EP0909218A1

EP0909218A1 - Catalyst and a process for preparation of aldehydes in the presence of said catalyst

Info

Publication number: EP0909218A1
Application number: EP97929208A
Authority: EP
Inventors: Helmut Bahrmann; Dieter Regnat; Peter Lappe
Original assignee: Celanese GmbH
Current assignee: Celanese Sales Germany GmbH
Priority date: 1996-06-24
Filing date: 1997-06-18
Publication date: 1999-04-21
Also published as: KR20000022119A; TW372199B; ZA975540B; ID17186A; JP2001502594A; BR9709955A; CA2258280A1; PL330789A1; AU3340197A; DE19625168A1; WO1997049490A1; DE19654908A1

Abstract

The invention relates to a catalyst containing rhodium and a compound of the general formula (I), in which R?1, R2 and R3¿ are identical or different and independently of each other are hydrogen, an alkyl group or alkoxy group with 1 to 4 carbon atoms, an alkenyl group with 2 to 4 carbon atoms, or R?1 and R2¿ including the carbon atoms connected therewith in each case form a ring with 6 carbon atoms, m and n independently of each other are 0 or 1, and (m+n) is equal to 1 or 2, and R is an unsubstituted phenyl radical or naphthyl radical or a phenyl radical or naphthyl radical substituted by an alkyl group with 1 to 4 carbon atoms, an amino group or dialkyl amino group with a total of 2 to 8 carbon atoms. The invention also relates to a process for preparation of aldehydes by reaction of an olefinic compound having 2 to 20 carbon atoms with carbon monoxide and hydrogen in the presence of said catalyst.

Description

description

Catalyst and a process for the preparation of aldehydes in the presence of this catalyst

The present invention relates to a new catalyst and a process for the preparation of aldehydes by reacting olefinic compounds with carbon monoxide and hydrogen in the presence of this catalyst.

Due to their chemical properties, aldehydes represent an important group of organic compounds. They can be converted, for example by aldol reaction with themselves or another C-H acid compound (methylene component), into the corresponding aldols or, after dehydration of the aldol, into the corresponding unsaturated condensation products. Furthermore, aldehydes can be oxidized to the corresponding carboxylic acids or reduced to the corresponding alcohols. By reacting aldehydes with ammonia or amines, imines or Schiff's bases are accessible, which give the corresponding amines by reaction with hydrogen.

Aldehydes are obtained on an industrial scale by the hydroformylation of olefinic compounds. As a result of the reaction of the carbon-carbon double bonds with carbon monoxide and hydrogen, mixtures of straight-chain and branched aldehydes are formed, as the following reaction equation shows schematically using a terminal olefin. CH = CH ₂ ^► R CH CH ₃ + R CH ₂ CH ₂ CHO

CHO

These mixtures are obtained in different compositions depending on the reaction conditions. In many cases, mixtures with the highest possible proportion of straight-chain aldehydes and the lowest possible proportion of branched aldehydes are desired. In addition to the reaction conditions such as pressure and temperature, the hydroformylation catalyst used has a decisive influence on the course of the reaction and the composition of the reaction mixture.

In the hydroformylation of olefins, rhodium catalysts which contain phosphorus-containing ligands have proven particularly useful as hydroformylation catalysts. Suitable ligands containing phosphorus are phosphines or phosphites. Such a hydroformylation process is described in DE-PS 1 7 93 069.

However, it is disadvantageous that the phosphites and in particular the phosphines are not stable to oxygen and sulfur and are oxidized even by very small amounts of oxygen and / or sulfur. This creates phosphates, thiophosphates, phosphine oxides and / or phosphine sulfides. The oxygen mainly enters the reaction via the olefin used as the starting material, while the sulfur is fed to the reaction in the form of sulfur-containing compounds, for example as H ₂ S, via the synthesis gas.

Even the smallest amounts of oxygen and / or sulfur have a detrimental effect, since, after hydroformylation has taken place, the catalyst is usually separated from the reaction product, for example by distillation, and enters the stage the hydroformylation is used again. There it in turn comes into contact with the oxygen originating from the feed olefin and the sulfur or the sulfur-containing compound supplied with the synthesis gas. As a result, further proportions of phosphite or phosphine are reacted with oxygen and / or sulfur.

The resulting phosphinic acids, thiophosphates, phosphine oxides and phosphine sulfides no longer function as a complexing ligand and are therefore no longer catalytically active. Sulfur-containing compounds also frequently impair catalytic processes and act as catalyst poisons. The phosphates, thiophosphates, phosphine oxides and phosphine sulfides formed are undesirable in the hydroformylation and must therefore be separated off. Separating them, like working up the catalyst or rhodium, proves to be difficult and requires a high level of technical effort.

The phosphites are somewhat less sensitive to oxygen and / or sulfur than the phosphines. In contrast to these, however, they are sensitive to water and hydrolyze even under the influence of small to very small amounts of moisture. Small amounts of water reach the reaction via the olefin used and the synthesis gas. By recycling the catalyst containing the phosphites, they come together again and again with the water originating from the olefin and synthesis gas, with the result that the hydrolysis proceeds and more and more phosphite is hydrolytically split. The hydrolysis products of the phosphites no longer have a complexing effect and are also no longer catalytically active.

In view of the disadvantages described with the use of phosphites and phosphines, there is a need to provide a catalyst which does not have these disadvantages and is therefore insensitive to oxygen and / or sulfur and which is also not degraded by hydrolysis. The catalyst should also have sufficient hydroformylation activity and, after use, should also be able to be used again in the hydroformylation step without any appreciable loss of hydroformylation activity. Furthermore, the catalyst should also withstand thermal stress, which does not take place under the conditions of the hydroformylation, without being damaged. This is the case, for example, under the conditions of a distillation where, due to the presence of carbon monoxide and hydrogen, the complexed metal carbonyls or hydridometal carbonyls formed in the hydroformylation, which presumably form the actually active catalyst, no longer stabilize.

In this context, it should be noted that the resulting hydroformylation mixture is initially expanded in two stages, with excess synthesis gas being separated off and fed back to the hydroformylation, optionally after recompression.

The reaction product freed from the synthesis gas goes into a multi-stage distillation in which the product of value is separated from the distillation residue containing higher boilers and subsequently fractionally distilled. The hydroformylation catalyst remains in the distillation residue. As a result of the thermal load, the hydroformylation catalyst can be deactivated, for example by decomposition or deposition of colloidal metal. However, such a deactivated catalyst is no longer suitable for reuse.

For these reasons, it is necessary for a catalyst to withstand the conditions of distillation without any significant loss of hydroformylation activity and also hydroformylation selectivity and, for example, as a distillation residue containing a catalyst, to be successfully used again in the hydroformylation stage. In addition, the catalyst should be able to be produced without great technical outlay and comparatively readily accessible starting materials should be used in its production.

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

wherein R ¹ , R ² and R ^{3 are the} same or different and independently of one another represent 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 , including those each connected to them Carbon atoms form a ring with 6 carbon atoms, m and n independently of one another are 0 or 1 and (m + n) are 1 or 2, and R for an unsubstituted or through an alkyl group with 1 to 4 carbon atoms, an amino or dialkylamino group with a total of 2 to 8 carbon atoms substituted phenyl or naphthyl radical.

The compounds of the formula (I) are bisether containing 2,2'-bisaryl. These compounds and their preparation are the subject of a German patent application filed on the same day as the present patent application (file number 1 9 625 1 67.2).

The bisethers containing the 2,2'-bisaryl radical are resistant to both oxygen and sulfur. Furthermore, they are also subject to the conditions of Hydroformylation not hydrolyzable. They also transfer these advantageous properties to the catalyst according to the invention containing rhodium and a compound of the formula (I).

It is surprising that the catalyst according to the invention has a hydroformylation activity and hydroformylation selectivity comparable to pure rhodium, since ligand-containing rhodium catalysts usually have a significantly reduced hydroformylation activity and changed hydroformylation selectivity compared to pure rhodium.

The hydroformylation selectivity is expressed, inter alia, in the ratio in which n-aldehydes and i-aldehydes are formed and the extent to which isomerization of the olefinic compounds takes place, for example with migration of the carbon-carbon double bond.

The comparatively high thermal load capacity of the rhodium complex catalysts described, for example, in DE-PS 1 7 93 063 is due to the pronounced ability of the phosphites and phosphines used to form stable complexes with rhodium. The trivalent phosphorus acts as a coordination partner towards rhodium.

In view of this, it is also surprising that the catalyst according to the invention also has a high thermal stability, although the compound of the formula (I) does not contain trivalent phosphorus. The extraordinarily high thermal load capacity is demonstrated by the fact that the reaction mixture obtained in the hydroformylation can be distilled off and the catalyst remaining in the distillation residue is not decomposed or deactivated, but can instead be used again in the hydroformylation reaction. Compared to an uncomplexed catalyst which only contains rhodium without a ligand, the catalyst according to the invention has a significant increase in stability, as can be seen from the comparative examples carried out using unmodified pure rhodium (rhodium without ligand) as the hydroformylation catalyst.

The catalyst contains rhodium and in particular a compound of the formula (I), in which R ¹ , R ² and R ^{3 are} identical or different and independently of one another represent hydrogen, an alkyl or alkoxy group having 1 to 2 carbon atoms or R ¹ and R ² form a ring with 6 carbon atoms including the carbon atoms connected to them.

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

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

Of particular interest are catalysts in which the compound of the general formula (I) of the formula (II) or (III)

equivalent. In the compound of the formula (II), R ¹ and R ² each form a ring, including the carbon atoms of the respective benzene ring connected to them, giving a 1, 1-binaphthyl substituted in the 2,2'-position, while in formula (III ) R ¹ and R ^{2 represent} hydrogen. R ³ is both in formula (II) and in formula (III) hydrogen.

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

The solvent used here should be inert under the conditions of the hydroformylation. Examples of such a solvent are toluene, o-xylene, m-xylene, p-xylene, mixtures of isomeric xylenes, ethylbenzene, mesitylene or species-specific reaction products which are recirculated with the catalyst.

However, it is also possible to use the reaction product formed in the hydroformylation as a solvent. The catalyst containing rhodium and the compound of formula (I) can be used directly in the hydroformylation, that is to say without additional treatment.

However, it is also possible to first subject the catalyst containing rhodium and the compound of the formula (I) to a pretreatment in the presence of hydrogen and carbon monoxide under pressure and, if appropriate, elevated temperature, and to prepare the actually active catalyst species by means of this preforming. The conditions for the preforming usually correspond to the conditions of a hydroformylation.

The catalyst usually contains rhodium and the compound of formula (I) in a molar ratio of 1: 1 to 1: 1000, in particular 1: 1 to 1:50, preferably 1: 2 to 1:20.

If a larger excess of the compound of the formula (I) is desired, the catalyst can contain rhodium and the compound of the formula (I) in a molar ratio of 1: 1,000 to 1: 5000, in particular 1: 1,000 to 1: 2000.

The present invention further relates to a method for producing aldehydes. It is characterized in that an olefinic compound having 2 to 20 carbon atoms in the presence of a rhodium and a compound of the general formula (I)

wherein R ¹ , R ^2, R ³ , m, n and R have the meaning explained above, containing catalyst with carbon monoxide and hydrogen at a pressure of 1 0 to 500 bar and a temperature of 90 to 1 50 ° C.

The reaction can be carried out in the presence or absence of a solvent which is inert under the conditions of the hydroformylation. Suitable solvents are, for example, toluene, o-xylene, m-xylene, p-xylene, mixtures of isomeric xylenes, ethylbenzene, mesitylene or species-specific reaction products which are recirculated with the catalyst. Mixtures of these solvents can also be used.

The reaction product formed in the hydroformylation is usually also suitable as the solvent.

The olefinic compound can contain one or more than one carbon-carbon double bond. The carbon-carbon double bond can be arranged terminally or internally. Preferred are olefinic compounds with a terminal carbon-carbon double bond.

Examples of α-olefinic compounds (with a terminal carbon-carbon double bond) are alkenes, alkylalkenoates, alkenylalkanoates, alkenylalkyl ethers and alkenols, in particular those having 2 to 8 carbon atoms. Without any claim to completeness, the α-olefinic compounds are 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, allyiacetate, 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-octenoic acid, 7-buttenoic acid, 7-buttenoic acid, 7-butenoic acid, 3-butenoic acid, 3-butenoic acid, 7-butenoic acid, 3-butenoic acid, 7-butenoic acid, 3-butenoic acid, 3-butenoic acid, 3-butenoate 3-butenenitrile, called 5-hexenamide.

Examples of other suitable olefinic compounds are butene-2, diisobutylene, tripropylene, octol or dimersol (dimerization products of butenes), tetrapropylene, cyclohexene, cyclopentene, dicyclopentadiene, acyclic, cyclic or bicyclic terpenes, such as myrcene, limonene and pinene.

Containing catalyst (I) requires the rhodium and described above, the compound of the formula usually used in an amount of from 2x1 0 ^"6 to 5x 1 0 ^'2, in particular 5x1 ^{0" 6} to 5x10 ^"3, preferably 1 x1 ^{0" 5-1} x10 ^"4 moles of rhodium per mole of olefinic compound.

The amount of rhodium also depends on the type of olefinic compound to be hydroformylated. In some cases, it may suffice to use the catalyst in an amount of 1 x 10 ^{~ 6} moles of rhodium per mole of olefinic compound or less. Although such low catalyst concentrations are possible, they may not prove to be particularly useful in individual cases, since the reaction rate may be too slow and therefore not economical enough. The upper catalyst concentration can be up to 1 x10 ^{~ 1} mol of rhodium per mol of olefinic compound. Comparatively high rhodium concentrations, however, do not result in any special advantages. Therefore the upper limit is set 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 chosen within wide limits and is usually 1: 10 to 1 0: 1, in particular 5: 1 to 1: 5, preferably 2: 1 to 1: 2.

The process is particularly simple if hydrogen and carbon monoxide are used in a molar ratio of 1: 1 or approximately 1: 1.

In a large number of cases, it has proven useful to carry out the reaction at a pressure of 20 to 400, in particular 1 00 to 250 bar.

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

At this point it should be pointed out that the reaction conditions, in particular rhodium concentration, pressure and temperature, also depend on the type of olefinic compound to be hydroformylated. Comparatively reactive olefinic compounds require low rhodium concentrations, low pressures and low temperatures. On the other hand, the implementation of relatively unreactive olefinic compounds requires higher rhodium concentrations, higher pressures and higher temperatures.

The process can be carried out with particularly good success if a cc -olefinic compound is used. However, other olefinic compounds with internal carbon-carbon double bonds can also be implemented with good results.

After completion of the reaction, the hydroformylation mixture is freed of carbon monoxide and hydrogen and then distilled, the aldehyde-containing product of value usually being distilled off overhead. The catalyst containing rhodium and the compound of formula (I) remains in the distillation residue and can be used again in this form in the hydroformylation reaction.

If the catalyst is recirculated several times in this way, an increase in high boilers can occur, which accumulate in the respective distillation residue and is returned to the hydroformylation with the catalyst.

However, these higher boilers can largely be removed by distillation under more stringent conditions, for example by flash distillation in a falling-film evaporator, without the catalyst being damaged thereby.

Such separation of high boilers can advantageously bring about a significant increase in the activity of the recycled catalyst. In this way, the catalyst can be successfully reused in the hydroformylation reaction several times. It should be emphasized here that the rhodium losses, despite repeated recovery and repeated use of the catalyst, are barely measurable, or rather very low.

According to a special process variant, one can work as follows. The reaction product obtained after reaction with carbon monoxide and hydrogen is freed from the low-boiling constituents in a first distillation stage and from high-boiling thick oils in a second distillation stage under more stringent distillation conditions, and the bottom product containing the catalyst, which is obtained in the second distillation stage, is passed into the reaction of the olefinic compound back with carbon monoxide and hydrogen. The process according to the invention can be carried out continuously or batchwise, in particular continuously.

The following examples describe the invention in more detail without restricting it.

Experimental part

Preparation of the catalyst

The catalyst is made from 0.073 mmol rhodium and 0.73 mmol 2,2'-bis (phenoxymethyU-1, 1'-binaphthyl as ligand, corresponding to a molar ratio Rh: ligand of 1: 10 - as follows in the hydroformylation of propylene described in Example 1 - produced in situ.

The preparation of 2, 2'-bis (phenoxymethyl) -1, 1 '-binaphthyl is described in the previously mentioned German patent application (file number 1 9 625 1 67.2), filed on the same day as the present patent application.

The formula on which the 2,2'-bis- (phenoxymethyl) -1, 1'-binaphthyl is based can be found in the table below under the ligand heading.

example 1

a) Hydroformylation of propylene

400 g of toluene, 0.073 mmol of rhodium in the form of 1.48 ml of a toluene solution containing 5052.3 mg of Rh / liter and 0.73 mmol (0.34 g) of 2,2'- in a stirred autoclave (volume: 5 liters). Bis (phenoxymethyl) -1, 1'-binaphthyl presented as a ligand. The autoclave is thoroughly cleaned with nitrogen and

Synthesis gas flushed and it is added with synthesis gas

(CO: H ₂ = 1: 1) a pressure of 100 bar was set.

Then a temperature of 1 30 ° C is set with stirring and the

Pressure increased to 270 bar with the addition of synthesis gas (CO: H ₂ = 1: 1). Now 1,500 g of propylene are pumped in over 1 to 2 hours and at

1 30 ° C and 270 bar implemented. The implementation is exothermic.

The reaction temperature is controlled by cooling the autoclave by means of a blower and by the rate at which the propylene is pumped in.

After pumping in, the reaction is allowed to continue. The whole

Response time (pumping time + post-reaction time) can be found in the table below under the heading Time.

The autoclave is then cooled to room temperature and a

Cold trap relaxed to 2 to 5 bar. There are 6 g of liquid in the cold trap

Product.

With the residual pressure, the contents of the autoclave are immersed in a dip tube

6 I glass flask transferred and weighed (2763 g). A propylene conversion of 92% is calculated from the weight increase of the combined liquid products.

The ratio of n-butanal: i-butanal, determined by gas chromatography, is

52:48.

b) recovery of the catalyst

The hydroformylation product is transferred in one under N ₂ protection

Rotary evaporator and distilled the aldehydes (n-butanal and i-butanal) first at 80 ° C and towards the end at 100 ° C under one

Water jet vacuum, initially 1 00 mbar and towards the end of the distillation

Is 25 mbar.

To complete the separation is at 1 00 ° C and full

Water jet vacuum distilled for a further 1 5 minutes.

The total duration of the distillation is 2.5 hours. 1 6

The hydroformylation product obtained in Example 1 gives 47.9 g of a residue containing the catalyst (rhodium + ligand).

Examples 2 to 8

a) Hydroformylation of propylene with recycling (reuse) of the catalyst

The residue containing the catalyst is taken up in each case with so much butyral distillate that the total amount is about 400 g and thus gives the same level in the autoclave (volume: 5 liters), and is transferred back into the autoclave with N ₂ pressure. About 400 g of product (catalyst-containing residue + butyraldehyde distillate) are placed in the stirred autoclave used in Example 1. The autoclave is flushed thoroughly with nitrogen and synthesis gas and a pressure of 100 bar is set with the addition of synthesis gas (CO: H ₂ = 1: 1).

A temperature of 130 ° C. is then set with stirring and the pressure is increased to 270 bar with the addition of synthesis gas (CO: H ₂ = 1: 1). 1,500 g of propylene are then pumped in over the course of 1 to 2 hours and reacted at 130 ° C. and 270 bar. The implementation is exothermic.

The reaction temperature is controlled by cooling the autoclave by means of a blower and by the rate at which the propylene is pumped in. After pumping in, the reaction is allowed to continue. The total reaction time (pumping time + post-reaction time) can be found in the table below under the heading Time. 1 7

The autoclave is then cooled to room temperature and expanded to 2 to 5 bar via a cold trap. There is always a small amount of product in the cold trap. With the residual pressure, the contents of the autoclave are transferred to a 6 l glass flask via a dip tube and weighed.

The propylene conversion shown in the table below is calculated from the increase in weight of the combined liquid products (see sales category). The ratio of n-butanal: i-butanal, determined by gas chromatography, is 52:48 in each case.

b) recovery of the catalyst

The hydroformylation product obtained in Examples 2 to 7 is transferred to a rotary evaporator and the aldehydes (n-butanal and i-butanal) are first distilled at 80 ° C. and towards the end at 100 ° C. and a water jet vacuum, which is initially 100 mbar and towards the end the distillation is from 25 mbar.

To complete the separation, the mixture is distilled at 100 ° C. and a full water jet vacuum for a further 15 minutes. The residue obtained is used as a catalyst in the following example. The hydroformylation product obtained in Example 2 gives 1,51 g of residue and is used in Example 3 (2nd reuse), the hydroformylation product obtained in Example 3 gives 253 g of residue and is used in Example 4 (3rd reuse) and the one obtained in Example 4 Hydroformylation product 351 g of residue and is used in Example 5 (4th reuse) as a catalyst (rhodium and ligand).

When the residue of 351 g is used again, the conversion leads to a significant decrease to 45%. To separate the higher boilers, the hydroformylation product obtained in Example 5 (4th reuse) is subjected to film evaporation at a jacket temperature of 160 ° C. and 100 mbar. Here the amount of residue containing the catalyst is reduced to 1 87 g.

Thereafter, a conversion of 94% is achieved in Example 6 (5th reuse). The

Thick oils obviously have a deactivating effect on the catalyst.

According to Example 7 (6th reuse), high-boiling thick oil must be used again

Film evaporation at 1 60 ° C jacket temperature and 1 00 mbar are separated.

Then the residue containing the catalyst (rhodium and ligand) reduced to 1 37 g in Example 8 (7th reuse) again gives 94% conversion.

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

Comparative Example 1

a) Hydroformylation of propylene with rhodium without ligand

400 g of toluene and 0.073 mmol of rhodium in the form of 1.48 ml of a toluene solution containing 5052.3 mg of Rh / liter, but no ligand, are initially introduced into a stirred autoclave (volume: 5 liters), as indicated in Example 1. The reaction of propylene is then carried out in accordance with Example 1 at 130 ° C. and 270 bar. A propylene conversion of 93% is calculated from the increase in weight of the combined liquid products (product in the cold trap + content of the autoclave) (see also the table below)

b) recovery of the rhodium

The hydroformylation mixture is worked up as described in Example 1b) and 87.1 g of a rhodium-containing residue is obtained, which is used in Comparative Example 2 (1st reuse). Comparative Examples 2 to 4

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

The residue containing the rhodium is taken up in each case with so much butyraldehyde distillate that the total amount is about 400 g and thus in each case in the autoclave (volume: 5 liters) gives the same fill level, and is transferred again into the autoclave with N ₂ overpressure. Then one works as described in Examples 2 to 8 and carries out the implementation of

Propylene at 1 30 ° C and 270 bar. The total response time (pumping time

+ Post reaction time) can be found in the table below under the heading time.

Comparative example 2 gives a conversion of 88%, comparative example 3

(2nd reuse) shows a sharp drop in sales to 39% and

Comparative Example 4 (3rd reuse) shows that no propylene is reacted at all.

Since rhodium is recovered at over 90%, the deactivation is due to that

Absence of the ligand.

b) recovery of the rhodium

The hydroformylation 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 in Examples 2 to 8 under b) recovery of the catalyst. The hydroformylation product obtained in comparative example 2 gives 293 g of rhodium-containing residue, which is used in comparative example 3 (second reuse), and the hydroformylation product obtained in comparative example 3 gives 273 g of rhodium-containing residue, which is used in comparative example 4 (third reuse) . The results of Examples 1 to 8 and Comparative Examples 1 to 4 are summarized in the table below.

Table: Hydroformylation of propylene with Rhodium / 2,2'-Bιs (phenoxymethyl) -1, 1 '-binaphthyl and rhodium (without ligand) at 270 bar

H ₂ / CO, 130 ° C, 5 ppm Rh based on propylene (= 2.045x10 ⁶ mol Rh / mol propylene) o

for \ 3

* Separation of the high boilers (aldols, carboxylic acids) by film evaporation (1 60 ° C jacket temperature and

100 mbar) * * ratio of n-butanal: i-butanal determined by gas chromatographic analysis O

H

-J

O W v ©

Claims

claims

1 . Rhodium-containing catalyst and a compound of the general formula (I)

wherein R ¹ , R ² and R ^{3 are the} same or different and independently of one another represent 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 including each of them connected carbon atoms form a ring with 6 carbon atoms, m and n independently of one another are 0 or 1 and (m + n) is 1 or 2, and R for an unsubstituted or by an alkyl group with 1 to 4 carbon atoms, an amino or dialkylamino group is a total of 2 to 8 carbon atoms substituted phenyl or naphthyl.

Catalyst according to claim 1, characterized in that R ¹ , R ² and R ^{3 are the} same or different and independently of one another represent hydrogen, an alkyl or alkoxy group having 1 to 2 carbon atoms or R ¹ and R ² including each of them connected carbon atoms form a ring with 6 carbon atoms.

Catalyst according to claim 1 or 2, characterized in that m = 1 and n = 0 or m = 1 and n = 1.

4. Catalyst according to one or more of claims 1 to 3, characterized in that R represents an unsubstituted or a phenyl or naphthyl radical substituted by an alkyl group having 1 to 4 carbon atoms.

5. Catalyst according to one or more of claims 1 to 4, characterized in that R represents an unsubstituted or a phenyl radical substituted by an alkyl group having 1 to 4 carbon atoms.

6. Catalyst according to one or more of claims 1 to 5, characterized in that R represents a phenyl radical.

7. Catalyst according to one or more of claims 1 to 6, characterized in that the compound of general formula (I) of formula (II) or (III)

corresponds in which n and R have the meaning given above.

8. Catalyst according to one or more of claims 1 to 7, characterized in that it contains rhodium and the compound of formula (I) in a molar ratio of 1: 1 to 1: 1,000.

9. Catalyst according to one or more of claims 1 to 8, characterized in that it contains rhodium and the compound of formula (I) in a molar ratio of 1: 2 to 1:20.

1 0. A process for the preparation of aldehydes, characterized in that an olefinic compound having 2 to 20 carbon atoms in the presence of a rhodium and a compound of the general formula (I)

wherein R ¹ , R ² , R ³ , m, n and R have the meaning explained above, reacting catalyst containing carbon monoxide and hydrogen at a pressure of 10 to 500 bar and a temperature of 90 to 1 50 ° C.

1 1. A method according to claim 10, characterized in that an α-olefinic compound is used.

1 2. The method according to claim 10 or 1 1, characterized in that the catalyst is used in an amount of 2x1 0 ^"6 to 5x1 0 ^{" 2} moles of rhodium per mole of olefinic compound. 3. The method according to one or more of claims 10 to 1 2, characterized in that the reaction product obtained after reaction with carbon monoxide and hydrogen is freed from the low-boiling constituents in a first distillation stage and freed from higher-boiling thick oils in a second distillation stage under more stringent distillation conditions and that in the second distillation stage, the bottom product containing the catalyst is recycled into the reaction of the olefinic compound with carbon monoxide and hydrogen.