WO2003066642A1

WO2003066642A1 - Phosphorus chelate compounds

Info

Publication number: WO2003066642A1
Application number: PCT/EP2003/001245
Authority: WO
Inventors: Wolfgang Ahlers; Rocco Paciello
Original assignee: Basf Aktiengesellschaft
Priority date: 2002-02-08
Filing date: 2003-02-07
Publication date: 2003-08-14
Also published as: AU2003210225A1; DE10390373D2; DE10205361A1

Abstract

The invention relates to new phosphorus chelate compounds, catalysts containing at least one complex of a metal belonging to subgroup VIII and at least one such phosphorus chelate compound as a ligand, and a hydroformylation method using said catalysts.

Description

Phosphorehelatverbindungen

description

The present invention relates to new phosphorus chelate compounds, catalysts which comprise at least one complex of a metal from subgroup VIII with at least one such phosphorus chelate compound as ligands, and to a process for hydroformylation using these catalysts.

Hydroformylation or oxo synthesis is an important large-scale process and is used to produce aldehydes from olefins, carbon monoxide and hydrogen. These aldehydes can optionally be hydrogenated in the same operation with hydrogen to the corresponding oxo alcohols. The reaction itself is highly exothermic and generally takes place under elevated pressure and at elevated temperatures in the presence of catalysts. Co, Rh, Ir, Ru, Pd or Pt compound fertilizers or complexes are used as catalysts, which can be modified with N- or P-containing ligands to influence the activity and / or selectivity. In the hydroformylation reaction of olefins with more than two carbon atoms, the possible CO addition to each of the two carbon atoms of a double bond leads to the formation of mixtures of isomeric aldehydes. In addition, the use of olefins with at least four carbon atoms can also result in double bond isomerization, i. H. to shift internal double bonds to a terminal position and vice versa.

Because of the much greater technical importance of the α-aldehydes, the aim is to optimize the hydroformylation catalysts in order to achieve the highest possible hydroformylation activity with at the same time the lowest possible tendency to form double bonds which are not α-permanent. There is also a need for hydroformylation catalysts which, starting from internal linear olefins, lead to α-and in particular n-aldehydes in good yields. Here, the catalyst must allow both the establishment of an equilibrium between internal and terminal double bond isomers and, as selectively as possible, the hydroformylation of the terminal olefins. For example, for the production of ester plasticizers with good performance properties, there is a need for plasticizer alcohols with about 6 to 12 carbon atoms which are branched to a small degree (so-called semi-linear alcohols) and for corresponding mixtures thereof. These include, in particular, 2-propylheptanol and alcohol mixtures containing it. For their preparation, for example, butenes or C-hydrocarbon mixtures containing butenes and butanes can be subjected to hydroformylation and subsequent aldol condensation. When using hydroformylation catalysts with insufficient n-selectivity, hydroformylation can easily lead not only to the formation of n-valeraldehyde, but also to undesired product aldehydes, which means that the entire process is economically disadvantageous.

If technical mixtures, for example C ₄ cuts, are used for the hydroformylation, which are available in large quantities both from FCC plants and from steam crackers and which essentially consist of a mixture of 1-butene and 2-butene and generally butane, the hydroformylation catalyst used must selectively enable the hydroformylation of terminal olefins (1-butene) and / or be capable of shifting internal double bonds to a terminal position. There is also generally great technical interest in the provision of such hydroformylation catalysts.

It is known to use phosphorus-containing ligands in the rhodium low-pressure hydroformylation to stabilize and / or activate the catalyst metal. Suitable phosphorus-containing ligands are e.g. B. phosphines, phosphinites, phosphonites, phosphites, phosphoramidites, phospholes and phosphabenzenes. The currently most widely used ligands are triarylphosphines, such as. B. triphenylphosphine and sulfonated triphenylphosphine, since these have sufficient stability under the reaction conditions. However, a disadvantage of these ligands is that generally only very large excesses of ligands yield satisfactory yields, in particular of linear aldehydes.

No. 3,816,452 describes the production of differently substituted pyrrolyl monophosphines and their use as flame retardants.

AM Trzeciak et al. describe in J. Organomet. Chem. 552, pp. 159-164 (1998) unbridged trispyrrolylphosphine-rhodium complexes as catalysts for the hydrogenation of olefins and arenes. AM Trzeciak et al. describe in J. Chem. Soc, Dalton Trans. 1997, pp. 1831-1837 rhodium complexes with unbridged N-pyrrolylphosphines as ligands and the use of these complexes as hydroformylation catalysts.

A.M. Trzeciak et al. describe in C. R. Acad. Sei., Serie IIc, pp. 235-239 (1999) the hydroformylation of vinylsilanes with trispyrrolylphosphine-modified rhodium catalysts.

WO-A-00/56451 on the phosphorus atom relates, inter alia, to cyclic oxaphosphorines substituted with pyrrole derivatives and the use of these as ligands in catalysts for hydroformylation.

WO-A-99/52632 relates to a process for hydrocyanation using phosphorus-containing chelate ligands with 1, 1 'bisphenylene or 1, 1' bisnaphthylene backbone, in which the phosphorus atom can be substituted with unsubstituted pyrrole, indole or imidazole groups can, which are bonded to the phosphorus atom via a ring nitrogen atom.

No. 5,710,344 describes phosphorus atom-containing ligands with 1, 1'-biphenylene or 1, 1'-binaphthylene backbone, which can be substituted with unsubstituted pyrrole, imidazole or indole groups which are bonded to the phosphorus atom via a ring nitrogen atom. These ligands are suitable for hydroformylation catalysts based on metals from subgroup VIII.

J. Shen et al. describe in Organometallics 1998, 17, pp. 3000-3005 calorimetric studies on diphosphine chelate ligands, using, inter alia, hydrazide-bridged diphenylphosphines and alkylene-bridged dipyrrole phosphines.

Y. Gimbert et al. describe in J. Org. Chem. 1999, 64, p. 3492-3497 synthesis and properties of Co (0) complexes with diphosphinoamine ligands. This ligand includes N-bridged bispyrrole phosphines.

H. Brunner and H. Weber describe in Chem. Ber. 118, pp. 3380-3395 (1985) optically active aminophosphanes and their use in enantioselective hydrosilylation. These ligands are produced by condensation of 2-pyrrole carbaldehyde or 2-acetyl-pyrrole with 1-phenylethylamine and, if appropriate, further subsequent reactions and can have pyrrole nitrogen-phosphonated groups. WO 01/58589 describes compounds of phosphorus, arsenic and antimony based on diaryl-fused bicyclo [2.2.2] basic bodies and catalysts which contain these as ligands. In principle, hetaryl residues can also be bound to the atom of the 5th main group.

DE-A-100 23 471 describes a process for hydroformylation using a hydroformylation catalyst which comprises at least one phosphine ligand which has two triarylphosphine groups, each having an aryl radical of the two triarylphosphine groups via a single bond to a non-aromatic 5- to 8-group -linked carbocyclic or heterocyclic bridging group is bound. The phosphorus atoms may also have hetaryl groups as further substituents.

The unpublished German patent application P 100 46 026.7 describes a hydroformylation process in which the catalyst used is a complex based on a phosphorus, arsenic or antimony-containing compound as ligand, this compound in each case two a P-, As- or Sb atom and at least two further heteroatoms having groups bound to a xanthene-like molecular structure.

The unpublished international application PCT / EP02 / 09455 describes a hydroformylation process using a catalyst complex which has as ligands at least one pyrrole-phosphorus compound in which a substituted and / or pyrrole group integrated into a fused ring system is covalently linked to the phosphorus atom via its pyrrolic nitrogen atom ,

WO 02/83695 describes, inter alia, a process for the hydroformylation of olefins using a hydroformylation catalyst which comprises a complex of a metal from subgroup VIII with at least one pnicogen chelate compound as ligand. These ligands have two groups containing pnicogen atoms which are connected to one another via a xanthene-like or triptycene-like molecular structure and where at least one pyrrole group is covalently bound to each pnicogen atom via the nitrogen atom thereof.

R. Jackstell et al. describe in Eur. J. Org. Chem. 2001, 3871-3877 the synthesis of monodentate pyrrolyl, indolyl and carbazolyl phosphines and their use as ligands in the hydroformylation of 2-pentene. KG Moloy et al. describe in J. Am. Chem. Soc. 117, pp. 7696-7710 (1995) unsubstituted or non-fused mono- and dinuclear pyrrolyl compounds and their Rh and Mo complexes.

D.C. Smith et al. describe in Organometallics 19,

Pp. 1427-1433 (2000) platinum complexes of bis (dipyrrolylphosphino) alkanes.

EP-A-0 754 715 describes a catalyst composition comprising a metal from subgroup VIII and an alkylene-bridged di (proline-phenyl-phosphine) and their use for the preparation of polyketones.

WO-A-96/01831 describes chiral diphosphines of biheterocyclic compounds of aromatic, 5-atom heterocycles and their use in chiral catalysts for stereoselective reactions. The heterocyclic nuclei are linked by a single bond between two ring carbon atoms.

WO-A-99/52915 describes chiral phosphorus atom-containing ligands based on bicyclic compounds of carbocyclic and heterocyclic 5- to 6-atom compounds. The aromatic rings forming the bicyclus are linked to one another via a single bond between two ring carbon atoms.

None of the aforementioned documents describes phosphorus chelate compounds in which three nitrogen atoms are covalently bonded to each of the two phosphorus atoms, which are themselves part of an aromatic ring system.

The present invention is based on the object of providing new phosphorus chelate compounds which are suitable as ligands for transition metal complexes of metals of subgroup VIII, in order in this way to provide new catalysts based on these metal complexes. These ligands should preferably be easy to prepare and / or their complexes should be as stable as possible under the reaction conditions of the reactions to be catalyzed and have good catalytic activity. In the hydroformylation of α-olefins, the highest possible proportion of α-aldehydes or alcohols (α-selectivity) should preferably be achieved. In particular, catalysts based on these ligands are said to be suitable for the hydroformylation of internal linear olefins with high regioselectivity in favor of terminal product aldehydes. Accordingly, phosphorus chelate compounds of the general formula I

B ¹ PB ⁵ - B ⁶ PB ³

(I)

B ² B ^

found what

B ¹ , B ² , B ³ , B ⁴ , B ⁵ and B ⁶ independently of one another represent a heteroaromatic group which has at least one aromatic ring with a ring nitrogen atom bonded to the phosphorus atom, and

Y represents a chemical bond or a divalent bridging group with 1 to 20 bridge atoms in the chain between the flanking bonds.

In the context of the present invention, the expression alkyl includes straight-chain and branched alkyl groups. These are preferably straight-chain or branched C ₁ -C ₂ -alkyl, preferably C 1 -C ₂ -alkyl and particularly preferably C 1 -C 4 -alkyl and very particularly preferably C] _- C -alkyl groups. Examples of alkyl groups are in particular methyl, ethyl, propyl, isopropyl, n-butyl, 2-butyl, sec-butyl, tert-butyl, n-pentyl, 2-pentyl, 2-methylbutyl, 3 -Methylbutyl, 1,2-dimethylpropyl, 1, 1-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 2-hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,2 -Dimethylbutyl, 1,3-dimethylbutyl, 2, 3-dimethylbutyl, 1, 1-dimethylbutyl, 2, 2-dimethylbutyl, 3, 3-dimethylbutyl, 1, 1, 2-trimethylpropyl, 1,2,2 -Trimethylpropyl, 1-ethylbutyl, 2-ethylbutyl, l-ethyl-2-methylpropyl, n-heptyl, 2-heptyl, 3-heptyl, 2-ethylpentyl, 1-propylbutyl, octyl, nonyl, decyl.

The term alkyl also includes substituted alkyl groups. Substituted alkyl radicals preferably have 1, 2, 3, 4 or 5, particularly preferably 1, 2 or 3 and in particular 1 substituent, selected from cycloalkyl, aryl, hetaryl, halogen, NE ¹ E ² , (NE ¹ E ² E ³ ) ⁺ , Carboxyl, carboxylate, -S0 ₃ H and sulfonate.

The term alkylene stands for straight-chain and branched alkanediyl groups, preferably with 1 to 4 carbon atoms. The term cycloalkyl includes unsubstituted and substituted cycloalkyl groups. The cycloalkyl group is preferably a Cs-C ₇ -cycloalkyl group, such as cyclopentyl, cyclohexyl or cycloheptyl.

If the cycloalkyl group is substituted, it preferably has 1, 2, 3, 4 or 5, in particular 1, 2 or 3, substituents selected from alkyl, alkoxy or halogen.

The term heterocycloalkyl for the purposes of the present invention encompasses saturated, cycloaliphatic groups with generally 4 to 7, preferably 5 or 6 ring atoms, in which 1 or 2 of the ring carbon atoms are replaced by heteroatoms selected from the elements oxygen, nitrogen and sulfur, and the can optionally be substituted, wherein in the case of a

Substitution, these heterocycloaliphatic groups 1, 2 or 3, preferably 1 or 2, particularly preferably 1 substituent, selected from alkyl, aryl, C00R ^a , C00 "M ⁺ and NE ⁱ E ² , preferably alkyl, can carry. Exemplary of such heterocycloalipha - Tical groups are pyrrolidinyl, piperidinyl, 2, 2, 6, 6-tetramethyl-piperidinyl, imidazolidinyl, pyrazolidinyl, oxazolidinyl, morpholidinyl, thiazolidinyl, isothiazolidinyl, isoxazolidinyl, piperazinyl, tetrahydrothiophenyl, tetrahydrofuranyl, called tetrahydrofuranyl.

Aryl comprises unsubstituted and substituted aryl groups and is preferably phenyl, tolyl, xylyl, mesityl, naphthyl, fluorenyl, anthracenyl, phenanthrenyl, naphthacenyl and in particular phenyl or naphthyl.

Substituted aryl radicals preferably have 1, 2, 3, 4 or 5, in particular 1, 2 or 3, substituents selected from alkyl, alkoxy, carboxyl, carboxylate, trifluoromethyl, -S0 ₃ H, sulfonate, NE ¹ E ² , alkylene NE ⁱ E ² , nitro, cyano or halogen.

Hetaryl includes unsubstituted and substituted heteroaromatic groups and is preferably pyridyl, quinolinyl, acridinyl, pyridazinyl, pyrimidinyl or pyrazinyl, and the following subgroup of the "pyrrole group".

Substituted hetaryl radicals preferably have 1, 2 or 3 substituents selected from alkyl, alkoxy, carboxyl, carboxylate, -S0 ₃ H, sulfonate, NE ⁱ E ² , alkylene-NE ⁱ E ² , trifluoromethyl or halogen. For the purposes of the present invention, the term “pyrrole group” stands for a series of unsubstituted or substituted, heterocycloaromatic groups which are structurally derived from the pyrrole backbone and contain a pyrrolic nitrogen atom in the heterocycle which is covalent with other atoms, for example a phosphorus atom , can be linked. The term "pyrrole group" thus includes the unsubstituted or substituted groups pyrrolyl, imidazolyl, pyrazolyl, indolyl, purinyl, indazolyl, benzotriazolyl, 1,2, 3-triazolyl, 1, 3,4-triazolyl and carbazolyl, which in the case of a Substitution in general 1, 2 or 3, preferably 1 or 2, particularly preferably 1, selected from the groups alkyl, alkoxy, acyl, carboxyl, carboxylate, -S0 ₃ H, sulfonate, NE ⁱ E ² , alkylene NE ⁱ E ² , trifluoromethyl or halogen.

The above statements on alkyl, cycloalkyl and aryl radicals apply accordingly to alkoxy, cycloalkyloxy and aryloxy radicals.

For the purposes of the present invention, the term “acyl” stands for alkanoyl or aroyl groups with generally 2 to 11, preferably 2 to 8, carbon atoms, for example for the acetyl, propionyl, butyryl, pentanoyl, hexanoyl, heptanoyl, 2-ethyl-hexanoyl, 2-propylheptanoyl, benzoyl or naphthoyl group.

The NE ⁱ E ² and NE ⁴ E ⁵ radicals are preferably N, N-dimethylamino, N, N-diethylamino, N, N-dipropylamino, N, N-diisopropylamino, N, N-di-n-butylamino, N, N-di-tert. -butylamino, N, N-dicyclohexylamino or N, N-diphenylamino.

Halogen represents fluorine, chlorine, bromine and iodine, preferably fluorine, chlorine and bromine.

Carboxylate and sulfonate in the context of this invention preferably represent a derivative of a carboxylic acid function or a sulfonic acid function, in particular a metal carboxylate or sulfonate, a carboxylic acid or sulfonic acid ester function or a carboxylic acid or sulfonic acid amide function. These include e.g. B. the esters with -CC alkanols, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol and tert-butanol.

M ⁺ stands for a cation equivalent, ie for a monovalent cation or the portion of a multivalent cation corresponding to a positive single charge. Preferably M ⁺ stands for an alkali metal cation, such as. B. Li ⁺ , Na ⁺ or K ⁺ or for an alkaline earth metal cation, for NH ₄ ⁺ or a quaternary ammonium compound, as can be obtained by protonation or quaternization of amines is. Alkali metal cations are preferred, in particular sodium or potassium ions.

X- stands for an anion equivalent, i.e. H. for a monovalent anion or the proportion of a multivalent anion corresponding to a negative single charge. X- is preferably a carbonate, carboxylate or halide, particularly preferably Cl- and Br ~.

The values for x stand for an integer from 1 to 240, preferably for an integer from 3 to 120.

Condensed ring systems can be fused aromatic, hydroaromatic and cyclic compounds. Condensed ring systems consist of two, three or more than three rings. Depending on the type of linkage, a distinction is made between condensed ring systems between ortho annulation, i.e. H. each ring has an edge or two atoms in common with each neighboring ring, and a peri-annulation in which one carbon atom belongs to more than two rings. Preferred among the condensed ring systems are ortho-condensed ring systems.

The heteroaromatic groups B ¹ , B ² , B ³ , B ⁴ , B ⁵ and B ^{6 are} preferably pyrrole groups bonded to the phosphorus atom via a ring nitrogen atom. The meaning of the pyrrole groups corresponds to the definition given at the beginning.

B ¹ , B ² , B ³ and B ⁴ are preferably selected independently of one another from groups of the general formula II

wherein

R ¹ , R ² , R ³ and R ⁴ independently of one another for hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl, hetaryl, WC00R ^a , WC00 ^_ M ⁺ , W (S0 ₃ ) R ^a , W (S0 ₃ ) "M ⁺ , WPO ^ E ² , W (P0 ₃ ) ² "(M ⁺ ) ₂ , WNE ⁱ E ² , W (NE ^X E ² E ³ ) ⁺ X-, W0R ^a , WSR ^a , (CHR ^b CH ₂ 0) _x R ^a , (CH ₂ NE ¹ ) _x R ^a , (CH ₂ CH ₂ NE ¹ ) _x R ^a , halogen, trifluoromethyl, nitro, acyl or cyano,

wherein W represents a single bond or a divalent bridging group with 1 to 20 bridge atoms,

R ^a _t E ¹ , E ² , E ^{3 are} each the same or different radicals selected from hydrogen, alkyl, cycloalkyl or aryl,

R represents hydrogen, methyl or ethyl,

M ^{+ stands} for a cation equivalent,

X- stands for an anion equivalent and

x represents an integer from 1 to 240,

where two adjacent radicals R ¹ and R ² and / or R ³ and R ⁴ together with the carbon atoms of the pyrrole ring to which they are attached can also represent a condensed ring system with 1, 2 or 3 further rings.

According to the invention, the compounds of the formula II are bonded to a phosphorus atom of the phosphorus chelate compounds via the pyrroleic nitrogen atom.

In the compounds of the formula II, one or two of the radicals R ¹ , R ² , R ³ and R ⁴ are preferably one of the abovementioned substituents other than hydrogen and the rest are hydrogen. Compounds of the formula II are preferred which have a substituent other than hydrogen in the 2-position, 2,5-position or 3,4-position.

The substituents R ¹ to R ⁴ which are different from hydrogen are preferably selected independently of one another from C 1 -C 4, preferably C 1 -C 4 alkyl, especially methyl, ethyl, isopropyl and tert-butyl, alkoxycarbonyl, such as methoxycarbonyl, ethoxycarbonyl, isopro - pyloxycarbonyl and tert-butyloxycarbonyl and trifluoromethyl.

In the compounds of the formula II, the radicals R ¹ and R ² and / or R ³ and R ⁴ together with the carbon atoms of the pyrrole ring to which they are bonded preferably represent a condensed ring system with 1, 2 or 3 further rings. If R ¹ and R ² and / or R ³ and R ⁴ stand for a fused-on, ie fused-on ring system, it is preferably benzene or naphthalene rings. Fused benzene rings are preferably unsubstituted and have 1, 2 or 3, in particular 1 or 2, substituents which are selected from alkyl, alkoxy, halogen, SOH, sulfonate, NE ^ ² , alkylene-NE ^ ² , trifluoromethyl, nitro, COOR ^a , AI- koxycarbonyl, acyl and cyano. Fused naphthalene rings are preferably unsubstituted or have 1, 2 or 3, in particular 1 or 2, of the substituents previously mentioned for the fused benzene rings in the non-fused ring and / or in the fused ring. If R ¹ and R ^{2 are} a fused-on ring system, R ³ and R ^{4 are} preferably hydrogen or R ^{4 is} hydrogen and R ^{3 is} a substituent which is selected from Ci to Cg alkyl, preferably Ci to C-alkyl, especially methyl, ethyl, isopropyl or tert-butyl.

If the use of the compounds of the formula I is intended in an aqueous hydroformylation medium, at least one of the radicals R ¹ , R ² , R ³ and / or R ⁴ preferably represents a polar (hydrophilic) group, in which case, as a rule, during the formation of the complex result in water-soluble complexes with a Group VIII metal. The polar groups are preferably selected from C00R ^a , COO-M ⁺ , S0 ₃ R ^a , S0 ₃ "M ⁺ , NE ⁱ E ² , alkylene-NE ⁱ E ² , NE ¹ E ² E ³⁺ X", alkylene NE ¹ E ² E ³⁺ X ", OR ^a , SR ^a , (CHR ^b CH ₂ 0) _x R ^a or (CH ₂ CH ₂ N (E ¹ )) _x R ^a , where R ^a , E ¹ , E ² , E ³ , R ^b , M ⁺ , X- and x have the meanings given above.

According to a preferred embodiment, B ¹ , B ² , B ³ and B ^{4 are} indolyl radicals. The pyrrole ring in the 3-position may have a substituent other than hydrogen, preferably a C 1 -C 4 -alkyl radical.

The bridging heteroaromatic groups B ⁵ and B ⁶ are preferably selected independently of one another from groups of the general formula III

wherein

R ⁵ , R ⁶ , R ⁷ and R ⁸ independently of one another for hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl, hetaryl, WC00R ^a , WC00 "M ⁺ , W (S0 ₃ ) R ^a , W (S0 ₃ ) ^~ M ⁺ , WP0 ₃ E ¹ E ² , W (P0 ₃ ) ² "(M ⁺ ) ₂ , WNE ^ ² , W (NE ¹ E ² E ³ ) ⁺ X", WOR ^a , WSR ^a , (CHR ^b CH ₂ 0 ) _x R ^a , (CH ₂ NE ¹ ) _x R ^a , (CH ₂ CH ₂ NE ¹ ) _x R ^a , halogen, trifluoromethyl, nitro, acyl or cyano,

R ^a ₍ E ¹ , E ² , E ³ each represent the same or different radicals selected from hydrogen, alkyl, cycloalkyl or aryl,

R ^{b represents} hydrogen, methyl or ethyl,

M ^{+ stands} for a cation equivalent,

X- stands for an anion equivalent and

x represents an integer from 1 to 240,

where two adjacent radicals R ⁵ and R ⁶ and / or R ⁷ and R ⁸ together with the carbon atoms of the pyrrole ring to which they are attached can also represent a condensed ring system with 1, 2 or 3 further rings,

with the proviso that one of the radicals R ⁵ , R ⁶ , R ⁷ or R ^{8 stands} for a chemical bond to a divalent bridging group Y or together with a group Y stands for a chemical bond which bonds the radicals B ⁵ and B ^{6 to} one another combines.

According to the invention, the compounds of the formula III are bonded to a phosphorus atom of the phosphorochelate compounds via the pyrrolic nitrogen atom. Furthermore, one of the radicals R ⁵ to R ^{8 stands} for a chemical compound, that is to say the point of attachment of the compound of the formula III to a bridging group Y, or in the case that Y itself is a chemical compound, to a further compound of the formula III , If two compounds of the formula III are directly linked to one another via a chemical bond, the compounds of the formula III can be the same or different, and the compounds of the formula III can be the same or different radicals R ⁵ to R ⁸ (ie the same or different positions of the pyrrole ring).

In the compounds of the formula III, one of the radicals in the 2-position of the pyrrole ring (ie R ⁵ or R ⁸ ) preferably represents a chemical bond, that is to say the point of attachment to the bridging group Y.

In the compounds of the formula III, one, two or three of the radicals R ⁵ , R ⁶ , R ⁷ and R ⁸ which do not represent a chemical bond are preferably one of the abovementioned of water Substance of various substituents. Preferred compounds of the formula III are those in which the 2-position represents a chemical bond and the 5-position or the 3, 4, 5 position represents a substituent other than hydrogen.

The substituents R ⁵ to R ⁸ which are different from hydrogen are preferably selected independently of one another from Cχ-C ₈ -, preferably C; _L -C ₄ alkyl, especially methyl, ethyl, isopropyl and tert-butyl, alkoxycarbonyl, such as methoxycarbonyl, ethoxycarbonyl, isopropyloxycarbonyl and tert-butyloxycarbonyl and trifluoromethyl.

Furthermore, in the compounds of the formula III, one of the residues in the 2-position of the pyrrole ring (R ⁵ or R ⁸ ) preferably represents a chemical bond and one of the residues in the 5-position together with a residue in the 4-position (R ⁵ and R ⁶ and / or R ⁷ and R ⁸ ) together with the carbon atoms of the pyrrole ring to which they are attached, for a condensed ring system with 1, 2 or 3 further rings. With regard to suitable and preferred condensed ring systems, reference is made to the previous statements relating to corresponding radicals R ¹ and R ² and / or R ³ and R ⁴ in compounds of the formula II. The compound of the formula III then preferably represents an indolyl group.

If the use of the compounds of the formula I is intended in an aqueous hydroformylation medium, at least one of the radicals R ⁵ , R ⁶ , R ⁷ and / or R ⁸ preferably represents a polar (hydrophilic) group, as previously for the radicals R ¹ to R ⁴ defines what is referred to here.

According to a first preferred embodiment, the bridging group Y stands for a chemical bond, ie in the phosphorus chelate compounds of the general formula I the heteroaromatic groups B ⁵ and B ^{6 are} directly linked to one another.

According to a further preferred embodiment, the bridging group Y is selected from groups of the formulas IV.1 to IV.15

RU

R ° RIO R ¹¹ R ¹² Rl3 _R 1 Rl

\ / L C

/ \

CH - - CH

- (CH ₂ ) ^' _m (CH ₂ ) _n 1

(IV.1) (IV.2)

(IV. 3) ²

(IV.4) (IV.5) (IV.6)

(IV.10) (IV.11) (IV.12)

(IV.13) (IV.14)

(IV.15) in which

R ⁹ and R ¹⁰ independently represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl, where R ⁹ and Rio together with the carbon atom to which they are attached are also a 3- to 8-membered carbocycle or heterocycle which may optionally also be fused once, twice or three times with cycloalkyl, heterocycloalkyl, aryl and / or hetaryl,

Ιι _R, _R i2 _{f R} i3, _R i4 i5 _R _{f R} i6, _R i7 _{# R} ^ι β, _R ιi ', _R i2- _R i3' _un d R14 _'¬ inde pendently represents hydrogen, alkyl, cycloalkyl, heterocycloalkyl , Aryl, hetaryl, alkoxy, halogen, S0 ₃ H, sulfonate, NE ⁴ E ⁵ , alkylene-NE ⁴ E ⁵ , trifluoromethyl, nitro, alkoxycarbonyl, carboxyl or cyano, where E ⁴ and E ⁵ each have the same or different radicals, selected from hydrogen, alkyl, cycloalkyl and aryl,

M represents a zero-valent transition metal, in particular Fe,

m and n both represent 0 or both represent 1,

Z stands for 0, S, NR ¹⁹ or SiR ¹⁹ R ²⁰ , where

R ¹⁹ and R ²⁰ independently of one another represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl,

or Z represents a Ci to C ₃ alkylene bridge which can have a double bond and / or an alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl substituent,

or Z represents a C - to C ₃ -alkylene bridge which is interrupted by O, S or NR ¹⁹ or SiR ¹⁹ R ²⁰ ,

A ¹ and A ² independently of one another represent 0, S, SiR ¹⁹ R ²⁰ , NR ¹⁹ or CR ²¹ R ²² , where

R ²¹ and R ²² independently of one another represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl or the group R ²¹ together with another group R ²ⁱ or the group R ²² together with another group R ^{22 form} an intramolecular bridge group D,

D a two-gang bridge group selected from the groups

is where R ²³ and R ²⁴ independently of one another represent hydrogen, alkyl, cycloalkyl, aryl, halogen, trifluoromethyl, carboxyl, carboxylate or cyano or are connected to one another to form a C 1 -C 6 -alkyl bridge,

R ²⁵ , R ²⁶ , R ²⁷ and R ²⁸ independently of one another for hydrogen,

Alkyl, cycloalkyl, aryl, halogen, trifluoromethyl, COOH, carboxylate, cyano, alkoxy, S0 ₃ H, sulfonate, NE ⁴ E ⁵ , alkylene-NE ⁴ E ⁵ E ⁶⁺ X-, acyl or nitro, where X- is there is an anion equivalent, and

c is 0 or 1.

Y is preferably a group of the formula IV.1, where R ⁹ and R ^{10 are} hydrogen and m and n are both 0.

Y further preferably represents a group of the formula IV.1, in which R ^{9 is} -C ₄ -alkyl, in particular methyl or ethyl, C ₁ -C ₄ -alkoxy, in particular methoxy, or phenyl and in which R ^{10 is} Hydrogen stands. In these compounds, m and n are preferably both 0.

Y is furthermore preferably a compound of the formula IV.1, in which R ⁹ and R ^{10 are} both selected independently of one another from C 1 -C ₄ -alkyl radicals. In particular, R ⁹ and R ¹⁰ are both methyl.

Furthermore, Y preferably represents a group of the formula IV.1, where R ⁹ and R ¹⁰ together with the carbon atom to which they are attached represent a 3 to 8-membered carbocycle or heterocycle which optionally additionally, once, twice or three times with cycloalkyl, heterocycloalkyl, aryl and / or hetaryl. In these compounds m and n are preferably either both 0 or both 1. Particularly preferably R ⁹ and R ¹⁰ together represent cyclopentyl.

Furthermore, Y preferably represents a group of the formula IV.3, in which R ¹¹ and R ¹² are selected independently of one another from hydrogen and C 1 -C ₄ -alkyl radicals.

Y is furthermore preferably a group of the formula IV.5, where R ¹¹ and R ^{i2 are} hydrogen.

In formulas IV.6 and IV.7, R ¹¹ and R ^{12 are} preferably both hydrogen. Furthermore, Y preferably represents a group of the formula IV.8, in which R ¹¹ , R ⁱ² , R ¹³ and R ¹⁴ stand for hydrogen.

Y is furthermore preferably a group of the formula IV.9, where M is Fe and R ^U , R ¹² , R ⁱ³ , R ¹⁴ , R ^U ', R ² ', R ¹ 'and Rl' are hydrogen. The two cyclopentadienyl rings of the metalocene IV.9 can exist in an ecliptic and staggered conformation. The planes of the cyclopentadienyl rings can be parallel or inclined, for example depending on the central metal.

Y is furthermore preferably a group of the formula IV.11, where R ⁿ , R ¹² , R ¹³ and R ^{14 are} hydrogen.

Y is furthermore preferably a group of the formula IV.15.

In the bridging group Y of the formula IV.15 may groups A ^l and A ² in general independently of one another O, S, SiR ⁹ R ^20, NR ¹⁹ or CR ²¹ R ^22, the substituents R ¹⁹ and R ²⁰ in the general - mean independently of one another the meaning hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl, whereas the groups R ²¹ and R ²² independently represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl or the group R ²¹ together with another group R ²¹ or the group R ²² together with another group R ²² can form an intramolecular bridge group D.

D is a double-bonded bridge group that is generally selected from the groups

in which R ²³ and R ²⁴ independently of one another represent hydrogen, alkyl, cycloalkyl, aryl, halogen, trifluoromethyl, carboxyl, carboxylate or cyano or are connected to one another to form a C ₃ -C -alkylene group and R ²⁵ , R ²⁶ , R ²⁷ and R ²⁸ independently of one another for hydrogen, alkyl, cycloalkyl, aryl, halogen, trifluoromethyl, COOH, carboxylate, cyano, alkoxy, S0 ₃ H, sulfonate, NE ⁴ E ⁵ , alkylene-NE ⁴ E ⁵ E ⁶⁺ X. - Aryl or nitro can stand. The groups R ²³ and R ²⁴ are preferably hydrogen, -CC-alkyl or carboxylate and the groups R ²⁵ , R ²⁶ , R ²⁷ and R ^{28 are} hydrogen, -CC-alkyl, halogen, in particular fluorine, chlorine or bromine , Trifluoromethyl, -CC alkoxy, carboxylate, sulfonate or C ₆ -c ₈ aryl. R ²³ , R ²⁴ , R ²⁵ , R ²⁶ , R ²⁷ and R ²⁸ are particularly preferably hydrogen. For use in an aqueous reaction medium, preference is given to those compounds in which 1, 2 or 3, preferably 1 or 2, in particular 1 of the groups R ²⁵ , R ²⁶ , R ²⁷ and / or R ²⁸ for a COO ^~ M ⁺ , S0 ₃ "M ⁺ or a NEE ² E ³⁺ χ-- group, where M ⁺ and X- have the meaning given above.

Particularly preferred bridge groups D are the ethylene group

CH CH

and the 1, 2-phenylene group

If R ²¹ forms an intramolecular bridge group D with a further group R ^2X or R ²² with a further group R ²² , ie the index c in this case is 1, it necessarily results that both A ¹ and A ^{2 are} CR ²¹ R ²² group and the bridging group Y in this case has a triptycene-like carbon skeleton.

In addition to those with a triptycene-like carbon skeleton, preferred bridging groups Y are those in which the index c is 0 and the groups A ¹ and A ^{2 are} selected from groups 0, S and CR ²¹ R ²² , in particular under 0, S , the methylene group (R ²¹ = R ²² = H), the dimethylmethylene group (R ²ⁱ = R ²² = CH ₃ ), the di-n-propylmethylene group (R ²¹ = R ²² = n-propyl) or the di-n -butylmethylene group (R ²¹ = R ²² = n-butyl). In particular, those bridging groups Y are preferred in which A ^l is different from A ² , where A ^{1 is} preferably a CR ²¹ R ²² group and A ^{2 is} preferably a 0 or S group, particularly preferably an oxa group 0.

Particularly preferred bridge groups Y of the formula IV.15 are therefore those which are composed of a triptycene-like or xanthene-like (A ¹ : CR ²¹ R ²² , A ² : 0) framework.

In formula IV.15, the substituents R ¹¹ , R ⁱ² , R ¹³ and R ^{i4 are} preferably hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl and hetaryl. R ¹¹ and R ¹³ are preferably hydrogen and R ⁱ² and R ^{14 are} -CC ₄ alkyl, such as. B. methyl, ethyl, n- Propyl, n-butyl or tert-butyl.

In formula IV.15, the substituents R ¹¹ , I ² , R ¹³ and R ¹⁴ are preferably all hydrogen.

If in formula IV.15 R ^u and / or R ¹³ stand for a fused-on, ie fused, ring system, it is preferably benzene or naphthalene rings. Fused benzene rings are preferably unsubstituted or have 1, 2 or 3, in particular 1 or 2, substituents which are selected from alkyl, alkoxy, halogen, SO ₃ H, sulfonate, NE ^X E ² , alkylene NE ⁱ E ² , trifluoro methyl, nitro, C00R ^a , alkoxycarbonyl, acyl and cyano. Fused naphthalene rings are preferably unsubstituted or have a total of 1, 2 or 3, in particular 1 or 2, of the substituents mentioned above for the fused benzene rings in the non-fused ring and / or in the fused ring.

Some are listed below only to illustrate phosphorus chelate compounds according to the invention:

(1) (2)

(3)

(5) (6)

(7)

10

(8th)

(9)

(10)

(11)

45

(12)

(13)

(14)

The phosphor chelate compounds of the general formula I according to the invention can be prepared, for example, according to the following scheme: 1 eq Hß, 1 eq HB ²

P (Hal) ₃ .► B ⁱ ß ² PHal

-2 HHal

2 eq HB ^1. ",,"".

P (Hal) _{3 ►} (B ⁱ ) ₂ PHal

-2 HHal

HB ⁵ -YB ⁶ -H, _c

2 (ßl) ₂ PHal _► (ß ^l ) ₂ PB ⁵ -Y- _B ⁶ -P (B ^l ) ₂

-2 HHal

Hai = CI, Br

e.g.

In it, B ¹ , B ² , B ⁵ , B ⁶ , R ¹ , R ² , R ³ and R ^{4 have} the aforementioned meaning independently of one another.

For example, phosphorus chelate compounds with a bis-indolyl backbone can be produced starting from toluidines according to the following scheme:

Such syntheses are described, for example, in GB 330,332 and by Madelung in Chem. Ber. 1912, 45, pp. 1131ff, which are referred to in their entirety here.

The preparation of phosphorus-chelate compounds with backbones, in which two indole groups are connected to one another by different bridging groups Y, can be carried out according to the Fischer-indole synthesis starting from phenylhydrazone and the corresponding di-ketones. This is explained using the following scheme as an example:

Such syntheses are described, for example, in Houben-Weyl, Georg-Thieme Verlag Stuttgart, 1994, Hetarene I, Part 2b, pp. 716-735; Robinson, Chem. Rev. 1969, 69, pp. 227-250 and Schöpf, Chem. Ber, 1954, 87, pp. 455-463, to which reference is made in full here.

The preparation of phosphorus-chelate compounds with backbones, in which two indole groups are connected to one another by different bridging groups Y, can also be carried out according to the following scheme respectively:

10

Such syntheses are described, for example, in Babu et al., Synthetic Commun. 30 (9), 1609-1614 (2000); Dittmann, Arch. Pharm. 1985, 30 318, N4, pp. 340-350 and Brieskorn, Arch. Pharm. 1979, 312 NO 12, pp. 1046-1051, to which reference is made in full here.

The invention furthermore relates to a catalyst comprising at least one complex of a metal from subgroup VIII with at least one compound of the formula I according to the invention, as previously defined.

The catalysts according to the invention and used according to the invention can have one or more of the compounds of the general formula I as ligands. In addition to the ligands of the general formula I described above, you can also use at least one further ligand, which is selected from halides, amines, carboxylates, acetylacetonate, aryl or alkyl sulfonates, hydride, CO, olefins, dienes, cycloolefins, Nitriles, N-containing heterocycles, aromatics and heteroaromatics, ethers, PF ₃ , phospholes, phosphabenzenes as well as one, two and have multidentate phosphine, phosphinite, phosphonite, phosphoramidite and phosphite ligands.

The metal of subgroup VIII is preferably cobalt, ruthenium, rhodium, palladium, platinum, osmium or iridium and in particular cobalt, rhodium, ruthenium and iridium.

In general, under hydroformylation conditions, catalytically active species of the general formula H _x M _y (CO) _z L _{q are} formed from the catalysts or catalyst precursors used in each case, where M is a metal of subgroup VIII, L is a phosphorus-containing compound of the formula I. and q, x, y, z are integers, depending on the valency and type of the metal and the binding nature of the ligand L. Preferably, z and q are independently at least 1, such as. B. 1, 2 or 3. The sum of z and q is preferably from 2 to 5. The complexes can, if desired, additionally have at least one of the other ligands described above.

According to a preferred embodiment, the hydroformylation catalysts are prepared in situ in the reactor used for the hydroformylation reaction. If desired, however, the catalysts of the invention can also be prepared separately and isolated by customary processes. For in situ production of the catalysts according to the invention, z. B. at least one compound of general formula I, a compound or a complex of a metal of subgroup VIII, optionally at least one further additional ligand and optionally an activating agent in an inert solvent under the hydroformylation conditions.

Suitable rhodium compounds or complexes are e.g. B. rhodium (II) and rhodium (III) salts, such as rhodium (III) chloride, rhodium (III) nitrate, rhodium (III) sulfate, potassium rhodium sulfate, rhodium (II ) or rhodium (III) carboxylate, rhodium (II) and rhodium (III) acetate, rhodium (III) oxide, salts of rhodium (III) acid, trisammonium hexachlororhodate (III) etc. Also suitable rhodium complexes such as rhodium biscarbonylacetylacetonate, acetyl acetonatobisethylene rhodium (I) etc. Rhodium biscarbonylacetylacetonate or rhodium acetate are preferably used.

Ruthenium salts or compounds are also suitable. Suitable ruthenium salts are, for example, ruthenium (III) chloride, ruthenium (IV) -, ruthenium (VI) - or ruthenium (VIII) oxide, alkali metal salts of ruthenium oxygen acids such as K ₂ Ru0 or KRu0 ₄ or complex compounds, such as, for. B. RuHCl (CO) (PPh ₃ ). They can also Metal carbonyls of ruthenium such as trisruthenium dodecacarbonyl or hexaruthenium octadecacarbonyl, or mixed forms in which CO is partly replaced by ligands of the formula PR ₃ , such as Ru (CO) ₃ (PPh ₃ ) ₂ , are used in the process according to the invention.

Suitable cobalt compounds are, for example, cobalt (II) chloride, cobalt (II) sulfate, cobalt (II) carbonate, cobalt (II) nitrate, their amine or hydrate complexes, cobalt carboxylates, such as cobalt acetate, cobalt ethyl hexanoate, cobalt naphthanoate, and the cobalt caprolactamate -Complex. Here too, the carbonyl complexes of cobalt such as dicobalt octacarbonyl, tetracobalt dodecacarbonyl and hexacobalt hexadecacarbonyl can be used.

The above-mentioned and other suitable compounds of cobalt, rhodium, ruthenium and iridium are known in principle and are adequately described in the literature, or they can be prepared by the skilled worker analogously to the already known compounds.

Suitable activating agents are e.g. B. Brönsted acids, Lewis acids, such as. B. BF, AlCl ₃ , ZnCl ₂ , and Lewis bases.

The solvents used are preferably the aldehydes which are formed in the hydroformylation of the respective olefins, and also their higher-boiling secondary reaction products, for. B. the products of aldol condensation. Likewise suitable solvents are aromatics, such as toluene and xylenes, hydrocarbons or mixtures of hydrocarbons, also for diluting the above-mentioned aldehydes and the secondary products of the aldehydes. Other solvents are esters of aliphatic carboxylic acids with alkanols, for example ethyl acetate or Texanol ™, ethers such as tert. -Butylmethyl ether and tetrahydrofuran. If the ligands are sufficiently hydrophilized, alcohols, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, ketones, such as acetone and methyl ethyl ketone, etc., can also be used. So-called "ionic liquids" can also be used as solvents. These are liquid salts, for example N, N'-dialkylimidazolium salts such as the N-butyl-N'-methylimidazolium salts, tetraalkylammonium salts such as the tetra-n-butylammonium salts, N-alkylpyridinium salts such as the n-butylpyridinium salts, tetra - Phosphonium salts such as the trishexyl (tetradecyl) phosphonium salts, e.g. B. the tetrafluoroborates, acetates, tetrachloroaluminates, hexafluorophosphates, chlorides and tosylates.

It is also possible to carry out the reactions in water or aqueous solvent systems which, in addition to water, contain a water-miscible solvent, for example an alcohol such as metha- nol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, a ketone such as acetone and methyl ethyl ketone or another solvent. For this purpose, ligands of the formula I are used which are modified with polar groups, for example ionic groups such as SO ₃ Me, CO ₂ Me with Me = Na, K or NH ₄ or as N (CH ₃ ) ₃ ⁺ . The reactions then take the form of two-phase catalysis, the catalyst being in the aqueous phase and feedstocks and products forming the organic phase. The implementation in the "Ionic Liquids" can also be designed as a two-phase catalysis.

The molar ratio of phosphorus-containing ligand to metal of subgroup VIII is generally in a range from about 1: 1 to 1000: 1.

In principle, all compounds which contain one or more ethylenically unsaturated double bonds are suitable as substrates for the hydroformylation process according to the invention. These include e.g. B. olefins, such as α-olefins, internal straight-chain and internal branched olefins. Suitable α-olefins are e.g. B. ethylene, propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonen, 1-decene, 1-undecene, 1-dodecene etc.

Suitable branched, internal olefins are preferably C -C ₂ Q olefins, such as 2-methyl-2-butene, 2-methyl-2-pentene, 3-methyl-2-pentene, branched, internal heptene mixtures, branched, internal Octene mixtures, branched, internal non-mixtures, branched, internal decene mixtures, branched, internal undecene mixtures, branched, internal dodecene mixtures etc.

Suitable olefins to be hydroformylated are furthermore C ₅ -C ₈ -cycloalkenes, such as cyclopentene, cyclohexene, cycloheptene, cyclooctene and their derivatives, such as, for. B. whose -CC ₂ o-alkyl derivatives with 1 to 5 alkyl substituents. Suitable olefins to be hydroformylated are also vinyl aromatics, such as styrene, α-methylstyrene, 4-isobutylstyrene etc. Suitable olefins to be hydroformylated are furthermore α, β-ethylenically unsaturated mono- and / or dicarboxylic acids, their esters, half-esters and amides, such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, methyl 3-pentenoate, methyl 4-pentenoate, methyl oleic acid, methyl acrylate, methyl methacrylate, unsaturated nitriles, such as 3-pentenenitrile, 4-pentenenitrile, and acrylate Vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether etc., -C-C ₂ o-alkenols, alkene diols and alkadienols, such as 2, 7-0ctadienol-l. Suitable substrates are also di- or polyenes with isolated or conjugated double bonds. These include e.g. B. 1,3-butadiene, 1,4-pentadiene, 1,5-hexadiene, 1,6-hepta- diene, 1, 7-octadiene, vinylcyclohexene, dicyclopentadiene, 1,5,9-cyclooctatriene and butadiene homo- and copolymers.

The unsaturated compound used for the hydroformylation is preferably selected from internal linear olefins and olefin mixtures which contain at least one internal linear olefin. Suitable linear (straight-chain) internal olefins are preferably C ₄ -C ₂ o-olefins, such as 2-butene, 2-pentene, 2-hexene, 3-hexene, 2-heptene, 3-heptene, 2-0ctene, 3-octene , 4-0cten etc. and mixtures thereof.

Preferably, an industrially accessible olefin mixture is used in the hydroformylation process according to the invention, which contains in particular at least one internal linear olefin. These include e.g. B. the Ziegler olefins obtained by targeted ethene oligomerization in the presence of alkyl aluminum catalysts. These are essentially unbranched olefins with a terminal double bond and an even number of carbon atoms. These also include the olefins obtained by ethene oligomerization in the presence of various catalyst systems, e.g. B. the predominantly linear α-olefins obtained in the presence of alkyl aluminum chloride / titanium tetrachloride catalysts and the α-olefins obtained in the presence of nickel-phosphine complex catalysts according to the Shell Higher Olefin Process (SHOP). Suitable technically accessible olefin mixtures are still used in the paraffin dehydrogenation of corresponding petroleum fractions, e.g. B. the so-called petroleum or diesel oil fractions obtained. Essentially three processes are used to convert paraffins, primarily n-paraffins to olefins:

thermal cracking (steam cracking), catalytic dehydration and chemical dehydration by chlorination and dehydrochlorination.

Thermal cracking leads predominantly to α-olefins, while the other variants result in olefin mixtures which generally also have relatively large proportions of olefins with an internal double bond. Suitable olefin mixtures are furthermore the olefins obtained in metathesis or telomerization reactions. These include e.g. B. the olefins from the Phillips-triolefin process, a modified SHOP process from ethylene oligomerization, double bond isomerization and subsequent metathesis (ethanolysis). Suitable industrial olefin mixtures which can be used in the hydroformylation process according to the invention are furthermore selected from dibutenes, tributenes, tetrabutenes, dipropenes, tripropenes, tetrapropenes, mixtures of butene isomers, in particular raffinate II, dihexenes, dimers and oligomers from the Dimersol® process from IFP, Octolprocess® of Hüls, polygas process etc.

A process is preferred which is characterized in that the hydroformylation catalyst is prepared in situ, using at least one compound of the formula I, a compound or a complex of a metal from subgroup VIII and optionally an activating agent in an inert solvent under the hydroformylation conditions Brings reaction.

The hydroformylation reaction can be carried out continuously, semi-continuously or batchwise.

Suitable reactors for the continuous reaction are known to the person skilled in the art and are described, for. B. in Ulimann's Encyclopedia of Industrial Chemistry, Vol. 1, 3rd Edition, 1951, p. 743 ff.

Suitable pressure-resistant reactors are also known to the person skilled in the art and are described, for. B. in Ulimann's Encyclopedia of Industrial Chemistry, Vol. 1, 3rd Edition, 1951, pp. 769 ff. In general, an autoclave is used for the method according to the invention, which can, if desired, be provided with a stirring device and an inner lining.

The composition of the synthesis gas of carbon monoxide and hydrogen used in the process according to the invention can vary within wide ranges. The molar ratio of carbon monoxide and hydrogen is usually about 5:95 to 70:30, preferably about 40:60 to 60:40. A molar ratio of carbon monoxide to hydrogen in the range of approximately 1: 1 is particularly preferably used.

The temperature in the hydroformylation reaction is generally in the range from about 20 to 180 ° C., preferably about 50 to 150 ° C. The reaction is usually carried out at the partial pressure of the reaction gas at the selected reaction temperature. In general, the pressure is in a range from about 1 to 700 bar, preferably 1 to 600 bar, in particular 1 to 300 bar. The reaction pressure can be varied depending on the activity of the hydroformylation catalyst according to the invention used. In general, the catalysts based on phosphorus-containing compounds according to the invention permit setting in a range of low pressures, such as in the range of 1 to 100 bar.

The hydroformylation catalysts used according to the invention and the hydroformylation catalysts according to the invention can be separated from the discharge of the hydroformylation reaction by customary processes known to the person skilled in the art and can generally be used again for the hydroformylation.

The catalysts according to the invention described above, which comprise chiral compounds of the general formula I, are suitable for enantioselective hydroformylation.

The catalysts described above can also be suitably, e.g. B. by connection via functional groups suitable as anchor groups, adsorption, grafting, etc. to a suitable carrier, for. B. made of glass, silica gel, synthetic resins etc., immobilized. They are then also suitable for use as solid-phase catalysts.

The hydroformylation activity of catalysts based on ligands of the formula I is surprisingly generally higher than the isomerization activity with regard to the formation of central double bonds. The catalysts according to the invention and those used according to the invention advantageously show a high selectivity in favor of the α-aldehydes or alcohols in the hydroformylation of α-olefins. In addition, good yields of α-aldehydes or alcohols and in particular also of n-aldehydes or alcohols are also generally obtained in the hydroformylation of internal linear olefins (isomerizing hydroformylation). Furthermore, these catalysts generally have a high stability under the hydroformylation conditions, so that they generally achieve a longer catalyst service life than with catalysts known from the prior art based on conventional chelate ligands. The catalysts according to the invention and those used according to the invention advantageously also have a high activity, so that the corresponding aldehydes or alcohols are generally obtained in good yields. In the hydroformylation of α-olefins and of internal, linear olefins, they also show a very low selectivity for the hydrogenation product of the olefin used.

Another object of the invention is a process for the preparation of 2-propylheptanol, in which a) butene or a butene-containing C -hydrocarbon mixture is hydroformylated in the presence of a catalyst, as previously defined, with carbon monoxide and hydrogen to give a hydroformylation product containing n-valeraldehyde,

b) if appropriate, subjecting the hydroformylation product to a separation to obtain a fraction enriched in n-valeraldehyde,

c) subjecting the hydroformylation product obtained in step a) or the fraction enriched in n-valeraldehyde obtained in step b) to an aldol condensation,

d) the products of the aldol condensation are hydrogenated catalytically to give alcohols, and

e) optionally subjecting the hydrogenation products to separation to obtain a fraction enriched in 2-propylheptanol.

a) Hydroformylation

Suitable starting materials for the hydroformylation are both essentially pure 1-butene and mixtures of 1-butene with 2-butene and technically available C ₄ hydrocarbon streams which contain 1-butene and / or 2 butene. C ₄ cuts, which are available in large quantities from FCC systems and from steam crackers, are preferably suitable. These consist essentially of a mixture of the isomeric butenes and butane.

Suitable C -carbon streams as feed contain z. B. 50 to 99, preferably 60 to 90 mol% of butenes and 1 to 50, preferably 10 to 40 mol% of butanes. The butene fraction preferably comprises 40 to 60 mol% of 1-butene, 20 to 30 mol% of 2-butene and less than 5 mol%, in particular less than 3 mol%, of isobutene (based on the butene fraction). The so-called raffinate II, which is an isobutene-depleted C-section from an FCC system or a steam cracker, is used as a particularly preferred feedstock.

Hydroformylation catalysts based on the phosphorus chelate compounds used as ligands advantageously have a high n-selectivity, even when using 2-butene and 2-butene-containing hydrocarbon mixtures as feedstock. Thus, in the method according to the invention such feedstocks can also be used economically, since the desired n-valeraldehyde results in good yields.

b) separation

According to a suitable process variant, the product-enriched fraction obtained in step a) after separation of the catalyst system is subjected to a further separation in order to obtain a fraction enriched in n-valeraldehyde. The hydroformylation product is separated into an n-valeraldehyde-enriched fraction and an n-valeraldehyde-depleted fraction by conventional methods known to those skilled in the art. Distillation is preferred using known separation apparatuses, such as distillation columns, e.g. B. tray columns, which can optionally be equipped with bells, sieve plates, sieve trays, valves etc., evaporators, such as thin-film evaporators, falling film evaporators, wiper blade evaporators etc.

c) aldol condensation

Two molecules of Cs-aldehyde can be condensed to α, β-unsaturated Cio-aldehydes. The aldol condensation takes place in a manner known per se, for. B. by the action of an aqueous base such as sodium hydroxide solution or potassium hydroxide solution. Alternatively, a heterogeneous basic catalyst, such as magnesium and / or aluminum oxide, can also be used (see, for example, EP-A 792 862). The condensation of two molecules of n-valeraldehyde results in 2-propyl-2-heptenal. If the hydroformylation product obtained in step a) or after the separation in step b) has further Cs aldehydes, such as 2-methylbutanal and, if appropriate, 2,2-dimethylpropanal, these also undergo aldol condensation, where then the condensation products of all possible aldehyde combinations result, for example 2-propyl-4-methyl-2-hexenal. A portion of these condensation products, e.g. B. of up to 30 wt .-%, an advantageous further processing to 2-propylheptanol-containing Cio-alcohol mixtures suitable as plasticizer alcohols does not stand in the way.

d) hydrogenation

The products of the aldol condensation can be hydrogenated catalytically with hydrogen to CIO alcohols, such as, in particular, 2-propylheptanol.

In principle, the hydroformylation catalysts are also generally suitable for the hydrogenation of the cio-aldehydes to the cio-alcohols at a higher temperature; in general, however, more selective hydrogenation catalysts preferred, which are used in a separate hydrogenation stage. Suitable hydrogenation catalysts are generally transition metals, such as. B. Cr, Mo, W, Fe, Rh, Co, Ni, Pd, Pt, Ru etc. or mixtures thereof, which to increase the activity and stability on supports such. B. activated carbon, aluminum oxide, diatomaceous earth, etc. can be applied. To increase the catalytic activity, Fe, Co and preferably Ni, also in the form of the Raney catalysts, can be used as a metal sponge with a very large surface area. The hydrogenation of the cio-aldehydes takes place depending on the activity of the catalyst, preferably at elevated temperatures and elevated pressure. The hydrogenation temperature is preferably about 80 to 250 ° C., the pressure is preferably about 50 to 350 bar.

The crude hydrogenation product can by conventional methods, e.g. B. by distillation to the Cχo alcohols.

e) separation

If desired, the hydrogenation products can be subjected to a further separation to obtain a fraction enriched in 2-propylheptanol and a fraction depleted in 2-propylheptanol. This separation can be carried out by customary methods known to those skilled in the art, such as, for. B. by distillation.

Hydroformylation catalysts which have a complex of at least one metal from transition group VIII of the Periodic Table, which has at least one chelate phosphorus compound of the general formula I as ligands, are advantageously suitable for use in a process for the preparation of 2-propyl-heptanol. The catalysts have a high n-selectivity, so that both when using essentially pure 1-butene and when using 1-butene / 2-butene-containing hydrocarbon mixtures, such as C-cuts, for example, a good one Yield of n-valeraldehyde is obtained. Furthermore, the catalysts used according to the invention are also suitable for double bond isomerization from an internal position to a terminal position, so that n-valeraldehyde is obtained in good yields even when using 2-butene and higher concentrations of hydrocarbon mixtures containing 2-butene. Advantageously, the catalysts based on heteroaromatics used according to the invention show essentially no decomposition under the hydroformylation conditions, ie in the presence of aldehydes. Advantageously, even in the presence of atmospheric oxygen and / or light and / or acids and / or at room temperature and elevated temperatures, such as up to about 150 ° C. no decomposition products are formed, so that the use of complex measures to stabilize the hydroformylation catalyst used, in particular during the workup, can be dispensed with.

Another object of the invention is the use of catalysts comprising at least one complex of a metal of subgroup VIII with at least one compound of the general formula I, as described above, for hydroformylation, hydrocyanation, carbonylation and for hydrogenation.

The hydrocyanation of olefins is a further area of application for the catalysts according to the invention. The hydrocyanation catalysts according to the invention also comprise complexes of a metal from subgroup VIII, in particular cobalt, nickel, ruthenium, rhodium, palladium, platinum, preferably nickel, palladium and platinum and very particularly preferably nickel. As a rule, the metal is zero-valued in the metal complex according to the invention. The metal complexes can be prepared as previously described for use as hydroformylation catalysts. The same applies to the in situ production of the hydrocyanation catalysts according to the invention.

A suitable nickel complex for the preparation of a hydrocyanation catalyst is e.g. B. Bis (1,5-cyclooctadiene) nickel (0).

If appropriate, the hydrocyanation catalysts can be prepared in situ, analogously to the process described for the hydroformylation catalysts.

The invention therefore furthermore relates to a process for the preparation of nitriles by catalytic hydrocyanation, in which the hydrocyanation takes place in the presence of at least one of the catalysts according to the invention described above. Suitable olefins for hydrocyanation are generally the olefins previously mentioned as starting materials for hydroformylation. A special embodiment of the process according to the invention relates to the production of mixtures of monoolefinic Cs-mononitriles with a non-conjugated C = C and C≡N bond by catalytic hydrocyanation of 1,3-butadiene or 1,3-butadiene-containing hydrocarbon mixtures and the isomerization / Further reaction to saturated C ₆ dinitriles, preferably adiponitrile in the presence of at least one catalyst according to the invention. When using hydrocarbon mixtures for the production of monoolefinic Cs-mononitriles by the process according to the invention, a hydrocarbon mixture is preferably used which has a 1,3-butadiene content of at least 10% by volume, preferably at least 25 vol .-%, in particular at least 40 vol .-%, has.

Hydrocarbon mixtures containing 1,3-butadiene are available on an industrial scale. So z. B. in the processing of petroleum by steam cracking of naphtha a C -cut hydrocarbon mixture with a high total olefin content, with about 40% on 1,3-butadiene and the rest on mono-olefins and polyunsaturated hydrocarbons and Al- kane is dropped. These streams always contain small amounts of generally up to 5% of alkynes, 1,2-dienes and vinyl acetylene.

Pure 1,3-butadiene can e.g. B. be isolated by extractive distillation from commercially available hydrocarbon mixtures.

The catalysts according to the invention can advantageously be used for the hydrocyanation of such olefin-containing, in particular 1,3-butadiene-containing, hydrocarbon mixtures, as a rule also without prior purification of the hydrocarbon mixture by distillation. Possible contained, the effectiveness of the catalysts impairing olefins, such as. B. alkynes or cumulenes, can optionally be removed from the hydrocarbon mixture by selective hydrogenation before the hydrocyanation. Suitable processes for selective hydrogenation are known to the person skilled in the art.

The hydrocyanation according to the invention can be carried out continuously, semi-continuously or batchwise. Suitable reactors for the continuous reaction are known to the person skilled in the art and are described, for. B. in Ullmann's Encyclopedia of Industrial Chemistry, Volume 1, 3rd edition, 1951, p. 743 ff. A stirred tank cascade or a tubular reactor is preferably used for the continuous variant of the process according to the invention. Suitable, optionally pressure-resistant reactors for semi-continuous or continuous execution are known to the person skilled in the art and are described, for. B. in Ullmann's Encyclopedia of Industrial Chemistry, Volume 1, 3rd Edition, 1951, pp 769 ff. In general, an autoclave is used for the method according to the invention, which can, if desired, be provided with a stirring device and an inner lining.

The hydrocyanation catalysts according to the invention can be separated from the discharge of the hydrocyanation reaction by customary processes known to the person skilled in the art and can generally be used again for the hydrocyanation. The invention further relates to a process for carbonylation of compounds which contain at least one ethylenically unsaturated double bond by reaction with carbon monoxide and at least one compound having a nucleophilic group in the presence of a carbonylation catalyst, in which a catalyst based on a carbonylation catalyst is used Ligands of the general formula I used.

The carbonylation catalysts according to the invention also comprise complexes of a metal from subgroup VIII, preferably nickel, cobalt, iron, ruthenium, rhodium and palladium, in particular palladium. The metal complexes can be prepared as previously described for the hydroformylation catalysts and hydrocyanation catalysts. The same applies to the in situ production of the carbonylation catalysts according to the invention.

Suitable olefins for carbonylation are the olefins which have generally been mentioned above as starting materials for hydroformylation and hydrocyanation.

The compounds having a nucleophilic group are preferably selected from water, alcohols, thiols, carboxylic acid esters, primary and secondary amines.

A preferred carbonylation reaction is the conversion of olefins with carbon monoxide and water to carboxylic acids (hydrocarbylation). This particularly includes the conversion of ethylene with carbon monoxide and water to propionic acid.

The invention is illustrated by the following, non-limiting examples.

Examples

Example 1: Synthesis of Ligand I.

Ligand I

a) Synthesis of bisindolyl:

120 ml of THF were introduced under nitrogen and 37 ml (425 mmol) of oxalyl chloride were added dropwise. After cooling to 0 ° C., a solution of 90 g (840 mmol) of o-toluidine and 117 ml (840 mmol) of triethylamine in 190 ml of THF was added dropwise. The mixture was stirred at 0 ° C. for 2 h, then the mixture was allowed to warm to room temperature with stirring. About 600 ml of water, then 900 ml of ethyl acetate were carefully added and the mixture was warmed to 100.degree. The resulting solid was filtered off and washed with petroleum ether. Yield: 65%.

33.5 g (859 mmol) of potassium were added to 600 ml of tert-butanol with stirring and the mixture was stirred at 50 ° C. for 4 h until the potassium had reacted completely. 46 g (172 mmol) of N, N-bis-o-tolyloxamide were then added. The mixture was heated in a sand bath and the tert-butanol distilled off completely at 88 ° C. When the solvent was removed, the temperature rose to 190 ° C and a white voluminous solid sublimated. The reaction temperature then rose to 300 ° C and was held for 1 h. The mixture was then cooled to room temperature. 300 ml of water was carefully added. The solid was filtered off with suction and heated under reflux with 200 ml of ethanol. The solid was then filtered off, washed with pentane and dried. Yield: 50%.

b) Synthesis of ligand I.

8.8 g (38 mmol) of bisindolyl were placed in 250 ml of THF at -78 ° C. Thereafter, first 10.4 g (76 mmol) of PC1 ₃ and then 16 g (160 mmol) of triethylamine were added. 17.8 g (152 mmol) indole and 16 g (160 mmol) triethylamine were dissolved in 100 ml THF and added at -75 ° C. The reaction mixture was stirred at room temperature for three days. The triethylamine hydrochloride was then filtered off, the THF was removed from the filtrate in vacuo and the residue was stirred with a mixture of hexane / methanol (90:10). The resulting white solid was filtered off and washed with ^• methanol. Yield: 80%. ( ³¹ P NMR: 57 ppm).

Example 2: Hydroformylation of a butene / butane mixture with 5 ligand I.

5.1 mg Rh (C0) ₂ acac and 150 mg Ligand I (100 ppm Rh, L: M = 10: 1) were weighed in separately, dissolved in 7.5 g THF, mixed and mixed at 100 ° C with 10 bar Synthesis gas (CO: H ₂ = 1: 2) gassed. To

10 30 min. The pressure was released, then 5.3 g of butene / butane mixture (45% 1-butene, 40% 2-butene, 15% butanes) were pressed in and hydroformylated for 4 h at 120 ° C. and 17 bar (C0: H ₂ = 1: 1). The conversion of butene was 58%, the aldehyde selectivity 92% and the linearity 70%.

15

0

5

0

5

0

5

Claims

claims

1. Phosphorus chelate compounds of the general formula I

ß ^l PB ⁵ YB ⁶ PB ³

I I (i)

B ² B ⁴ in which

Y represents a chemical bond or a divalent bridging group with 1 to 20 bridge atoms.

2. Compounds according to claim 1, wherein B ¹ , B ² , B ³ and B ^{4 are} independently selected from groups of the general formula II

wherein

R ^l , R ² , R ³ and R ⁴ independently of one another for hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl, hetaryl, WCOOR ^a , WCOO-M ⁺ , W (S0 ₃ ) R ^a , W (S0 ₃ ) ~ M ⁺ , WP0 ₃ E ^l E ² , W (P0 ₃ ) ² "(M ⁺ ) ₂ , WNE ^l E ² , W (NE ^! E ² E ³ ) ⁺ X-, W0R ^a , WSR ^a , (CHR ^b CH ₂ 0) _x R ^a ,

(CH ₂ NE ¹ ) _x R ^a , (CH ₂ CH ₂ NE ¹ ) _x R ^a , halogen, trifluoromethyl, nitro, acyl or cyano,

wherein

W represents a single bond or a divalent bridging group with 1 to 20 bridge atoms, R ^a , E ⁱ , E ² , E ³ each represent the same or different radicals selected from hydrogen, alkyl, cycloalkyl or aryl,

R ^{b represents} hydrogen, methyl or ethyl,

M ^{+ stands} for a cation equivalent,

X- stands for an anion equivalent and

x represents an integer from 1 to 240,

3. Compounds according to claim 1, wherein B ⁵ and B ^{6 are} independently selected from groups of the general formula III

wherein

R ⁵ , R ⁶ , R ⁷ and R ⁸ independently of one another for hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl, hetaryl, WC00R ^a , WC00 "M ⁺ , W (S0 ₃ ) R ^a , W (S0 ₃ ) -M ⁺ , P0 ₃ E ^l E ² , W (P0 ₃ ) ^{2 ~} (M ⁺ ) ₂ , WNE ^X E ² , W (NE ¹ E ² E ³ ) ⁺ X ", W0R ^a , WSR ^a , (CHR ^b CH ₂ 0) _x R ^a , (CH ₂ NE) _x R ^a , (CH ₂ CH ₂ NE ¹ ) _x R ^a , halogen, trifluoromethyl, nitro, acyl or cyano,

wherein

W represents a single bond or a divalent bridging group with 1 to 20 bridge atoms,

R ^{b represents} hydrogen, methyl or ethyl, M ^{+ stands} for a cation equivalent,

stands for an anion equivalent and

represents an integer from 1 to 240,

Compounds according to one of the preceding claims, wherein the bridging group Y is selected from groups of the formulas IV.1 to IV.15

2

(IV. L) (IV. 2) (IV. 3)

(IV. 10) (IV. 1 1) (IV. 12)

(IV.13) (IV.14)

(IV.15) in which

R ⁹ and R ⁱ ° independently of one another represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl, where R ⁹ and R ⁱ ° together with the carbon atom to which they are bonded also represent a 3- to 8-membered carbo - or heterocycle, which is optionally additionally fused one, two or three times with cycloalkyl, heterocycloalkyl, aryl and / or hetaryl,

R ^U , R ^l2 , R ⁱ³ , R ⁱ , R ⁱ⁵ , R ^iß , R ^l7 , R ^l8 , R ^U ', R ⁱ² ', R ^l3 'and R ^l4 ' independently of one another for hydrogen, alkyl, cycloalkyl, heterocycloalkyl, Aryl, hetaryl, alkoxy, halogen, S0 ₃ H, sulfonate, NE ⁴ E ⁵ , alkylene-NE ⁴ E ⁵ , trifluoromethyl, nitro, alkoxycarbonyl, carboxyl or cyano, where E ⁴ and E ^{5 are} each the same or different radicals, selected mean under hydrogen, alkyl, cycloalkyl and aryl,

M represents a zero-valent transition metal, in particular Fe,

m and n both represent 0 or both represent 1, Z represents O, S, NR ^IQ or SiR ¹⁹ R ²⁰ , where

R ⁱ⁹ and R ²⁰ independently of one another represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl,

or Z represents a C ₂ -C ₃ -alkylene bridge which is interrupted by O, S or NR ⁱ⁹ or SiR ⁱ⁹ R ²⁰ ,

A ⁱ and A ² independently of one another represent 0, S, SiR ^IQ R ²⁰ , NR ⁱ⁹ or CR ²ⁱ R ²² , where

R ²ⁱ and R ²² independently of one another represent hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl or the group R ²ⁱ together with another group R ²ⁱ or the group R ²² together with another group R ^{22 form} an intramolecular bridge group D,

D a two-gang bridge group selected from the groups

is where

R ²³ and R ²⁴ independently of one another represent hydrogen, alkyl, cycloalkyl, aryl, halogen, trifluoromethyl, carboxyl, carboxylate or cyano or are connected to one another to form a C ₃ - to C ₄ -alkylene bridge,

Alkyl, cycloalkyl, aryl, halogen, trifluoromethyl, COOH, carboxylate, cyano, alkoxy, S0 ₃ H, sulfonate, NE ⁴ E ⁵ , alkylene-NE ⁴ E ⁵ E ⁶⁺ χ-, acyl or nitro, where X ^{~ stands} for there is an anion equivalent, and

c is 0 or 1.

5. Catalyst comprising at least one complex of a metal from subgroups VIII. The ligands used as ligands are at least one compound of the general formula I, as in one of the claims

1 to 4 defined.

6. A process for the hydroformylation of compounds which contain at least one ethylenically unsaturated double bond by reaction with carbon monoxide and hydrogen in the presence of a catalyst, as defined in claim 5.

Process for the preparation of 2-propylheptanol, in which

a) butene or a C-hydrocarbon mixture containing butene in the presence of a catalyst as defined in claim 5, hydroformylated with carbon monoxide and hydrogen to give a hydroformylation product containing n-valeraldehyde,

b) optionally subjecting the hydroformylation product to separation to obtain a fraction enriched in n-valeraldehyde,

8. Use of a catalyst as defined in claim 5 for hydroformylation, carbonylation, hydrocyanation or for hydrogenation.