JPS5810139B2 - Catalyst for hydroformylation reaction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydroformylation catalyst suitable for hydroformylating α,β-unsaturated esters to produce aldehydes.

Conventionally, dicobalt occucarbonyl (CO2
(CO)a) is known, but this catalyst has lower activity and stability than other catalysts, such as rhodium complex catalysts.
At a reaction temperature of 0 to 130°C, a carbon monoxide gas pressure of about 15 to 25 kg/cm' was required.

As a result of extensive research to overcome the drawbacks of conventional catalysts, the present inventors discovered trivalent catalysts that have alkyl groups, aryl groups, etc. bonded to each other in the molecule and are connected to each other via carbon chains. It was discovered that a cobalt carbonyl compound coordinated with an organic phosphorus compound containing at least two phosphorus atoms satisfies the objective, and based on this finding, the present invention was accomplished.

That is, the present invention consists of an organic phosphorus compound containing in the molecule at least two trivalent phosphorus atoms bonded to an organic residue and connected to each other via a carbon chain, and a cobalt carbonyl compound. The present invention provides a catalyst for the hydroformylation reaction of α,β-unsaturated esters, which is characterized by the following.

An example of the organic phosphorus compound used in the catalyst of the present invention is a phosphine compound in which at least two phosphino groups substituted with an alkyl group, an aryl group, etc. are connected via a carbon chain.

Preferred examples of such phosphine compounds include those represented by the following general formula.

(In the formula, R1, R2, R3 and R4 are aliphatic groups including alkyl groups such as methyl group, ethyl group, propyl group, alkoxy groups such as methoxy group and ethoxy group, and phenyl group, methoxyphenyl group, ethoxyphenyl group) , and an aromatic group including a benzyl group, which may be the same or different from each other.

In addition, A1 has the general formula -(CH2)- (n in the formula is 1 to 10
(preferably an integer from 2 to n)). Examples of other preferable phosphine compounds include those represented by the following general formula.

(R5-R15 in the formula have the same meaning as R1-R4 above and may be the same or different from each other, and R16 represents an alkyl group such as a methyl group or an ethyl group or a hydrogen atom.

Further, A2 to A5 have the same meaning as A1 described above, and may be the same or different from each other, and are preferably a methylene group, an ethylene group, or a trimethylene group.

) In the present invention, examples of the cobalt carbonyl compound to which the organic phosphorus compound is coordinated include dicobalt octacarbonyl, tetracobalt dotecacarbonyl, alkylidine tricobalt nonacarbonyl, and the like.

The catalyst of the present invention can be prepared by mixing the above-mentioned organic phosphorus compound and a cobalt carbonyl compound in a solvent to prepare the catalyst in advance, or by reacting with carbon monoxide under hydroformylation reaction conditions to convert it into a cobalt carbonyl compound. There is a method in which a cobalt compound is charged into a reaction vessel together with an organic phosphorus compound, and the cobalt compound is prepared on the spot before the start of the hydroformylation reaction.

The cobalt compounds used in this latter method include:
cobalt acetate, cobalt naphthenate, cobalt hydroxide,
Examples include cobalt oxide and cobalt carbonate.

The amount of the organic phosphorus compound used in the catalyst of the present invention is 0.05 per cobalt atom of the cobalt carbonyl compound.
A range of 1 to 1 mole is appropriate, and a range of 0.1 to 0.4 mole is preferred.

As the proportion of the organic phosphorus compound increases, the thermal stability of the catalyst improves, but when it exceeds the upper limit of 5.0 times the mole, the catalytic activity decreases.

On the other hand, if it is less than the lower limit of 0.05 times the mole, only a product with insufficient activity and thermal stability will be obtained.

The catalyst of the present invention is used in the hydroformylation reaction in the presence of a solvent, and such solvents include those commonly used in this type of reaction, such as benzene, toluene, and ethyl acetate.

The hydroformylation reaction using the catalyst of the present invention is carried out at a reaction temperature of 50 to 300°C, preferably 100 to 130°C, and a reaction pressure of usually 1 to 300 kg/cm', preferably 10 to 150 kg/cm'. Hydrogen-carbon monoxide mixed gas and α mixed in the ratio.

This can be carried out by reacting a β-unsaturated ester with a β-unsaturated ester in the presence of the catalyst of the present invention.

The raw material α, β-unsaturated esters used in this case are those that have been used in conventional hydroformylation reactions, and are not particularly limited, but include methyl acrylate, methyl methacrylate, dimethyl maleate, dimethyl fumarate, etc. Particularly preferred are α, β-unsaturated esters.

The catalyst of the present invention has the excellent advantage of exhibiting about 3 to 5 times more activity than the conventional dicobalt octacarbonyl catalyst in the above-mentioned hydroformylation reaction.

It also has good thermal stability, under reaction conditions that would decompose conventional cobalt catalysts (for example, 110°C and 10kg of CO pressure).
/cm'), it maintains its activity as a homogeneous complex without decomposition.

The catalyst of the present invention has such characteristics and can carry out the reaction under considerably milder conditions than the conventional dicobalt octacarbonyl catalyst, which is very advantageous in terms of the reaction process.

Next, the present invention will be explained in more detail based on examples.

Example 1 Dicobalt octacarbonyl 0.0854 g (0,25
mmol), ■, 2-upper 2-diphenylphosphino)ethane 0.04979 (0,125 mmol), toluene 41.4 g and methyl acrylate 4 as the olefin.
．． 3 g (50 mmol) was placed in a stainless steel electromagnetic stirring autoclave with an internal volume of 100 m1, and heated to H2
After expelling the air with a mixed gas of /C0-1 (volume ratio), a gas of the same composition was introduced at 50 kg/cm',
The reaction was carried out at 120°C.

The initial gas reduction rate (hereinafter referred to as γi) determined from the amount of gas pressure reduction in the pressure accumulator at this time is 4.3 m mol /
miη, and the yield of β-formyl compound (β-formyl compound/introduced methyl acrylate) determined by gas chromatography after 35 minutes of reaction was 86%, β-formyl compound/d-formyl compound-18, 3, and the yield of methyl propionate, which is a hydride of the raw material olefin, is 10
It was 0%.

Comparative Example 1 The reaction was carried out in the same manner as in Example 1 except that 2-diphenylphosphino)ethane was not used.
i = 1.2, meaning that the catalyst activity was lower than 1/3 of that in Example 1.

Comparative Example 2 The reaction was carried out in the same manner as in Example 1, except that 0.125 m mob of triphenylphosphine was added instead of 2-diphenylphosphino)ethane.
i was reduced to 0.5, less than 1/8 of that in Example 1.

Moreover, this value is considerably lower than that of Comparative Example 1 in which no phosphine was added.

Example 2 ■, 0.0 of 2-upper 2-diphenylphosphino)ethane
When the reaction was carried out in the same manner as in Example 1 except that 249 g (0,062 mmol) was used, γ1 was 3.6 m
mol/min, and the yield of β-formyl compound after 48 minutes of reaction was 87%, and the yield of β-formyl compound/α-formyl compound=172 methyl propionate was 0.5%.

Example 3 ■, 0.0 of 2-upper 2-diphenylphosphino)ethane
When the reaction was carried out in the same manner as in Example 1 using 995 g (0.25 mmol), γi was 1.6 m
In terms of mol and /mln, the values were slightly lower than those in Examples 1 and 2.

After reaction for 12020 minutes - yield of formyl compound is 80.7%
, β-formyl body/α-formyl body = 20.9, but the yield of methyl propionate, which is a hydride, was 3.6.
It showed a slightly high value of %.

Examples 4 to 7 In place of 1,2-bis(diphenylphosphino)ethane in Example 1, Same as Example 1 except that the same moles of ethylene (III, 1,2=bis(diphenylphosphino)acetylene Cl) or bis(2-diphenylphosphinoethyl)phenylphosphine (IV) were used as the ligand. The results of the reaction were summarized in the table below.

From the results in this table, it can be seen that in each case, the catalytic activity was slightly lower than that of Example 1, but significantly higher than that of Comparative Example 1.

Furthermore, the small amount of methyl propionate produced indicates that hydrogenation of olefins hardly occurs.

Example 8 The reaction was carried out in the same manner as in Example 1 except that the CO pressure was as low as 10 kg/cm' for Co and 25 kg/cm' for H (each constant) and the reaction temperature was 110°C.
= 3.1.The yield of β-formyl body after reaction for 60 minutes is 92%, β-formyl body/α-formyl body = 18.1
The yield of methyl propionate was 0.7%, and the solution taken out from the autoclave after the reaction was homogeneous and no precipitate was observed.

Comparative Example 3 The reaction was carried out in the same manner as in Example 8 except that 2-2-diphenylphosphino)ethane was not added.
Not only did γl decrease to 14, which is 1/2 or less of that of Example 8, but also the catalyst partially decomposed (precipitation was observed after the reaction was completed).

The rate after 15,353 minutes of reaction was as low as 63%.

Example 9 When a mixed gas of H2/C0-1 (volume ratio) was used and the gas pressure was set to 30 kg/c4, the reaction was carried out in the same manner as in Example 8. After reaction for γi = 1.52.107 minutes, β-
The yield of formyl compound was 77%, the yield of β-formyl compound/α-formyl compound = 23,1 hydride was 0.2%, and no decomposition of the catalyst was observed during the reaction.

Comparative Example 4 A reaction was carried out in the same manner as in Example 9 except that 1.2-bis(diphenylphosphino)ethane was not added.

At this time, γi=0.47, which is not more than 1/3 of that in Example 9, but the dicobalt octacarbonyl catalyst is completely decomposed during the reaction, so the reaction stops.

As a result, after reaction for 31212 minutes, the yield of formyl compound was:
It was only 34%.

Example 10 Dimethyl fumarate was used instead of methyl acrylate, and the reaction pressure was 100 kg/cm' (H2/C0=1.
The reaction was carried out in the same manner as in Example 1 except that the volume ratio was changed.

At this time, γl was 3.0 mmol/min, and the yield of α-formyl compound after 47 minutes of reaction was 46.2%, and the yield of dimethyl succinate, which was a hydride, was 25.1%.

Comparative Example 5 (1) The reaction was carried out in the same manner as in Example 10, except that 2-diphenylphosphino)ethane was not added.

At this time, γi is 11, which is about 1/3 of Example 10,
In addition, after reaction for 19090 minutes, the yield of formyl compound was 28%.
and is much lower than that of Example 10.

Comparative Example 6 An experiment was conducted in the same manner as in Example 1 except that tetra(phenyl)diphosphine was used instead of 1,2-bis(diphenylphosphino)ethane. The reaction results were worse than those obtained when no organic phosphorus compound was added.

Claims (1)

[Scope of Claims] 1. An organophosphorus compound containing in its molecule at least two trivalent phosphorus atoms bonded to an organic residue and connected to each other via a carbon chain, and a cobalt carbonyl compound. α characterized by becoming. Catalyst for hydroformylation reaction of β-unsaturated esters 2. Claims in which the organic phosphorus compound is a phosphine compound having at least two phosphino groups substituted with groups selected from aliphatic groups and aromatic groups. The catalyst for hydroformylation reaction according to item 1.