MXPA06004383A - Method for the production of nickel(0)-phosphorous ligand complexes - Google Patents

Abstract

The invention relates to a method for the production of nickel(0)-phosphorous ligand complexes from nickel(II)-ether adducts.

Description

113881 PROCEDURE FOR THE PREPARATION OF NICKEL (0) COMPLEXES WITH PHOSPHORUS LIGANDS Description The present invention relates to a process for the preparation of nickel (0) complexes with phosphorus ligands. Another object of the present invention are mixtures containing the complexes of nickel (0) with phosphorus ligands, obtainable by this process, as well as their use in the hydrocyanation of alkenes or, where appropriate, the isomerization of unsaturated nitriles.

Nickel complexes with phosphorus ligands are suitable catalysts for alkene hydrocyanates. Thus, for example, nickel complexes with monodental phosphites are known, which catalyze the hydrocyanation of butadiene for the preparation of a mixture consisting of isomeric pentenonitriles. These catalysts are also suitable in a subsequent isomerization of 2-methyl-3-butenonitrile to transform it into linear 3-pentenenitrile and hydrocyanation of 3-pentenenitrile to transform it into adiponitrile, an important intermediate in the manufacture of nylon.

US 3,903,120 describes the preparation of zero-valent nickel complexes with monodental phosphite ligands from nickel powder. The ligands containing phosphorus have, in that process, the general formula PZ3, in which Z corresponds to an alkyl, alkoxy or aryloxy group. In this process, finely distributed elemental nickel is used. Also, the transformation is preferably carried out in the presence of a solvent containing nitrite and in the presence of an excess of ligand.

US 3,846,461 describes a process for the preparation of zero-valent nickel complexes with triorganophosphite ligands by reacting triorganophosphite compounds with nickel chloride in the presence of a finely distributed reducing metal that is more electropositive than nickel. The transformation according to US 3,846,461 is carried out in the presence of a promoter selected from the group consisting of NH3, NH4X, Zn (NH3) 2X and mixtures of NH4X and ZnX2, wherein X corresponds to a halogenide.

New developments have shown that it is advantageous to apply complexes of nickel with chelate ligands (multidentate ligands) in the hydrocyanation of nickel complexes alkenes, since with them both greater activities and greater selectivities can be achieved when the resting time is increased. The processes described above of the state of the art are not suitable for preparing nickel complexes with chelate ligands. However, it is also known from the prior art methods that enable the preparation of nickel complexes with chelate ligands.

US 5,523,453 describes a process for the preparation of nickel-containing hydrocyanation catalysts, containing bidentary phosphorus ligands. The preparation of these complexes is carried out starting from soluble complexes of nickel (0) by transcompletion with chelate ligands. The starting compounds used are Ni (C0D) 2 u (oTTP) 2Ni (C2H4) (COD = 1.5 cyclooctadiene; oTTP = P (0-ortho-C6H4CH3) 3). This process is expensive because the preparation of the nickel starting compounds is expensive.

Alternatively, it is possible to prepare nickel (0) complexes by reduction starting from nickel compounds and bivalent chelate ligands.

When this method is applied, it is usual to work with elevated temperatures, so that the thermally labile ligands within the complex eventually decompose.

US 2003/0100442 Al discloses a process for the preparation of a nickel (0) -chelate complex, in which nickel chloride is reduced, in the presence of a chelate ligand and a nitrile-containing solvent, using a metal that is more electropositive than nickel, in particular zinc or iron. In order to achieve high space-time performance, an excess of nickel salt is used, which after the complexation has to be separated again. The process is usually carried out with nickel chloride hydrate, which can lead, in particular, if ligands are used which are unstable before hydrolysis, to which they decompose. When working with anhydrous nickel chloride, in particular, when using ligands which are unstable towards hydrolysis, it is essential, according to US 2003/0100442 A1, that the nickel chloride be dried as the first step in accordance with a special procedure, in which very small particles with a large surface area and therefore with high reactivity are obtained.A disadvantage of the process resides particularly in the fact that this fine powder of nickel chloride, obtained by spray drying, is carcinogenic Another disadvantage of this method is that it usually works with high reaction temperatures, which can lead to the decomposition of the ligands or the complex, especially when the ligands are unstable with respect to temperature. to work with an excess of reagents, in order to obtain reactive degrees of reaction.These excesses have to be eliminated, once the reaction, at a high cost, and eventually be returned.

GB 1 000 477 and BE 621 207 relate to processes for the preparation of nickel (0) complexes by reduction of nickel (II) compounds, using phosphorus-containing ligands.

Accordingly, the object of the present invention was to create a process for preparing nickel (0) complexes with phosphorus ligands which substantially avoids the previously described drawbacks of the state of the art. To this end, a source of anhydrous nickel should be used in particular, so that ligands which are unstable against hydrolysis are not decomposed during complexation. In addition, it is intended that the reaction conditions are preferably with due care, so that unstable ligands do not decompose against the temperature and the resulting complexes. Also, the method according to the invention should preferably enable not to apply an excess of reagents, or only a small excess, so that it is not necessary, as far as possible, to separate these substances once the complex has been prepared. The procedure must also be appropriate for preparing nickel (0) complexes with phosphorus ligands, by applying chelate ligands.

According to the invention, this object is achieved by a process for the preparation of a nickel (0) complex with phosphorus ligands, which contains at least one central nickel atom and at least one ligand containing phosphorus.

The process according to the invention is characterized in that a nickel (II) adduct with ether is reduced in the presence of at least one phosphorus-containing ligand.

The process according to the invention is preferably carried out in the presence of a solvent. When this is done, the solvent is selected particularly from the group consisting of organic nitriles, aromatic hydrocarbons, aliphatic hydrocarbons and mixtures of the aforementioned solvents. As regards organic nitriles, acetonitrile, propionitrile, n-butyronitrile, n-valeronitrile, cyanocyclopropane, acrylonitrile, crotonitrile, allyl cyanide, cis-2-pentenenitrile, trans-2-pentenenitrile, cis-3-pentenenitrile, are preferably used. trans-3-pentenenitrile, 4-pentenenitrile, 2-methyl-3-butenonitrile, Z-2-methyl-2-butenonitrile, E-2-methyl-2-butenonitrile, ethylsuccinonitrile, adiponitrile, methylglutarnitrile, or mixtures thereof. As for the aromatic hydrocarbons, benzene, toluene, o-xylene, m-xylene, p-xylene, or mixtures thereof may preferably be used. The aliphatic hydrocarbons may preferably be selected from the group of linear or branched aliphatic hydrocarbons, particularly preferably those from the group of cycloaliphatic compounds, such as cyclohexane or methylcyclohexane, or mixtures thereof. With particular preference, cis-3-pentenenitrile, trans-3-pentenenitrile, adiponitrile, methylglutarnitrile or mixtures thereof are used as solvents.

Preference is given to the use of an inert solvent.

The concentration of the solvent is preferably 10 to 90% by mass, with 20 to 70% by mass, in particular 30 to 60% by mass, particularly in the case of the finished reaction mixture being particularly preferred.

The nickel (II) adduct with ether used in the process according to the invention is preferably anhydrous and contains, in a preferred embodiment, a nickel halide.

Nickel halides, nickel bromide and nickel iodide are considered as nickel halides. Preference is given to nickel chloride.

The nickel (II) adduct with ether used in the process according to the invention preferably comprises an ether containing oxygen, sulfur or a mixture of oxygen and sulfur. That ether is preferably selected from the group consisting of tetrahydrofuran, dioxane, diethyl ether, di-n-propyl ether, diisopropyl ether, di-n-bultyl ether, di-sec-butyl ether, diallyl ether of ethylene glycol, dialkyl ether of diethylene glycol and dialkyl ether of triethylene glycol. Ethylene glycol dimethyl ether (1,2-dimethoxyethane, glyme) and ethylene glycol diethyl ether are preferred as dialkyl ether of ethylene glycol. As diethylene glycol dialkyl ether it is preferred to use diethylene glycol dimethyl ether (diglyme). As triethylene glycol dialkyl ether, it is preferred to use the triethylene glycol dimethyl ether (triglyme).

In a special embodiment of the present invention, the use of the nickel (II) chloride adduct with ethylene glycol dimethyl ether (NiCl2-dme), of the nickel (II) chloride adduct with dioxane (NiCl2) is preferred. dioxane) and the nickel (II) bromide adduct with ethylene glycol dimethyl ether (NiBr2-dme). Especially preferred is the use of NiCl2-dme, which can be prepared, for example, according to Example 2 of DE 2052 412. In that process, the nickel chloride dihydrate is transformed in the presence of 1,2-dimethoxyethane using triethyl orthoformate as a dehydrating agent. As an alternative, the transformation can also be carried out with the aid of trimethyl orthoformate. NiCl 2 -dioxane and NiBr 2 -dme can be prepared in analogous reactions, with dioxane being applied instead of 1,2-dimethoxyethane or, where appropriate, nickel bromide hydrate instead of nickel chloride hydrate.

In a preferred embodiment of the present invention, the nickel (II) adduct is prepared with ether by adding an aqueous solution of the nickel halide of the corresponding ether and a diluent, optionally stirring, the water being subsequently removed and, if necessary, the excess of ether. In that process, the diluent is preferably selected from the appropriate group of solvents to form the complex. The removal of the water and, if necessary, the excess of ether is preferably carried out by distillation. Below, a detailed description is made of the synthesis of the nickel (II) adduct with ether.

It is possible to use the nickel (II) adduct with ether directly in the solution or suspension thus obtained, for the preparation of nickel (0) complexes with phosphorus ligands. As an alternative, it is also possible to isolate the adduct first and, if necessary, dry it, to dissolve it again or, if necessary, to resuspend it for the preparation of the nickel (0) complex with phosphorus ligands. Isolation of the adduct from the suspension can be achieved by methods that are known per se to the skilled person, such as filtration, centrifugation, sedimentation or by hydrocyclones, as, for example, described in Ullmann's Encyclopedia of Industrial Chemistry, Unit Operation I, vol. B2, VCH, Weinheim, 1988, in chapter 10, p.10-1 to 10-50, chapter 11, p. 11-1 to 11-27 and chapter 12, pages. 12-1 to 12-61.

Ligands Phosphorus-containing ligands, preferably selected from the group consisting of mono- or bidentate phosphines, phosphites, phosphinites and phosphonites, are applied in the process according to the invention.

These phosphorus-containing ligands preferably have the formula I: P (XXRX) (X2R2) (X3R3) (I) By compound I is meant, in the sense given to it in the present invention, an individual compound or a mixture of various compounds of the above-mentioned formula.

According to the invention, X1, X2, X3 are, independently of one another, oxygen or individual compound. In case all the groups X1, X2 and X3 represent individual compounds, the compound I represents a phosphine of the formula P (R1R2R3), with the meanings given in this description for Ra, R2 and R3.

In case two of the groups X1, X2, X3 represent individual compounds and one represents oxygen, the compound I represents a phosphinite of the formula P (ORx) (R2) (R3) or P (RX) (OR2) (OR3) ) or P (R1) (R2) (OR3) with the meanings given below for R1, R2 and R3.

In case one of the groups X, X2 and X3 represents individual compounds and two represent oxygen, the compound I represents a phosphonite of the formula P1OR1) (OR2) (R3) or PIR1) (OR2) (OR3) or P ( OR1) (R2) (OR3) with the meanings given in this description for R1, R2 and R3.

In a preferred embodiment, all groups X1, X2, X3 should represent oxygen, so that compound I conveniently represents a phosphite of the formula P1OR1) (OR2) (OR3) with the meanings given below for R1 , R2 and R3.

According to the invention, R1, R2 and R3 represent, independently of one another, identical or different organic residues. As R.sub.1, R.sub.2 and R.sub.3, independently of one another, alkyl radicals, preferably with 1 to 10 carbon atoms, such as methyl, ethyl, ethyl, n-propyl, i-propyl, n-butyl, -butyl, s-butyl, t-butyl, aryl groups, such as phenyl, o-tolyl, m-tolyl, p-tolyl, 1-naphthyl, 2-naphthyl, or hydrocarbyl, preferably with 1 to 20 carbon atoms, such as 1, 1 '-biphenol, 1,1' -bullphol. The groups R1, R2 and R3 can be linked directly with one another, ie not only through the central phosphorus atom. Preferably, the groups R1, R2 and R3 are not directly linked to one another.

In a preferred embodiment, radicals R 1, R 2 and R 3 are selected from the group consisting of phenyl, o-tolyl, m-tolyl and p-tolyl. In a particularly preferred embodiment, two of the groups R 1, R 2 and R 3, at most, should be phenyl groups.

In another preferred embodiment, two of the groups R1, R2 and R3, at most, should be o-tolyl groups.

As especially preferred compounds I, those which are of the formula I can be applied to (o-tolyl) -0-) w (m-tolyl-0-) x (p-tolyl-0) and (phenyl-0-) zP (I a) meaning w, x, y and z a natural number, and giving the following conditions: w + x + y + z = 3 and w, z _ < 2.

These compounds I a are for example (p-tolyl-O-) (phenyl-0-) 2P, (m-tolyl-O) (phenyl-O-) 2P, (o-tolyl-O-) (phenyl-0) -) 2P, (p-tolyl-0-) 2 (phenyl-0-) P, (m-tolyl-O-) 2 (phenyl-O-) P, (o-tolyl-O-) 2 (phenyl- O-) P, (m-tolyl-O-) (p-tolyl-O) (phenyl-O-) P, (o-tolyl-O) (p-tolyl-O-) (phenyl-O) -P , (o-tolyl-O-) (m-tolyl-O-) (phenyl-O-) P, (p-tolyl-0-) 3P, (m-tolyl-O-) (p-tolyl-0- ) 2P, (o-tolyl-O-) (p-tolyl-0-) 2P, (m-tolyl-O-) 2 (p-toluyl-0-) P, (o-tolyl-0-) 2 ( p-tolyl-O-) P, (o-tolyl-O-) (m-tolyl-O) (p-tolyl-O) P, (m-tolyl-0-) 3P, (o-tolyl-O- ) (m-tolyl-0-) 2P, (o-tolyl-O-) 2 (m-tolyl-O) -P, or mixtures of such compounds.

Mixtures containing (m-tolyl-O-) 3P, (m-tolyl-O-) 2 (p-tolyl-O-) P, (m-tolyl-O-) (p-tolyl-O-) can be obtained ) 2P and (p-tolyl-O-) 3P, for example, by transforming a mixture containing m-cresol and p-cresol, in particular, in a molar ratio of 2: 1, as is produced in the oil distillation process , with a phosphoric trihalide, such as phosphorus trichloride.

In another, equally preferred embodiment, the phosphites of the formula I-b described in more detail in DE-A 199 53 058 are included as phosphorus-containing ligands: PÍO-R1) * (0-R) y (0-R3) z (0-R4) p (I b) being R1: an aromatic radical with a C-C18 alkyl substituent in the ortho position with respect to the oxygen atom linking the phosphorus atom with the aromatic system, or with an aromatic substituent in the ortho position with respect to the oxygen atom which binds to the phosphorus atom with the aromatic system, or with an aromatic system condensed in the ortho position with respect to the oxygen atom that joins the phosphorus atom with the aromatic system; R2: an aromatic radical with a C-C18 alkyl substituent in the meta position with respect to the oxygen atom linking the phosphorus atom with the aromatic system, or with an aromatic substituent in the meta position with respect to the oxygen atom that binds to the phosphorus atom with the aromatic system, or with an aromatic system condensed in meta position with respect to the oxygen atom that joins the phosphorus atom with the aromatic system, carrying the aromatic radical that is in ortho position with respect to the oxygen atom that joins the phosphorus atom with the aromatic system, a hydrogen atom; R3: an aromatic radical with an alkyl-Ci-Ciß substituent in para position with respect to the oxygen atom linking the phosphorus atom with the aromatic system, or with an aromatic substituent in para position with respect to the oxygen atom that binds the phosphorus atom with the aromatic system, carrying the aromatic radical that is in the ortho position with respect to the oxygen atom that joins the phosphorus atom with the aromatic system, a hydrogen atom; R4: an aromatic radical which, being in ortho, meta or para position with respect to the oxygen atom that joins the phosphorus atom with the aromatic system, carries other substituents than those defined for R1, R2 and R3, bearing the aromatic radical that it is in the ortho position with respect to the oxygen atom that joins the phosphorus atom with the aromatic system, a hydrogen atom; X: 1 or 2; y, z, p: independently of each other, 0, 1 or 2, provided that x + y + z + p = 3.

From the reading of DE-A 199 53 058, preferred phosphites of the formula I-b are released. As radical R1, suitable groups of o-tolyl, o-ethyl-phenyl, on-propyl-phenyl, o-isopropyl-phenyl, on-butyl-phenyl, o-sec-butyl-phenyl, o-ter- butyl-phenyl, (o-phenyl) -phenyl or 1-naphthyl.

As the radical R2, the groups m-tolyl, m-ethyl-phenyl, mn-propyl-phenyl, m-isopropyl-phenyl, mn-butyl-phenyl, m-sec-butyl-phenyl, m -tr-butyl-phenyl are preferred. , (m-phenyl) -phenyl or 2-naphthyl.

Suitable radicals R3 include p-tolyl, p-ethyl-phenyl, p-propyl-phenyl, p-isopropyl-phenyl, p-butyl-phenyl, p-sec-butyl-phenyl, p-ter- butyl-phenyl or (p-phenyl) -phenyl.

As the radical R 4, phenyl is preferred. It is preferred that p is equal to zero. For the indices x, y, z and p in compound I the following possibilities are given: Preferred phosphites of the formula I b are those in which p is equal to zero, and R1, R2 and R3 have been selected, independently from each other, from o-isopropyl-phenyl, m-tolyl and p-tolyl, and R 4 is phenyl.

Especially preferred phosphites of the formula I b are those in which R 1 is the o-isopropyl phenyl radical, R 2 is the m-tolyl radical and R 3 is the p-tolyl radical with the indices given in the table above; in addition they are those in which R1 is the o-tolyl radical, R2 is the m-tolyl radical and R3 is the p-tolyl radical with the indices given in the Table above; -also those are those in which R1 is the 1-naphthyl radical, R2 is 1 m-tolyl radical and R3 is the p-tolyl radical with the indices given in the table above; also those in which R1 is the o-tolyl radical, R2 is the 2-naphthyl radical and R3 is the p-tolyl radical with the indices given in the table above; and finally those in which R1 is the o-isopropyl-phenyl radical, R2 is the 2-naphthyl radical and R3 is the p-tolyl radical with the indices given in the table above; as well as mixtures of those phosphites.

Phosphites of the formula I-b can be obtained a) transforming a phosphoric trihalogenide with an alcohol selected from the group consisting of R ^ OH, R2OH, R3OH "and R4OH or mixtures thereof obtaining a monoester of dihalogenophosphoric acid, b) transforming said monoester of dihalogenophosphoric acid with an alcohol selected from the group consisting of R 1 OH, R 2 OH, R 30 H and R 4 OH or mixtures thereof obtaining a diester of monohalogenophosphoric acid, c) transforming said diester of monohalogenophosphoric acid with an alcohol selected from the group consisting of R ^ H, R2OH, R3OH and R4OH or mixtures thereof obtaining a phosphite of the formula I-b.

The transformation can be carried out in three separate steps. In the same way two of the three steps can be combined, that is a) with b) or b) with c). As an alternative, steps a), b) and e) may also be combined.

In that process, parameters and amounts of suitable alcohols selected from the group consisting of RxOH, R2OH, R3OH and R4OH or mixtures thereof can be easily determined by some simple preliminary tests.

As the phosphoric trihalogenide, in principle, all phosphorus trihalides are involved, preferably those in which chlorine, bromine, iodine, particularly chlorine, are applied as halides, as well as mixtures of these. Mixtures of various phosphines substituted by halide in the same or different manner can also be used as phosphoric trihalide. PC13 is especially preferred. Further details regarding the reaction conditions in the preparation of the phosphites I-b and in terms of the treatment result from the reading of DE-A 199 53 058.

The phosphites 1-b can also be used as a ligand in the form of a mixture of various phosphites I-b. A mixture of this kind can occur, for example, in the preparation of the phosphites I-b.

It is preferred, of course, that the ligand with phosphorus content be polidentary, in particular bidentate. Therefore, the ligand employed preferably has the formula II in which X11, X12, X13, X21, X22, X23 mean, independently of each other, hydrogen or individual bond, R11, R12 signify, independently of one another, identical or different organic, individual or bridge residues, R21, R22 signify, independently of each other, identical or different organic resins, individual or bridged, And it means bridge group.

Compound II is understood in the sense of the present invention as an individual compound or a mixture of different compounds of the previously indicated formula.

In a preferred embodiment X11, X12, X13, X21 ,. X22, X23 can represent oxygen. In such a case, the bridge group Y is linked with phosphite groups.

In another preferred embodiment, X11 and X12 can represent oxygen and X13 a single bond or X11 and X13 represent oxygen and X12 a simple bond, so that the phosphorus atom surrounded by X11, X12 and X13 is the central atom of a phosphonite In such a case, X21, X22 and X23 can be oxygen or X21 and X22 are oxygen and X23 is a simple union or X21 and X23 are oxygen and X22 represents a simple union or X23 oxygen and X21 and X22 are a simple union or X21 is oxygen and X22 and X23 are a simple union or X21, X22 and X23 represent a simple union, so that the phosphorus atom surrounded by X21, X22 and X23 is the central atom of a phosphite, a phosphonite, a phosphinite or a phosphine , preferably of a phosphonite.

In another preferred embodiment, X13 may represent oxygen and X11 and X12 may be a single ion or X11 is oxygen and X12 and X13. they are a simple union, so that the phosphorus atom surrounded by X11, X12 and X13 is the central atom of a phosphonite. In such a case, X21, X22 and X23 can represent oxygen or X23 is oxygen and X21 and X22 are a simple union or X21 is oxygen and X22 and X23 are a simple union or X21, X22 and X23 represent a simple union, so that the phosphorus atom surrounded by X21, X22 and X23 is the central atom of a phosphite, a phosphinite or a phosphine, preferably a phosphinite.

In another preferred embodiment, X11, X12 and X13 may represent a single bond, such that the phosphorus atom surrounded by X "1, X12 and X13 is the central atom of a phosphine." In one such case, X21, X22 and X23 may represent oxygen or X21, X22 and X23 a single bond, such that the phosphorus atom surrounded by X21, X22 and X23 is the central atom of a phosphite or a phosphine, preferably a phosphine.

As the bridging group Y, substituted aryl groups are preferably included, for example with C 1 -C 4 alkyl, halogen, such as fluorine, chlorine, bromine, halogenated alkyl, such as trifluoromethyl, aryl, such as phenyl, or unsubstituted aryl groups, preferably those with 6 to 20 carbon atoms in the aromatic system, especially pyrocatechol, bis (phenol) or bis (naphthol).

The radicals R11 and R12 can independently represent identical or different organic radicals. Advantageously, radicals R11 and R12 are included as aryl radicals, preferably those with 6 to 10 carbon atoms, which can be unsubstituted or single or multiple-substituted, especially with C alquilo-C4 alkyl, halogen, as fluorine , chlorine, bromine, halogenated alkyl, such as trifluoromethyl, aryl, such as phenyl, or unsubstituted aryl groups.

The radicals R21 and R22 independently of one another can represent the same or different organic radicals. Advantageously, radicals R21 and R22 are advantageously included as aryl radicals, preferably those with 6 to 10 carbon atoms, which can be unsubstituted or simple or multiply substituted, especially with C?-C4 alkyl, halogen, such as fluorine, chlorine, bromine, halogenated alkyl, such as trifluoromethyl, aryl, such as phenyl, or unsubstituted aryl groups.

The radicals R11 and R12 can be individual or bridged. Also the radicals R21 and R22 can be individual or bridged. The radicals R11, R12, R21 and R22 can be all individual, two bridge and two individual or all four can be bridged as described.

In a particularly preferred embodiment, the compounds mentioned in US Pat. No. 5,723,641 of Formula I, II, III, IV and V are included. In a particularly preferred embodiment, the compounds mentioned in US Pat. No. 5,512 are included. 696 of Formula I, II, III IV, V, VI and VII, especially the compounds indicated in Examples 1 to 31. In an especially preferred embodiment, the indicated compounds of Formula I, II, III, IV are included , V, VI, VII, VIII, IX, X, XI, XII, XIII, XIV and XV, in US 5,821,378 especially the compounds indicated in Examples 1 to 73.

In a particularly preferred embodiment, the compounds set forth in US 5,512,695 of Formula I, II, III, IV, V and VI, especially the compounds indicated therein in Examples 1 to 6, are included. especially preferred embodiment, the compounds described in US 5,981,772 of Formula I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII, XIII and XIV, particular compounds include applied in Examples 1 to 66.

In a particularly preferred embodiment, the compounds set forth in US 6,127,567 and the compounds applied in Examples 1 to 29 are included. In an especially preferred embodiment, the compounds of Formula I, II, III are included , IV, V, VI, VII, VIII, IX and X, mentioned in US 6,020,516, especially the compounds applied in Examples 1 to 33. In an especially preferred embodiment, the compounds indicated in US Pat. 5,959,135 and the compounds applied therein in Examples 1 to 13.

In a particularly preferred embodiment, the compounds of Formula I, II and III mentioned in US 5,847,191 are included. In a particularly preferred embodiment, the compounds set forth in US 5,523,453 are included, especially the compounds represented therein in formulas 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 and 21. In a particularly preferred embodiment, the compounds indicated in O 01/14392 are included, preferably the compounds represented therein in formulas V, VI, VII, VIII, IX, X, XI, XII, XIII, XIV, XV, XVI, XVII, XXI, XXII, XXIII.

In a particularly preferred embodiment, the compounds indicated in WO 98/27054 are included. In a particularly preferred embodiment, the compounds indicated in WO 99/13983 are included. In a particularly preferred embodiment, the compounds indicated in WO 99/64155 are included.

In a particularly preferred embodiment, the compounds mentioned in German patent application DE 100 380 37 are included. In a particularly preferred embodiment, the compounds indicated in German patent application DE 100 460 25 are included. Particularly preferred embodiment include the compounds indicated in the German patent application DE 101 502 85.

In a particularly preferred embodiment, the compounds mentioned in German patent application DE 101 502 86 are included. In a particularly preferred embodiment, the compounds indicated in German patent application DE 102 071 65 are included. In another form of Particularly preferred embodiment includes phosphorus-containing chelate ligands indicated in US 2003/0100442 Al.

In another particularly preferred embodiment, the phosphorus-containing chelate ligands included in the German patent application pre-published with file DE 103 50 999.2 of 30-10-2003 are included.

The compounds described I, 1 a, I b and II, as well as their preparation, are known per se. Mixtures containing at least two of the compounds I, 1 a, I b and II can also be used as a ligand with phosphorus content.

In a particularly preferred embodiment of the process of the invention, the phosphorus-containing ligand of the nickel complex (0) and / or the phosphorus-containing free ligand is selected from tritolyl phosphite, ligands of bidentate chelates with phosphorus content, as well as the phosphites of Formula I b P (0-R1) x (0-R2) and (0-R3) z (0-R4) p (Ib) wherein R1, R2 and R3 are independently selected from o-isopropyl-phenyl, m-tolyl and p-tolyl, R4 is phenyl; x is equal to 1 or 2, and y, z, p independently of each other are 0, 1 or 2, provided that x + y + z + p = 3; and its mixtures.

In the process according to the invention, the concentration of the ligand in the solvent is preferably 1 to 90% by weight, particularly preferably 5 to 80% by weight, especially 50 to 80% by weight.

In the method according to the invention, the ligand to be used can also be present in a ligand solution, which was already used as a catalyst solution in hydrocyanation reactions and is depleted of nickel (0). This "retrocatalyst solution" usually has the following composition: 2 to 60% by weight, especially 10 to 40% by weight of pentenenitrile, - 0 to 60% by weight, especially 0 to 40% by weight of adiponitrile, - 0 to 10% by weight, especially 0 to 5% by weight of other nitriles, - 10 to 90% by weight, especially 50 to 90% by weight of the phosphorus content ligand and - 0 to 2% by weight, especially 0 to 1% by weight of nickel (0).

The free ligand contained in the retrocatalyzed solution can therefore be converted back into a nickel (0) complex according to the process according to the invention.

The reducing agent used in the process according to the invention is preferably selected from the group consisting of metals that are more electropositive than nickel, metal alkyls, electric current, complex hydrides and hydrogen.

When a metal that is more electropositive than nickel is used as the reducing agent in the process according to the invention, this metal is preferably selected from the group consisting of sodium, lithium, potassium, magnesium, calcium, barium, strontium, titanium. , vanadium, iron, cobalt, copper, zinc, cadmium, aluminum, gallium, indium, tin, lead and thorium. Iron and zinc are particularly preferred here. If aluminum is used as a reducing agent, it is advantageous if it is pre-activated by the reaction of a catalytic amount of mercury (II) salt or metal alkyl. For the preactivation preferably, the triethylaluminum is used in an amount of preferably 0.05 to 50 Mol-%, especially preferably 0.5 to 10 Mol-%. The reduction metal is preferably finely distributed, with the term "finely distributed" meaning that the metal is used at a particle size less than a 10 mesh aperture, particularly preferably less than a 20 mesh aperture.

When a metal which is more electropositive than nickel is used as the reducing agent in the process according to the invention, this amount of metal is preferably from 0.1 to 50% by weight, based on the reaction mass.

When metal alkyls are used as reducing agents in the process according to the invention, they are preferably lithium alkyls, sodium alkyls, magnesium alkyls, especially Grignard reagents, zinc alkyls or aluminum alkyls. Especially preferred are aluminum alkyls, such as trimethylaluminum, triethylaluminum, triisopropylaluminum or mixtures thereof, especially triethylaluminum. Metal alkyls may be dissolved in a substance or in inert organic solvent, such as hexane, heptane or toluene.

When complex hydrides are used as the reducing agent in the process according to the invention, metal-aluminum hydrides, such as lithium-aluminum hydrides, or metal-boron hydrides, such as sodium borohydride, are preferably used.

The molar ratio of the redox equivalent between the source of nickel (II) and the reducing agent of preference is from 1: 1 to 1: 100, especially preferably from 1: 1 to 1: 50, especially from 1: 1 to 1. : 5.

In the method according to the invention, the duration of said method according to the invention is preferably 30 minutes to 24 hours, particularly preferably 30 minutes to 10 hours, especially 1 to 3 hours.

The molar ratio between the nickel (II) -ether adduct and the ligand is preferably 1: 1 to 1: 100, especially preferably 1: 1 to 1: 3, especially 1: 1 to 1: 2. The reduction is preferably carried out at a temperature of from 30 to 90 ° C, especially preferably from 35 to 80 ° C, especially from 40 to 70 ° C. But according to the invention it is also possible to work with higher temperatures, where a lower temperature is especially recommended for the transformation of temperature sensitive ligands.

The process according to the invention can be carried out at any pressure. For practical reasons, pressure values are preferably between 0.1 bar and 5 bar, more preferably 0.5 bar and 1.5 bar.

The process according to the invention is preferably carried out under an inert gas, for example argon or nitrogen.

The process according to the invention can be carried out by the system in batches or continuously.

In a special embodiment of the present invention, the method according to the invention includes the following process steps: (1) Preparation of a solution or suspension of the nickel (II) source, containing nickel bromide, nickel iodide and a mixture thereof in a solvent under an inert gas, (2) Agitation of the solution or suspension originated from the step of the procedure (1) with a precomplexation temperature of 20 to 120 ° C and precomplexation period of 1 minute to 24 hours, (3) Aggregate of at least one reducing agent to the solution or suspension originated from step of the process (2) with an addition temperature of 20 to 120 ° C, (4) Agitation of a suspension or solution originating from the process step- (3) during a transformation period of 30 minutes to 24 hours with a transformation temperature of 20 to 120 ° C.

The precomplexation, aggregate and transformation temperatures can each rise independently from 20 ° C to 120 ° C. The precomplexation, the aggregation and the transformation, the temperatures of 30 ° C to 80 ° C are of special preference.

The periods of precomplex ation, aggregation and transformation can rise in each case independently of each other, from 1 minute to 24 hours. The precomplexation period especially is from 1 minute to 3 hours. The aggregate period "is preferably 1 minute to 30 minutes, the preferential transformation period is 20 minutes to 5 hours.

The process according to the invention has the advantage of a high reactivity of nickel bromide or nickel iodide. An expensive drying process is unnecessary, as is required for nickel chloride according to US 2003/0100442 Al, since the reactivity of the nickel sources used according to the invention is achieved independently of the size of the crystals. Thus, a transformation at low temperatures is already possible. Furthermore, it is not necessary to use an excess of nickel salt, as is known in the state of the art. In addition, a complete transformation of the nickel (II) bromide or nickel iodide and the reducing agent can be achieved, so that further cleavage is avoided. Due to the high reactivity, nickel: ligand ratios up to 1: 1 can be obtained.

Another object of the present invention are solutions containing the complexes of nickel (0) -phosphorus ligands obtainable by means of the process according to the invention, as well as their use in the hydrocyanation of alkenes and unsaturated nitriles, especially in the hydrocyanation of butadiene to prepare a mixture of pentenenitriles and the hydrocyanation of pentenenitriles in adiponitrile. The present invention also relates to its use in the isomerization of alkenes and unsaturated nitriles, in particular of 2-methyl-3-butenonitrile in 3-pentenenitrile.

Another example of the present invention is a process for preparing an adduct of nickel (II) ether. This nickel (II) ester adduct can be used in a preferred embodiment of the present invention in the process described above to prepare nickel (0) -phosphorus ligand complexes as educts. This process for preparing an adduct of nickel ether (II) is characterized in that a nickel (II) halide with water content is mixed with an ether and a diluent, optionally under stirring, and then the water, the diluent and, if appropriate, the water is removed. the excess ether.

The nickel halide (II) containing water and ether are preferably stirred for 3 minutes to 24 hours, with special preference for 5 minutes to 3 hours. In this case, the nickel (II) halide and the ether can be stirred in the presence of a diluent. Alternatively, it is also possible to add the diluent just after shaking.

In the preparation of the nickel ether (II) adduct, the water and possibly the excess ether are removed by means of azeotropic distillation with a diluent. The azeotropic distillation is preferably carried out by removing the water from a mixture containing nickel (II) halide with water content, the ether and the diluent, using a diluent whose boiling point, in the case of a non-azeotropic formation of the diluent with water under the conditions of pressure of the distillation mentioned below, is greater than the boiling point of water and is liquid at this boiling point of water or which forms an azeotrope or a heteroazeotrope with water under pressure conditions of the distillation temperature mentioned below, and distilling the mixture containing the nickel halide (II) containing water, ether and. the diluent, with removal of the water, optionally the excess ether or the aforementioned azeotrope or the aforementioned heteroazeotrope from this mixture and obtaining an anhydrous mixture containing the nickel ether (II) adduct and the aforementioned diluent.

With regard to the nickel halides and ethers to be used, reference is made to the above embodiments of the process according to the invention for preparing nickel (0) -phosphorus ligand complexes.

The nickel halide (II) with water content is a nickel halide which is selected from the group of nickel chloride, nickel bromide and nickel iodide containing at least 2% by weight of water. Examples thereof are nickel chloride dihydrate, nickel chloride hexahydrate, an aqueous solution of nickel chloride, nickel bromide trihydrate, an aqueous solution of nickel bromide, nickel iodide hydrate or an aqueous solution of iodide of Nickel In the case of nickel chloride, nickel chloride hexahydrate or an aqueous solution of nickel chloride are preferably used. In the case of nickel bromide and nickel iodide, aqueous solutions are preferably used. An aqueous solution of nickel chloride is especially preferred.

In the case of an aqueous solution, the concentration of the nickel (II) halide in water is not critical in itself. A proportion of the nickel halide was advantageous (II) in the sum of the weight of nickel halide (II) and water of at least 0.01% by weight, preferably at least 0.1% by weight, with special preference of at least 0.25% by weight , especially of at least 0.5% by weight. A proportion of the nickel halide was advantageous (II) in the sum of weights of nickel halide (II) and water in the range of at most 80% by weight, preferably not more than 60% by weight, with special preference of at most 40% by weight . For practical reasons, it is advantageous not to exceed a proportion of nickel halide in the mixture of nickel halide and water which results in a solution under the given conditions of pressure and temperature. In the case of an aqueous solution of nickel chloride, it is advantageous to choose at room temperature, for reasons of practicality, a proportion of nickel halide in the sum of nickel chloride weights and water of at most 31% by weight. At higher temperatures higher concentrations may be selected, respectively, which result from the solubility of nickel chloride in water.

The ether used is preferably an ether with an oxygen content, with sulfur content or with oxygen and sulfur content mixed. This is preferably selected from the group consisting of tetrahydrofuran, dioxane, diethyl ether, di-n-propyl ether, diisopropyl ether, di-n-butyl ether, di-sec-butyl ether, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether and triethylene glycol alkyl ether .

Ethylene glycol dimethyl ether (1,2-dimethoxyethane, glyme) and ethylene glycol diethyl ether are preferably used as the ethylene glycol alkyl ether. Diethylene glycol dimethyl ether (diglyme) is preferably used as diethylene glycol alkyl ether. The triethylene glycol dimethyl ether (triglyme) is preferably used as triethylene glycol alkyl ether.

The ratio of nickel halide to ether used is preferably from 1: 1 to 1: 1.5, with special preference from 1: 1 to 1: 1.3.

The starting mixture for the azeotropic distillation can be composed of nickel (II) halide with water and ether content. The starting mixture may contain, in addition to nickel halide (II) with water and ether content, other components such as ionic or nonionic, organic or inorganic compounds, especially those which are miscible with the starting mixture in one phase homogeneously or soluble in the starting mixture.

The pressure conditions for the next distillation are not critical in themselves. Pressures of at least 104 MPa, preferably of at least 10 ~ 3 MPa, especially of at least 5 • 10 ~ 3 MPa, are advantageous. Pressures of at most 1 MPa, preferably of at most 5 • 10"1 MPa, in particular of at most 1.5 • 10" 1 MPa, are advantageous.

Depending on the pressure conditions and the composition of the mixture to be distilled, the distillation temperature is then regulated. In the case of this temperature, the diluent is preferably present in liquid form. In the sense of the present invention, diluent means both a single diluent and also a mixture of diluents, wherein in the case of a mixture of this type the physical properties mentioned in the present invention refer to this mixture.

On the other hand, the diluent preferably has a boiling point under these conditions of pressure and temperature which, in the case of non-azeotropic formation of the diluent with water, is higher than that of water, preferably at least 5 ° C, in special at least 20 ° C, and preferably at most 200 ° C, especially at most 100 ° C.

In a preferred embodiment, diluents that form an azeotrope or heteroazeotrope with water can be employed. The amount of diluent with respect to the amount of water in the mixture is not "critical." Preferably, more liquid diluent should be used than those corresponding to the amounts to be distilled by the azeotropes, so that there remains a surplus diluent as residual product.

If a diluent that does not form an azeotrope with water is used, the amount of diluent against the amount of water in the mixture is not critical in itself.

The diluent used is selected in this case, in particular, from the group consisting of organic nitriles, aromatic hydrocarbons, aliphatic hydrocarbons and mixtures of the aforementioned solvents. As regards organic nitriles, acetonitrile, propionitrile, n-butyronitrile, n-valeronitrile, cyanocyclopropane, acrylonitrile, crotonitrile, allyl cyanide, cis-2-pentenenitrile, trans-2-pentenenitrile, cis-3-pentenenitrile, 3-pentenenitrile, 4-pentenenitrile, 2-methyl-3-butenonitrile, Z-2-methyl-2-butenonitrile, E-2-methyl-2-butenonitrile, ethylsuccinitrile, adiponitrile, methylglutarnitrile or mixtures thereof. With respect to aromatic hydrocarbons, benzene, toluene, o-xylene, m-xylene, p-xylene or mixtures thereof can preferably be used. Aliphatic hydrocarbons may preferably be selected from the group of linear or branched aliphatic hydrocarbons, with particular preference of the group of cycloaliphatic compounds such as cyclohexane or methylcyclohexane, or mixtures thereof. Especially preferred are cis-3-pentenenitrile, trans-3-pentenenitrile, adiponitrile, methylglutarnitrile or mixtures thereof as solvents.

If an organic nitrile or mixtures containing at least one organic nitrile is used as diluent, it was advantageous to choose the amount of diluent so that, in the finished mixture, the proportion of nickel halide (II) in the sum of halide weights of nickel (II) and diluent is at least 0.05% by weight, preferably at least 0.5% by weight, particularly preferably at least 1% by weight.

If an organic nitrile or mixtures containing at least one organic nitrile is used as diluent, it was advantageous to choose the amount of diluent so that, in the finished mixture, the proportion of nickel halide (II) in the sum of halide weights of nickel (II) and diluent is at most 50% by weight, preferably not more than 30% by weight, particularly preferably not more than 20% by weight.

According to the invention, the mixture containing the nickel halide (II) containing the water, the ether and the diluent is distilled by separating the water and, if necessary, the excess ether from this mixture and obtaining an anhydrous mixture containing the ether adduct of nickel (II) and the aforementioned diluent. In a preferred embodiment, the mixture is first prepared and then distilled. In a further preferred embodiment, the nickel halide containing water, particularly preferably the aqueous solution of the nickel halide, is added progressively to the boiling diluent during the distillation. In this way, the formation of a viscous solid, which is difficult to handle in the process technique, can essentially be avoided.

In a special embodiment of the present invention, the diluent is identical to the solvent that is used in the process described according to the invention to prepare the complex of nickel (0) -phosphorus ligands.

The temperature of the azeotropic distillation depends essentially on the ether used and the diluent used. In this system, in which 1, 2-dimethoxyethane is used as ether and 3-pentenenitrile as diluent, the residual temperature is, for example, 110 to 160 ° C in the azeotropic distillation at normal pressure. In the same system it is also possible to perform azeotropic distillation at reduced pressure. For example, it is also possible to remove 1,2-dimethoxyethane and water at a pressure of 150 mbar and a residual temperature of 80 ° C.

In the case of pentenonitrile as a diluent, the distillation may preferably be carried out at a pressure of not more than 200 kPa, preferably not more than 100 kPa, in particular not more than 50 kPa, with a special preference of at most 20 kPa.

In the case of pentenonitrile as a diluent, the distillation may preferably be carried out at a pressure of at least 1 kPa, preferably at least 5 kPa, more preferably at least 10 kPa.

By selecting appropriate process conditions, the formation of various nickel (II) ether adducts can be controlled in this case. For example, in a system of nickel (II) chloride, 1,2-dimethoxyethane and 3-pentenenitrile in a distillation at normal pressure and then at elevated temperature, NiCl 2 - 0.5 dme can be obtained, while in a distillation under vacuum and thus at lower temperatures, NiCl2 • dme is obtained.

The distillation is advantageously carried out by evaporation in one step, preferably by distillation by fractionation in one or several, such as 2 or 3 distillation equipment. Common equipment for distillation is used here as described, for example, in: Quirk-Othmer, Encyclopedia of Chemical Technology, 3rd Ed., Vol. 7, John Wiley & Sons, New York, 1979, pages 870-881, as columns with sieve plates, column of dishes with bell-type floors, packaging columns, columns with 'filling bodies, columns with lateral exit or column with dividing partition.

The process may be carried out discontinuously or continuously.

The process is suitable, in particular, for preparing nickel (II) chloride adducts with 1,2-dimethoxyethane and dioxane.

The present invention will be explained in greater detail by way of the following examples.

Exemplary embodiments In the examples for the synthesis of the complex, a solution of the chelate phosphonite 1 was used as a solution of the chelate ligand 1 in 3-pentenenitrile (65% by weight of the chelate, 35% by weight of 3-pentenenitrile).

In order to determine the yield, its content of complex active Ni (0) was studied in the prepared solutions of the complex. For this, the solutions were mixed with tri (m / p-tolyl) phosphite (usually 1 g of phosphite per 1 g of solution) and kept approx. 30 min. at 80 ° C, in order to achieve total recomplexation. Next, for the electrochemical oxidation in a cyclo-voltammetric measuring device, the current-voltage curve in a solution at rest with respect to a reference electrode, which determines the peak current proportional to the concentration y, was measured. corrects, through a calibration with solutions of known concentrations of Ni (0), the Ni (0) content of the test solution, by the amount of the subsequent dilution with tri (m / p-tolyl) phosphite. The values of Ni (0) mentioned in the examples indicate the content of Ni (0) in. % by weight determined by this method, with respect to the total of the reaction solution.

In Examples 1-9 zinc powder was used as a reducing agent: Example 1: To a 500 ml flask with stirrer was suspended under argon 18.3 g (83 mmol) of NiCl2-dme in 13 g of 3-pentenenitrile and mixed with 100 g of chelate solution (86 mmol of ligand) and stirred 15 min. . at 80 ° C. After cooling to 50 ° C, 8 g of zinc powder (122 mmol, 14 eq.) Were added and the mixture was stirred at 50 ° C for 3 h. A Ni (0) value of 3.0% (86% yield) was measured.

Example 2: A reaction was performed analogously to Example 1, but only 7.2 g of Zn (110 mmol, 1.3 eq.) Was added. After 3.5 h a Ni (0) value of 3.3% (94% yield) was measured.

Example 3: A reaction was performed analogously to Example 1, but only 6 g of Zn (91 mmol, 1.1 eq.) Was added. After 12 h a Ni (0) value of 3.1% (89% yield) was measured.

Example 4: A reaction was performed analogously to Example 1, but only 17.4 g of NiCl 2 -dme (79 mmol) was used, and the temperature was reduced prior to the addition of the zinc powder at 30 ° C. After 4 h a Ni (0) value of 3.0% (90% yield) was measured.

Example 5: A reaction was performed analogously to Example 1, but the ligand and the nickel salt were previously stirred at a temperature of only 60 ° C. The temperature was then reduced prior to the addition of the zinc powder at 40 ° C. After 4 h a Ni (0) value of 2.8% (80% yield) was measured.

Example 6: To a 500 ml flask with stirrer was suspended under argon 9.1 g (41 mmol) of NiCl 2 -dme in 13 g of 3-pentenenitrile and 100 g of chelate solution (86 mmol of ligand) and stirred 15 min. at 40 ° C, 4 g of zinc powder (61 mmol, 1.4 eq.) were added and the mixture was stirred at 40 ° C for 4 h. A Ni (0) value of 1.8% (94% yield) was measured.

Example 7: In a 4 1 flask with agitator, 367 g (1.67 mol) of NiCl 2 -dme in 260 g of 3-pentenenitrile and 2000 g of chelate solution (1.72 mol of ligand) were suspended under argon at 50 ° C. Then 120 g of zinc powder (1.84 mol, 1.1 eq.) Were added in 30 g portions and the mixture was stirred for 4 h at 50-55 ° C. A Ni (0) value of 3.44% (96% yield) was measured.

Example 8: In a 250 ml flask with stirrer, 9.2 g (42 mmol) of NiCl2-dme in 25 g adiponitrile and 50 g of chelate solution (43 mmol of ligand) were suspended under argon and stirred 15 min. at 80 ° C. After cooling to 30 ° C, 3 g of zinc powder (46 mmol, 1.1 eq.) Were added and the mixture was stirred at 50 ° C for 5 h. A Ni (0) value of 2.6% (93% yield) was measured.

Example 9: A reaction was performed analogously to Example 8, but prior to the addition of the zinc powder, the temperature was reduced to 50 ° C. After 5 h a Ni (0) value of 2.4% (86% yield) was measured.

In Examples 10-13, iron powder was used as the reducing agent.

Example 10: In a 500 ml flask with stirrer was suspended under argon 18.3 g (83 mmol) of NiCl2-dme in 13 g of 3-pentenenitrile and 100 g of chelate solution (86 mmol of ligand) and stirred 15 min. at 80 ° C. After cooling to 30 ° C, 5.3 g of iron powder (95 mmol, 1.1 eq.) Was added and the mixture was stirred at 30 ° C for 4 h. A Ni (0) value of 2.8% (79% yield) was measured.

Example 11: A reaction was performed analogously to Example 10, but the temperature was reduced prior to the addition of the iron powder at 60 ° C. After 4 h a Ni (0) value of 3.0% (84% yield) was measured.

Example 12: A reaction was performed analogously to Example 10, but the temperature was maintained during the addition of the iron powder at 80 ° C. After 4 h a Ni (0) value of 2.2% (62% yield) was measured.

Example 13: A reaction was performed analogously to Example 10, but only 4.5 g of iron powder (81 mmol, 0.98 eq.) Was added. After 4 h a Ni (0) value of 2.4% (67% yield) was measured.

In Example 14 Et3Al was used as a reducing agent.

Example 14: •, Into a 500 ml flask with stirrer was suspended under argon 6.4 g (29 mmol) of NiCl2-dme in 67.3 g of chelate solution (58 mmol of ligand) and cooled to 0 ° C. Then 20.1 g of a 25% solution of triethylaluminum in toluene (44 mmol) were slowly added. After heating the solution at room temperature, stirring was continued for a further 4 h. A Ni (0) value of 1.8% (99% yield) was measured.

In Examples 15-17, nickel bromide adduct DME was used as the nickel source.

Example 15: In a 250 ml flask with stirrer was dissolved under argon 8.9 g (29 mmol) of NiBr2-dme in 4.3 g of 3-pentenenitrile and 33 g of chelate solution (29 mmol of ligand) and stirred 10 min. at 80 ° C. After cooling to 25 ° C, 2.4 g of zinc powder (37 mmol, 1.25 eq.) Were added and the mixture was stirred at 25 ° C for 4 h. A Ni (0) value of 2.8% (81% yield) was measured.

Example 16: A reaction was carried out analogously to Example 13, but prior to the addition of the zinc powder, the temperature was reduced to 30 ° C. After 4 h a Ni (0) value of 2.4% (69% yield) was measured.

Example 17: A reaction was carried out analogously to Example 13, but prior to the addition of the zinc powder, the temperature was reduced to 45 ° C. After 4 h a Ni (0) value of 2.5% (72% yield) was measured.

In Examples 18-20 a "retrocatalyst solution" was used as the ligand solution, which had already been used as a catalyst solution in hydrocyanation reactions and was strongly depleted in Ni (0). The composition of the solution amounts to approx. 20% by weight of pentenenitrile, approx. 6% by weight adiponitrile, approx. 3% by weight other nitriles, approx. 70% by weight of ligand (composed of a mixture of 40 Mol-% chelated phosphonite 1 and 60 Mol-% Tri (m / p-tolyl) phosphite) and a nickel content (0) of only 0.8% by weight.

Example 18: In a 250 ml flask with stirrer, 9.1 g (41 mmol) of NiCl-dme in 24 g of 3-pentenenitrile was suspended under argon, mixed with 100 g of retrocatalyzed solution and stirred for 15 min. at 60 ° C. Then 3.4 g of zinc powder (61 mmol, 1.5 eq.) Were added and the mixture was stirred at 60 ° C for 4 h. A Ni (0) value of 1.25% was measured (according to a P: Ni ratio of 6.5 .- 1).

Example 19: A reaction was performed analogously to Example 18, but only 2.8 g of zinc powder (43 mmol, 1.1 eq.) Was used. After 4 h a Ni (0) value of 1.2% was measured (according to a P: Ni ratio of 6.7: 1).

Example 20: A reaction was performed analogously to Example 18, but only 3.1 g (15 mmol) of NiCl2-dme and 1 g of zinc powder (15 mmol, 1.0 eq.) Were used. After 4 h a Ni (0) value of 1.2% was measured (according to a P: Ni ratio of 6.7: 1).

In Examples 21 to 23 it was used as tri (m / p-tolylphosphiu) ligand.

Example 21: In a 250 ml flask with stirrer, 10.0 g (45.5 mmol) of NiCl2-dme in 52 g of 3-pentenenitrile were suspended under argon, mixed with 64.2 g (182 mmol) of tri (m / p-tolylphosphite) and it stirred 5 min. at 50 ° C. Then 3.3 g of zinc powder (50 mmol, 1.1 eq.) Was added and stirred 4 h at 50 ° C. A Ni (0) value of 1.6% (75% yield) was measured.

Example 22: A reaction was performed analogously to Example 21, but only 73 g of 3-pentenenitrile and 96.2 g (96 mmol) of tri (m / p-tolylphosphite) were used. A Ni (0) value of 1.1% (75% yield) was measured.

Example 23: In a 250 ml flask with stirrer, 5.0 g (22.8 mmol) of NiCl -dme in 100 g of 3-pentenenitrile was suspended under argon, mixed with 144.4 g (410 mmol) of tri (m / p-tolylphosphite) and it stirred 5 min. at 50 ° C. Then 1.7 g of zinc powder (25 mmol, 1.1 eq.) Were added and the mixture was stirred at 50 ° C. for 4 h. A Ni (0) value of 0.5% (98% yield) was measured.

In Examples 24 and 25, a NiCl2-DME adduct prepared according to Example 33 was used.

Example 24: An adduct of NiCl2-DME (83 mmol Ni) prepared according to Example 33 was resuspended in 13 g of 3-pentenenitrile and mixed with 100 g of chelate solution (86 mmol of ligand). Then 8 g of zinc powder (122 mmol, 1.5 eq.) Were added at 50 ° C and the mixture was stirred for 2.5 h at approx. 55 ° C. A Ni (0) value of 2.2% (63% yield) was established, which also did not increase after 4 h at 50-55 ° C.

Example 25: An adduct of NiCl2-DME (41 mmol Ni) prepared according to Example 33 was resuspended in 3 g of 3-pentenenitrile and mixed with 50 g of chelate solution (43 mmol of ligand) and stirred for 10 min. at 80 ° C. Then 4 g of zinc powder (61 mmol, 1.5 eq.) Were added at 80 ° C and the mixture was stirred for 4 h at approx. 80 ° C. A Ni (0) value of 2.6% (71% yield) was established.

In Example 26 a NiCl2 • 0.5dme adduct prepared according to Example 32 was used.

EXAMPLE 26: An adduct of NiCl2 • 0.5dme (83 mmol Ni) prepared according to Example 32 was resuspended in 26 g of 3-pentenenitrile and mixed with 200 g of chelate solution (172 mmol of ligand). Then 7 g of zinc powder (107 mmol, 1.3 eq.) Were added at 40 ° C and the mixture was stirred for 1 h at 40 ° C. A Ni (0) value of 1.2% (63% yield) was established.

In Example 27 the suspension of NiCl2-0.5dmé in 3-pentenenitrile prepared according to Example 34 was used.

Example 27: The suspension of the NiCl 2-0.5dme adduct (815 mmol Ni) in 3-pentenenitrile prepared according to Example 34 was mixed with 1000 g of chelate solution (860 mmol of ligand) and stirred for several hours at 60-70 ° C. until a homogeneous suspension is produced. It was then cooled to 50 ° C, a total of 65 g of zinc powder (994 mmol, 1.2 eq.) Was added in four portions, the mixture was heated to 80 ° C and stirred for 4 h. There, a clear, homogeneous solution was obtained. A Ni (0) value of 2.7% (96% yield) was established.

In Examples 28-31, the synthesis of the NiCl2-dioxane adduct and its use in the synthesis of the complex is described.

Example 28: In a 250 ml flask with stirrer and reflux refrigerator, 73 g of NiCl2-2H20 (440 mmol) were suspended in 189 g of 1,4-dioxane (2.15 mol, 4.8 eq.) And mixed with 104 g of trimethylortoformate (980 mmol). , 2.2 eq.). The mixture was heated to 65 ° C and refluxed 3.5 h. Next, the yellow suspension was aspirated through an inverse frit after cooling and the residue was dried in a stream of argon. After the subsequent vacuum drying in an oil pump, 95 g of NiCl 2 • dioxane (99%) was obtained as a yellow powder.

Elementary analysis: Observation regarding the analysis: the cations can alter the oxygen value.

Example 29: In a 250 ml flask with stirrer, 9.2 g (42 mmol) of NiCl 2 -dioxane in 25 g of 3-pentenenitrile and 50 g of chelate solution (43 mmol of ligand) were suspended under argon and stirred for 15 min. at 80 ° C. Then 3 g of zinc powder (46 mmol, 1.1 eq.) Was added and stirred 4 h at 80 ° C. A Ni (0) value of 2.2% (79% yield) was measured.

Example 30: A reaction was carried out analogously to Example 29, but before addition of the zinc powder it was cooled to 50 ° C. After 4 h a Ni (0) value of 2.2% (79% yield) was measured.

Example 31: A reaction was performed analogously to Example 29, but prior to the addition of the zinc powder it was cooled to 30 ° C.

After 3.5 h, a Ni (0) value of 2.0% (71% yield) was measured.

In the comparative examples 1-4 anhydrous nickel chloride was used for sale in the market as nickel source: Comparative example 1: In a 500 ml flask with stirrer, 11 g (885 mmol) of NiCl 2 in 13 g of 3-pentenenitrile were suspended under argon, mixed with 100 g of chelate solution (86 mmol of ligand) and stirred 15 min. at 80 ° C. After cooling to 40 ° C, 8 g of zinc powder (122 mmol, 1.4 eq.) Were added and the mixture was stirred at 40 ° C for 4 h. A Ni (0) value of 0.05% (1% yield) was measured.

Comparative example 2: A reaction was carried out analogously to Comparative Example 1, but the temperature was maintained during the addition of the zinc powder at 80 ° C. After 5 h a Ni (0) value of 0.4% (10% yield) was measured.

Comparative example 3: In a 500 ml flask with stirrer, 11 g (85 mmol) of NiCl 2 in 13 g of 3-pentenenitrile were suspended under an argon, 100 g of chelate solution (86 mmol) were added as a ligand and stirred for 15 min. at 80 ° C. After cooling to 60 ° C, 5.3 g of zinc powder (95 mmol, 1.1 eq.) Was added and stirred at 60-65 ° C. for 10 h.A Ni (0) value of 0.16% (4% yield) was measured. .

Comparative example 4: A reaction was carried out analogously to Comparative Example 3, but the temperature was maintained during the addition of the iron powder at 80 ° C. After 10 h a Ni (0) value of 0.4% (10% yield) was measured.

In Examples 32-35 the synthesis of the nickel chloride adduct DME is described: Example 32: In a 500 ml agitation device with water centrifuge, 19.4 g (82 mmol) of NiCl2-6H20 in 20 g of water were dissolved, mixed with 11.1 g (123 mmol, 1.5 eq.) 1,2-dimethoxyethane and stirred at room temperature until the next day. Then approx. 150 ml 3-pentenenitrile and under normal pressure under reflux the water is removed (settling temperature 110-116 ° C). After approx. 30 min. 36 ml of aqueous phase were obtained (with excess of DME separated by distillation). The residue, a yellow pasty solid, was concentrated practically to dryness, a small sample was extracted and dried under vacuum in an oil pump.

Elementary analysis: Example 33: In a 250 ml agitation device with a water centrifuge, 19.7 g (83 mmol) of NiCl2-6H20 were dissolved in 20 g of water, mixed with 11.3 g (125 mmol, 1.5 eq.), 1,2-dimethoxyethane and 100 g. g of 3-pentenenitrile and the biphasic mixture was stirred 3 at room temperature. Then heat to approx. 150 mbar under reflux (decanted max 80 ° C) and the water is removed (30.5 g aqueous phase). After no more water was left, the mixture was concentrated to dryness. A small sample was extracted and dried under vacuum in an oil pump.

Elementary analysis: Observation regarding the analysis: the cations can alter the oxygen value.

Example 34: In a 2 1 agitator with a water centrifuge, 135 g (815 mmol) of NiCl2-2H20 were suspended in 212 g (2.35 mol, 2.9 eq.) 1,2-dimethoxyethane and 500 g of 3-pentenenitrile. The water and the excess DME were then removed under normal pressure under reflux. A very thick, partly non-homogeneous suspension of 3-pentenenitrile was obtained.

Example 35: In an Erlenmeyer flask, 98.5 g (410 mmol) of NiCl2-6H20 were dissolved in 100 g of water, mixed with 56.5 g (630 mmol, 1.5 eq.) 1,2-dimethoxyethane and stirred at room temperature for a few hours ( Solution 1) In a 1 1 agitator device with a water centrifuge, 350 g of 3-pentenenitrile were heated at 150 mbar under reflux. Then solution 1 was added dropwise to the 3-pentenenitrile under reflux, at the same rate, at which water was extracted from the reaction mixture by the water centrifuge. A fine suspension was obtained, which remained stable for several days.

A small sample (approximately 70 g) was extracted from the suspension, sucked and dried under vacuum in an oil pump.

Elementary analysis: Observation regarding the analysis: the cations can alter the oxygen value.

Comparative Example 5 describes the NiCl2 • dme synthesis assay from NiCl2 and DME.

Comparative example 5: In a 250 ml stirring device, 25.9 g of crystalline water-free nickel chloride was suspended under argon in 83 g of 1,2-dimethoxyethane and heated under reflux for 10 hours at boiling. It was then filtered through an inverse frit, dried until the next day under argon flow and then the vacuum drying was completed in an oil pump at 30-40 ° C. 26.5 g of residue were obtained.

Elementary analysis In Example 36 the synthesis of the nickel-dioxane chloride adduct is described: Example 36: In an Erlenmeyer flask, 49.3 g (207 mmol) of NiCl2 • 6H20 were dissolved in 50 g of water, mixed with 27.8 g (316 mmol, 1.5 eq.) 1,4-Dioxane and stirred at room temperature for 2 hours ( Solution 1) In a 250 ml agitation device with a water centrifuge, 350 g of 3-pentenenitrile were heated under reflux under normal pressure. Then solution 1 was added dropwise to the 3-pentenenitrile under reflux, at the same rate, at which the water was extracted from the reaction mixture by the water centrifuge. A fine suspension was obtained.

A small sample was extracted from the suspension, sucked and dried under vacuum in an oil pump.

Elementary analysis:

Claims (14)

1. A process to prepare a complex nickel ligand (0) - phosphorus containing at least one central nickel atom and at least one phosphorus ligand, the process consists in reducing a nickel (II) -ether adduct in the presence of at least one phosphorus ligand selected from the group It consists of phosphites and phosphonites and phosphines and phosphinites with three aromatic substituents.

2. The process according to claim 1, characterized in that the nickel (II) -ether adduct contains an ether selected from a group consisting of tetrahydrofuran, dioxane, diethyl ether, diisopropyl ether, dibutyl ether, ethylene glycol dialkyl ether, diethylene. glycol dialkyl ether and triethylene glycol dialkyl ether.

3. The process according to claims 1 and 2, characterized in that the phosphorus ligand is bidentate.

4. The process according to any of claims 1 to 3, characterized in that the ligand / phosphorus comes from a ligand solution that has already been used as a catalyst solution in hydrocyanation reactions.

5. The process according to any of claims 1 to 4, characterized in that the reducing agent is selected from the group consisting of metals that are more electropositive than nickel, metal alkyls, electric current, complex hydrides and hydrogen.

6. The process according to any of claims 1 to 5, characterized in that the reduction is carried out in the presence of a solvent which is selected from the group consisting of organic nitriles, aromatic or aliphatic hydrocarbons, and mixtures thereof.

7. The process according to any of claims 1 to 5, characterized in that it comprises the following steps of the process: (1) preparing a solution or suspension of at least one nickel (II) -ether adduct and at least one ligand in a solvent, under an inert gas (2) stir the solution or suspension proceeding from step (1) of the process at a temperature from 20 to 120 ° C for one. time from 1 minute to 24 hours for precomplexing (3) at a temperature from 20 to 120 ° C add the reducing agent to the solution or suspension that comes from step (2) of the process (4) stirring the solution or suspension proceeding from step (3) of the process, at a temperature from 20 to 120 ° C.

8. A mixture containing ligands-nickel (0) -phosphorus complexes, which can be obtained by a process according to any of claims 1 to 7.

9. The use of the mixtures containing the complex nickel (0) -phosphorus ligands according to claim 8 in the hydrocyanation and isomerization of alkenes and in the hydrocyanation and isomerization of unsaturated nitriles.

10. A process for preparing a nickel (0) -phosphorus complex ligand according to any of claims 1 to 9, which consists of dissolving a nickel (II) halide in water, mixing with an ether and a diluent, if it is appropriate with stirring, and then separate water and ether in excess.

11. The process according to claim 10, characterized in that the nickel halides (II) are selected from the group consisting of nickel (II) halide, nickel (II) bromide and nickel (II) iodide.

12. The process according to claim 10 or 11, characterized in that the nickel (II) -ether adduct is prepared by a process to separate the water from a mixture containing the corresponding nickel (II) acid halide, and the corresponding ether , by combining the mixture with a diluent whose boiling point, in the case that the diluent mentioned does not form an azeotrope with the water under the pressure conditions of the distillation mentioned below [sic], is greater than the boiling point of the water and is liquid at this boiling point of the water, or forming an azeotrope or heteroazeotrope with water under the conditions of pressure and temperature of the distillation mentioned below [sic], and distilling from this mixing, the mixture containing the aqueous nickel (II) halide, the ether and the diluent to remove water or the aforementioned azeotrope or the aforementioned heteroazeotrope, to obtain an anhydrous mixture containing Nickel (II) oxide and the diluent.

13. The process according to claim 12, characterized in that the diluent is an organic diluent having at least one nitrile group.

14. The process according to any of claims 10 to 13, characterized in that ether is used which is selected from the group consisting of tetrahydrofuran, dioxane, diethyl ether, diisopropyl ether, dibutyl ether, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether. PROCEDURE FOR THE PREPARATION OF NICKEL (0) COMPLEXES WITH PHOSPHORUS LIGANDS SUMMARY Object of the present invention is a process for the preparation of nickel (0) complexes with phosphorus ligands from nickel (II) -ether adducts.