KR20000022119A - Catalyst and method for preparing aldehyde under catalyst - Google Patents

Abstract

PURPOSE: A catalyst and a method for preparing aldehyde under the catalyst are provided. CONSTITUTION: The catalysts consists of rhodium and a compound of the following formula, where R¬1, R¬2 and R3 are same or different from one another, and each R¬1, R¬2 and R3 is independently selected from hydrogen, alkyl group having 1-4 carbon atoms, alkoxy group having 1-4 carbon atoms and alkenyl group having 2-4 carbon atoms, and R¬1, R¬2 and one carbon atom form a ring having 6 carbon atoms; m and n are independently 0 or 1, and (m+n) is 1 or 2; R is selected from phenyl radical, naphthyl radical, phenyl radical or naphthyl radical substituted by substituent selected from alkyl group having 1-4 carbon atoms, dialkylamino group having 2-8 carbon atoms and amino group having 2-8 carbon atoms. The aldehyde is prepared by reacting carbon monoxide with hydrogen under the catalyst.

Description

Process for preparing aldehyde in presence of catalyst and said catalyst

The present invention relates to a novel catalyst and a method for preparing aldehydes by reacting an olefin compound with carbon monoxide and hydrogen in the presence of the catalyst.

Aldehydes are important organic compound groups because of their chemical properties. These can be converted to the corresponding aldol, or to the corresponding unsaturated condensation products after dehydration of the aldol, for example, by aldol reaction with them or with other C-H-acid compounds (methylene component). Aldehydes can also be oxidized to produce or reduce the corresponding carboxylic acid to convert to the corresponding alcohol. The reaction of aldehydes with ammonia or amines can produce imine or Schiff bases, which can be reacted with hydrogen to form the corresponding amines.

Aldehydes are obtained on an industrial scale by hydroformylating olefin compounds. The reaction of carbon-carbon double bonds with carbon monoxide and hydrogen forms a mixture of straight and branched aldehydes as depicted in the following scheme for the terminal olefins.

Depending on the reaction conditions, mixtures with different compositions are obtained. In many cases, mixtures with as high content of straight chain aldehydes and as low as possible side chain aldehydes are preferred. Apart from reaction conditions such as pressure and temperature, the hydroformylation catalyst used has a decisive influence on the reaction path and the composition of the reaction mixture.

In hydroformylation of olefins, hydroformylation catalysts that have been found to be particularly useful are rhodium catalysts containing phosphorus-containing ligands. Suitable phosphorus-containing ligands are phosphines or phosphites. DE-C 17 93 069 describes such a hydroformylation process.

However, the drawback is that phosphites and in particular phosphines are not stable to oxygen and sulfur, so that they are oxidized to produce phosphates, thiophosphates, phosphine oxides and / or phosphine sulfides even in very small amounts of oxygen and / or sulfur. . Oxygen is mainly involved in the reaction through the olefins used as starting materials, while sulfur is introduced into the reaction in the form of sulfur-containing compounds, for example H ₂ S, via the synthesis gas.

Oxygen and / or sulfur have an adverse effect, even in very small amounts, because even after hydroformylation is complete, the catalyst is usually separated from the reaction product, for example by distillation, and reused in the hydroformylation step. Because. Here, the catalyst is again brought into contact with sulfur or sulfur-containing compounds introduced with oxygen and synthesis gas derived from the starting olefins. As a result, an additional amount of phosphite or phosphine reacts with oxygen and / or sulfur. The resulting phosphinic acid, thiophosphate, phosphine oxide and phosphine sulfide no longer function as complexing ligands and no longer have catalytic activity. In addition, sulfur-containing compounds often adversely affect the catalytic process and act as catalyst poisons. The phosphates, thiophosphates, phosphine oxides and phosphine sulfides formed are undesirable for hydroformylation and should be removed. Their removal has been found to be as difficult as the post-treatment of catalysts, more precisely rhodium and is technically complex.

Phosphite is less sensitive to oxygen and / or sulfur than phosphine, but it is more sensitive to water than the latter and hydrolyzes even when small to very small amounts of water are present. Small amounts of water are introduced into the reaction via the olefins used and the synthesis gas. Due to the recycling of the catalyst containing phosphine, they are brought into repeated contact with the moisture derived from the olefins and the synthesis gas so that hydrolysis proceeds and more and more phosphite is hydrolytically cleaved. The hydrolysis products of phosphites no longer act as complexing ligands and are therefore no longer catalytically active.

Given the disadvantages associated with the use of phosphites and phosphines, it is necessary to supply a catalyst which does not have the above disadvantages and which is not sensitive to oxygen and / or sulfur and which does not decompose by hydrolysis.

The catalyst must also have sufficient hydroformylation activity, and also be able to be reused in the hydroformylation step after use without loss of significant hydroformylation activity. In addition, the catalyst must also tolerate lossy thermal stresses that occur under hydroformylation conditions. This is the case, for example, under distillation conditions where the complexed metal carbonyl or metal hydride carbonyl produced in the hydroformylation reaction, which is considered to be the actual active catalyst, is no longer stabilized by the presence of carbon monoxide and hydrogen.

In this regard, the hydroformylation mixture obtained is first decompressed usually in two stages to separate excess synthesis gas and, if necessary, after recompression, return to hydroformylation.

Next, the reaction product from which the synthesis gas has been removed is fed to multistage distillation to separate the desired product from the distillation residue containing the high boiling point, followed by fractional distillation. The hydroformylation catalyst remains in the distillation residue. As a result of the thermal stress, the hydroformylation catalyst can be inactivated, for example, by decomposition or precipitation of colloidal metals. However, catalysts deactivated in this way are no longer stable enough to be reused.

For this reason, it is also necessary for the catalyst to withstand distillation conditions without significant loss of hydroformylation activity and hydroformylation selectivity and to be successfully reused in the hydroformylation step as catalyst-containing distillation residues.

In addition, the catalyst should be able to be prepared without great technical difficulty, and its preparation should use starting materials that are relatively readily available.

This object is achieved by a catalyst comprising rhodium and a compound of formula (I):

In the above formula,

R ¹ , R ² and R ³ are the same or different and independently of one another are hydrogen, an alkyl or alkoxy group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms, or R ¹ and R ² are carbon atoms connecting them Form a ring with 6 carbon atoms,

m and n are each independently 0 or 1, (m + n) is 1 or 2,

R is a phenyl or naphthyl radical which may be unsubstituted or substituted by alkyl groups having 1 to 4 carbon atoms or amino or dialkylamino groups having 2 to 8 carbon atoms in total.

Compounds of formula I are bisethers containing 2,2'-bisaryl radicals. These compounds and their preparation are the subject of the German patent application (No. 19 625 167.2) filed on the same date as the present application.

Bisethers containing 2,2'-bisaryl radicals are stable to both oxygen and sulfur. In addition, they are not hydrolyzed even under the conditions of hydroformylation. They also convey these advantageous properties to the catalysts of the invention comprising rhodium and formula (I).

It is understood that the catalysts of the present invention have hydroformylation activity and hydroformylation selectivity comparable to pure rhodium, whereas ligand-containing rhodium catalysts usually have significantly lower hydroformylation activity and altered hydroformylation selectivity than pure rhodium. It's amazing because

Hydroformylation selectivity is expressed, in particular, by the ratio at which n-aldehydes and i-aldehydes are produced, to this extent, for example, isomerization of the olefin compound with the transfer of carbon-carbon double bonds.

The relatively high thermal stress of rhodium complex catalysts, such as those described in DE-C 17 93 063, stems from the remarkable ability of the phosphites and phosphines used to form stable complexes with rhodium. Here, trivalent phosphorous coordinates with rhodium.

In view of this, it is surprising that the catalyst of the present invention has a similarly high thermal stress even if the compound of formula (I) does not contain trivalent phosphorus. The unusually high thermal stress is due to the fact that the reaction mixture formed in the hydroformylation reaction can be distilled off and the catalyst remaining in the distillation residue can be reused in the hydroformylation reaction since it is not decomposed or inactivated by this process. Proven.

Compared to uncomplexed catalysts containing only rhodium without ligand, the catalysts of the invention are very high, as can be seen in the comparative examples carried out using pure rhodium (rhodium without ligand) as a hydroformylation catalyst. Have stability.

These catalysts are rhodium and in particular, R ¹ , R ² and R ³ are the same or different and independently of one another are hydrogen, an alkyl or alkoxy group having 1 to 2 carbon atoms, or R ¹ and R ² are the carbon atoms connecting them; And a compound of formula (I) which together form a ring of 6 carbon atoms.

In particular in the compounds of formula (I) m = 1 and n = 0 or m = 1 and n = 1.

In the compounds of formula (I), R is usually an unsubstituted phenyl or naphthyl radical, or a phenyl or naphthyl radical substituted by an alkyl group having 1 to 4 carbon atoms, in particular an unsubstituted phenyl radical or alkyl having 1 to 4 carbon atoms. Phenyl radicals substituted by groups, preferably phenyl radicals.

Of particular interest are compounds in which the compounds of formula I correspond to the following formulas II or III.

In compounds of formula (II), R ¹ and R ² form a ring with the carbon atoms of each benzene ring connecting them to form a 1,1-vinaphthyl group substituted at the 2 and 2 ′ positions, In R ¹ and R ² is hydrogen. R ³ is hydrogen in both Formulas II and III.

The catalyst can be prepared in a simple manner, for example by combining rhodium in salt form with a compound of formula (I). Rhodium in the form of a salt soluble in an organic solvent, for example as a rhodium salt of aliphatic carboxylic acid having 2 to 10 carbon atoms, for example as rhodium acetate, rhodium butyrate, rhodium 2-ethylhexanoate or rhodium acetylacetonate It is particularly useful to dissolve in an organic solvent together with the compound of formula (I). It is also possible to first dissolve the rhodium salt and then add the compound of formula (I), or reversely dissolve the compound of formula (I) and then add the rhodium salt.

The solvent used here should be inert under the conditions of hydroformylation. Examples of such solvents are toluene, o-xylene, m-xylene, p-xylene, mixtures of xylene isomers, ethylbenzene, mesitylene or intrinsically reaction products that are recycled together with the catalyst.

However, it is also possible to use the reaction product generated in the hydroformylation reaction as a solvent.

Catalysts comprising rhodium and compounds of formula (I) can be used in the hydroformylation reaction directly, ie without further treatment.

However, it is also possible to pretreat the catalyst comprising rhodium and the compound of formula I in the presence of hydrogen and carbon monoxide under pressure and possibly elevated temperatures to produce the actual active catalyst species by such preactivation. The conditions of preactivation typically correspond to hydroformylation conditions.

The catalyst typically comprises rhodium and the compound of formula I in a molar ratio of 1: 1 to 1: 1000, in particular from 1: 1 to 1:50, preferably from 1: 2 to 1:20. When aiming at excess amounts of the compound of formula (I), the catalyst may comprise rhodium and the compound of formula (I) in a molar ratio of 1: 1000 to 1: 5000, in particular 1: 1000 to 1: 2000.

The invention also relates to a process for the preparation of aldehydes. The method comprises reacting an olefin compound of 2 to 20 carbon atoms with carbon monoxide and hydrogen at a pressure of 10 to 500 bar and a temperature of 90 to 150 ° C. in the presence of a catalyst comprising rhodium and a compound of formula (I). .

Formula I

In the above formula,

R ¹ , R ² , R ³ , m, n and R are as defined above.

The reaction can be carried out in the presence or absence of a solvent which is inert under the conditions of hydroformylation. Suitable solvents are, for example, intrinsic reaction products which are recycled together with toluene, o-xylene, m-xylene, p-xylene, mixtures of xylene isomers, ethylbenzene, mesitylene or a catalyst. It is also possible to use mixtures of these solvents. The reaction product produced in the hydroformylation reaction is usually also suitable as a solvent.

The olefin compound may contain one or more carbon-carbon double bonds. The carbon-carbon double bond may be terminal or internal. Preference is given to olefin compounds having terminal carbon-carbon double bonds.

Examples of? -Olefin compounds (with terminal carbon-carbon double bonds) are alkenes, alkyl alkenoates, alkenyl alkanoates, alkenyl alkyl ethers and alkenols, especially compounds having from 2 to 8 carbon atoms.

Although not charged for all elements, as the ∀-olefin compound, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-octadecene , 2-ethyl-1-hexene, styrene, 3-phenyl-1-propene, allyl chloride, 1,4-hexadiene, 1,7-octadiene, 3-cyclohexyl-1-butene, allyl alcohol, hex -1-en-4-ol, oct-1-en-4-ol, vinyl acetate, allyl acetate, 3-butenyl acetate, vinyl propionate, allyl propionate, allyl butyrate, methyl methacrylate, vinyl Cyclohexene, 3-butenyl acetate, vinyl ethyl ether, vinyl methyl ether, allyl ethyl ether, n-propyl-7-octenoate, 3-butene acid, 7-octenic acid, 3-butenenitrile and 5-hexenamide May be mentioned.

Examples of further suitable olefin compounds include 2-butene, diisobutylene, tripropylene, octol or dimersol (dimerization product of butene), tetrapropylene, cyclohexene, cyclopentene, dicyclopentadiene, and myrcene Mention may be made of acyclic, cyclic or acyclic terpenes such as, limonene and pinene.

Such catalysts comprising rhodium and compounds of formula (I) are typically 2 × 10 ⁻⁶ to 5 × 10 ⁻² mol, in particular 5 × 10 ⁻⁶ to 5 × 10 ⁻³ mol, preferably per mol of olefin compound It is used in an amount of 1 × 10 ^-5 to 1 × 10 ^-4 mol.

The amount of rhodium also depends on the kind of olefin compound to be hydroformylated. In some cases, it may be sufficient to use a catalyst in an amount of up to 1 × 10 ⁻⁶ mol of rhodium per mol of olefin compound. While such low catalyst concentrations are possible, they may turn out to be not particularly advantageous as the reaction rates are so slow in individual cases that the economy is insufficient. The upper concentration limit of the catalyst may be up to 1 × 10 ⁻¹ mol of rhodium per mol of olefin compound concentration. However, relatively high rhodium concentrations do not give particular advantages. Thus, the upper limit is determined by the high cost of rhodium.

The reaction is carried out in the presence of hydrogen and carbon monoxide. The molar ratio of hydrogen to carbon monoxide can be selected within a wide range and is usually 1:10 to 10: 1, especially 5: 1 to 1: 5, preferably 2: 1 to 1: 2. The process is particularly simple when hydrogen and carbon monoxide are used in a molar ratio of 1: 1, or approximately 1: 1.

In many cases, it has been found useful to carry out the reaction at pressures of 20 to 400 bar, in particular 100 to 250 bar.

In many cases, it is sufficient to carry out the reaction at a temperature of 100 to 150 ° C, in particular 110 to 130 ° C.

It can be pointed out at this point that the reaction conditions, in particular rhodium concentration, pressure and temperature, also depend on the kind of olefin compound to be hydroformylated. Reactive olefin compounds require low rhodium concentrations, low pressures and low temperatures. In contrast, reactions of relatively non-reactive olefin compounds require higher rhodium concentrations, higher pressures, and higher temperatures.

If the ∀-olefin compounds are used, the process can be carried out particularly successfully. However, other olefin compounds having carbon-carbon double bonds therein can also be reacted with good results.

After completion of the reaction, the carbon monoxide and hydrogen are removed from the hydroformylation mixture by depressurizing, and then distillation is performed to distill the desired product including aldehyde through the top. Catalysts comprising rhodium and compounds of formula I remain in the distillation residue and can be reused in this form for hydroformylation reactions.

Recycling the catalyst in this manner multiple times can result in an increase in the high boiling point accumulated in each distillation residue, which is returned to the hydroformylation reaction with the catalyst.

However, these high boilers can be almost eliminated without damaging the catalyst thereby by distillation under more intense conditions, for example by flash distillation in a falling film evaporator. Such removal of high boilers advantageously significantly increases the activity of the recycled catalyst. In this way, the catalyst can be successfully reused many times in the hydroformylation reaction. It should be emphasized that, despite repeated recovery and multiple reuse of catalysts, rhodium loss is rarely detected or very low.

In a particular process alternative, the following procedure may be used. The reaction product obtained after the reaction of carbon monoxide with hydrogen removes the low boiling point component in the first distillation step, the concentrated oil of the high boiling point in the second distillation step under intense distillation conditions, and the catalyst obtained in the second distillation step. The containing bottoms product is returned to the reaction of the olefin compound with carbon monoxide and hydrogen.

The process of the invention can be carried out continuously or batchwise, in particular continuously.

The following examples illustrate the present invention without limiting it.

Experiment Division

Preparation of the catalyst

As described below for hydroformylation of propylene in Example 1, 0.073 mmol of rhodium and 2,2'-bis (phenoxymethyl) -1,1, corresponding to a molar ratio of Rh: ligand of 1:10 Catalysts are prepared in situ from 0.073 mmol of '-vinaptyl.

The preparation of 2,2'-bis (phenoxymethyl) -1,1'-binafyl is described in the above-mentioned German patent application (No. 19 625 167.2) filed on the same date as the present application.

The structural formula of 2,2'-bis (phenoxymethyl) -1,1'-binafthyl is shown in the following table under the heading "ligand".

Example 1

a) hydroformylation of propylene

In a stirred autoclave (volume: 5 L), 0.073 mmol of rhodium in the form of 400 g of toluene, 1.48 ml of a 5052.3 mg Rh / L toluene solution and 2,2'-bis (phenoxymethyl) -1,1'-binaf as ligand Charge 0.73 mmol (0.34 g) of teal. The autoclave is thoroughly washed with nitrogen and synthesis gas and the synthesis gas (CO: H ₂ = 1: 1) is added to set a pressure of 100 bar. Then, while stirring, a temperature of 130 ° C. is set and a synthesis gas (CO: H ₂ = 1: 1) is added to increase the pressure to 270 bar. Next, 1500 g of propylene was pumped in over a period of 1 to 2 hours and the reaction was carried out at 130 ° C. and 270 bar. The reaction proceeds exothermicly. The reaction temperature is controlled by cooling the autoclave with a blower and also by the pumping rate of propylene. After pumping all the propylene, the mixture is reacted further. The total reaction time (pump input time + post-reaction time) is given in the table below in the heading "Time" column. The autoclave is then cooled to room temperature and depressurized through a cold trap to 2-5 bar. 6 g of liquid product is collected in a cold trap. Residual pressure causes the contents of the autoclave to move through a immersed tube into a 6 L glass flask and weigh (2763 g). From the weight gain of the combined liquid products, the conversion of propylene is calculated at 92%. The n-butanal: i-butanal ratio is 52:48 as determined by gas chromatography.

b) recovery of the catalyst

The hydroformylation product is transferred into a rotary evaporator under an N ₂ blanket and distilled off the aldehydes (n-butanal and i-butanal), starting at 80 ° C and ending at 100 ° C in the water pump vacuum at the beginning. The vacuum is initially 100 mbar and brought to 25 mbar as it nears the distillation end. To complete the separation, distillation is continued for 15 minutes at 100 ° C. and complete water pump vacuum. The total distillation period is 2.5 hours. The hydroformylation product obtained in Example 1 gave 47.9 g of a residue containing a catalyst (rhodium + ligand).

Examples 2 to 8

a) Hydroformylation of propylene while recycling (reusing) the catalyst

In each case, the residue containing the catalyst was combined with the butyraldehyde distillate in an amount equivalent to about 400 g in total to provide the same level in the autoclave (volume: 5 L) and again transferred into the autoclave using N ₂ pressure. Let's do it. The stirred autoclave used in Example 1 is charged with 400 g of product (catalyst-containing residue + butyraldehyde distillate). The autoclave is thoroughly washed with nitrogen and synthesis gas and the synthesis gas (CO: H ₂ = 1: 1) is added to set a pressure of 100 bar.

The temperature is then set to 130 ° C. with stirring and the synthesis gas (CO: H ₂ = 1: 1) is added to increase the pressure to 270 bar. Next, 1500 g of propylene was pumped in over a period of 1 to 2 hours and reacted at 130 ° C. and 270 bar. The reaction proceeds exothermicly.

The reaction temperature is controlled by cooling the autoclave with a blower and also by the pumping rate of propylene. After all the propylene has been pumped in, the mixture continues to react. The total reaction time (pump input time + post-reaction time) is given in the heading "Time" column in the following table.

The autoclave is then cooled to room temperature and reduced to 2-5 bar through a cold trap. Small amounts of product are always obtained in cold traps. By the residual pressure, the contents of the autoclave are transferred to a 6 L flask through the submerged tube and weighed.

From the weight gain of the combined liquid products, the propylene conversion is given in the following table (see heading "Conversion"). As measured by gas chromatography, the n-butanal: i-butanal ratio is 52:48 in each case.

b) recovery of the catalyst

The hydroformylated product obtained in Examples 2 to 7 was transferred into a rotary evaporator and distilled off the aldehydes (n-butanal and i-butanal), starting at 80 ° C. and ending with a water pump vacuum. Accordingly at 100 ° C. and the vacuum is initially 100 mbar and brought to 25 mbar as it approaches the distillation end point. To complete separation, distillation is continued for 15 minutes at 100 ° C. and complete water pump vacuum. The residue obtained in each case is used as a catalyst in the following examples. In the hydroformylation product obtained in Example 2, 151 g of residue was obtained and used in Example 3 (reuse for the second time), and the hydroformylation product obtained in Example 3 provided 253 g of residue to be used in Example 4. Hydroformylation product obtained in Example 4 is used as catalyst (rhodium and ligand) in Example 5 (4th reuse).

In the fourth reuse of the 351 g residue, the reaction resulted in a significantly lower conversion of 45%. The hydroformylation product obtained in Example 5 (4th reuse) to remove high boilers is membrane evaporated at 100 mbar and wall temperature 160 ° C. This reduces the amount of residue containing the catalyst to 187 g. Subsequently, in Example 6 (5th reuse), a conversion of 94% is obtained. It is clear that the concentrated oil has an inactivation effect on the catalyst. After Example 7 (6th reuse), the relatively high boiling concentrated oil must be removed again by membrane evaporation at 100 mbar and wall temperature of 160 ° C. The catalyst (rhodium and ligand) containing residue, which was then reduced to 137 g, again provided 94% conversion in Example 8 (7th reuse).

These results demonstrate the very high stability of the catalyst and at the same time very high catalytic activity.

Comparative Example 1

a) Hydroformylation of propylene using only rhodium without ligand

As shown in Example 1, a stirred autoclave (volume: 5 L) is charged with 0.073 mmol of rhodium in the form of 1.48 ml of toluene solution containing 400 g of toluene and 5052.3 mg Rh / L, but no ligand. The reaction of propylene is then carried out at 130 ° C. and 270 bar as described in Example 1. From the weight gain of the combined liquid product (product in the cold trap + contents in the autoclave), the propylene conversion is calculated at 93% (see table below).

b) recovery of rhodium

The hydroformylation mixture is worked up as described in Example 1b) to give 87.1 g of rhodium-containing residue which is used in Comparative Example 2 (first reuse).

Comparative Examples 2 to 4

a) Hydroformylation of propylene with recycling (reuse) of rhodium

If the residue containing a rhodium each, the total amount is about 400g autoclave (capacity: 5ℓ) when the level in each using combined with the same amount of butyraldehyde distilled water N ₂ pressure again Auto Move in the clave. The subsequent procedure is the same as described in Examples 2-8 and the reaction of propylene is carried out at 130 ° C. and 270 bar. The total reaction time (pump input time + post-reaction time) is shown in the heading "Time" column in the following table.

Comparative Example 2 provides 88% conversion and Comparative Example 3 (second reuse) shows a severely lowered conversion rate of 39%, whereas Comparative Example 4 (third reuse) shows that propylene no longer reacts at all. Appears to be. Since more than 90% of rhodium was recovered, this inactivation is believed to be due to the absence of ligand.

b) recovery of rhodium

The hydroformylated product obtained in Comparative Examples 2 and 3 is transferred to a rotary evaporator and the aldehydes (n-butanal and i-butanal) are distilled off as described under the recovery of the catalyst b) of Examples 2-8. . The hydroformylated product obtained in Comparative Example 2 gave 293 g of rhodium-containing residue which was used in Comparative Example 3 (second reuse), and the hydroformylated product obtained in Comparative Example 3 contained 273 g of rhodium -Containing residue was provided, which residue was used in Comparative Example 4 (third reuse).

The results of Examples 1 to 8 and Comparative Examples 1 to 4 are shown in the table below.

H ₂ / CO 270 bar, 130 ° C., rhodium / 2,2′-bis (phenoxymethyl) -1,1′- at 5 ppm Rh (2.045 × 10 ⁻⁶ mol Rh / propylene mol) based on propylene Hydroformylation of Propylene Using Binaphthyl and Rhodium (Legand-Free) Rh / ligand molar ratio = 1: 10 Unmodified Rh (no ligand) Ligand Reuse count Examples 1-8 Comparative Examples 1 to 4 % Conversion Time (hours) % Conversion Time (hours) 01234567 9288948945 ^★ 9492 ^★ 94 3.33.13.33.82.83.74.13.8 9388390 3.02.83.83.5 n / i ratio ^★★ 52/48 52/48 Rh recovery 100 93 ^★ Removal of high boilers (aldols, carboxylic acids) by membrane evaporation (100 mbar and wall temperature 160 ° C.) ^{★ ★} n-butanal as determined by gas chromatography analysis: ratio of i-butanal

Claims (13)

A catalyst comprising rhodium and a compound of formula (I). Formula I In the above formula, R ¹ , R ² and R ³ are the same or different and independently of one another are hydrogen, an alkyl or alkoxy group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or R ¹ and R ² are carbon atoms connecting them Form a ring with 6 carbon atoms, m and n are each independently 0 or 1, (m + n) is 1 or 2, R is a phenyl or naphthyl radical which may be unsubstituted or substituted by alkyl groups having 1 to 4 carbon atoms or amino or dialkylamino groups having 2 to 8 carbon atoms in total. The compound of claim ¹ , wherein R ¹ , R ² and R ³ are the same or different and are independently of each other hydrogen, an alkyl or alkoxy group having 1 to 2 carbon atoms, or R ¹ and R ² together with the carbon atoms connecting them A catalyst that forms a ring of 6 carbon atoms. The catalyst of claim 1 or 2 wherein m = 1 and n = 0 or m = 1 and n = 1. The catalyst of claim 1 wherein R is an unsubstituted phenyl or naphthyl radical or a phenyl or naphthyl radical substituted by an alkyl group having 1 to 4 carbon atoms. The catalyst according to any one of claims 1 to 4, wherein R is an unsubstituted phenyl radical or a phenyl radical substituted by an alkyl group having 1 to 4 carbon atoms. The catalyst of any one of claims 1 to 5 wherein R is a phenyl radical. The catalyst of claim 1 wherein the compound of formula I corresponds to formula II or III. 8. Formula II Formula III In the above formula, n and R are as defined above. 8. The catalyst of claim 1 comprising rhodium and a compound of formula I in a molar ratio of 1: 1 to 1: 1000. 9. The catalyst of any one of claims 1 to 8 comprising rhodium and a compound of formula I in a molar ratio of 1: 2 to 1:20. A method for producing an aldehyde comprising reacting an olefin compound having 2 to 20 carbon atoms with carbon monoxide and hydrogen at a pressure of 10 to 500 bar and a temperature of 90 to 150 ° C. in the presence of a catalyst comprising rhodium and a compound of formula (I). Formula I In the above formula, R ¹ , R ² , R ³ , m, n and R are as defined above. The method of claim 10, wherein the? -Olefin compound is used. The process according to claim 10 or 11, wherein the catalyst is used in an amount corresponding to 2 × 10 ⁻⁶ to 5 × 10 ⁻² mol of rhodium per mol of the olefin compound. The reaction product obtained after the reaction with carbon monoxide and hydrogen is free of the low boiling point component in the first distillation step, and the concentrated oil of high boiling point concentration is intense in the second distillation step. Removed under distillation conditions and the catalyst-containing bottom product obtained in the second distillation step is returned to the reaction of the olefin compound with carbon monoxide and hydrogen.