner as in Example 1, except that 3.2 x 10-5 mol of 1,1'-bis(diphenylardino)ferrocene was used as the bipartite ligand. As a result, the pressure decreased within 1 hour. stopped and the relative velocity was 1020, the product distribution was 513% aldehyde with 90% linear content, 42% hydride.
．． 3%, and isomerized products were 6.4%.

Comparative Example 3 The reaction was carried out in the same manner as in Example 2 except that 6.4 x 10" moles of triphenylarsine was used as the ligand. As a result, it took 25 hours to stop the pressure drop and the relative velocity was 220
Met.

The product distribution was 32.9 aldehydes with a linear content of 83%.
%, hydride 32.1%, and isomerate 34.9%.

Example 3 The reaction was carried out in the same manner as in Example 2 except that 1.6Xl]-4 mol of tin bromide was used as the tin halide.
Within minutes the pressure drop stopped and the relative velocity was 1670.

Product distribution: 563% aldehyde with linear content 92%;
The hydrides were 34.6% and the isomers were 9.1%.

Claims (1)

[Claims] 1. Heating an olefin in the presence of a platinum catalyst and a promoter,
In a method for hydroformylating olefins by reaction with hydrogen and carbon monoxide under pressure with or without the use of a solvent, a tin halide is used as the cocatalyst, and the general formula or arsenic, R is 1. A method for producing aldehydes, which comprises coexisting in a reaction system a divalent ligand represented by a phenyl group. 2. The method for producing aldehydes according to claim 1, wherein the olefin is an alkene, alkyl alkenoate, alkenyl alkyl ether, or alkenol having 2 to 20 carbon atoms. 3 Tin halide is 5nC12 or SnBr
2. The method for producing aldehydes according to claim 1. 4 Hydrogen (H2) and carbon monoxide (CO) in molar ratio (H2
/Co) 0.1 to 10, the method for producing aldehydes according to claim 1. 5. The method for producing aldehyde i according to claim 1, wherein the hydroformylation is carried out at 40 to 200°C. 6. The method for producing aldehydes according to claim 1, wherein the hydroformylation is carried out at 5 to 500 Barr.