JPH05255167A - Method for hydroformylating olefin - Google Patents

Abstract

PURPOSE:To carry out the hydroformylation of an olefin, having high reactional activity and a high formation ratio of the branched derivative/a linear derivative and useful as a synthetic intermediate, etc., for medicines, agricultural chemicals, etc., in the presence of a catalyst composed of a specific diphosphine and rhodium. CONSTITUTION:The hydroformylation of an olefin expressed by formula II (X is 1-11C alkyl, aryl, aralkyl or carboxylic acid ester) is carried out in the presence of a catalyst composed of a diphosphine, expressed by formula I (R<1> to R<4> are 1-8C alkyl, 6-18C aryl, 6-18C aralkyl, etc.) and having a bicyclo[2.2.2]octane skeleton and rhodium.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to general formula (1)

[0002]

[Chemical 3] (In the formula, R ¹ , R ² , R ³ and R ⁴ are an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 18 carbon atoms and 6 to 6 carbon atoms.
It is a group selected from 18 aralkyl groups, which may be the same or different from each other, and R ¹ and R ² and / or R ³ and R ⁴ are other than a phosphorus atom. An alkyl group, which may be linked by a bond of
The present invention relates to a method for hydroformylating an olefin in the presence of a catalyst composed of diphosphine having a bicyclo [2.2.2] octane skeleton represented by an aryl group or an aralkyl group) and rhodium.

[0003]

2. Description of the Related Art Conventionally, cobalt catalysts such as dicobalt octacarbonyl have been well known as catalysts for olefin hydroformylation reaction. However, these catalysts have low activity and require high temperature and high pressure. It wasn't right. Therefore, as an industrial hydroformylation reaction catalyst that overcomes these drawbacks, a large number of rhodium complex catalysts that have high activity under relatively mild conditions have been developed and widely used.

This hydroformylation reaction not only allows the production of major industrial chemicals by converting various olefin compounds into carbonyl compounds, but also medicines, agricultural chemicals,
It is a basic and very important reaction that provides a synthetic intermediate for fine chemicals such as fragrances. Therefore, this reaction is an extremely valuable reaction for producing useful chemicals not only in simple olefins but also in hydroformylation of olefins having a functional group. However, in the hydroformylation reaction of an olefin having a functional group, generally, the
Two kinds of products, a ch isomer and a linear isomer, are produced, and the selectivity thereof becomes a problem, and rather the selectivity of the desired isomer is low.

For example, α-phenylpropionaldehyde, which is a raw material for synthesizing α-phenylpropionic acid, which is a very important compound as a synthetic intermediate for drugs such as ibuprofen, is produced by a hydroformylation reaction of styrene into a branch type. You can In carrying out this reaction, many rhodium and platinum complex catalysts having mainly phosphine-based ligands have been proposed. In particular, various ligands and cocatalysts have been proposed in order to carry out a stereoselective formylation reaction. For example, 2,2-dimethyl-
4,5-bis [(diphenylphosphino) methyl]-
PtCl2 (PPh3) 2 in the presence of 1,3-dioxolane
And a method of reacting styrene with a hydroformylation reaction using SnCl2 catalyst system. Although proposed by Kollar et al. (J. Organomet. Chem., 198.
9,370 (1-3), 257-61), 88.8% e
Although the extremely high stereoselectivity of e.e. is achieved, the ratio of branch isomer / linear isomer is 0.
Even if the reaction time was 3 or less and 200 hours or more, the conversion was as low as 14% and the reaction activity was low. Further, a method of carrying out a hydroformylation reaction of p-isobutylstyrene in the presence of Pt (II), N-tert-butoxycarbonyl-4-diphenylphosphino-2-[(diphenylphosphino) methyl] pyrrolidine and SnCl2 catalyst is available. J. K. Although proposed by Stille et al. (J. Am. Chem. Soc., 198).
No. 7,109 (23), 7122-7), the production ratio of the branch / linear form is about 0.5, the conversion rate is 50% at 78% ee, which is an extremely unsatisfactory reaction result, and triethyl, which is expensive as a solvent, is used. It had the disadvantage of requiring an orthoformate.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a catalyst having an extremely high reaction activity suitable for industrial production in the hydroformylation reaction of an olefin, and br
It is an object of the present invention to extremely remarkably improve the generation ratio of an ant body / linear body.

[0007]

DISCLOSURE OF THE INVENTION The inventors of the present invention have eagerly designed a ligand based on a new concept in order to develop a complex catalyst having industrially favorable high reaction activity and more desirable reaction characteristics. As a result, they found a complex catalyst having extremely excellent reaction activity and reaction characteristics, and completed the present invention.

That is, the present invention is represented by the general formula (1)

[0009]

[Chemical 4] (In the formula, R ¹ , R ² , R ³ and R ⁴ are an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 18 carbon atoms and 6 to 6 carbon atoms.
It is a group selected from 18 aralkyl groups, which may be the same or different from each other, and R ¹ and R ² and / or R ³ and R ⁴ are other than a phosphorus atom. In the presence of a catalyst consisting of a diphosphine having a bicyclo [2.2.2] octane skeleton represented by an alkyl group, an aryl group or an aralkyl group which may be linked by a bond of The present invention provides a method of reacting, particularly in the general formula (2) (Wherein X represents an alkyl group, an aryl group, an aralkyl group or a carboxylic acid ester group having 1 to 11 carbon atoms), and a method for hydroformylating an olefin. In addition, the above "R ³ and R ⁴
Represents an alkyl group, an aryl group or an aralkyl group which may be linked by a bond other than a phosphorus atom. "

[0010]

[Chemical 5] (Here, Y is an atom such as oxygen, nitrogen, metal, or C ₁
~C is through a Y or directly as ₃ represent an atomic group such as a carbon chain of) like R ³ and R ⁴ are bonded. The present invention will be described in more detail.

The present inventors have designed a diphosphine based on a new concept, and have invented a method for hydroformylation of an olefin by a rhodium complex catalyst having a novel diphosphine ligand. The diphosphine of the present invention is
It is a very precisely designed ligand based on a bicyclo [2.2.2] octane skeleton, in which two methylene groups at the 2,5-position branch into endo and endo, and P is bonded. Detailed structural analysis of the diphosphine ligand having the bicyclo [2.2.2] octane skeleton and its metal complex has not been completed yet. However, C.I. for diphosphine ligands having a bicyclo [2.2.1] heptane skeleton is not shown. P. Calculation results of Casey et al. (J. Or.
g. Chem. , 1990, 55, 1394-96), the coordination at which the angle formed by P-metal-P when coordinating with a metal is about 120 ° is due to the strain applied to the ligand relating to the present invention. It is expected that the energy will be the minimum and the configuration will be the most stable.

On the other hand, many diphosphine ligands such as DIOP having a well-known bidentate coordination ability have been analyzed for their three-dimensional structures, and P-metal in the case of coordinating with a metal has been studied. It has been confirmed from experimental fact that the angle of −P is approximately 90 ° or less than 90 °. Also, C.I. P. According to the same calculation by Casey et al., They have a result that they cannot have a large coordination angle of 120 °. Therefore, this diphosphine ligand having a bicyclo [2.2.2] octane skeleton is a diphosphine having a novel coordination design, which is quite different from many conventionally known bidentate ligands.

The only compound similar to the diphosphine ligand used in the catalyst of the present invention is C. P. Ca
sey et al's report (supra) and the inventors (Synle)
t, 1990, 711-712).
2.1] Only diphosphine having a heptane skeleton is known. The diphosphine ligand having a bicyclo [2.2.2] octane skeleton of the present invention can be produced, for example, by a known production method (for example, M. Tichy et al., Tetrahedron Letters, 1969, No. 53, 4609 to 461).
Formula (5) [Chemical formula 6] on page 3)

[0014]

[Chemical 6] (Wherein R represents H, an alkyl group or the like), which is easily obtained by subjecting a dicarboxylic acid or diester represented by the formula (I) to a reduction treatment with LiAlH ₄ or the like.
Endo-2,5-bishydroxymethylbicyclo [2.2.2] octane can be converted into ditosylate by a conventional method and can be produced by a substitution reaction with a desired phosphine. For example, like the reaction formula shown in Formula (6) [Chemical Formula 7],

[0015]

[Chemical 7] (Wherein R ′ and R ″ are the same as R ^{1 to} R ⁴ ) The diol can be produced by converting it to a ditosylate and subjecting it to a substitution reaction with a desired phosphine. It can be manufactured.

Examples of the substituent of phosphorus for which the diphosphine of the present invention can be used as a ligand include dimethylphosphine, diethylphosphine, dipropylphosphine, dibutylphosphine, dioctylphosphine or dicyclohexylphosphine, and other alkylphosphines, diphenylphosphine, Dinaphthylphosphine, di-m-tolylphosphine, di-o-tolylphosphine or di (m
-Sulfophenyl) phosphine and other arylphosphines, dibenzylphosphine, bis (naphthylmethyl)
Examples of the effective phosphine include aralkylphosphine such as phosphine, and cyclic phosphine such as diphenylenephosphine group, but the phosphine is not limited thereto.
Further, phosphines having different substituents such as methylphenylphosphine, ethylphenylphosphine, t-butylphenylphosphine or cyclohexylphenylphosphine may be used. The method for converting the metal complex having diphosphine as a ligand of the present invention can be converted by various conventionally known production methods and is not particularly limited. In particular, the rhodium complex catalyst exhibits excellent activity and selectivity for the hydroformylation reaction.

The olefins which undergo hydroformylation reaction using the catalyst of the present invention include ethylene, propylene and 1
-Butene, 1-pentene, 1-hexene, 1-octene, 1-decene and other linear α-olefins, 2-butene, 2-pentene, 2-hexene, 3-hexene, 2-
Linear internal olefins such as octene and 3-octene, isobutylene, 2-methyl-1-butene, 2-methyl-1
-Pentene, 3-methyl-1-pentene, 2-methyl-
Branched α-olefins such as 1-hexene, 3-methyl-1-hexene, 2-methyl-1-heptene, 3-methyl-1-heptene, 4-methyl-1-heptene, 2,3
-Dimethyl-1-butene, 2,3-dimethyl-1-pentene, 2,4-dimethyl-1-pentene, 2,3-dimethyl-1-hexene, 2,4-dimethyl-1-hexene, 2,5 -Dimethyl-1-hexene, hyperbranched α-olefins of 3,4-dimethyl-1-hexene, cyclohexene, 2-norbornene or bicyclo [2.2.
2] Cyclic olefins such as octene-2 and double bond isomers thereof, styrene, p-methylstyrene, p-isobutylstyrene, aryl-substituted olefins such as 2-vinylnaphthalene, aralkyl-substituted olefins such as 3-phenylpropylene, Examples include unsaturated alcohols such as allyl alcohol, unsaturated ethers such as acrolein acetal or phenyl vinyl ether, unsaturated esters such as methyl acrylate or methyl oleate, and unsaturated carboxylic acids such as cinnamic acid. it can.
Particularly preferably, styrene, p-isobutylstyrene,
It is preferably used for the hydroformylation reaction of α-olefins such as 2-methoxy-6-vinylnaphthalene and methyl acrylate.

In the hydroformylation reaction using rhodium with the novel diphosphine ligand according to the present invention, the rhodium concentration is usually 0.1 to 1000 pp as Rh atom.
m, reaction temperature is 0 to 200 ° C., pressure is 20 to 300 Kg
/ Cm ² G, and the hydrogen / CO ratio (volume ratio) of 0.3 to 5 is performed under the reaction conditions. The reaction solvent does not usually have to be used, but an organic solvent inert to the reaction such as benzene, toluene, xylene or THF can also be used. If desired, it is also possible to use a high boiling by-product or the product aldehyde as a solvent.

[0019]

The present invention will be described in more detail with reference to the following examples. Example 1 [endo, endo-2,5-bis ((diphenylphosphino) methyl) bicyclo [2.2.2] octane]
Preparation of Rhodium (I) Catalyst 0.03 ml 70% HClO ₄ and 0.4 ml distilled T
88 mg in 5.4 ml dry THF in a mixed solution of HF
Norbornadiene (acetylacetonato) Rh (I)
A solution in which (0.30 mmol) was dissolved was added, and this mixed solution was stirred at room temperature for 40 minutes. Here, 150 mg of endo, endo-2,5-bis ((diphenylphosphino) methyl) bicyclo [2.
2.2] A solution in which octane (0.30 mmol) was dissolved was added, and the mixture was further stirred at room temperature for 1.5 hours. Next, 7m
l of ether was added and the mixture was stirred at room temperature for another 20 hours to form crystals, and 193 mg of (norbornadiene) [en
do, endo-2,5-bis ((diphenylphosphino) methyl) bicyclo [2.2.2] octane] Rh
(I) Perchlorate yellow crystals were collected by filtration (79).
%yield).

³¹ P NMR (200 MHz, CDC
l ₃ , external H ₃ PO ₄ ); 21.1
(D, J = 164.4 Hz)

Example 2 5 ml of anhydrous benzene was added to a 50 ml micro-autoclave.
1, styrene 1 mmol, the Rh catalyst 0.
Add 005 mmol, 4 with CO / hydrogen = 1/1 gas
The pressure was increased to 0 atm and the reaction was performed at 25 ° C. for 24 hours. When the obtained reaction liquid was analyzed by gas chromatography, the conversion of styrene was 96%, and the selectivities of 2-phenylpropanal and 3-phenylpropanal were 99% and 1%, respectively. The branch body / linear body ratio was extremely high, and very high reaction activity was obtained at low temperature.

Example 3 The reaction was carried out in the same manner as in Example-2 except that the pressure was 80 atm. As a result of analysis, styrene conversion is 100%, 2-
The phenylpropanal and 3-phenylpropanal selectivities were 99% and 1%, respectively. The branch body / linear body ratio was extremely high, and very high reaction activity was obtained at low temperature.

Example 4 The reaction was carried out in exactly the same manner as in Example-3 except that the reaction time was 15 hours. As a result of analysis, styrene conversion rate is 76%, 2
-Phenylpropanal, 3-phenylpropanal and ethylbenzene selectivity is 96%, 2% and 2% respectively
Met. The branch body / linear body ratio was extremely high, and very high reaction activity was obtained at low temperature.

[0024]

As described above, in the hydroformylation reaction using the novel diphosphine ligand according to the present invention, a high reaction activity is realized at a moderate reaction temperature and an extremely high bra
An nch body / linear body production ratio can be obtained.
In particular, the achievement of a branch body production ratio of 99% is almost unknown reaction result in the conventional hydroformylation reaction.
That is, the present invention can carry out the reaction under mild conditions industrially, and can be applied to many useful derivatives.
formyl compound of anch form is obtained very selectively,
It provides a reaction method that is extremely useful in industry. Further, the diphosphine ligand used in the metal complex of the present invention is a chiral ligand having C2 symmetry and can be developed into an enantioselective reaction by taking out an optically active substance for use in the reaction. Low temperature high activity, high b required for
It has an essential advantage that the basic performance of the Ranch body / linear body selectivity is effectively used, and provides a catalyst which is extremely useful in industry.

Claims (4)

[Claims] 1. Formula (1) [Chemical Formula 1] (In the formula, R ¹ , R ² , R ³ and R ⁴ are an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 18 carbon atoms and 6 to 6 carbon atoms.
It is a group selected from 18 aralkyl groups, which may be the same or different from each other, and R ¹ and R ² and / or R ³ and R ⁴ are other than a phosphorus atom. A diphosphine having a bicyclo [2.2.2] octane skeleton represented by an alkyl group, an aryl group or an aralkyl group which may be linked by a bond with a rhodium catalyst is present. A method for hydroformylation of olefins, which comprises: 2. The olefin has the formula (2) The method for hydroformylation according to claim 1, wherein X represents an alkyl group, an aryl group, an aralkyl group, or a carboxylic acid ester group having 1 to 11 carbon atoms. 3. Formula (3) [Chemical formula 2] A method for hydroformylation of olefins, characterized in that the reaction is carried out in the presence of a catalyst composed of diphosphine having a bicyclo [2.2.2] octane skeleton represented by and rhodium. 4. The olefin has the formula (2) The method of hydroformylation according to claim 3, wherein X represents an alkyl group, aryl group, aralkyl group or carboxylic acid ester group having 1 to 11 carbon atoms. .