JPS587340B2 - Catalyst for hydroformylation reaction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydroformylation catalyst suitable for use in producing aldehydes by hydroformylating α,β-unsaturated nitriles.

Conventionally, dicobalt octacarbonyl (Co2
(CO)8) is known, but compared to other catalysts such as rhodium complex catalysts, this catalyst not only has lower activity but also poor stability.
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 intensive research to overcome the drawbacks of conventional catalysts, the present inventors discovered a trivalent catalyst in which alkyl groups, aryl groups, etc. are bonded in the molecule and 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 nitriles, 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.

(R1, R2, R3 and R4 in the formula are aliphatic groups including alkyl groups such as methyl, ethyl and propyl groups, alkoxy groups such as methoxy and ethoxy groups, and phenyl, methoxyphenyl and ethoxyphenyl groups) It is selected from aromatic groups including enyl groups and benzyl groups, and they may be the same or different from each other.

In addition, A1 has the general formula -(CH2)n- (n in the formula is 1 to 1
0, preferably an integer of 2 to 3), a vinyl group or an ethylene group) In addition, other preferred examples of phosphine compounds include those represented by the following general formula. .

(R5 to R15 in the formula have the same meaning as R1 to R4 described above and may be the same or different from each other. 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 above, and may be the same or different from each other, and preferred are methylene group, ethylene group, or 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, or by reacting with carbon monoxide under hydroformylation reaction conditions to form 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 1.0 to 1.0 times the mole is appropriate, and a range of 0.1 to 0.4 times the mole is preferred.

As the proportion of organic phosphorus compounds increases, the thermal stability of the catalyst improves; however, when it exceeds the upper limit of 1.0 times the mole, the catalytic activity decreases, while when it is less than the lower limit of 0.05 times the mole, the activity and thermal stability decrease. You will only get something that is insufficient.

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 1
Hydrogen mixed at any ratio between 0 and 150 kg/cm
Carbon monoxide mixed gas and α,β-unsaturated nitrile,
This can be carried out by reacting in the presence of the catalyst of the present invention.

The raw material α,β-unsaturated nitriles used in this case are those that have been used in conventional hydroformylation reactions, and are not particularly limited, but include aliphatic and aromatic nitriles such as acrylonitrile, methacrylonitrile, and cinnamate nitrile. α of the family
, β-unsaturated nitriles.

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).
/cm2), 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), 1,2-bis(diphenylphosphino)ethane 0.0497 g (0.125 mmol), toluene 41.4 g and acrylonitrile 2.65 g, (50 m
mol) was placed in a stainless steel electromagnetic stirring autoclave with an internal volume of 100 ml, and after expelling air with a mixed gas of H2/CO = 1 (volume ratio), a gas of the same composition was introduced at a rate of 50 kg/cm. , the reaction was carried out at 110°C.

The initial gas reduction rate (hereinafter referred to as γi) determined from the amount of gas pressure decrease in the pressure accumulator at this time was 0.8 mmol/mm, and the yield of β-formyl compound (β - formyl compound/introduced acrylonitrile) is 65%, and the yield of propionitrile, which is a hydrogenated product of raw material acrylonitrile, is 0.
It was 8%.

Comparative Example 1 The reaction was carried out in the same manner as in Example 1 except that 1,2-bis(diphenylphosphino)ethane was not used.
The catalytic activity was reduced to 1/3 of that of Example 1, i=0.26.

Comparative Example 2 The reaction was carried out in the same manner as in Example 1, except that triphenylphosphine or tetra(phenyl)diphosphine was used instead of 1,2-bis(diphenylphosphino)ethane. The reaction results were inferior to those shown in Comparative Example 1 when no phosphorus compound was used.

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. A catalyst for the hydroformylation reaction of α,β-unsaturated nitriles, characterized in that: 2. The catalyst for hydroformylation reaction according to claim 1, wherein the organic phosphorus compound is a phosphine compound having at least two phosphino groups substituted with groups selected from aliphatic groups and aromatic groups.