MXPA00011522A - Catalyst comprising a complex of a metal from subgroup viii based on a bidentate phosphonite ligand, and method for producing nitriles - Google Patents

Abstract

The invention relates to a catalyst comprising at least one complex of a metal from subgroup VIII with at least one bidentate phosphonite ligand of general formula (I) or salts or mixtures therof, to a method for producing mixtures of monoolefinic C5-mononitriles, to a method for the catalysed isomerization of branched aliphatic monoalkene nitriles and to a method for producing adipodinitrile.

Description

CATALYST THAT COMPRISES A COMPLEX OF A METAL FROM THE HIV SUBGROUP BASED ON A PHOSPHONIC LIGAND BIDENTED AND PROCEDURE FOR PREPARATION OF N-TRILES Description The present invention relates to a catalyst comprising a complex of a metal of subgroup VIII, which comprises at least one bidentate phosphonyl ligand, to a process for the preparation of mixtures of monoolefin C5 mononitriles and to a process for the preparation of adiponitrile by catalytic hydrocyanuration in the presence of such a catalyst. For the preparation on an industrial scale of polyamides there is a great worldwide requirement for α-alkylene diamines, which are used as an important starting product. The a,? -alkylenediamines, as for example. , hexamethylenediamine, are obtained almost exclusively by hydration of the corresponding dinitriles. Almost all roads for the preparation of hexamethylenediamines on an industrial scale are therefore substantially variants of the preparation of adiponitrile, of which approximately 1.0 million tons are produced annually worldwide. In K. eissermel, H.-J. Arpe, "Industrieile Organische Chemie", 4th. edition, VCH Weinheim, p. 266 ss. four different routes are described in principle for the preparation of dinitrile of adipic acid, among others, direct hydrocyanuration of 1,3-butadiene with hydrocyanic acid. According to the last-mentioned process, a mixture of isomeric pentenonitriles is obtained in a first step by monoaddition, which in a second step is isomerized mainly to 3- and 4-pentenenitrile. Then, in a third step by the addition of anti-Markownikow hydrocyanic acid to 4-pentenenitrile, the adipic acid dinitrile is formed. In "Applied Homogeneous Catalysis with Organometalic Compounds", Vol. 1, VCH einheim, p. 465 ss. In general, the heterogeneous and homogeneous catalyzed addition of hydrocyanic acid to defines is described. For this purpose, catalysts based on phosphine, phosphite and nickel-palladium phosphine complexes are used. For the preparation of dinitrile of adipic acid by hydrocyanidation of butadiene, mainly nickel (0) phosphite catalysts are used, optionally in the presence of a Lewis acid as a promoter. In J. Chem. Soc., Chem. Commun., 1991, p. 1292 chiral aryl diphosphites are disclosed as ligands for hydrocyanuration catalysts. In these ligands, the phosphite group is bound through two of its oxygen atoms to the 3 and 3 'positions of a 2,2'-biphenyl unit, with which it thus forms a 7-membered heterocycle.

Additionally, two of these heterocycles can also be linked through a 2, 2'-biphenyl unit forming a bidentate chelate ligand. In J. Chem. Soc., Chem., Commun., 1991, p. 803 ff., Nickel (0) and platinum (0) chelatodiphosphite complexes are also described, where instead of a 2, 2 t -bublthyl unit a 2,2'-biphenyl unit is used as a bridge-forming group . US-A-5,449,807 discloses a process for the gas phase hydrocyanination of diolefins in the presence of a supported nickel catalyst based on at least one bidentate phosphite ligand, both phosphite groups being linked by a bridge. Group 2, 2'-unsubstituted or substituted biphenyl. US-A-5 40,067 discloses a process for the gas-phase isomerization of 2-alkyl-3-monoalkenonitriles to linear 3- and / or 4-monoalkenonitriles in the presence of the catalysts described in US-A-5,449,807. WO 95/14659 describes a process for the hydrocyanuration of monoolefins in which catalysts based on zero-valent nickel and bidentate phosphite ligands are used. In these ligands the phosphite groups together with two of their oxygen atoms are part of an aryl-fused 7-membered heterocycle. Every two of these phosphite groups are linked through the oxygen atoms, which are not part of the heterocycle, by means of a bridge of alkylene aryl-fused groups. US-A 5,512,695 also describes a process for the hydrocyanination of monolefins in the presence of a nickel catalyst, which comprises a bidentate phosphite ligand. WO 96/11182 describes a process for the hydrocyanuration in the presence of a nickel catalyst based on a bidentate or polydentate phosphite ligand in which the phosphite groups are not an integral part of a heterocycle. The groups used for the formation of the bridge between the phosphite groups correspond to those described in WO 95/14659. US-A-5,523,453 discloses a process for hydroxyaging, in the presence of a nickel catalyst based on a bidentate ligand, comprising at least one phosphinite group and another phosphorus-containing group, which is chosen from phosphinites and phosphites. The two phosphorus-containing groups of these bidentate ligands are in turn linked by aryl-fused groups. WO 97/23446 describes a process for the hydrocyanination of diolefins as well as for the isomerization of 2-alkyl-3-monoalkenonitriles in the presence of catalysts, which correspond to those described in US-A-5,523,453.

WO 96/22968 also describes a process for the hydrocyanuration of diolefin compounds and for the isomerization of the resulting unconjugated 2-alkyl-3-monoalkenonitriles using a nickel (0) catalyst based on a polydentate phosphite ligand in the presence of the promoter. of a Lewis acid as a motor. The phosphite groups of these polydentate ligands are themselves integral parts of aryl-fused heterocycles and are optionally bridged via aryl-fused groups. None of the aforementioned bibliographical references describes hydrocyanuration catalysts based on phosphonite ligands. In particular, catalysts based on bidentate chelate phosphonites are not described. US-A-3,766,237 discloses a process for the hydrocyanuration of ethylenically unsaturated compounds, which may have other functional groups, such as e.g. , nitriles, in the presence of a nickel catalyst. These nickel catalysts carry four ligands of the general formula M (X, Y, Z), wherein X, Y and Z independently of one another represent a radical R or OR, and R is selected from alkyl and aryl groups with up to 18 carbon atoms. Here, however, only phosphines and phosphites are explicitly named and used in the examples for hydrocyanuration. On the other hand, it is not revealed that the phosphonites can be used as ligands for the nickel (0) hydrocyanuration catalysts. In particular, bidentate chelate phosphonite ligands are not described. The object of the present invention is to provide new catalysts based on a metal of subgroup VIII. These must preferably have a good selectivity and a good catalytic activity in the hydrocyanination of 1,3-butadiene and mixtures of hydrocarbons containing 1,3-butadiene. They preferably also have to be suitable for the catalytic isomerization of monoalkenonitriles and for the second addition of hydrocyanic acid thereto, e.g. , for the preparation of adiponitrile. Surprisingly, catalysts were found based on metal complexes of subgroup VIII, which comprise at least one bidentate phosphonite ligand. Therefore, an object of the present invention is a catalyst comprising a complex of a metal of subgroup VIII, with at least one bidentate phosphonyl ligand of the general formula I: RI-OP-OR.2 (I) ^ -OP-OR2 'R1' wherein: A represents a C2 to C7 alkylene bridge, which may have 1, 2 or 3 double bonds and / or 1, 2 or 3 substituents, selected from alkyl, cycloalkyl and aryl, wherein the aryl substituent may additionally have 1, 2 or 3 substituents selected from alkyl, alkoxy, halogen, trifluoromethyl, nitro, alkoxycarbonyl or cyano, and / or the C2 to C7 alkylene bridge may be interrupted by 1, 2 or 3 non-neighboring heteroatoms, optionally substituted, and / or the C2 to C7 alkylene bridge may be fused one, two or three times with aryl and / or hetaryl, wherein the fused aryl and hetaryl groups may have 1, 2 or 3 substituents selected from alkyl, cycloalkyl, aryl, alkoxy, cycloalkoxy, aryloxy, acyl, halo geno, trifluoromethyl, nitro, cyano, carboxyl, alkoxycarbonyl or NE1E2, wherein E1 and E2 may be the same or different and represent alkyl, cycloalkyl or aryl, R1 and R1 'independently of each other represent alkyl, cycloalkyl, aryl or hetaryl, which they may have 1, 2 or 3 substituents selected from alkyl, cycloalkyl and aryl, R2 and R2 'independently of one another represent alkyl, cycloalkyl, aryl or hetaryl, wherein the aryl and hetaryl groups may have 1, 2 or 3 substituents selected from alkyl, cycloalkyl, aryl, alkoxy, cycloalkoxy, aryloxy, acyl, halogen, trifluoromethyl, nitro, cyano, carboxyl, alkoxycarbonyl E ^ 2 where they have the meanings indicated above, or salts and mixtures thereof. In the context of the present invention, the term "alkyl" comprises straight or branched chain alkyl groups. Preferably, it refers to C alquilo-C8 alkyl groups, preferably C_-C6 alkyl, more preferably C_-C4 alkyl, linear or branched. Examples of alkyl groups are especially 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, ethyl-2-methylpropyl, n-heptyl, 2-heptyl, 3-heptyl, 2-ethylpentyl, 1-propylbutyl, octyl. The cycloalkyl group is preferably a C5-C7 cycloalkyl group, such as cyclopentyl, cyclohexyl or cycloheptyl. When the cycloalkyl group is substituted, it preferably has 1, 2, 3, 4 or 5, especially 1, 2 or 3 substituents, selected from alkyl, alkoxy, halogen or trifluoromethyl. Aryl preferably represents phenyl, tolyl, xylyl, mesityl, naphthyl, anthracenyl, phenanthrenyl, naphthacenyl and especially phenyl or naphthyl. When the aryl group is substituted, it preferably has 1, 2, 3, 4 or 5, especially 1, 2 or 3 substituents and especially 1 or 2 substituents, in any position. Hetaryl preferably represents pyridyl, quinolinyl, acridinyl, pyridazinyl, pyrimidinyl or pyrazinyl. Substituted hetaryl residues preferably have 1, 2 or 3 substituents, selected from alkyl, alkoxy, halogen or trifluoromethyl. The clarifications indicated above with reference to alkyl, cycloalkyl and aryl residues are correspondingly suitable for alkoxy, cycloalkyloxy and aryloxy radicals. The NEXE2 moieties preferably represent N, N-diraethyl, N, N-diethyl, N, N-dipropyl, N, N-diisopropyl, N, N-di-n-butyl, N, N-di-tert-butyl, N, N-dicyclohexyl or N, N-diphenyl. Halogen represents fluorine, chlorine, bromine and iodine, preferably fluorine and chlorine. In the phosphonite ligands of the general formula I, the radicals R1 and R2 and / or R1 'and R2' are not linked together by a bridge. The residue A then represents, preferably a C2 to C7 alkylene bridge which is fused 1, 2 or 3 times with aryl and which may additionally have a substituent selected from alkyl, cycloalkyl and aryl optionally substituted and / or which may be further interrupted by a eventually substituted heteroatom.

In the condensed aryl of the A moieties, it is preferably benzene or naphthalene. The fused benzene rings are preferably unsubstituted or have 1, 2 or 3, especially 1 or 2 substituents, selected from alkyl, alkoxy, halogen, trifluoromethyl, nitro, carboxyl, alkoxycarbonyl and cyano. The condensed naphthalenes are preferably unsubstituted or have in the non-condensed ring and / or in the fused ring 1, 2 or 3, especially 1 or 2 of the substituents mentioned above in the fused benzene rings. The condensed naphthalenes, which are substituted in the fused ring, preferably have a substituent in the ortho position with respect to the phosphonite group. It then preferably represents alkyl or alkoxycarbonyl. In the substituents of the fused aryls alkyl preferably represents C_ to C4 alkyl and especially methyl, isopropyl and tert-butyl. Alkoxy preferably represents C to C4 alkoxy and especially methoxy. Alkoxycarbonyl preferably represents alkoxycarbonyl Cx to C4. Halogen represents especially fluorine and chlorine. When the C2 to C7 alkylene bridge of residue A is interrupted by 1, 2 or 3 optionally substituted heteroatoms, they are selected from 0, S or NR5, where R5 represents alkyl, cycloalkyl aryl.

Preferably, the C2 to C7 alkylene bridge of residue A is interrupted by an optionally substituted heteroatom. When the C2 to C7 alkylene bridge of the A moiety is substituted, it has 1, 2 or 3, especially 1 substituent selected from alkyl, cycloalkyl and aryl, wherein the aryl substituent may additionally have 1, 2 or 3 substituents selected from alkyl, alkoxy, halogen, trifluoromethyl, nitro, alkoxycarbonyl and cyano. Preferably the alkylene bridge A has a substituent selected from methyl, ethyl, isopropyl, phenyl, p- (Cx to C4 alkyl) phenyl, preferably p-methylphenyl, p- (C to C4 alkoxy) phenyl, preferably p-methoxyphenyl, p- halogen-phenyl, preferably p-chlorophenyl and p-trifluoromethylphenyl. Preferably, the residue A represents a C4 to C7 alkylene bridge which is condensed and / or substituted and / or interrupted by optionally substituted heteroatoms, as mentioned above. Especially the residue A represents a C4 to C5 alkylene bridge which is once or twice condensed with phenyl and / or naphthyl, wherein the phenyl or naphthyl groups may have 1, 2 or 3, especially 1 or 2, of the abovementioned substituents . A represents especially a remainder of formulas II.1 to II.5: (II.) (II.5) wherein: X represents 0, S, NR5, wherein: R5 represents alkyl, cycloalkyl or aryl, or X represents a C_ to C3 alkylene bridge, which may have a double bond and / or an alkyl, cycloalkyl or aryl substituent, wherein the aryl substituent may have 1, 2 or 3 substituents selected from alkyl, alkoxy, halogen, trifluoromethyl, nitro, alkoxycarbonyl or cyano, or X represents a C2 to C3 alkylene bridge, interrupted by O, S or NR5, RJ R3 ', R3", R3" ', R4, R4', R4"and R4" independently of one another represent hydrogen, alkyl, alkoxy, halogen, trifluoromethyl, nitro, alkoxycarbonyl or cyano. A preferably represents a residue of Formula II.1, wherein R3 and R4 represent hydrogen. A preferably represents a residue of Formula II.2a: wherein: R represents hydrogen or C_ to C alkyl, preferably methyl, isopropyl or tert-butyl, R4 represents hydrogen, C_ to C4 alkyl, preferably methyl, isopropyl or tert-butyl, C to C4 alkoxy, preferably methoxy, fluorine, chlorine or trifluoromethyl. Preferably A represents a radical of Formula II.3a: where: R3 and R4 have the meaning indicated above in Formula II.2a, R9 represents hydrogen, C_ to C4 alkyl, preferably methyl or ethyl, phenyl, p- (C_ to C4 alkoxy) phenyl, preferably p-methoxyphenyl, p-fluorophenyl, p-chlorophenyl or p- (trifluoromethyl) phenyl. Preferably A represents a residue of Formula II.4, wherein R3, R3 ', R3", R3"', R4, R4 ', R4"and R4"' represent hydrogen. Preferably A represents a residue of Formula II.4, wherein R3, R3 ', R4, R4', R4"and R4" 'represent hydrogen and the radicals R3", R3"', independently of one another represent alkoxycarbonyl, preferably methoxy-, ethoxy-, n-propyloxy- or isopropyloxycarbonyl. Especially the remains R3", R3 *" are in ortho position with respect to the fssphonite group. Preferably in Formula I the radicals R1 and R1 'independently represent one of the other alkyl or aryl, especially phenyl, 1-naphthyl or 2-naphthyl.

Preferably, the radicals R2 and R2 'represent, independently of one another, phenyl substituents, which may optionally have 1 or 2 substituents selected from alkyl, alkoxy, halogen, trifluoromethyl, nitro, cyano, alkoxycarbonyl or carboxyl.

According to a preferred embodiment, the phosphonite ligand of Formula I is selected from among the ligands of the formulas: wherein in the Formula the substituents R3, R4, R7 and R8 have the following meanings: in Formula Ib the substituents R4, R7, R8 and R9 have the following meanings: in the Formula the substituents R7 and R8 have the following meanings: Another subject of the invention are phosphonite ligands of the general Formula I: Rl I -0-P-OR2 (I) ^ -OP-OR2 'R1' as defined above, wherein: R2 and R2 'independently from each other represent alkyl, cycloalkyl, aryl or hetaryl, wherein the aryl groups and hetaryl may each have 1 or 2 substituents selected from alkyl, cycloalkyl, aryl, alkoxy, cycloalkoxy, aryloxy, acyl, halogen, trifluoromethyl, nitro, cyano, carboxyl, alkoxycarbonyl or NE1E2, wherein E1 and E2 may be the same or different and they may represent alkyl, cycloalkyl or aryl. Preferably R2 and R2 'independently of one another represent phenyl groups which may have 1 or 2 of the above-mentioned substituents. The catalysts according to the invention may have one or more of the phosphonite ligands of the general Formula I. In addition to the above-mentioned ligands of the general Formula I, they may also have at least one other ligand selected from cyanide, halides, amines, carboxylates, acetylacetone, aryl- or alkylsulfonates, hydrides, CO, olefins, dienes, cycloolefins, nitriles, heterocycles having N, aromatics and heteroaromatics, ethers, PF3 as well as phosphine, phosphinite, phosphonite and mono-, bi- and phosphite ligands. and polidentados. These additional ligands can also be mono-, bi- or polydentate and coordinate to the metal of subgroup VIII. Other suitable phosphorus-containing ligands are, e.g. the phosphine, phosphinite and phosphite ligands mentioned above as the state of the art. In the case of subgroup VIII metal, it is preferably cobalt, rhodium, ruthenium, palladium or nickel. if the catalysts according to the invention are used for hydrocyanuration, then in the case of the metal of subgroup VIII, it is especially nickel. For the preparation of the phosphonite ligands of the general Formula I used in the catalysts according to the invention, it is possible to react according to the following scheme first a dihalógenophosphorus compound III (III) wherein R1 (or R1 ') has the meanings above indicated, with an IV monoalcohol, wherein R2 (OR2 ') has the meanings given above, to a compound of Formula V. If desired, this compound V can be isolated and / or purified according to known procedures, e.g. , by distillation, before continuing to react. Compound V is then reacted with a diol of Formula VI to the bidentate phosphonite ligand of Formula (I). For the case that in Formula I R1 = R1 'and R2 = R2', two equivalents of Formula V can be reacted in a one-step reaction with one equivalent of Formula VI. Otherwise, an equivalent of Formula V is reacted with an equivalent of Formula VI and after the monocondensation product is formed, a second compound of Formula (V) Cl-PR 1'-OR 2 'is added and reacted. to the phosphonite of Formula (I). Ri - HX R1 PX2 HOR2 OR2 (III) (IV) (V) l 2HX -í > OR2 + HO- 0H- (I) (V) (VI) X = Cl, Br In the case of the compound of the formula (III), it is preferably a dichlorophosphorus compound (III). Suitable compounds with the aforementioned radicals R1 are known. When R1 represents, for ex. , phenyl, then it is a dichlorophenylphosphine. Suitable alcohols of Formula IV, wherein R2 has the meanings indicated above, are also known. Suitable aromatic alcohols of the formula HOR2 are, for example. , 2-tert-butyl-4-methylphenol, 2-isopropylphenol, 2-tert-butylphenol, 4-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,4-di-tert-butylphenol , 2, 6-di-tert-butylphenol, 2, -dimethylphenol, 2,5-dimethylphenol, 2,6-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol, 2-ethylphenol, 3-ethylphenol, 4- ethylphenol, 5-isopropyl-2-methylphenol, m-cresol, o-cresol, p-cresol, 1-naphthol, 2-naphthol, phenol, l-bromo-2-naphthol, 3-bro-ofenol, 5-chloroquinolin-8 -ol, 4-chloro-3,5-dimethylphenol, 2-chloro-5-methylphenol, 4-chloro-3-methylphenol, 2-chloro-6-nitrophenol, 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, 4 -chlororesorcin, 2,3-dichlorophenol, 2,4-dichlorophenol, 2,5-dichlorophenol, 2,6-dichlorophenol, 3,4-dichlorophenol, 2-fluorophenol, 3-fluorophenol, 4-fluorophenol, 3-methyl-4 -nitrophenol, 3-isopropyl-4-nitrophenol, 3-isopropyl-4-nitrophenol, 2-nitroanisole, 4-nitrobrenzcatechin, 2-nitrophenol, 3-nitrophenol, 2-methoxy-3-methylphenol, 2-methoxy-4-methylphenol , 2-methoxyphenol, 3-methoxyphenol, 4-methoxyphenol. Preferred alcohols of formula HOR1 are 2-isopropylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,4-di-tert-butylphenol, 2,6-di-tert-butylphenol, phenol, 2-fluorophenol, 3-fluorophenol, 4-fluorophenol, 4-nitrobrenzcatequina, 2-methoxy-4-methylphenol, 2-trifluoromethyl-phenol, 3, 5-bis (trifluoromethyl) phenol, 4-cyanophenol, etc. Suitable alcohols of the formula HO-A-OH, wherein A has the meanings mentioned above, are known.

Among them are biphenyl-2, 2'-diol and binaphthyl-2, 2'-diol. Other suitable diols are mentioned in US-A-5,312,996, column 19, to which reference is made here. Both the reaction of the compound (III) with (IV) to (V) and also the subsequent reaction to the bidentate phosphonite ligand of the general Formula (I) is generally carried out at an elevated temperature in the range of approx. 40 to approx. 200 ° C. The two reactions can be performed in the presence of a base, eg. , an aliphatic amine, such as diethylamine, propylamine, dibutylamine, trimethylamine, tripropylamine and preferably triethylamine or pyridine. Preferably, the dehydrohalogenation is carried out in the first reaction step in purely thermal form. Advantageously, the preparation of the phosphonite ligand of the Formula I used according to the invention is carried out without using organic magnesium or lithium compounds. The simple reaction sequence allows a wide possibility of variation of the ligands. The representation is therefore achieved efficiently and economically from educts that are easily obtained. For the preparation of the catalysts according to the invention, at least one phosphonite ligand of the Formula I can be reacted with a metal of subgroup VIII, eg. , nickel, or with a metal compound in the presence of a reducing agent or a metal complex in an inert solvent. Suitable nickel compounds are, for example. , compounds in which the transition metal takes an oxidation step greater than 0, and those which during the reaction with the phosphonite ligand of Formula I, optionally in the presence of a suitable reducing agent, are reduced in situ. It can be mentioned among them, eg. , the halides, preferably the chlorides, and the acetates of the transition metals mentioned above. Preferably, NiCl2 is used. Suitable reducing agents are, for example. , metals, preferably alkali metals, such as Na and K, aluminum, zinc as well as trialkylaluminum compounds. If complex compounds of the transition metal are already used for the preparation of the phosphonite-nickel (O) complexes, then the transition metal is preferably at zero valence. Preferably complexes are used for the preparation with ligands corresponding to the aforementioned additional ligands of the complexes according to the invention. In this case, the preparation is carried out by partial or complete exchange of ligands with the phosphonite ligands of the aforementioned Formula I. The nickel (1,5-cyclooctadiene) nickel (0) nickel complex is preferred. Suitable inert solvents for the preparation of the nickel (0) complexes are, for example, aromatic compounds, such as benzene, toluene, ethylbenzene, chlorobenzene, ether, preferably diethyl ether and tetrahydrofuran, or haloalkanes, for example, dichloromethane, chloroform, dichloroethane and trichloroethane. Suitable solvents are also the educts and / or liquid products of the catalyzed reaction. The temperature is for this in a range from -70 ° C to 150 ° C, preferably from 0 ° C to 100 ° C, preferably at approx. room temperature. If, for the preparation of the nickel-phosphonite (0) complexes, elemental nickel is used, then it is preferably in powder form. The transformation of nickel and phosphonyl ligand is preferably carried out in a product of the catalyzed reaction, such as the hydrocyanuration reaction as a solvent, e.g. , in a mixture of C5-onoolefin mononitriles or preferably in 3-pentenenitrile or 2-methyl-3-butenonitrile. Eventually the ligand can also be used as the solvent. The temperature is in a range of approx. 0 to 150 ° C, preferably 60 to 100 ° C. Preferably, the ratio of the molar amount of metal of subgroup VIII to the bidentate phosphonite ligand is in the range of approx. 1: 1 to 1: 5, preferably 1: 1 to 1: 3. Another object of the invention is a process for preparing mixtures of monoolefin C3-mononitriles with C = C- and C = non-conjugated bonds by catalytic hydrocyanuration of butadiene or a mixture of hydrocarbons containing 1,3-butadiene, characterized in that the hydrocyanuration is carried out in the presence of at least one of the catalysts according to the invention described above. For the preparation of mixtures of monoolefin C5-mononitriles, which contain, for example. , 3-pentenenitrile and 2-methyl-3-butenonitrile, and which are suitable as intermediates for further processing to adiponitrile, pure butadiene or mixtures of hydrocarbons containing 1,3-butadiene can be used. If a mixture of hydrocarbons is used according to the process according to the invention, it has a content of 1,3-butadiene of at least 10 vol.%, Preferably at least 25 vol.%, More preferably at least 40% in vol. Mixtures of hydrocarbons containing 1,3-butadiene can be obtained on an industrial scale. This is obtained, for example. , during the processing of petroleum by cracking naphtha vapor a mixture of hydrocarbons called fraction C4 with a large part of total olefin, corresponding approximately 40% to 1,3-butadiene and the rest to monoolefins and hydrocarbons several times unsaturated as well as alkanes. These streams also always contain small amounts of, in general, up to 5% of alkynes, 1,2-dienes and vinylacetylene. It is possible to isolate 1, 3-butadiene pure, eg. , by extractive distillation from mixtures of hydrocarbons that are obtained technically. The C4 fractions are eventually liberated from the hydrocyanuration of alkynes, as for example. , propino or butino, of 1,2-dienos, as for ex. , propadieno, and of alqueninos, as for ex. , vinylacetylene. Otherwise, products are obtained in which a C = C double bond is found in conjugation with the C = N bond. These can act in some cases as poisons of catalysts for the first step of the preparation of adipic acid, the monoadition of hydrocyanic acid. For this reason, components that can give poisons of catalysts in catalytic hydrocyanuration, especially alkynes, 1,2-dienes and mixtures thereof, are possibly partially or completely removed from the hydrocarbon mixture. To remove these components, the C4 fraction is subjected before the addition of hydrocyanic acid to a partial catalytic hydration. This partial catalytic hydration is carried out in the presence of a hydration catalyst, which is capable of selectively hydrating alkynes and 1,2-dienes together with other dienes and monoolefins. Heterogeneous catalyst systems suitable for selective hydration are known and generally comprise a transition metal compound on an inert carrier. In particular, those described in US patent applications US-A-4,587,369; US-A-.704,492 and US-A-4,493,906, to which reference is made here in its entirety. Other suitable catalyst systems based on Cu are marketed by Dow Chemical as KLP catalysts. The addition of hydrocyanic acid to 1, 3-butadiene or to a mixture of hydrocarbons containing 1,3-butadiene, e.g. , a partially hydrated C4 fraction, previously treated, can be carried out continuously, semicontinuously or discontinuously. Reactors suitable for the reaction are known to the person skilled in the art and are described, e.g. in "üllmanns Enzyklopadie der technischen Chemie", vol. 1, 3ra. ed., 1951, p. 743 ss. and p. 769 et seq. Preferably a cascade agitation reactor or a tube reactor is used for a continuous process. If the addition of hydrocyanic acid to 1,3-butadiene or to a mixture containing 1,3-butadiene is carried out in a semi-continuous or discontinuous manner, then it is used for the process according to the invention, e.g. , an autoclave, which can be provided if desired with a stirring device and an inner lining. A suitable semi-continuous process comprises: a) Filling a reactor with 1,3-butadiene or with the mixture of hydrocarbons, optionally a part of the hydrocyanic acid and a hydrocyanuration catalyst according to the invention, possibly produced in situ, as well as optionally a solvent Suitable solvents are those mentioned above in the preparation of the catalysts according to the invention, preferably aromatic hydrocarbons, such as toluene and xylene or tetrahydrofuran. b) Transformation of the mixture at elevated temperature and high pressure. The reaction temperature is generally in the range of approx. 0 to 200 ° C, preferably approx. 50 to 150 ° C. The pressure is generally in a range of approx. 1 to 200 bar, preferably approx. 1 to 100 bar, especially 1 to 50 bar, more preferably 1 to 20 bar. During the reaction, hydrocyanic acid is fed as it is consumed. c) Eventually the transformation is completed by subsequent reaction and subsequent processing. To complete the reaction, a reaction time of from 0 minutes to approx. 5 hours, preferably approx. 1 hour to 3.5 hours, during which no more hydrocyanic acid is fed to the autoclave. The temperature is maintained during this time substantially constant at the reaction temperature previously adjusted. The processing is carried out according to usual procedures and comprises the separation of unreacted 1,3-butadiene and unreacted hydrocyanic acid, e.g. , by washing or extraction and the distillation processing of the remaining reaction mixture for the separation of the valuable products and obtaining the still active catalyst. According to another suitable variant of the process according to the invention, the addition of hydrocyanic acid to the hydrocarbon mixture containing 1,3-butadiene is carried out batchwise. For this the reaction conditions described for the semicontinuous process are maintained, but in step b) no additional hydrocyanic acid is fed, but this is added in its entirety. Preferably, the addition of hydrocyanic acid to 1,3-butadiene or to the mixture of hydrocarbons containing 1,3-butadiene is carried out continuously. The development of the reaction is generally carried out in such a way that substantially no greater quantities of hydrocyanic acid are present in the reactor which have not reacted.

Suitable procedures for continuous hydrocyanuration are known to the person skilled in the art. Among them is, for e. , a feeding process, in which 1, 3-butadiene and prussic acid are fed through separate feeds to the extent of "-N their consumption." The catalyst is added together with one of the educts or through of a separate feed Suitable reactors, preferably of good mixing, are also known to the person skilled in the art. same are, for ex. , stirring vessels, cascades of containers and tube reactors, which may optionally be provided with an inner lining. Preferably the processing of the reaction products is carried out according to a usual continuous process.

In general, the quantitative ratio between 3-pentenenitrile and 2-methyl-3-butenonitrile obtained with the monoaddition of hydrocyanic acid to 1,3-butadiene or to the hydrocarbon mixture containing 1,3-butadiene immediately after the addition is complete (there is no cyanhydric acid that has not reacted) is at least 0.4: 1. Advantageously, at higher reaction temperatures and / or with longer reaction times in the presence of the catalysts according to the invention, an isomerization is additionally produced, the ratio then being The quantity obtained from 3-pentenenitrile and 2-methyl-3-butenonitrile in general of ca. 2: 1, preferably 5: 1, especially 8: 1. In general, the preparation of adipic acid dinitrile from butadiene or a butadiene-containing mixture by the addition of 2 molar equivalents of hydrocyanic acid can be divided into three steps: 1. Preparation of mixtures of C5 monoolefins with nitrile function. 2. Isomerization of the 2-methyl-3-butenonitrile contained in these mixtures to 3-pentenenitrile and isomerization of the 3-pentenenitrile thus formed and already contained in the mixtures of step 1 to various n-pentenenitriles. For this purpose, a significant proportion of 3-pentenenitrile and / or 4-pentenenitrile and a possible reduced portion of 2-pentenenitrile and 2-methyl-2-butenonitrile conjugate and optionally acting as a catalyst poison should be formed. 3. Preparation of dinitrile of adipic acid by addition of hydrocyanic acid to 3-pentenenitrile formed in step 2, which is isomerized before, in situ "to 4-pentenenitrile Advantageously the catalysts according to the invention are suitable based on its phosphonite ligands also for position and double-bond isomerization in step 2 and / or the second addition of hydrocyanic acid in step 3. Another object of the invention is therefore a process for the catalytic isomerization of branched aliphatic onoalquenonitriles with C = C bond and CsN non-conjugated to linear monoalkennonitriles, characterized in that the isomerization is carried out in the presence of a catalyst according to the invention. Suitable branched aliphatic monoalkennonitriles are preferably acyclic, aliphatic, unconjugated 2-alkyl-3-monoalkenonitriles and especially 2-methyl-3-butenonitrile, preferably mixtures are used for isomerization e C5 monoolefin mononitriles, as can be obtained by the aforementioned process for the catalytic hydrocyanuration of butadiene or mixtures of hydrocarbons containing 1,3-butadiene. Advantageously, the catalysts according to the invention show good activity with respect to the formation of linear monoalkenonitriles. Isomerization can optionally be carried out in the presence of usual promoters, e.g. , a Lewis acid, such as A1C13 or ZnCl2. Advantageously, the catalysts according to the invention generally enable isomerization without the addition of a promoter. For this, the selectivity of the catalysts according to the invention in the isomerization without the addition of a promoter is generally greater than with the addition of a promoter. In addition, a costly separation of the promoter after isomerization can be dispensed with. In this way, only a catalyst circuit for hydrocyanuration is required in principle, isomerization and optionally a second addition of hydrocyanic acid. The saving of the promoter and the simplification of the possible principle of the development of the process make it possible in general to reduce the costs with respect to known procedures. The temperature during isomerization is found in the range of approx. 50 to 160 ° C, preferably 70 to 130 ° C. A further object of the invention is a process for the preparation of dinitrile of adipic acid by catalytic hydrocyanuration of linear monoolefin C5 mononitriles, characterized in that hydrocyanuration is carried out in the presence of a catalyst according to the invention. Advantageously, a mixture of monoolefin C5 mononitriles, which can be obtained according to the process according to the invention for the catalytic hydrocyanuration of butadiene or a mixture, is used for hydrocyanuration. of hydrocarbons containing 1,3-butadiene and which was optionally subjected to further processing and / or isomerization according to the isomerization process according to the invention, described above. According to a suitable embodiment of the method according to In accordance with the invention, the hydrocyanuration of the monoolefin C5 mononitriles is carried out in the presence of a promoter, e.g. , a Lewis acid, such as A1C13, ZnCl2, BF3, B (C6H5) 3, SnCl4, Sn (C6H5) 3OS02CF3, etc. According to a suitable embodiment of the process according to the invention for the preparation of dinitrile of adipic acid, catalytic hydrocyanuration of butadiene or a mixture of hydrocarbons containing 1,3-butadiene (Step 1) and isomerization is carried out (Step 2) in the sense of a reaction of a container without isolation of the hydrocyanuration products. For this, hydrocyanuration and isomerization can be carried out, for example. , in a reactor, increasing the temperature of the reaction eventually after finishing the addition of hydrocyanic acid. The hydrocyanuration and isomerization can also be carried out in separate reactors, passing the reaction mixture containing the catalyst, e.g. , after finishing the monoaddition of hydrocyanic acid in a first reactor, without isolation and processing to a second reactor and isomerizing therein. According to another suitable embodiment of the process according to the invention, the three steps of the preparation of adipic acid dinitrile, that is, preparation of monoolefin C5 mononitriles, isomerization and second addition of hydrocyanic acid, are carried out as a reaction of a container.

An object of the invention is therefore a process for the preparation of dinitrile of adipic acid, comprising: a) Preparation of a mixture of monoolefin C5 mononitriles with C = C and C = N non-conjugated bond by catalytic hydrocyanuration of butadiene or a mixture of hydrocarbons containing 1,3-butadiene, b) catalytic isomerization of the mixture of a), c) catalytic hydrocyanuration of the isomerized mixture of b), characterized in that steps a), b) and c) are carried out in presence of at least one catalyst according to the invention and without isolation of the product (s) from step a) and / or b). The catalysts according to the invention can be prepared easily and therefore economically from previous steps that can be obtained easily and partly commercially. Advantageously they show a high activity and a good selectivity with respect to the monoadition products and / or isomerization products obtained in the hydrocyanuration of mixtures of hydrocarbons containing 1,3-butadiene. In general, they have a greater stability with respect to hydrocyanic acid than the usual hydrocyanuration catalysts and can be mixed during the hydrocyanuration also with an excess of hydrocyanic acid, without producing a marked separation of inactive nickel (II) compounds, such as for ex. , nickel (II) cyanide. In contrast to known hydrocyanuration catalysts based on non-complex phosphine and phosphite ligands, the catalysts according to the invention are not only suitable for continuous hydrocyanation processes, in which an excess of hydrocyanic acid in the process can be effectively avoided in general. reaction mixture, but are also suitable for semi-continuous processes and batch (v) procedures, in which a strong excess of hydrocyanic acid is generally found.Such catalysts used according to the invention and the processes They are generally based on the same hydrocyanuration ratios that have higher catalyst recovery ratios and a longer catalyst life than the known processes, and this, together with a better cost effectiveness, also under ecological aspects, is advantageous, since the cyanide of Nickel that is formed from the active catalyst with hydrocyanic acid is very poisonous and has to be recycled or disposed of with high costs.In addition during the preparation of the catalysts according to the invention in general no small excess of ligand is required or required with respect to the metal of subgroup VIII in comparison with the usual catalysts.

In addition to being suitable for the hydrocyanuration of hydrocarbon mixtures containing 1, 3-butadiene, the catalysts of the formula I are also generally suitable for all common hydrocyanation processes. Among them, the hydrocyanuration of non-activated olefins, e.g. , of styrene and 3-pentenenitrile. The catalysts described above, which comprise the chiral phosphonite ligands of the formula I, are suitable for enantioselective hydrocyanuration. The invention is explained in more detail based on the following non-limiting examples. Examples' In Examples 1 and 3 the following ligand I was used, in Examples 2 and 4 ligand II was used: (LigandoI) Example 1 (according to the invention): Semi-continuous hydrocyanuration of 1,3-butadiene In a glass autoclave, 0.41 g (1.5 mmoles) of bis (1,5-cyclooctadiene) nickel (0), 2.14 g of Ligand I are placed under argon at room temperature. 10 ml of Toluene is added and the mixture is stirred for 10 minutes, the reaction mixture being reddish-brown in color. Then a mixture of 7.9 g (146 mmol) of 1,3-butadiene and 40 g of toluene is added. The glass autoclave closes well and the reaction mixture is heated to 70 ° C, adjusting an initial pressure of 1.2 bar. A mixture of 3.2 g (118 mmol) of freshly distilled prussic acid in 40 g of toluene is continuously added over a period of 90 minutes. Then the pressure dropped to 0.5 bar. Then it must be reacted still 120 minutes to approx. 70 ° C to complete the reaction. For After washing the reaction product, toluene is used. The - * - development of the reaction is followed by measuring the pressure and temperature. In a determination of cyanide made below according to Volhard, a conversion of hydrocyanic acid of more than 99% is determined. GC analysis (column: 30 m of stable wax, temperature program: 5 minutes isothermal at 50 ° C, then heat with a speed of 5 ° C / min to 240 ° C, gas chromatograph: Hewlett Packard HP 5890) with standard internal (benzonitrile): 99.4% of 3-pentenenitrile, 4-pentenenitrile and 2-methyl-3-butenonitrile, with respect to the hydrocyanic acid used. Ratio 3-pentenenitrile: 2-methyl-3-butenonitrile = 0.41: 1. As demonstrated by the following Example 2, the ratio between 3-pentenenitrile and 2-methyl-3-butenonitrile is displaced by a prolongation of the reaction time beyond the end of the addition of hydrocyanic acid in favor of 3-pentenenitrile. It is not necessary to add a promoter. Example 2 (according to the invention): Semi-continuous hydrocyanuration of 1,3-butadiene with isomerization In a glass autoclave, 0.41 g (1.5 mmol) of bis (1.5) are placed under an argon atmosphere at room temperature. -cyclooctadiene) nickel (0), 2.9 g of Ligand II and 10 g of toluene and stirring for 10 minutes, the reaction mixture being reddish-brown in color. Then a mixture of 8.1 g (150 mmol) of 1,3-butadiene and 40 g of toluene is added. The glass autoclave closes well and the reaction mixture is heated to 90 ° C. A mixture of 4.0 g of freshly distilled prussic acid in 40 g of toluene is continuously added over a period of 90 minutes. When the feeding is finished, the temperature is increased to 110 ° C. The development of isomerization (ratio between 3-pentenenitrile and 2-methyl-3-butenonitrile) is examined at regular intervals (0, 3, 6, 22 hs) by means of GC analysis, as described in Example 1. Results are presented in Table 1. Table 1: As due to the extraction of samples for gas chromatography it was not possible to perform an exact determination of the yield, the reaction was carried out again without sample extraction. There was no subsequent reaction time. Yield: 99.6%. Ratio 3-pentenenitrile: 2-methyl-3-butenonitrile = 0.22: 1 (Determination of yield: see Example 1). Example 3 (according to the invention): Isomerization of 2-methyl-3-butenonitrile to 3-pentenenitrile 0.27 g of ligand I, 15 ml of toluene and 0.14 g (0.5 mmoles) of bis (1,5-cyclooctadiene) nickel (0) are placed under an argon atmosphere and stirred at room temperature for 45 minutes. minutes From the first homogeneous solution precipitates the catalyst complex that is formed. The volatile components are removed at high vacuum. The remaining solid is mixed with 40.5 g (500 mmol) of 2-methyl-3-butenonitrile. The solution is heated to 110 ° C. The development of the reaction is examined at regular intervals by means of gas chromatography. The product ratio after 300 minutes of reaction time is indicated in Table 2. All the products and byproducts indicated therein were assigned by means of gas chromatography, GC-MS, GC-MS-IR as well as NMR. All values are given in percent of GC by area. Weight of the sample: 1.0160 g Standard weight: 1.4416 g abla 2: Product ratio after 300 minutes of reaction time Conversion: 72.65% Selectivity: > 99% (Note: the material for use already contains about 1% cis- and trans-2-methyl-2-butenonitrile).

As shown in Example 3, with the catalysts according to the invention, isomerization is also possible without the addition of a promoter. Example 4 (according to the invention): Isomerization of 2-methyl-3-butenonitrile to 3-pentenenitrile 0.39 g of ligand II, 8 ml of toluene and 0.07 g (0.25 mmoles) of bis (1,5-cyclooctadiene) nickel (0) are placed under an argon atmosphere and the mixture is stirred at room temperature for 30 minutes. minutes From the first homogeneous red solution precipitates a part of the catalyst complex that is formed. The volatile components are removed at high vacuum. The remaining solid is mixed with 20.2 g (250 mmol) of 2-methyl-3-butenonitrile. The solution is heated to 125 ° C. The development of the reaction is examined at regular intervals by means of a gas chromatograph. The product ratio after 300 minutes of reaction time is indicated in Table 3. All the products and byproducts indicated therein were assigned above by means of gas chromatography, GC-MS, GC-MS-IR as well as NMR. All values are given in percent of GC by area. Weight of the sample: 1.2109 g Standard weight: 1.00262 g Table 2: Product ratio after 300 minutes of reaction time or Conversion: 95.74% 15 r twenty

Claims (1)

1. A catalyst consisting of a complex of a metal of subgroup VIII, with a bidentate phosphonyl ligand of the formula I wherein R1 and R2, and R1 'and R2', are not linked together, and A is an alkylene bridge of C2 to C7 which may have 1, 2 or 3 double bonds and / or 1, 2 or 3 substituents which are selected from alkyl, cycloalkyl and aryl, it being possible for the aryl substituent to also carry 1, 2 or 3 substituents which are selected from alkyl, alkoxy, halogen, trifluoromethyl, nitro, alkoxycarbonyl and cyano, and / or the alkylene bridge of C2 to C7 may be interrupted by 1, 2 or 3 heteroatoms which are not adjacent, unsubstituted or substituted, and / or the alkylene bridge of C2 to C7 may be fused with 1, 2 or 3 aryl and / or hetaryl groups, it being possible for the fused aryl and hetaryl groups to each carry 1, 2 or 3 substituents which are selected from: alkyl, cycloalkyl , aryl, alkoxy, cycloalkoxy, aryloxy, acyl, halogen, trifluoromethyl, cyano, nitro, carboxyl, alkoxycarbonyl and NE ^? 2, where E and E are identical or different and are each alkyl, cycloalkyl or aryl, R1 and R1 ' , independent of each other, are each alkyl, cycloalkyl, aryl or hetaryl, each of which can carry 1, 2 or 3 substituents which are selected from alkyl, cycloalkyl and aryl, R2 and R2 ', independent of each other, are each alkyl, cycloalkyl, aryl or hetaryl, it being possible for Aryl and hetaryl groups have 1, 2 or 3 substituents selected from alkyl, cycloalkyl, aryl, alkoxy, cycloalkoxy, aryloxy, acyl, halogen, trifluoromethyl, nitro, cyano, EESUMEN DB THE INVENTION The present invention relates to a catalyst comprising at least one metal complex of subgroup VIII with at least one bidentate phosphonyl ligand of general Formula I: or salts and mixtures thereof, a process for the preparation of C5 mononitrile monolefin mixtures, a process for the catalytic isomerization of branched aliphatic monoalkennonitriles and a process for the preparation of adiponitrile.