DE19730867A1 - Process for the preparation of monoalkyl metal complexes chelated with bidentate ligands - Google Patents

Abstract

The invention relates to a method for producing monoalkyl metal complexes chelated with bidentate ligands, by reacting a transition-metal compound of general formula M(X)k (I) with a bidentate ligand in a polar protic solvent, in the presence of an alkaline, alkaline earth or ammonium halide or in the presence of benzonitrile, replacing said polar protic solvent with a non-coordinating polar aprotic solvent, and adding a tetraorgano tin compound to the resulting mixture.

Description

The present invention relates to processes for the production of monoalkyl metal complexes chelated with bidentate ligands and their use as catalysts in the copolymerization of carbon monoxide and vinyl aromatic compounds.

Bidentate ligand systems and complexes with them metals are known. Neutral ligand systems are mostly used Use in which, for example, nitrogen, phosphorus, arsenic, Oxygen or sulfur atoms are able to use a free one Pair of electrons to a neutral or charged metal center coordinate. Chelated metal complexes are increasingly found Dimensions as catalysts for a wide variety of reaction types. For example, according to Brookhart et al., J. Am. Chem. Soc. 1995, 117, 6414 cationic palladium (II) and nickel (II) bisimin complexes in the polymerization of α-olefinically unsaturated Connections used. Carbon monoxide and ethylene can be copolymerize in the presence of a palladium bisphosphine complex (see also EP-A-0 121 965). Also with the stereo or regioselective Functionalization of organic compounds, such as epoxidation of allyl alcohols with a titanium tartrate complex plays the two toothy chelation to the metal center an essential Role for its catalytic activity (see also Sharpless et al., Pure and Appl. Chem., 1983, 55, 1823). As Brookhart et al. J. Am. Chem. Soc. 1994, 116, 3641 could show are suitable cationic monoalkyl complexes of palladium and nickel with neutral bidentate bisimine ligands for copolymerization of styrene and carbon monoxide.

Neutral bisimin palladium (II) monoalkyl complexes are according to Rülke et al., Inorg. Chem. 1993, 32, 5769 accessible via a three-step synthesis. First, palladium dichloride is converted into a (COD) PdCl ₂ complex (COD = cyclooctadiene), which is monoalkylated after isolation and purification with tetramethyltin, whereupon the COD ligand, again after isolation and purification, is substituted by a bisimine ligand. Another approach to neutral bisimin palladium (II) monoalkyl complexes is in Rix et al., J. Am. Chem. Soc. 1995, 117, 1137. Starting from palladium dichloride, a (TMEDA) PdCl ₂ complex (TMEDA = N, N, N ', N'-tetramethylethylenediamine) leads to a (TMEDA) palladiumdimethyl complex, the TMEDA ligand of which passes through in a further reaction step by reaction with methyl lithium a bisimin ligand is exchanged. After the dialkylated palladium complex has been separated off by means of diffusion crystallization, the controlled protolysis with the conjugated acid of the anion to be introduced into the complex provides the desired monoalkyl complex.

The synthetic routes described for the representation of with bidentates Ligand chelated monoalkyl complexes are multistage and complex and each require isolation of the intermediate Products. In addition, the desired end product usually falls only in low yield.

Accordingly, there is a need for simple manufacturing processes of monoalkyl chelated with bidentate bisimine ligands complex.

The present invention was therefore based on the object Process for the preparation of bidentate ligands to provide chelated monoalkyl complexes, which have a synthetically easy access to the metal mentioned deliver complex and with which at the same time bidentate ligand systems regardless of the substitution pattern or steric Claim to be introduced effectively in the monoalkyl complexes can.

Accordingly, there have been processes for making bidentates Ligands chelated transition metal complexes as well as the Use of the monoalkyl metal com obtainable in this way plexes as catalysts for the copolymerization of coal monoxide and vinyl aromatic compounds found.

In a process according to the invention, monoalkyl metal complexes chelated with bidentate ligands are obtained by:

• a) a transition metal compound of the general formula M (X) _k (I) in which
  M for an element of group VIII B of the periodic table and
  X represents a chloride, bromide or iodide and
  k represents an integer corresponding to the formal oxidation state of M,
  in the presence of an alkali, alkaline earth or ammonium halide or in the presence of benzonitrile with a bidentate ligand of the general formula (IIa) or (IIb)
  in which
  R ¹ and R ² independently of one another are hydrogen, straight-chain or branched C ₁ -C ₁₀ -alkyl, preferably C ₁ -C ₆ -alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i -Butyl, t-butyl, partially or perhalogenated C ₁ -C ₁₀ -alkyl, preferably C ₁ -C ₆ -alkyl, such as trifluoromethyl or trichloromethyl or 2,2,2-trifluoroethyl, substituted or unsubstituted C ₃ - to C ₁₀ cycloalkyl, preferably C ₃ to C ₆ cycloalkyl, such as cyclopropyl, cyclopentyl, cyclohexyl, 1-methylcyclohexyl or 4-t-butylcyclohexyl, C ₆ to C ₁₄ aryl, preferably C ₆ to C _10- aryl, such as phenyl or naphthyl, in particular phenyl, with functional groups based on the elements from groups IVA, VA, VIA and VIIA of the periodic table of the elements, partially or per-substituted C ₆ to C ₁₄ aryl, preferably C ₆ to C ₁₀ aryl, such as straight-chain or branched C ₁ to C ₁₀ alkyl, preferably C ₁ to C ₆ alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl , t -Butyl, partially or perhalogenated C ₁ - to C ₁₀ -alkyl, preferably C ₁ - to C ₆ -alkyl, such as trifluoro or tri chloromethyl or 2,2,2-trifluoroethyl, triorganosilyl, for example trimethyl, triethyl, tri -t-butyl-, triphenyl- or t-butyl-di-phenylsilyl, amino, for example NH2, dimethylamino, di-i-propylamino, di-n-butylamino, diphenylamino or dibenzylamino, C ₁ - to C ₁₀ -alkoxy, preferably C ₁ to C ₆ alkoxy, for example methoxy, ethoxy, n-propoxy, i-propoxy, t-butoxy or halogen, for example fluoride, chloride, bromide or iodide; C ₄ to C ₁₃ heteroaryl, preferably C ₄ to C ₉ heteroaryl, such as pyridyl, pyrimidyl, quinolyl or isoquinolyl, alkylaryl having 1 to 10 C atoms, preferably 1 to 6 C atoms in the alkyl and 6 to 14 carbon atoms, preferably 6 to 10 carbon atoms in the aryl radical, such as benzyl, or Si (R ⁶ ) ₃ or together with C ^a and N are a five-, six- or seven-membered aromatic or aliphatic substituted or unsubstituted heterocycle, where R ^{1 is} not Wasseroff,
  R ³ and R ⁴ independently of one another are hydrogen, straight-chain or branched C ₁ -C ₁₀ -alkyl, preferably C ₁ -C ₆ -alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i -Butyl, t-butyl, partially or perhalogenated C ₁ -C ₁₀ -alkyl, preferably C ₁ -C ₆ -alkyl, such as trifluoromethyl or trichloromethyl or 2,2,2-trifluoroethyl, substituted or unsubstituted C ₃ - to C ₁₀ cycloalkyl, preferably C ₃ to C ₆ cycloalkyl, such as cyclopropyl, cyclopentyl, cyclohexyl, 1-methylcyclohexyl or 4-t-butylcyclohexyl, C ₆ to C ₁₄ aryl, preferably C ₆ to C _10- aryl, such as phenyl or naphthyl, in particular phenyl, with functional groups based on the elements from groups IVA, VA, VIA and VIIA of the periodic table of the elements, partially or per-substituted C ₆ to C ₁₄ aryl, preferably C ₆ to C ₁₀ aryl, such as straight-chain or branched C ₁ to C ₁₀ alkyl, preferably C ₁ to C ₆ alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl , t -Butyl, partially or perhalogenated C ₁ - to C ₁₀ -alkyl, preferably C ₁ - to C ₆ -alkyl, such as trifluoro or tri chloromethyl or 2,2,2-trifluoroethyl, triorganosilyl, for example trimethyl, triethyl, tri -t-butyl-, triphenyl- or t-butyl-di-phenylsilyl, amino, for example NH2 'dimethylamino, di-i-propylamino, di-n-butylamino, diphenylamino or dibenzylamino, C ₁ - to C ₁₀ -alkoxy, preferably C ₁ to C ₆ alkoxy, for example methoxy, ethoxy, n-propoxy, i-propoxy, t-butoxy or halogen, for example fluoride, chloride, bromide or iodide; C ₄ to C ₁₃ heteroaryl, preferably C ₄ to C ₉ heteroaryl, such as pyridyl, pyrimidyl, quinolyl or isoquinolyl, alkylaryl having 1 to 10 C atoms, preferably 1 to 6 C atoms in the alkyl and 6 to 14 carbon atoms, preferably 6 to 10 carbon atoms in the aryl radical, such as benzyl, or Si (R ⁶ ) ₃ , or together with Cb and N or P a substituted or unsubstituted five-, six- or seven-membered aromatic or aliphatic heterocycle form, wherein R ^{4 is} not hydrogen,
  R ⁵ independently of one another is hydrogen, straight-chain or branched C ₁ -C ₁₀ -alkyl, preferably C ₁ -C ₆ -alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, especially methyl, substituted or unsubstituted C ₃ to C ₁₀ cycloalkyl, preferably C ₃ to C ₆ cycloalkyl, such as cyclopropyl, cyclopentyl, cyclohexyl, 1-methylcyclohexyl or 4-t-butylcyclohexyl, especially cyclohexyl, C ₆ to C ₁₄ aryl, preferably C ₆ to C ₁₀ aryl, such as phenyl or naphthyl, in particular phenyl, alkylaryl having 1 to 10 C atoms, preferably 1 to 6 C atoms in the alkyl and 6 to 14 C atoms, preferably 6 to 10 C atoms in the aryl radical, such as benzyl or Si (R ⁶ ) ₃ , particularly preferably represent hydrogen or methyl,
  m denotes 0 or 1, in particular 0,
  R ^6, independently of one another, is straight-chain or branched C ₁ -C ₁₀ -alkyl, preferably C ₁ -C ₆ -alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, in particular methyl or t-butyl, C ₃ to C ₁₀ cycloalkyl, preferably C ₃ to C ₆ cycloalkyl, such as cyclopropyl, cyclopentyl or cyclohexyl, in particular cyclohexyl, substituted or unsubstituted C ₆ to C ₁₄ aryl, preferably C ₆ to C ₁₀ aryl, such as phenyl or naphthyl, in particular phenyl, alkylaryl having 1 to 10 C atoms, preferably 1 to 6 C atoms in the alkyl and 6 to 14 C atoms, preferably 6 to 10 C atoms in the aryl radical represents in particular benzyl,
  reacted in a polar protic solvent,
• b) the polar protic solvent by a non coordinating polar aprotic solvent replaced and
• c) a tetraorganotin compound (SnR ' ₄ ) is added to the mixture obtained.

All elements of group VIII B come as metals M in (I) of the periodic table of the elements, i.e. iron, cobalt, nickel, Ruthenium, rhodium, palladium, osmium, iridium or platinum in Consideration. Nickel, rhodium, palladium or platinum are preferred used, with palladium being particularly preferred. Iron and There are generally two cobalt in the metal compounds (I)  Triple or triple charged before, palladium, platinum and Nickel has two positive charges and rhodium has three positive charges loaded before.

As counterion X in the metal salt (I) are chlorides, bromides or Iodides, preferably chlorides or bromides and especially chlorides suitable.

Among the metal compounds (I) in question is before relies on cobalt (II) chloride, cobalt (II) bromide, Iron (III) chloride and in particular on nickel (II) chloride, Rhodium (III) chloride, palladium (II) bromide, palladium (II) chloride or platinum (II) chloride. Is particularly preferred Palladium (II) chloride.

The transition metal compounds M (X) _k and their preparation are generally known from the literature and are often also commercially available.

Suitable alkali and alkaline earth halides are, for example, those of lithium, sodium, potassium, cesium, magnesium, calcium or barium. Among the halide counterions, chloride, bromide and iodide are preferred. For reasons of accessibility, the chlorides are mostly used. Preferred alkali metal halides are the chlorides and bromides of lithium, sodium, potassium or cesium, and preferred alkaline earth metal halides are the chlorides and bromides of magnesium and calcium. Sodium chloride, potassium chloride and magnesium chloride are particularly preferred among the alkali and alkaline earth metal halides. Likewise, ammonium halides such as ammonium chloride, ammonium bromide or ammonium iodide can be used, preferably using ammonium chloride. Among the halides described, sodium chloride is particularly preferred. Any mixtures of the halides mentioned can of course also be used. The halide compounds mentioned are known from the literature and can generally be purchased commercially. Based on the metal compound (I), they are usually used in a double molar amount or in excess, in particular in a two to one hundred times, particularly preferably in a two to twenty times, excess. If alkaline earth metal halides are used, they can also be added in only an equimolar amount. An amount of alkali metal, alkaline earth metal or ammonium compound which is sufficient to convert the transition metal salt (I) into the corresponding complex salt is particularly preferred. For example, palladium (II) chloride is converted into Na ₂ PdCl ₄ by stirring in the presence of two equivalents of sodium chloride under protic conditions.

Instead of the halide compounds, benzonitrile can also be used. The amount of benzonitrile is advantageously calculated in such a way that the secondary valences of the metal M in (I) are coordinatively saturated. The reaction of palladium (II) chloride with benzonitrile to form PdCl ₂ (NCC ₆ H ₅ ) ₂ is particularly preferred.

The radicals R ¹ and R ² in (IIa) or (IIb) together with N and C ^{a can form} a five- and six-membered aliphatic ring system, for example based on pyrrolidyl, piperidyl or oxazolyl, or a five- or six-membered aromatic ring system , for example based on pyrazolyl or pyridyl, or a fused aromatic heterocycle, such as quinolyl or isoquinolyl. The ring systems listed can be both unsubstituted and substituted, for example with alkyl radicals, such as methyl, ethyl, i-propyl or t-butyl, partially or perhalogenated alkyl radicals, such as trifluoromethyl or 2,2,2-tri-fluoroethyl, aryl radicals such as phenyl or Naphthyl, triorganosilyl residues, such as trimethyl, tri-i-propyl, tri-n-butyl, triphenyl or t-butyl-di-phenylsilyl, or halogen, such as fluoride, chloride, bromide or iodide, are present. R ¹ and R ² together with N and Ca preferably form a six-membered aromatic substituted or unsubstituted heterocycle. This heterocycle can for example be substituted with alkyl groups such as methyl or fused with aromatic ring systems such as benzene.

In the ligand compounds (IIa) and (IIb), the vicinal residues R ³ and R ⁴ together with N and C ^b or with P and C ^{b can also be} a substituted or unsubstituted five-, six- or seven-membered aromatic or aliphatic heterocycle form. For example, an aromatic six-membered heterocycle such as pyridyl or a fused heterocycle such as quinolyl is suitable for (IIa). Aliphatic heterocycles such as pyrrolidyl can also be used. Furthermore, the cycle can contain several heteroatoms, for example oxygen and nitrogen, such as in oxazoline, nitrogen and nitrogen, such as in pyrazole or pyrimidine, or nitrogen and phosphorus as in phosphazole. The free valences of the atoms forming the ring can instead of with hydrogen with alkyl radicals, such as methyl, ethyl, i-propyl or t-butyl, partially or perhalogenated alkyl radicals, such as trifluoromethyl or trichloromethyl or 2,2,2-trifluoroethyl, aryl radicals, such as phenyl or naphthyl, substituted aryl radicals such as tolyl or 2- or 4-trifluoromethylphenyl, alkoxy radicals such as methoxy, ethoxy, i-propoxy or t-butoxy, or amino radicals such as dimethylamino, diphenylamino or dibenzylamino. According to the above statements, vicinal radicals R ³ and R ^{4 can form} in (IIa) heterocycles which correspond completely to the six-membered ring systems formed via the radicals R ¹ and R ² . Both monoalkyl metal complexes with C ₂ -symmetrical and with non-C ₂ -symmetric ligand systems (IIa) are possible with the process according to the invention. Ligands (IIa) or (IIb) in which R ³ and R ⁴ do not form a cycle are preferably used. Among the radicals R ³ are hydrogen, methyl, ethyl, i-propyl, t-butyl, methoxy, ethoxy, i-propoxy, t-butoxy, trifluoromethyl, phenyl, naphthyl, tolyl, 2-i-propylphenyl, 2-t -Butylphenyl, 2,6-di-i-propylphenyl, 2-trifluoromethylphenyl, 4-methoxyphenyl, pyridyl or benzyl and in particular hydrogen, methyl, ethyl, i-propyl or t-butyl are preferred. Suitable radicals R ⁴ are, for example, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, neopentyl, trifluoromethyl or trichloromethyl, 2,2,2-trifluoroethyl, cyclopropyl, cyclopentyl, Cyclohexyl, 1-methylcyclohexyl, 4-t-butylcyclohexyl, phenyl, 1- or 2-naphthyl, 2-i-propylphenyl, 2-t-butylphenyl, 2,6-di-i-propylphenyl, 2,6-bis (trimethylsilyl ) phenyl, 2-trifluoromethyl phenyl, 4-methoxyphenyl, pyridyl, pyrimidiyl, quinolyl, iso quinolyl or benzyl.

The bidentate ligands (IIa) can be 2-pyridinecarbaldehyde or Quinoline-2-carbaldehyde derivatives by reaction with primary ones Amines such as n-butylamine, i-butylamine, t-butylamine, cycolhexyl amine, 2-trifluoromethylaniline, 2-isopropylaniline, 2-t-butylaniline, 1-naphthylamine, 2,6-bis (trimethylsilyl) aniline or 2,6-diisopro pylaniline according to the instructions of Jiang et al., Macromolecules 1994, 27, 2694 and by van der Poel and van Koten, Inorg. Chem. 1981, 20, 2950. The primary amines listed are usually commercially available. Access to stick Substance-heteroaromatic bisimine ligands is analogous to the ge called process by reacting 2-pyridinecarbaldehyde derivatives possible with aromatic or primary aliphatic amines.

Come as polar, protic solvents for step a) for example low molecular weight alcohols, such as methanol, ethanol or i-propanol. Is preferred on methanol or Ethanol. Mixtures of different types can also be used polar protic solvents can be used. Likewise it is possible to use mixtures of protic polar solvents use with aprotic polar solvents, for example a low molecular alcohol together with dichloromethane. The amount of solvent is usually determined so that the Starting compounds in solution at the beginning of the reaction available.  

The polar protic solvent system used in step a) can in principle in step b) by all non-coordinating polar aprotic solvent to be replaced. Is preferred halogenated hydrocarbons such as dichloromethane or Chlorobenzene used. Of course you can too Solvent mixtures on non-coordinating polar aprotic Solvents are used. It has come in handy proven that the solvent by evacuation in vacuo released residue according to a) in approximately the same amount of non- coordinating polar aprotic solvent.

A tetraorganotin compound (SnR ' ₄ ), preferably in an equimolar amount, based on the metal compound (I), is added to the solution obtained according to b). The tetraorganotin compound can be added to the reaction mixture in pure form or else dissolved in a non-coordinating polar aprotic solvent. Preferred tetraorganotin compounds are generally those which have no hydrogen atom in the β position to the tin. For example, the methyl, neopentyl or the benzyl group or their substituted derivatives, such as trifluoromethyl or trichloromethyl, 4-methoxybenzyl or trimethylsilylmethyl, are suitable as radicals R '. Suitable tetraorganotin compounds are, for example, tetramethyltin, tetraneopentyltin, tetrabenzyltin or tetrakistrimethylsilylmethylene tin, tetramethyltin being particularly preferred.

Among the bidentate ligands (IIa) and (IIb), particular preference is given to those which come under the formulas (IIa ₁ ) or (IIb ₁ ):

Stand in it
R ³ for hydrogen, methyl, ethyl, i-propyl, t-butyl, methoxy, ethoxy, i-propoxy, t-butoxy, trifluoromethyl, phenyl, naphthyl, tolyl, 2-i-propylphenyl, 2-t-butyl phenyl, 2,6-di-i-propylphenyl, 2-trifluoromethylphenyl, 4-methoxyphenyl, pyridyl or benzyl, especially hydrogen, methyl, ethyl, i-propyl or t-butyl,
R ⁴ for methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, neopentyl, trifluoromethyl or trichloromethyl, 2,2,2-trifluoroethyl, cyclopropyl, cyclopentyl, cyclohexyl, 1 -Methylcyclohexyl, 4-t-butylcyclohexyl, phenyl, 1- or 2-naphthyl, 2-i-propylphenyl, 2-t-butylphenyl, 2,6-di-i-propylphenyl, 2,6-bis (tri methylsilyl) phenyl , 2-trifluoromethylphenyl, 4-methoxyphenyl, pyridyl, pyrimidiyl, quinolyl, isoquinolyl or benzyl, especially for cyclohexyl, 1- or 2-naphthyl, 2-i-propylphenyl, 2-t-butylphenyl, 2,6-di i- propylphenyl or 2-trifluoromethylphenyl,
R ⁷ to R ^{10 are} hydrogen, straight-chain or branched C ₁ to C ₆ alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, in particular methyl, substituted or unsubstituted C ₃ - to C ₆ -cycloalkyl, such as cyclopropyl, cyclopentyl, cyclohexyl, 1-methylcyclohexyl or 4-t-butylcyclohexyl, C ₆ - to C ₁₀ -aryl, such as phenyl or naphthyl, especially phenyl, with functional groups on the Basis of the elements from groups IVA, VA, VIA and VIIA of the periodic table of the elements partially or persubstituted C ₆ to C ₁₀ aryl, such as straight-chain or branched C ₁ to C ₆ alkyl, for example methyl, ethyl, n- Propyl, i-propyl, n-butyl, i-butyl, t-butyl, partially or perhalogenated C ₁ -C ₆ -alkyl, such as trifluoromethyl or trichloromethyl or 2,2,2-trifluoroethyl, triorganosilyl, for example trimethyl, Triethyl- or tri-t-butyl-, triphenyl- or t-butyl-di-phenylsilyl, amino, for example NH2 'dimethylamino, di-i-propylamino, di-n-butylami no, diphenylamino or dibenzylamino, C ₁ to C ₆ alkoxy, for example methoxy, ethoxy, n-propoxy, i-propoxy, t-butoxy, or halogen, for example fluoride, chloride, bromide or iodide; C ₄ to C ₉ heteroaryl, such as pyridyl, pyrimidyl, quinolyl or isoquinolyl, alkylaryl having 1 to 6 C atoms in the alkyl and 6 to 10 C atoms in the aryl radical, such as benzyl, or triorganosilyl, for example trimethyl, Triethyl or tri-t-butyl, triphenyl or t-butyl-di-phenylsilyl, where vicinal radicals, in particular R ⁷ and R ⁸ , can form a five- or six-membered, aromatic or aliphatic cycle.

R ⁴ particularly preferably takes a sterically demanding aliphatic or aromatic radical, such as t-butyl, neopentyl, cyclohexyl, substituted cyclohexyl, such as 1-methylcyclohexyl or 4-t-butylcyclohexyl, phenyl, substituted phenyl, such as 2-i-propylphenyl, 2 -t-butylphenyl, 2,6-di-i-propylphenyl, 2,6-bis (trimethylsilyl) phenyl, 2-trifluoromethylphenyl, or sub-substituted or unsubstituted naphthyl, such as 1- or 2-naphthyl.

Compounds (IIa ₁ ) or (IIb ₁ ) in which R ^{7 represents} hydrogen, methyl, ethyl, i-propyl or t-butyl, in particular methyl, or in which R ⁷ and R ⁸ together form a fused benzene ring are particularly preferred .

It is also possible that the radicals R ¹⁰ and R ³ in (IIa ₁ ) or (IIb ₁ ) form a five-, six- or seven-membered, aromatic or aliphatic carbo- or heterocycle. For (IIa ₁ ), for example, 4,5-phenanthroline is suitable as a bidentate ligand compound.

Usually the metal compound (I), the bidentate Ligand (IIa) or (IIb) and, for example, the alkali salt Temperatures in the range of -20 to 60 ° C, preferably in the range of 0 to 40 ° C stirred in a protic polar solvent. in the the reaction times are generally between 1 and 2 hours and several days. The reaction is carried out at room temperature , the desired metal dihalo compound is obtained in usually within one to three days. To the protic Removing polar solvents is more convenient a vacuum distillation at temperatures in the range of 15 to 60 ° C. The solid obtained usually does not need washed with further amount of liquid not further washed up to be cleaned, but can be done directly with a non-coordination polar aprotic solvent. The Tetraorganotin compound can then either be in pure form or dissolved in a non-coordinating polar aprotic Solvents are added to the chelated metal complex. The reaction times for the monoalkylation are usually at 12 hours to two days, but can also last for 14 days and extend over it. For the isolation of the monoalkyl complex it is often sufficient to filter the reaction solution and distill off the solvent. In addition, the reak tion product after filtration also directly from the reaction solution be crystallized out.

For example, monoalkyl metal complexes such as [quinoline-2- (R ⁴ ) carbaldimine] M (R ') X or [pyridine-2- (R ⁴ ) carbaldimine] M (R') X are accessible by the process according to the invention described. These include [quinoline-2- or [pyridine-2- (cyclohexyl) carbaldimine] Pd (Me) Cl, [quinoline-2- or [pyridine-2- (2-isopropylphenyl) carbaldimine] Pd (Me) Cl or [Quinoline-2- or [pyridine-2- (2-t-butylphenyl) carbaldimine] Pd (Me) Cl.

In a further process according to the invention for the preparation of monoalkyl metal complexes chelated with bidentate ligands, a complex compound of the general formula (IIIa) or (IIIb) is used,

in which
M 'for an element of group VIII B of the periodic table and
Y represents chloride, bromide or iodide, preferably chloride and bromide and in particular chloride,
R ¹¹ and R ¹² together with N and Ca form a five-, six- or seven-membered aromatic or aliphatic, substituted or unsubstituted heterocycle,
R ¹³ and R ¹⁴ independently of one another are hydrogen, straight-chain or branched C ₁ -C ₁₀ -alkyl, preferably C ₁ -C ₆ -alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i -Butyl, t-butyl, partially or perhalogenated C ₁ -C ₁₀ -alkyl, preferably C ₁ -C ₆ -alkyl, such as trifluoromethyl or trichloromethyl or 2,2,2-trifluoroethyl, substituted or unsubstituted C ₃ - to C ₁₀ cycloalkyl, preferably C ₃ to C ₆ cycloalkyl, such as cyclopropyl, cyclopentyl, cyclohexyl, 1-methylcyclohexyl or 4-t-butylcyclohexyl, C ₆ to C ₁₄ aryl, preferably C ₆ to C _10- aryl, such as phenyl or naphthyl, in particular phenyl, with functional groups based on the elements from groups IVA, VA, VIA and VIIA of the periodic table of the elements, partially or per-substituted C ₆ to C ₁₄ aryl, preferably C ₆ to C ₁₀ aryl, such as straight-chain or branched C ₁ to C ₁₀ alkyl, preferably C ₁ to C ₆ alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl , t-butyl, partially or perhalogenated C ₁ to C ₁₀ alkyl, preferably C ₁ to C ₆ alkyl, such as trifluoro or tri chloromethyl or 2,2,2-trifluoroethyl, triorganosilyl, for example trimethyl, triethyl, Tri-t-butyl-, triphenyl- or t-butyl-di-phenylsilyl, amino, for example NH2 'dimethylamino, di-i-propylamino, di-n-butylamino, diphenylamino or dibenzylamino, C ₁ - to C ₁₀ -alkoxy, preferably C ₁ to C ₆ alkoxy, for example methoxy, ethoxy, n-propoxy, i-propoxy, t-butoxy or halogen, for example fluoride, chloride, bromide or iodide; C ₄ to C ₁₃ heteroaryl, preferably C ₄ to C ₉ heteroaryl, such as pyridyl, pyrimidyl, quinolyl or isoquinolyl, alkylaryl having 1 to 10 C atoms, preferably 1 to 6 C atoms in the alkyl and 6 to 14 carbon atoms, preferably 6 to 10 carbon atoms in the aryl radical, such as benzyl, or triorganosilyl, for example trimethyl, triethyl, tri-t-butyl, triphenyl or t-butyldiphenylsilyl, are or together with Cb and N or P form a substituted or unsubstituted five-, six- or seven-membered aromatic or aliphatic heterocycle, where R ^{14 is} not hydrogen,
in a polar aprotic noncoordinating solvent with a metal complex of the general formula M '' (B-B ') (R ¹⁵ ) _n (IV) in which
M '' for an element of group VIII B of the periodic table and
BB 'represents a bidentate, 1,2-ethylene-bridged diamine, diphosphane or amine / phoshan ligand, and
R ^{15 is} C ₁ to C ₂₀ alkyl, preferably C ₁ to C ₁₀ alkyl, which has no hydrogen atoms in the β position to the metal center M ″, and
n represents an integer corresponding to the formal oxidation state of M ''.

All metals come independently of one another as metals M 'and M' ' Elements of the 8th subgroup of the Periodic Table of the Elements, So iron, cobalt, nickel, ruthenium, rhodium, palladium, Os mium, iridium or platinum in question. Nickel is preferred, Rhodium, palladium and platinum are used, with palladium or Nickel, especially palladium, is particularly preferred. Advantage Luckily, according to the inventive method, metal  complex (IIIa) or (IIIb) and (IV) used in which M ' and M '' match. Iron and cobalt are in the metal compounds (IIIa), (IIIb) and (IV) in general twice or triple positive charge before, palladium, nickel and platinum two positive and rhodium triple positive.

For R ¹¹ , R ¹² , R ¹³ and R ¹⁴ , the statements made above for R ¹ , R ² , R ³ and R ⁴ apply accordingly with regard to the preferred embodiments.

(B-B ') represents a bidentate, 1,2-ethylene bridged diamine, Diphosphane or amine / phoshan ligands. These include Compounds such as N, N, N ', N'-tetramethylethylenediamine or P, P, P ', P'-tetraphenylethylene diphosphine, i.e. compounds which the respective nitrogen or phosphorus substituents ali can be phatic as well as aromatic in nature. In addition to methyl and phenyl, the heteroatoms nitrogen and phosphorus can also with aliphatic radicals, such as ethyl, n-propyl, i-propyl, n-butyl, i-butyl or t-butyl, with cycloaliphatic radicals, such as cyclo propyl, cyclopentyl or cyclohexyl or with aromatic radicals such as phenyl, naphthyl or tolyl. Farther can the carbon-hydrogen valences in the ethylene bridge by aliphatic radicals, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, or aromatic radicals, such as phenyl or pyridyl. These vicinal remnants can too together with the ethylene bridge a saturated or unsaturated form saturated carbocycle or heterocycle. For example come as bridge ligands 2,3-N, N-, 2,3-N, P- or 2,3-P, P-butyl compounds or ethylene systems in which the water partial or complete substance valences due to phenyl residues are substituted, in question. Two are particularly preferred dentate, 1,2-ethylene-bridged diamine ligands, such as N, N, N ', N'- Tetramethylethylenediamine used.

The radical R ¹⁵ or the radicals R ¹⁵ independently of one another represent C ₁ to C ₂₀ alkyl groups, preferably C ₁ to C ₁₀ alkyl groups, which have no hydrogen atoms in the β position to the metal center M ″. These valences can be substituted by straight-chain or branched C ₁ to C ₁₀ alkyl, preferably C ₁ to C ₆ alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-Butyl, partially or perhalogenated C ₁ to C ₁₀ alkyl, preferably C ₁ to C ₆ alkyl, such as trifluoromethyl or trichloromethyl or 2,2,2-trifluoroethyl, substituted or unsubstituted C ₃ to C ₁₀ Cycloalkyl, preferably C ₃ to C ₆ cycloalkyl, such as cyclopropyl, cyclopentyl, cyclohexyl, substituted or unsubstituted C ₆ to C ₁₄ aryl, preferably C ₆ to C ₁₀ aryl, such as phenyl, 4-methoxyphenyl, Tolyl or naphthyl, amino, for example NH2, dimethylamino, di-i-propylamino, di-n-butylamino, diphenylamino or dibenzylamino, C ₁ - to C ₁₀ -alkoxy, preferably C ₁ to C ₆ -alkoxy, for example methoxy, Ethoxy, n-propoxy, i-propoxy, t-butoxy or halogen, for example fluoride, chloride, bromide or iodide; C ₄ to C ₁₃ heteroaryl, preferably C ₄ to C ₉ heteroaryl, such as pyridyl or pyrimidyl, alkylaryl having 1 to 10 C atoms, before adding 1 to 6 C atoms in the alkyl and 6 to 14 C Atoms, preferably 6 to 10 carbon atoms in the aryl radical, such as benzyl or triorganosilyl, for example trimethyl, triethyl, tri-t-butyl, triphenyl or t-butyl-di-phenylsilyl. Trialkylsilylmethylene residues such as trimethylsilylmethylene can also be used. The radicals R ¹⁵ used are preferably methyl, t-butyl, neopentyl, trimethylsilylmethylene or benzyl. In principle, longer-chain linear or branched aliphatic chains are also possible, for example saturated C ₁₀ , C ₁₂ or C ₁₄ chains, provided that they have no hydrogen atoms as described in the β position to the metal center.

The number of R ¹⁵ radicals is generally determined by the formal oxidation number in the metal complex (IV).

Compounds such as (TMEDA) PdMe ₂ are particularly preferably used as metal complexes (IV). These complexes are, for example, according to a regulation by de Graaf et al., Rec. Trav. Chim. Pay-Bas, 1988, 107, 299 accessible from the corresponding dichloride complexes.

Coming as polar aprotic non-coordinating solvents halogenated hydrocarbons such as dichloromethane or chlorine benzene in question.

The complexes (IIIa), (IIIb) and (IV) are described for the Transmetalation reaction usually in an equimolar amount set. The transmetallation is often already after a few Hours completed. The one with the bidentate bisimin or Imine / phosphine ligand chelated monoalkyl complex can without further from the reaction mixture by diffusion crystallization be won. It is advantageous to remove before Crystallization process solid particles by means of filtration from the reaction mixture.

With the described method according to the invention, monoalkyl metal complexes such as [quinoline-2- (R ¹⁴ ) carbaldimine] M '(R ¹⁵ ) Y or [pyridine-2- (R ¹⁴ ) carbaldimine] M' (R ¹⁵ ) Y can be prepared. Examples are compounds such as [quinoline-2 or [pyridine-2- (2,6-diisopropylphenyl) carbaldimine] Pd (Me) Cl, [quinoline-2 or [pyridine-2- (2-trifluoromethylphenyl) carbaldimine] Pd (Me) Cl or [quinoline-2 or [pyridine-1-naphthyl) carbaldimine] Pd (Me) Cl available.

Another method according to the invention for the preparation of monoalkyl metal complexes chelated with bidentate ligands is that a transition metal complex (V) complexed with neutral ligands, in which the transition metal is taken from group VIII B of the periodic table and is present in the formal oxidation state 0, in an aprotic polar Solvents in the presence of a bidentate ligand of the general formula (VIa) or (VIb),

in which
R ¹⁶ to R ^{19 are} hydrogen, straight-chain or branched C ₁ to C ₁₀ alkyl, preferably C ₁ to C ₆ alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl , t-Butyl, substituted or unsubstituted C ₃ - to C ₁₀ -cycloalkyl, preferably C ₃ - to C ₆ -cycloalkyl, such as cyclopropyl, cyclopentyl, cyclohexyl, 1-methylcyclohexyl or 4-t-butylcyclohexyl, C ₆ - bis C ₁₄ aryl, preferably C ₆ to C ₁₀ aryl, such as phenyl or naphthyl, in particular phenyl, with functional groups based on the elements from groups IVA, VA, VIA and VIIA of the periodic table of the elements, partially or per-substituted C ₆ to C ₁₄ aryl, preferably C ₆ to C ₁₀ aryl, such as straight-chain or branched C ₁ to C ₁₀ alkyl, preferably C ₁ to C ₆ alkyl, such as methyl, ethyl, n-propyl, i-Propyl, n-butyl, i-butyl, t-butyl, partially or perhalogenated C ₁ - to C ₁₀ -alkyl, preferably C ₁ - to C ₆ -alkyl, such as trifluoromethyl or trichloromethyl or 2,2,2 -Trifluoroethyl, triorganosilyl , for example trimethyl-, triethyl- or tri-t-butyl-, triphenyl- or t-butyl-di-phenylsilyl, amino, for example NH 2 ′ dimethylamino, di-i-propylamino, di-n-butylamino, diphenylamino or dibenzylamino, C ₁ - to C ₁₀ alkoxy, preferably C ₁ to C ₆ alkoxy, for example methoxy, ethoxy, n-propoxy, i-propoxy, t-butoxy or halogen, for example fluoride, chloride, bromide or iodide; C ₄ to C ₁₃ heteroaryl, preferably C ₄ to C ₉ heteroaryl, such as pyridyl, pyrimidyl, quinolyl or isoquinolyl, alkylaryl having 1 to 10 C atoms, preferably 1 to 6 C atoms in the alkyl and 6 to 14 carbon atoms, preferably 6 to 10 carbon atoms in the aryl radical, such as benzyl or triorganosilyl, for example trimethyl, triethyl, tri-t-butyl, triphenyl or t-butyldiphenylsilyl, with vicinal substituents, in particular R ¹⁶ and R ^{17 can form} a five- or six-membered, aromatic or aliphatic cycle,
R ²⁰ and R ²¹ independently of one another are hydrogen, straight-chain or branched C ₁ -C ₁₀ -alkyl, preferably C ₁ -C ₆ -alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i -Butyl, t-butyl, especially methyl, partially or perhalogenated C ₁ - to C ₁₀ -alkyl, preferably C ₁ - to C ₆ -alkyl, such as trifluoromethyl or trichloromethyl or 2,2,2-trifluoroethyl, substituted or unsubsti tuated C ₃ to C ₁₀ cycloalkyl, preferably C ₃ to C ₆ cycloalkyl, such as cyclopropyl, cyclopentyl, cyclohexyl, 1-methylcyclohexyl or 4-t-butylcyclohexyl, C ₆ to C ₁₄ aryl, preferably C ₆ to C ₁₀ aryl, such as phenyl or naphthyl, in particular phenyl, with functional groups based on the elements from groups IVA, VA, VIA and VIIA of the periodic table of the elements, partially or per-substituted C ₆ to C ₁₄ aryl, are preferred C ₆ to C ₁₀ aryl, such as straight-chain or branched C ₁ to C ₁₀ alkyl, preferably C ₁ to C ₆ alkyl, such as methyl, ethyl, n-propyl, i-propy l, n-butyl, i-butyl, t-butyl, partially or perhalogenated C ₁ -C ₁₀ -alkyl, preferably C ₁ -C ₆ -alkyl, such as trifluoromethyl or trichloromethyl or 2,2,2-trifluoroethyl , Triorganosilyl, for example trimethyl-, triethyl-, tri-t-butyl-, triphenyl- or t-butyl-di-phenylsilyl, amino, for example NH2 'dimethylamino, di-i-propylamino, di-n-butylamino, diphenylamino or Dibenzyl amino, C ₁ to C ₁₀ alkoxy, preferably C ₁ to C ₆ alkoxy, for example methoxy, ethoxy, n-propoxy, i-propoxy, t-butoxy or halogen, for example fluoride, chloride, bromide or iodide; C ₄ to C ₁₃ heteroaryl, preferably C ₄ to C ₉ heteroaryl, such as pyridyl, pyrimidyl, quinolyl or isoquinolyl, alkylaryl having 1 to 10 C atoms, preferably 1 to 6 C atoms in the alkyl and 6 to 14 carbon atoms, preferably 6 to 10 carbon atoms in the aryl radical, such as benzyl, or triorganosilyl, for example tri methyl, triethyl, tri-t-butyl, triphenyl or t-butyl-di-phenylsilyl or together with Cb and N or P form a substituted or unsubstituted five-, six- or seven-membered aromatic or aliphatic heterocycle, where R ^{21 is} not hydrogen,
with a compound of the general formula R ²² -Z (VII), in which
R ^{22 is} a C ₁ - to C ₂₀ -alkyl group, preferably a C ₁ - to C ₁₀ -alkyl group which has no hydrogen atom in the β-position to Z, and
Z represents chloride, bromide or iodide,
implements.

The transition metal complexes (V) are in the polar aprotic Solvents generally dissolved before. As dissolved metal complexes are especially those of nickel, rhodium, Palladium or platinum are available, provided they are in the formal Oxidation level 0 is present. The complexes are particularly suitable of the palladium.

The transition metal complexes (V) can be monodentate as well can also be complexed with bidentate neutral ligands. Suitable monodentate ligands are, for example, triarylphosphines, such as Triphenylphosphine, tritolylphosphine or tri-4-methoxyphenyl phosphane, especially triphenylphosphine.

As bidentate neutral ligands are those that come into question have lone pairs of electrons of oxygen that correspond to the over gear metal center can coordinate, regardless of whether it are carbonyl or ether oxygen atoms. Exemplary Acetylacetone (acac) and dibenzylidene acetone (dba) may be mentioned. Dibenzylidene acetone is particularly preferred.

Suitable transition metal complexes (V) are, for example, tetrakis triphenylphosphine palladium, palladium (0) -di-acetylacetone or Palladium (0) -di-benzylidene acetone, is particularly preferred Palladium (0) -di-benzylidene acetone used.

In a preferred embodiment of the ligand compound (VIa)

R ¹⁶ to R ^{19 are} hydrogen, methyl, ethyl, i-propyl, t-butyl, in particular hydrogen, or a six-membered substituted or unsubstituted aromatic cycle via vicinal substituents,
R ^{20 is} hydrogen, methyl, ethyl, i-propyl, t-butyl, especially hydrogen, and
R ²¹ t-butyl, cyclohexyl, 1- or 2-naphthyl, 2-t-butylphenyl, 2-trifluoromethylphenyl, 2-i-propylphenyl, 2,6-bis (trimethylsilyl) phenyl, 2,6-di-i- propylphenyl, especially 2,6-di-i-propylphenyl.

Suitable solvents are among the non-coordinating polar aprotic solvents. This includes for example dichloromethane, acetone, ether, such as diethyl ether or Tetrahydrofuran or dioxane. Acetone or a is preferred non-coordinating polar aprotic solvent mixture with Acetone used as an essential component. Especially before is acetone.

In general, suitable compounds R ²² -Z (VII) are those which can be added oxidatively to the transition metal complex (V) described. Suitable radicals R ²² can be C ₁ to C ₂₀ alkyl groups, preferably C ₁ to C ₁₀ alkyl groups, which have no hydrogen atom in the β position to Z or - after oxidative addition - to the metal center. These valences can be substituted, for example, by straight-chain or branched C ₁ to C ₁₀ alkyl, preferably C ₁ to C ₆ alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, partially or perfluorinated C ₁ to C ₁₀ alkyl, preferably C ₁ to C ₆ alkyl, such as trifluoro or or 2,2,2-trifluoroethyl, substituted or unsubstituted C ₃ to C ₁₀ Cycloalkyl, preferably C ₃ to C ₆ cycloalkyl, such as cyclopropyl, cyclopentyl, cyclohexyl, substituted or unsubstituted C ₆ to C ₁₄ aryl, preferably C ₆ to C ₁₀ aryl, such as phenyl, 4-methoxyphenyl, tolyl or Naphthyl, amino, for example NH2 'dimethylamino, di-i-propyla mino, di-n-butylamino, diphenylamino or dibenzylamino, C ₁ - to C ₁₀ -alkoxy, preferably C ₁ to C ₆ -alkoxy, for example methoxy, ethoxy, n -Propoxy, i-propoxy, t-butoxy, C ₄ - to C ₁₃ heteroaryl, preferably C ₄ - to C ₉ heteroaryl, such as pyridyl or pyrimidyl, alkylaryl having 1 to 10 C atoms, preferably 1 bi s 6 C atoms in the alkyl and 6 to 14 C atoms, preferably 6 to 10 C atoms in the aryl radical, such as benzyl, triorganosilyl, for example trimethyl, triethyl, tri-t-butyl, triphenyl or t- Butyl-di-phenylsilyl, or fluoride. In addition to the methyl, t-butyl or neopentyl group, alkylaryl groups with one carbon atom in the alkyl group and 6 to 14, preferably 6 to 10, carbon atoms in the aryl radical, such as phenyl or naphthyl, for example the benzyl group, are particularly preferred . Trialkylsilylmethylene radicals, in particular trimethylsilylmethylene, can also be used. In principle, longer-chain linear or branched aliphatic chains R ^{22 are also} possible, for example saturated C ₁₀ , C ₁₂ or C ₁₄ chains, provided that they have no hydrogen atoms in the β position to the metal center.

Suitable halides Z can be chloride, bromide and iodide, bromide and iodide are particularly advantageous. Among the Particularly suitable compounds (VII) are methyl bromide and Methyl iodide, especially methyl iodide, and benzyl bromide and Benzyl iodide, especially benzyl bromide, to be particularly emphasized.

Monoalkyl metal complexes with C ₂ -symmetric and with non-C ₂ -symmetric ligands are accessible in good yield by the process according to the invention.

The components transition metal complex (V), halide compound (VII) and bidentate ligand (VIa) or (VIb) are usually at a temperature in the range of -10 to 60 ° C, preferably in Range from 0 to 45 ° C implemented with each other. It turned out to be proven particularly practical, the reaction at room temperature to take place.

The response times generally depend on the chosen one Temperature and the concentration of the reactants from time to time usually range from a few minutes to to several days. Most of the time it is enough to respond for run for a maximum of 24 hours at room temperature.

Monoalkyl metal complexes such as [quinoline-2- (R ²¹ ) carbaldimine] Pd (R ²² ) Z or [pyridine-2- (R ²¹ ) carbaldimine] Pd (R ²² ) Z, for example [quinoline- 2- or [pyridine-2- (2,6-diisopropylphenyl) carbaldimine] Pd (Bn) Br (Bn = benzyl), [quinoline-2- or [pyridine-2- (2,6-diisopropylphenyl) methylcarbaldimine] Pd (Bn) Br, [quinoline-2- or [6-methylpyridine-2- (2,6-diisopropylphenyl) carbaldimine] Pd (Bn) Br or [quinoline-2- or [pyridine-2- (2,6-diisopropylphenyl ) carbaldimine] Pd (Me) I (Me = methyl). There is also access to monoalkyl metal complexes which carry a bidentate imine / phosphine ligand, for example [8- (diphenylphosphinomethylene) quinoline] Pd (R ²² ) Z.

The mono obtainable by the processes according to the invention alkyl metal complexes can be according to Ver drive, for example by means of borate activation in the presence of a  coordinating solvent component, in the corresponding convert cationic monoalkyl metal complexes (see also Brookhart et al. J. Am. Chem. Soc. 1994, 116, 3641). These complexes can either in situ or via the isolated complex for the copoly merization of vinyl aromatic compounds, for example Styrene or 4-t-butylstyrene, and carbon monoxide can be used.

With the method according to the invention are ligands with bidentate chelated monoalkyl metal complexes based on the metals of Group VIII B of the Periodic Table of the Elements in simple Way accessible. The method according to the invention are also characterized by satisfactory yields.

Examples

All reactions were carried out using the Schlenk technique under inert carried out gas atmosphere. The solvents became several Hours over sodium (diethyl ether, pentane, tetrahydrofuran, Ethanol) or calcium hydride (dichloromethane) under reflux held, distilled off and before use in an ultrasonic bath degassed. Acetone was dried over molecular sieve A4.

The NMR spectra were obtained using a JEOL FX 90, a Bruker AC 250, Bruker WM 250 and a Bruker Avance DRX 600 Spektro meters added.

Carbon monoxide was obtained from Messer-Griesheim (purity 99.8%) related and used directly without further purification. Styrene was dried over calcium hydride and freshly distilled off.

Quinoline-2-carbaldehyde was prepared according to a regulation by K. Kaplan, J. Am. Chem. Soc. 1941, 63, 2654, 2-acetylquinoline after one Regulation of K.N. Campbell et al. J. Am. Chem. Soc. 1946, 68, Made in 1840. 6-methylpyridine-2-carbaldehyde and pyridine-2- carbaldehyde can be obtained from Aldrich, as are the Amines 2-trifluoromethylaniline, 2-isopropylaniline, 2-t-butylaniline, 1-naphthylamine, 2,6-diisopropylaniline and cyclohexylamine.

The complex (TMEDA) PdMe ₂ could according to a regulation by de Graaf et al., Rec. Trav. Chim. Pays-Bas 1988, 107, 299, palladium (0) dibenzylidene acetate (Pd (dba) ₂ ) according to Rettig et al., Inorganic Syntheses 1977, 17, 134.

I. Preparation of the ligands Pyridine-2- (2,6-diisopropylphenyl) carbaldimine

2.62 g of pyridine-2-carbaldimine were stirred at room temperature in 10 ml of ethanol with 4.33 g of 2,6-diisopropylaniline for 1 hour. The solvent was distilled off from the yellow solution. A yellow oil was obtained, 5.1 g. Elemental Analysis: Calculated for C ₁₈ H ₂₂ N ₂ (266.38): C, 81.15; H, 8.32; N, 10.51. Found: C, 81.01; H, 8.2; N, 10.36. ¹ H NMR (90 MHz): (CDCl ₃ ): δ = 1.1 - 1.9 (m, 12H, i-Pr); δ = 3.25 (m, 2H, i-Pr); δ = 7.25 (dt, J _{H, H} = 7.5 / 1.5 Hz, 1H, aryl); δ = 7.68 (dt, J _HH = 7.3 / 1.7 Hz, 1H, aryl); δ = 7.9 (m, 1H, aryl); δ = 8.37 (s, 1H, imine); δ = 8.61 (m, 1H, aryl).

Pyridine-2- (2,6-diisopropylphenyl) methyl carbaldimine

2.208 g of 2-acetylpyridine in 30 ml of ethanol were mixed with 2,6-diisopropylaniline (3.23 g) and with 0.2 ml of formic acid. After 4 days, light yellow crystals were isolated, 1.47 g. Elemental Analysis: Calculated for C ₁₉ H ₂₄ N ₂ (280.41): C, 81.38; H, 8.62; N, 9.99. Found: C, 80.06; H, 8.60; N, 10.37. ¹ H NMR (90 MHz, CDCl ₃ ): δ = 1.25 (d, J _{H, H} = 7.0 Hz, 12H, i-Pr); δ = 2.31 (s, 3H, Me (imine)); δ = 2.86 (spt, J _{H, H} = 6.8 Hz, 2H, i-Pr); δ = 7.0 - 7.6 (m, 4H, aryl); δ = 7.89 (dt, J _{H, H} = 6.9 / 0.8 Hz, 1H, aryl); δ = 8.45 (d, J _{H, H} = 6.8 Hz, 1H, aryl); δ = 8.78 (d, J _{H, H} = 4.9 Hz, 1H, aryl).

6-methylpyridine-2- (2,6-diisopropylphenylcarbaldimine

3.1 g of 6-methylpyridine-2-carbaldimine were stirred at room temperature in 10 ml of ethanol with 4.53 g of 2,6-diisopropylphenylaniline for 1 hour. The solvent was distilled off from the yellow solution. A yellow oil was isolated, 6.1 g. Elemen taranlyse: calculated for C ₁₉ H ₂₄ N ₂ (280.41): C, 81.38; H, 8.62; N, 9.99. Found: C, 81.03, H, 8.97; N, 9.97. ¹ H NMR (250 MHz, CDCl ₃ ): δ = 1.25 (d, J _{H, H} = 6.9 Hz, 12H, Me-i-Pr); δ = 3.05 (s, 3H, Me-pyridine); δ = 3.05 (spt, J _{H, H} = 6.9 Hz, 2H, I-Pr); δ = 7.2 - 7.3 (m, 2H, aryl); δ = 7.12 (d, J _{H, H} = 7.7 Hz, 1H); δ = 7.35 (d, J _{H, H} = 8.4 Hz, 1H); δ = 7.81 (t, J _{H, H} = 7.7 Hz, 1H); δ = 8.17 (d, J _{H, H} = 7.8 Hz, 1H, aryl); δ = 8.36 (s, 1H, imine).

6-methylpyridine-2- (cyclohexyl) carbaldimine

2.92 g of 6-methyl-pyridine-2-carbaldimine were stirred at room temperature in 10 ml of ethanol with 2.38 g of cyclohexylamine for 1 hour. The solvent was distilled off from the yellow solution. A yellow oil was isolated, 3.82 g. Elemental analysis calculated for C ₁₃ H ₁₈ N ₂ (202.29): C, 77.18; H, 8.96; N, 13.84. Found: C, 77.61; H, 9.14; N, 13.88. ¹ H NMR (90 MHz, CdCl ₃ ): δ = 0.9 - 1.9 (m, 10H, cyclohexyl); δ = 2.31 (s, 3H, Me-pyridine); δ = 3.1 (m, 1H, cyclohexyl); δ = 6.86 (d, J _{H, H} = 8.1 Hz, 1H, aryl); δ = 7.32 (t, J _{H, H} = 7.8 Hz, 1H); δ = 7.55 (d, J _{H, H} = 7.1 Hz, 1H, aryl); δ = 8.1 (s, 1H, imine).

Quinoline-2- (2-isopropylphenyl) carbaldimine

1.33 g of quinoline-2-carbaldehyde was stirred at 50 ° C in 30 ml of ethanol with 1.19 ml of 2-isopropylaniline (1.14 g) for 2 hours. The solvent was distilled off from the yellow solution under high vacuum at 50 ° C. An ocher yellow solid, 2.3 g, was obtained. Elemental Analysis: Calculated for C ₁₉ H ₁₈ N ₂ (274.36): C, 83.17; H, 6.61; N, 10.21. Found: C, 83.09; H, 6.72; N, 10.36. ¹ H NMR (250 MHz): (CDCl ₃ ): δ = 1.25 (d, J _{H, H} = 7.0 Hz, 6H, i-Pr); δ = 3.61 (spt, J _{H, H} = 6.8 Hz, 1H, i-Pr); δ = 7.0 - 7.4 (m, 4H), δ = 7.59 (dt, J _{H, H} = 8.4 / 1.0 Hz, 1H, aryl); δ 7.76 (dt, J _{H, H} = 8.4 / 1.5 Hz, 1H, aryl); δ = 7.86 (dd, J _{H, H} = 8.6 / 1 Hz, 1H, aryl); δ = 8.15 (d, J _{H, H} = 8.4 Hz, 1H, aryl); δ = 8.24 (d, J _{H, H} = 8.5 Hz, 1H, aryl); δ = 8.37 (d, J _{H, H} = 8.8 Hz, 1H, aryl); δ = 8.69 (s, 1H, imine).

Quinoline-2- (2-t-butylphenyl) carbaldimine

1.0 g quinoline-2-carbaldehyde was stirred at 50 ° C in 30 ml ethanol with 0.99 ml 2-t-butylaniline for 2 h. The solvent was distilled from the yellow solution in a high vacuum at 50 ° C. A yellow solid was isolated, 1.8 g. Elemental Analysis: Calculated for C ₂₀ H ₂₀ N ₂ (288.39): C, 83.29; H, 6.98; N, 9.71. Found: C, 83.40; H, 7.01; N, 9.62. ¹ H NMR (250 MHz, CDCl ₃ ): δ = 1.48 (s, 9H, t-Bu); δ = 6.9 - 7.4 (m, 4H, aryl); δ = 7.62 (dt, J _{H, H} = 8.4 / 1.0 Hz, 1H, aryl); δ =, 7.76 (Dt, J _{H, H} = 8.4 / 1.5 Hz, 1H, aryl); δ = 7.86 (dd, J _{H, H} = 8.6 / 1 Hz [1H]); δ = 8.16 (d, J _{H, H} = 8.4 Hz, 1H, aryl); δ = 8.26 (d, J _{H, H} = 8.5 Hz, 1H, aryl); δ = 8.36 (d, J _{H, H} = 8.6 Hz, 1H, aryl); δ = 8.63 (s, 1H, imine).

Quinoline-2- (2,6-diisopropylphenyl) carbaldimine

1.0 g of quinoline-2-carbaldehyde was stirred at 50 ° C. in 30 ml of ethanol with 1.2 ml of 2,6-diisopropylaniline for 1 hour. The solvent was distilled off from the yellow solution in a high vacuum at 50 ° C. A yellow solid, 2.0 g, was obtained. Elemental Analysis: Calculated for C ₂₂ H ₂₄ N ₂ (316.44): C, 83.50; H, 7.64; N, 8.85. Found: C, 83.72; H, 7.50; N, 8.77. ¹ H NMR (250 MHz, CDCl ₃ ): δ = 1.18 (d, J _{H, H} = 7.0 Hz, 12H, i-Pr); δ = 3.0 (spt, J _{H, H} = 6.8 HZ, 2H, i-Pr); δ = 7.09 - 7.23 (m, 3H, aryl); δ = 7.60 (dt, J _{H, H} = 8.4 / 1.0 Hz, 1H, aryl); δ = 7.76 (dt, J _{H, H} = 8.4 / 1.5 Hz, 1H, aryl); δ = 7.87 (dd, J _{H, H} = 8.4 / 0.8 Hz, 1H, aryl); δ = 8.17 (d, J _{H, H} = 8.4 Hz, 1H, aryl); δ = 8.27 (d, J _{H, H} = 8.6 Hz, 1H, aryl); δ = 8.41 (d, J _{H, H} = 8.5 Hz, 1H, aryl); δ = 8.47 (s, 1H, imine). ¹³ C { ¹ H} NMR (62.5 MHz, CDCl ₃ ): δ = 23.3 (s, i-Pr); δ = 27.9 (s, i-Pr); δ = 118.0, 123.0, 124.5, 127.7, 129.0, 129.8, 136.0, 137.0, 148.0, 148.4, 154.5 (s, aryl) ; δ = 163.4 (s, imine).

Quinoline-2- (cyclohexyl) carbaldimine

1.39 g of quinoline-2-carbaldehyde in 0.8 ml of cyclohexylamine was added in 20 ml of ethanol. The solvent was distilled off from the yellow solution. A yellow oil was isolated, 2.04 g (8.6 mmol). Yield 97%. Elemental Analysis: Calculated for C ₁₆ H ₁₈ N ₂ (238.33): C, 80.63; H, 7.61; N, 11.75. Found: C, 80.36; H, 7.63; N, 11.32. ¹ H NMR (600 MHz, CdCl ₃ ): δ = 1.2 - 2.0 (m, 10H, cyclohexyl, H13 - H15); δ = 3.39 (m, 1H, cyclohexyl, H12); δ = 8.18 (s, 1H, imine); δ = 8.71 (D, J _{H, H} = 8.8 Hz, 1H, H8); δ = 8.15 (d, J _{H, H} = 8.2 Hz, 1H, H4); δ = 7.5-7.9 (m, 4H, H4.5-7). ¹³ NMR (150 MHz, CDC ¹³ ): δ = 25.61 (t, J _{C, H} = 124 Hz, C15); δ = 34.15 / 24.64 (t, J _{C, H} = 127 Hz, Cl3 / 14); δ = 69.56 (d, J _{C, H} = 134 Hz, C12); δ = 160.21 (C11); δ = 155.24, 147.75, 128.66 (s, C2, 9.10); δ = 127.18 (dd, J _{C, H} = 8.7 / 160 Hz, aryl); δ = 127.64 (d, J _{C, H} = 159 Hz, aryl); δ = 129.50 / 129.63 (dd, J _{C, H} = 8.3 / 160 Hz, aryl); δ = 136.35 (dd, J _{C, H} = 4.9 / 163 Hz, C4); δ = 118.49 (d, J _{C, H} = 167 Hz, C3).

Quinoline-2- (2,6-diisopropylphenyl) methyl carbaldimine

0.92 g of 2-acetylquinoline was stirred in 30 ml of ethanol with 1.01 ml of 2,6-diisopropylaniline and with 0.2 ml of formic acid for 1 day. 0.5 g of NaHCO _{3 were} added, the solvent was distilled off from the yellow suspension under high vacuum at 50 ° C., extracted with Et ₂ O, recrystallized from 10 ml of dichloromethane and isolated yellow crystals, 1.92 g.
Elemental Analysis: Calculated for C ₂₂ H ₂₄ N ₂ (330.47): C, 83.59; H, 7.92; N, 8.47. Found: C, 83.46; H, 7.99; N, 8.44. ¹ H NMR (250 MHz, CDCl ₃ ): δ = 1.14 (d, J _{H, H} = 7.0 Hz, 12H, i-Pr); δ = 2.34 (s, 3H, Me-imine); δ = 2.79 (spt, J _{H, H} = 6.8 Hz, 2H, i-Pr); δ = 7.09 - 7.23 (m, 3H, aryl); δ = 7.58 (dt, J _{H, H} = 8.0 / 0.7 Hz, 1H, aryl); δ = 7.76 (dt, J _{H, H} = 7.0 / 1.5 Hz, 1H); δ = 7.86 (m, 1H, aryl); δ = 8.16 (d, J _{H, H} = 8.4 Hz, 1H, aryl); δ = 8.23 (d, J _{H, H} = 8.7 Hz, 1H); δ = 8.51 (d, J _{H, H} = 8.6 Hz, 1H, aryl).

Quinoline-2- (naphthyl) carbaldimine

1.235 g quinoline-2-carbaldehyde was stirred at 50 ° C in 30 ml ethanol with naphthylamine (1.289 g) for 24 h. The brown suspension was filtered off. A yellow solid was isolated, 2.13 g. Elemental Analysis: Calculated for C ₂₀ H ₁₄ N ₂ : (282.34): C, 85.08; H, 4.99; N, 9.92. Found: C, 85.11; H, 5.12; N, 9.95. ¹ H NMR (250 MHz, CDCl ₃ ): δ = 7.17 (d, H _{H, H} = 6.6 Hz, 1H, aryl); δ = 7.4 - 7.5 (m, 4H, aryl); δ = 7.6 - 7.8 (m, 4H, aryl); δ = 8.12 (d, H _{H, H} = 8.6 Hz, 1H, aryl); δ = 8.23 (d, J _{H, H} = 8.6 Hz, 1H, aryl); δ = 8.39 (m, 1H, aryl); δ = 8.48 (d, J _{H, H} = 8.6 Hz, 1H, aryl) δ = 8.83 (s, 1H, imine).

II. Process for the preparation of monoalkyl metal complexes 1) Representation from M (X) _k (I) [Quinoline-2- (cyclohexyl) carbaldimine] Pd (Me) Cl

0.24 g of PdCl _{2 was} stirred at room temperature in 20 ml of methanol with 0.16 g of sodium chloride and quinoline-2- (cyclohexyl) carbaldimine (0.33 g) for 2 days. The solvent was distilled off from the yellow suspension in a high vacuum at 50 ° C., then 30 ml of dichloromethane and 0.19 ml of SnMe _{4 were} added and the mixture was stirred for 2 days. The yellow solution was filtered off, the solvent was distilled off and washed three times with 20 ml of Et ₂ O. A yellow solid was isolated, 0.48 g. Elemental Analysis: Calculated for C ₁₉ H ₁₅ ClN ₂ Pd (395.23): C, 51.66; H, 5.35; N, 7.08. Found: C, 50.68; H, 5.515; N, 7.66. The (N, N) PdMeCl complex was formed in two isomeric forms in a ratio of 2/1.

[Quinolin-2- (2-isopropylphenyl) carbaldimin] PdCl ₂ .2NaCl

1.14 g of quinoline-2- (2-isopropylphenyl) carbaldimine were suspended at 50 ° C in 30 ml of ethanol with 0.736 g of PdCl ₂ and 0.48 g of sodium chloride. The yellow-brown suspension was stirred for 3 days and then the solvent was distilled off from the yellow suspension. A green-yellow solid was isolated, 2.12 g. Elemental Analysis: Calculated for C ₁₉ H ₁₈ Cl ₄ N ₂ NaPd (568.56): C, 40.14; H, 3.19; N, 4.93. Found: C, 40.66; H, 3.43; N, 5.20.

[Quinoline-2- (2-isopropylphenyl) carbaldimine] PdMeCl

1.14 g [quinoline-2- (2-iPr-phenyl) carbaldimine] PdCl ₂ .2NaCl was stirred at room temperature in 20 ml dichloromethane with 0.33 ml SnMe ₄ (0.43 g) for 14 days. The red solution was filtered and crystallized under diffusion control with 30 ml Et ₂ O. An orange-yellow solid was isolated, 0.1 g. Elemental Analysis: Calculated for C ₂₀ H ₂₁ ClN ₂ Pd (431.27): C, 55.70; H, 4.91; N, 6.49. Found: C, 55.28; H, 4.66; N, 6.44. ¹ H NMr (250 MHz, CdCl ₃ ): δ = 0.94 (s, 3H, Pd-Me); δ = 1.33 / 1.03 (d, J _{H, H} = 6.9 Hz, Me (iPr)); δ = 3.55 (spt, J _{H, H} = 6.9 Hz, 1H, H (iPr)); δ = 6.95 (d, J _{H, H} = 7.4 Hz, 1H, aryl); δ = 7.2 - 7.4 (m, 3H, aryl); δ = 7.65-8.0 (m, 4H, aryl); δ = 8.47 (d, J _{H, H} = 8.2 Hz, 1H, aryl); δ = 8.60 (s, 1H, imine); δ = 10.05 (d, J _{H, H} = 8.8 Hz, 1H, aryl).

[Quinoline-2- (2-t-butylphenyl) carbaldimine] PdCl ₂ .2 (NaCl)

0.93 g of quinoline-2- (2-t-butylphenyl) carbaldimine was suspended at 50 ° C in 30 ml of ethanol with 0.57 g of PdCl ₂ and 0.37 g of sodium chloride. The initially yellow suspension was stirred for 1 day and then the solvent was distilled off from the brown, loose suspension. A green-yellow solid was isolated, 1.74 g. Elemental Analysis: Calculated for C ₂₀ H ₂₀ Cl ₄ N ₂ NaPd (582.59): C, 41.23; H, 3.46; N, 4.81. Found: C, 38.44; H, 3.32; N, 4.57.

[Quinoline-2- (2-t-butylphenyl) carbaldimine] PdMeCl

1.07 g [quinoline-2- (2-t-butylphenyl) carbaldimine] - PdCl ₂ .2NaCl were stirred at room temperature in 30 ml dichloromethane with 0.3 ml SnMe _{4 for} 3 days. The green ocher solution was filtered, then diffusion-controlled, crystallized with 30 ml. A green-yellow solid was isolated, 0.15 g. Elemental Analysis: Calculated for C ₂₁ H ₂₃ ClN ₂ Pd (445.29): C, 56.64; H, 5.20; N, 6.29. Found: C, 57.18; H, 5.03; N, 7.02. ¹ H NMR (250 MHz, poorly soluble in CDCl ₃ ): δ = 1.0 (s, 3H, Pd-Me); δ = 1.45 (s, 9H, Me (t-Bu)); δ = 6.95 (dd, J _{H, H} = 8.6 / 1 Hz, 1H, aryl); δ = 7.2 - 8.0 (m, 6H, aryl); δ = 8.48 (d, J _{H, H} = 8.3 Hz, 1H, aryl); δ = 8.64 (s, 1H, imine); δ = 10.02 (d, J _{H, H} 0 8.7 Hz, 1H, aryl).

2) Representation using transmetallation [Quinoline-2- (2,6-diisopropylphenyl) carbaldimine] PdMeCl

0.26 g of Pd (TMEDA) Me ₂ was stirred at room temperature in 20 ml of dichloromethane in a double Schlenk vessel with 0.63 g of Pd [quinoline-2- (2,6-diisopropylphenyl) carbaldimine] - Cl ₂ .2NaCl for 2 h. It was filtered off and crystallized in a diffusion-controlled manner with 20 ml of pentane. After 48 h, red crystals were isolated, 0.25 g. Elemental Analysis: Calculated for C ₂₃ H ₂₇ ClN ₂ Pd (473.35): C, 58.36; H, 5.75; N, 5.91. Found: C, 57.26; H, 5.69; N, 5.91. ¹ H NMR (600 MHz, CDCl ₃ ): δ = 0.94 (s, 3H, H19); δ = 1.10 / 1.28 (d, J _{H, H} = 6.8 Hz, 12H, H17); δ = 3.30 (spt, J _{H, H} = 6.8 Hz, 2H, H16); δ = 7.31 (m, 1H, H15); δ = 7.24 (m, 2H, H14); δ = 7.73 (m, 1H); δ = 7.74 (m, 1H, H6); δ = 7.89 (m, 1H, H5); δ = 7.94 (m, 1H, H7); δ = 8.50 (d, J _{H, H} = 8.2 Hz, 1H, H4); δ = 8.51 (s, 1H, Hl1); δ = 10.17 (d, J _{H, H} = 8.8 Hz, 1H, H8). ¹³ C NMR (150 MHz, CDCl ₃ ): δ = 6.04 (q, J _{C, H} = 139 Hz, C19); δ = 24.91 / 22.61 (d, J _{C, H} = 127 Hz, C17 / C18); δ = 27.91 (d, J _{C, H} = 127 Hz, C16); δ = 128.01 (d, J _{C, H} = 168 Hz, C15); δ = 123.69 (d, J _{C, H} = 168 Hz, C14); δ = 168.64 (C11); δ = 131.08 (C8); δ = 132.69 (d, J _{C, H} = 164 Hz, C7); δ = 129.96 (d, J _{C, H} = 161 Hz, C6); δ = 127.38 (d, J _{C, H} = 157 Hz, C5); δ = 139.76 (d, J _{C, H} - 165 Hz, C4); δ = 122.01 (d, J _{C, H} = 166 Hz, C3).

3) Representation by means of oxidative addition [Pyridine-2- (2,6-diisopropylphenyl) carbaldimine] PdBnBr

0.169 g of pyridine-2- (2,6-diisopropylphenyl) carbaldimine was stirred at room temperature in 10 ml of acetone with 0.364 g of Pd (dba) ₂ and 0.075 ml of benzyl bromide for 12 h. The solvent was distilled off from the reddish suspension, washed three times with 15 ml Et ₂ O and extracted with 30 ml dichloromethane. The solvent was distilled off and an orange solid was isolated, 0.13 g. Elemental Analysis: Calculated for C ₂₅ H ₂₉ BrN ₂ Pd (543.84): C, 55.21; H, 5.37; N, 5.15. Found: C, 54.33; H, 5.28; N, 4.96. ¹ H NMR (250 MHz, CDCl ₃ ): δ = 1.11 / 1.03 (d, J _{H, H} = 6.8 Hz, 12H, Me-iPr); δ = 3.12 (s, 2H, CH ₂ -benzyl); δ = 3.14 (spt, J _{H, H} = 6.8 Hz, 2H, H-iPr); δ = 6.7 - 7.0 (m, 4H, aryl); δ = 7.2-7.45 (m, 4H, aryl); δ = 7.7 (m, 2H, aryl); δ = 7.99 (t, J _{H, H} = 7.6 Hz, 1H, aryl); J _{H, H} = 8.30 (s, 1H, imine); δ = 9.43 (d, J _{H, H} = 4.7 Hz, 1H, aryl).

[Pyridine-2- (2,6-diisopropylphenyl) methylcarbaldimine] - PdBnBr

0.68 g of Pd (dba) ₂ were stirred at room temperature in 10 ml of acetone with 0.33 g of pyridine-2- (2,6-diisopropylphenyl) methyl carbaldimine and 0.26 g of benzyl bromide for 12 h. The solvent was distilled off, washed six times with 15 ml Et ₂ O and extracted with 20 ml dichloromethane. After the solvent had been distilled off, an orange solid was isolated, 0.62 g. Elemental analysis: calculated for C ₂₆ H ₃₁ BrN ₂ Pd (557.87): C, 55.98; H, 5.60; N, 5.02. Found: C, 52.85; H, 4.52; N, 3.53. ¹ H NMR (250 MHz, CDCl ₃ ): δ = 1.05 / 1.02 (d, J _{H, H} = 6.8 Hz, 12H, Me-iPr); δ = 2.21 (s, 3H, Me-imine); δ = 2.94 (spt, J _{H, H} = 6.8 Hz, 2H, imine); δ = 2.97 (s, 2H, CH2-benzyl); δ = 6.72 (d, J _{H, H} = 7.2 Hz, 2H, aryl); δ = 6.91 (t, J _{H, H} = 7.4 Hz, 2H, aryl); δ = 7.01 (d, J _{H, H} = 6.4 Hz, 1H, aryl); δ = 7.3 - 7.75 (m, 5H, aryl); J _{H, H} = 7.82 (d, J _{C, H} = 7.8 Hz, 1H, aryl); δ = 7.96 (dt, J _{H, H} = 1.6 / 7.8 Hz, 1H, aryl); δ = 9.34 (s, br, 1H, aryl).

[6-methyl-pyridine-2- (2,6-diisopropylphenyl) carbaldimine] - PdBnBr

0.118 g of 6-methylpyridine-2- (2,6-diisopropylphenyl) carbaldimine was stirred at room temperature in 10 ml of acetone with 0.242 g of Pd (dba) ₂ and 0.053 ml of benzyl bromide for 2 hours. The solvent was distilled off from the reddish suspension, washed three times with 15 ml Et ₂ O and a green-yellow solid isolated, 0.18 g. Elemental Analysis: Calculated for C ₂₆ H ₃₁ BrN ₂ Pd (557.86): C, 55.98; H, 5.60; N, 5.02. Found: C, 56.47; H, 5.74; N, 4.32. ¹ H NMR (250 MHz, CDCl ₃ ): δ = 1.09 (d, J _{C, H} = 6.8 Hz, 12H, Me iPr); δ = 3.15 (s, 3H, Me-pyridine); δ = 3.25 (s, 2H, CH ₂ -benzyl); δ = 3.16 (spt, J _{H, H} = 6.8 Hz, 2H, H-iPr); δ = 7.25 (m, 4H, aryl); δ = 7.2 - 7.5 (m, 6H, aryl); δ = 7.80 (t, J _{H, H} = 7.8 Hz, 1H, aryl); δ = 8.26 (s, 1H, imine).

[Quinoline-2- (2,6-diisopropylphenyl) carbaldimine] PdBnBr

0.36 g of Pd (dba) _{2 was} stirred at room temperature in 20 ml of acetone with 0.2 g of quinoline-2- (2,5-diisopropylphenyl) carbaldimine and 0.113 g of benzyl bromide for 14 h. The solvent was distilled off, washed three times with 15 ml Et ₂ O and extracted with 20 ml dichloromethane. The solvent was distilled off from the red solution and a red solid was isolated, 0.18 g. Elemental analysis: calculated for C ₂₉ H ₃₁ BrN ₂ Pd (593.90): C, 58.65; H, 5.26; N, 4.71. Found: C, 58.21; H, 5.26; N, 4.91. ¹ H NMR (600 MHz, CDCl ₃ ) δ = 1.12 (d, J _{C, H} = 6.8 Hz, 12H, Me-IPr); δ = 3.24 (spt, J _{H, H} = 6.8 Hz, 2H, H-iPr): δ = 3.38 (s, 2H, CH ₂ -benzyl) δ = 6.90 (t, J _{H , H} = 7.3 Hz, 2H, H19); δ = 7.02 (d, J _{H, H} = 7.4 Hz, 2H, H18); δ = 7.03 (m, 1H, H20); δ = 7.32 (d, J _{H, H} = 7.7 Hz, 2H, H12); δ = 7.39 (t, J _{H, H} = 7.7 Hz, 1H, H13); δ = 7.69 (m, 1H, H6), δ = 7.69 (m, [1H]); δ = 7.86 (d, J _{H, H} = 8.1 Hz, 1H, H5); δ = 7.87 (m, 1H, H7); δ = 8.45 (d, J _{H, H} = 8.2 Hz, 1H, H4); δ = 8.52 (s, 1H, imine); δ = 9.96 (d, J _{H, H} = 8.6 Hz, 1H, H8). ¹³ C NMR (125 MHz, CDCl ₃ ): δ = 23.0 (q, J _{C, H} = 128 Hz, Me-iPr); δ = 25.66 (t, J _{C, H} = 144 Hz, CH ₂ benzyl); δ = 28.68 (d, J _{C, H} = 127 Hz, C-iPr); δ = 122.09 (d, J _{C, H} = 167 Hz, C3); δ = 123.99 (d, J _{C, H} = 160 Hz, C12); δ = 124.46 (d, J _{C, H} = 159 Hz, C20); δ = 127.36 (d, J _{C, H} = 162 Hz, C5); δ = 127.76 (C19); δ = 128.03 (d, J _{C, H} = 162 Hz, C13); δ = 129.56 (d, J _{C, H} = 160 Hz, C18); δ = 129.90 (d, J _{C, H} = 161 Hz, C6); δ = 131.83 (d, J _{C, H} = 161 Hz, C7); δ = 132.43 (d, J _{C, H} = 171 Hz, C8); δ = 139.70 (d, J _{C, H} = 167 Hz, C4); δ = 168.11 (d, J _{C, H} = 170 Hz, C-imine).

[Quinoline-2- (2,6-diisopropylphenyl) methyl carbaldimine] - PdBnBr

0.3 g of Pd (dba) _{2 was} stirred at room temperature in 10 ml of acetone with 0.18 g of quinoline-2- (2,6-diisopropylphenyl) methylcar baldimin and 0.093 g of benzyl bromide for 12 h. The solvent was distilled off, washed three times with 15 ml Et ₂ O and extracted with 20 ml dichloromethane. An orange solid was isolated, 0.116 g. Elemental analysis: calculated for C ₃₀ H ₃₃ BrN ₂ Pd (607.12): C, 59.35; H, 5.48; N, 4.61. Found: C, 56.67; H, 5.30; N, 4.88. ¹ H NMR (250 MHz, CdCl ₃ ): δ = 1.14 / 1.03 (d, JH.H = 6.8 Hz, 12H, Me-iPr); δ = 2.31 (s, 3H, Me-imine); δ = 3.05 (spt, J _{H, H} = 6.8 Hz, 2H, H-iPr); δ = 3.20 (s, 2H, CH ₂ -benzyl); δ = 6.8 - 7.1 (m, 5H, aryl); 7.3 - 7.5 (m, 3H, aryl); δ = 7.67 (t, J _{H, H} = 8.1 Hz, 1H, aryl); δ = 9.66 (d, J _{H, H} = 8.9 Hz, 1H, aryl); δ = 7.8 - 8.0 (m, 3H, aryl); δ = 8.45 (d, J _{H, H} = 8.5 Hz, 1H, aryl).

[8- (Diphenylphosphinomethylene) quinoline] PdBnBr

0.26 g of 8- (diphenylphosphinomethylene) quinoline and 0.456 g of Pd (dba) ₂ were mixed with 0.135 g of benzyl bromide in 10 ml of acetone. After 2 h the solvent was distilled off, washed eight times with 20 ml Et ₂ O and filtered off in 20 ml dichloromethane over Na ₂ SO ₄ . An ocher solid was isolated, 0.43 g. ¹ H NMR (250 MHz, CDCl ₃ ): δ = 10.42 (dd, J _{H, H} = 4.9 / 1.0 Hz, 1H, aryl); δ = 8.07 (dd, J _{H, H} = 8.3 / 1.4 Hz, 1H, aryl); δ = 7.57 (d, J _{H, H} = 7.7 Hz, 1H, aryl); δ = 7.5 - 7.2 (m, 15H, aryl); δ = 7.0 - 6.85 (m, 3H, aryl); δ = 4.23 (d, J _{H, H} = 12.4 Hz, 2H, CH ₂ -phosph homethylene); δ = 3.84 (d, J _{H, H} = 4.4 Hz, 2H, CH ₂ -benzyl).

[Quinoline-2- (2,6-diisopropylphenyl) carbaldamine] PdMeI

0.38 g of Pd (dba) ₂ and 0.209 g of quinoline-2- (2,6-diisopropylphenyl) carbaldimine were stirred at room temperature in 10 ml of acetone with 0.094 g of methyl iodide for 12 h. The solvent was distilled off, washed five times with 20 ml of Et ₂ O and filtered off in 20 ml of dichloromethane over Na ₂ SO ₄ . After the solvent had been distilled off, an orange-oily solid was isolated, 0.085 g. Elemental analysis: calculated for C ₂₃ H ₂₇ IN ₂ Pd (564.80): C, 48.91; H, 4.82; N, 4.96. Found: C, 48.04; H, 4.80; N, 4.82. ¹ H NMR (250 MHz, CDCl ₃ ): δ = 10.18 (d, J _{H, H} = 8.8 Hz, 1H, aryl); δ = 8.58 (s, 1H, imine); δ = 8.5 l (d, J _{H, H} = 7.3 Hz, 1H, aryl); δ = 7.9 (m, 2H, aryl); δ = 7.8 (m, 2H, aryl); δ = 7.25 (m, 3H, aryl); δ = 3.28 (spt, J _{H, H} = 6.9 Hz, 2H, H-iPr); δ = 1.15 / 1.12 (s, br, 12H, Me-iPr); δ = 0.86 (s, 3H, Me-Pd).

III. Copolymerization of styrene and carbon monoxide 1) Representation of cationic monoalkyl complexes [6-methylpyridine-2- (1-carbaldimine] PdMe (NCMe) (B (C ₆ F ₅ ) ₄ )

0.485 g (6-methyl-pyridine-2- (1-cyclohexyl) carbaldimine) PdMeCl was stirred at room temperature in 20 ml dichloromethane with 55.3 μl acetonitrile and 1.2 g NaB (C ₆ F ₅ ) for ₄ minutes , the resulting red-brown suspension was filtered off over Na ₂ SO ₄ and, after the solution had been distilled off, isolated using a brown-ocher solid, 1.39 g.
Elemental analysis: calculated for C ₄₈ H ₃₆ BF ₂₄ N ₃ Pd (1227.77): C, 46.95; H, 2.95; N, 3.42. Found: C, 46.66; H, 3.08; N, 3.12. ¹ H (250 MHz, CDCl ₃ ): δ = 1.08 (s, 3H, Me-Pd); δ = 1.1-1.5 (m, 5H, Cy); δ = 1.7 - 2.2 (m, 5H, Cy); δ = 2.25 (s, 3H, MeCN); δ = 2.48 (s, 3H, Me-pyridine); δ = 3.57 (t, br, 1H, Cy); δ = 7.3 - 7.7 (m, 15H, aryl); δ = 8.18 (s, 1H, imine).

2) Preparation of styrene / CO copolymers Copolymerization with [pyridine-2- (2,6-diisopropylphenyl) carbaldimine] PdMe (NCMe) ((C ₆ F ₅ ) ₄ ) (Example 1)

0.1 mmol [pyridine-2- (1-cyclohexyl) carbaldimine] PdMeCl were mixed with 89 mg NaB (C ₆ F ₅ ) ₄ and 6 μl acetonitrile. The mixture was stirred in 2 ml of dichloromethane under a 1 bar CO atmosphere for 10 minutes. The solvent was replaced by 10 ml of styrene, the solution saturated with 1 bar CO and then stirred at room temperature. After 3 h, the solution was diluted with dichloromethane, mixed with 0.2 g of tri phenylphosphine, filtered through diatomaceous earth and the polymer formed was precipitated in 500 ml of methanol. A colorless polymer was isolated.
The copolymerization with [pyridine-2- (2-trifluoromethylphenyl) carbaldimine] PdMe (NCMe) (BC ₆ F ₅ ) 4 (Example 2) was carried out analogously to Example 1. The polymer properties are shown in the table.

table

Claims (10)

1. Process for the preparation of monoalkyl metal complexes chelated with bidentate ligands, characterized in that

• a) a transition metal compound of the general formula M (X) _k (I) in which
  M for an element of group VIII B of the periodic table and
  X represents a chloride, bromide or iodide and
  k represents an integer corresponding to the formal oxidation state of M,
  in the presence of an alkali metal, alkaline earth metal or ammonium halide or in the presence of benzonitrile with a bidentate ligand of the general formula (IIa) or (IIb),
  in which the substituents and indices have the following meaning:
  R ¹ and R ^{2 are} hydrogen, C ₁ - to C ₁₀ -alkyl, partially or by halogenated C ₁ - to C ₁₀ -alkyl, C ₃ - to C ₁₀ -cycloalkyl, C ₆ - to C ₁₄ -aryl, with functional Groups based on the elements from groups IVA, VA, VIA and VIIA of the periodic table of the elements partially or per-substituted C ₆ to C ₁₄ aryl, C ₄ to C ₁₃ heteroaryl, alkylaryl with 1 to 10 carbon atoms in the Alkyl and 6 to 14 carbon atoms in the aryl radical or Si (R ⁶ ) ₃ or together with C ^a and N a five-, six- or seven-membered aromatic or aliphatic substituted or unsubstituted heterocycle, where R ^{1 is} not hydrogen,
  R ³ and R ^{4 are} hydrogen, C ₁ to C ₁₀ alkyl, partially or by halogenated C ₁ to C ₁₀ alkyl, C ₃ to C ₁₀ cycloalkyl, C ₆ to C ₁₄ aryl, with functional Groups based on the elements from groups IVA, VA, VIA and VIIA of the periodic table of the elements partially or per-substituted C ₆ to C ₁₄ aryl, C ₄ to C ₁₃ heteroaryl, alkylaryl with 1 to 10 carbon atoms in the Alkyl and 6 to 14 carbon atoms in the aryl radical or Si (R ⁶ ) ₃ or together with Cb and N or P a five-, six- or seven-membered aromatic or aliphatic heterocycle, where R ^{4 is} not hydrogen,
  R ^{5 is} hydrogen, C ₁ - to C ₁₀ -alkyl, C ₃ - to C ₁₀ -cyclo alkyl, C ₆ - to C ₁₄ -aryl, alkylaryl with 1 to 10 C-atoms in the alkyl and 6 to 14 C-atoms in the aryl radical or Si (R ⁶ ) ₃ ,
  m 0 or 1 and
  R ⁶ C ₁ to C ₁₀ alkyl, C ₃ to C ₁₀ cycloalkyl, C ₆ to C ₁₄ aryl, alkylaryl with 1 to 10 C atoms in the alkyl and 6 to 14 C atoms in the aryl radical,
  reacted in a polar protic solvent,
• b) the polar protic solvent is replaced by a non-coordinating polar aprotic solvent and
• c) the mixture obtained with a tetraorganotin compound.

2. The method according to claim 1, characterized in that as transition metal compound (I) palladium (II) chloride, as alkali metal halides, the chlorides or bromides of lithium, sodium, potassium or cesium, as bidentate ligands, a compound of formula (IIa), in of the
R ¹ and R ² together with N and C ^{a form} a six-membered aromatic substituted or unsubstituted heterocycle, and
R ^{3 is} hydrogen, methyl, ethyl, i-propyl or t-butyl,
R ⁴ t-butyl, cyclohexyl, 2-i-propylphenyl, 2-t-butyl phenyl, 2,6-di-i-propylphenyl, 2,6-bis (trimethyl silyl) phenyl, 2-trifluoromethylphenyl, 1- or 2 -Naphthyl, and
m 0
mean,
and tetramethyltin is used as the tetraorganotin compound. 3. The method according to claims 1 or 2, characterized in that as a polar protic solvent in step

• a) methanol or ethanol and as a non-coordinating polar aprotic solvent in step
• b) uses dichloromethane or chlorobenzene.

4. A process for the preparation of monoalkyl metal complexes chelated with bidentate ligands, characterized in that a complex compound of the general formula (IIIa) or (IIIb)
in which the substituents have the following meaning:
M 'is an element of group VIII B of the periodic table,
Y chloride, bromide or iodide,
R ¹¹ and R ¹² together with N and C ^{a form} a five-, six- or seven-membered aromatic or aliphatic, substituted or unsubstituted heterocycle,
R ¹³ and R ^{14 are} hydrogen, C ₁ to C ₁₀ alkyl, partially or by halogenated C ₁ to C ₁₀ alkyl, C ₃ to C ₁₀ cycloalkyl, C ₆ to C ₁₄ aryl, with functional Groups based on the elements from groups IVA, VA, VIA and VIIA of the periodic table of the elements partially or per-substituted C ₆ to C ₁₄ aryl, C ₄ to C ₁₃ heteroaryl, alkylaryl with 1 to 10 carbon atoms in the Alkyl and 6 to 14 carbon atoms in the aryl radical or triorganosilyl or together with C ^b and N or P a five-, six- or seven-membered aromatic or aliphatic heterocycle, where R ^{14 is} not hydrogen,
in a polar aprotic non-coordinating solvent
with a metal complex of the general formula M '' (B-B ') (R ¹⁵ ) _n (IV), in which
M '' for an element of group VIII B of the periodic table and
BB 'represents a bidentate, 1,2-ethylene-bridged diamine, diphosphane or amine / phoshan ligand, and
R ¹⁵ C ₁ - to C ₂₀ alkyl, which has no hydrogen atoms in the β position to the metal center M ″, and
n represents an integer that corresponds to the formal oxidation state of M ″,
implements. 5. The method according to claim 4, characterized in that
M 'and M''palladium or nickel,
Y chloride or bromide,
R ¹¹ and R ¹² together with N and C ^{a form} a six-membered aromatic, substituted or unsubstituted heterocycle,
R ^{13 is} hydrogen, methyl, ethyl, i-propyl or t-butyl,
R ¹⁴ t-butyl, cyclohexyl, 2-i-propylphenyl, 2-t-butyl phenyl, 2,6-di-i-propylphenyl, 2,6-bis (trimethyl silyl) phenyl, 2-trifluoromethylphenyl, 1- or 2 -Naphthyl,
BB 'a 1,2-ethylene bridged diamine ligand, and
R ^{15 is} methyl, benzyl, neopentyl, t-butyl or trimethyl silylmethylene
mean. 6. The method according to claims 4 or 5, characterized net that as polar aprotic non-coordinating Solvent dichloromethane or chlorobenzene used. 7. Process for the preparation of monoalkyl metal complexes chelated with bidentate ligands, characterized in that a transition metal complex (V) complexed with neutral ligands, in which the transition metal is taken from group VIII B of the periodic table and is present in the formal oxidation state 0, in one aprotic polar solvent in the presence of a bidentate ligand of the general formula (VIa) or (VIb),
in which
R ¹⁶ to R ^{19 are} hydrogen, C ₁ to C ₁₀ alkyl, C ₃ to C ₁₀ cycloalkyl, C ₆ to C ₁₄ aryl, with functional groups based on the elements from groups IVA, VA, VIA and VIIA of the periodic table of the elements partially or per-substituted C ₆ to C ₁₄ aryl, C ₄ to C ₁₃ heteroaryl, alkylaryl with 1 to 10 C atoms in the alkyl and 6 to 14 C atoms in the aryl radical or triorganosilyl stand or form a five- or six-membered, substituted or unsubstituted aromatic or aliphatic cycle via vicinal substituents,
R ²⁰ and R ^{21 are} hydrogen, C ₁ to C ₁₀ alkyl, partially or perhalogenated C ₁ to C ₁₀ alkyl, C ₃ to C ₁₀ cycloalkyl, C ₆ to C ₁₄ aryl, with functional groups based on the elements from groups IVA, VA, VIA and VIIA of the periodic table of the elements partially or per-substituted C ₆ to C ₁₄ aryl, C ₄ to C ₁₃ heteroaryl, alkylaryl with 1 to 10 C atoms in the alkyl - and 6 to 14 carbon atoms in the aryl radical or triorganosilyl or together with Cb and N or P form a substituted or unsubstituted five-, six- or seven-membered aromatic or aliphatic heterocycle, where R ^{21 is} not hydrogen,
with a compound of the general formula R ²² -Z (VII), in which
R ^{22 represents} a C ₁ to C ₂₀ alkyl group which has no hydrogen atom in the β position to Z, and
Z represents chloride, bromide or iodide,
implements. 8. The method according to claim 7, characterized in that the transition metal complex (V) palladium (0) -di-benzylidene acetone,
R ¹⁶ to R ^{19 are} hydrogen, methyl, ethyl, i-propyl, t-butyl or, via vicinal substituents, a six-membered substituted or unsubstituted aromatic cycle,
R ^{20 is} hydrogen, methyl, ethyl, i-propyl or t-butyl,
R ²¹ t-butyl, cyclohexyl, 2-i-propylphenyl, 2-t-butyl phenyl, 2,6-di-i-propylphenyl, 2,6-bis (trimethyl silyl) phenyl, 2-trifluoromethylphenyl, 1- or 2 -Naphthyl,
R ^{22 is} methyl, t-butyl, neopentyl, benzyl or trimethyl silylmethylene and
Z bromide or iodide
mean. 9. The method according to claims 7 or 8, characterized net that as a polar aprotic solvent acetone used. 10. Use of those obtainable according to claims 1 to 9 Monoalkyl metal complexes as catalysts in the copolymer sation of carbon monoxide and vinyl aromatic compounds.