DE60306796T2 - RACEMOSELECTIVE PREPARATION RAC-DIORGANOSILYL-BIS- (2-METHYLBENZO [E] INDENYL) ZIRCONIUM COMPOUNDS - Google Patents

Description

The The present invention relates to a process for racemoselective Synthesis of rac-diorganosilylbis (2-methylbenzo [e] indenyl) zirconium compounds, and especially for the racemoselective synthesis of rac-dimethylsilyl-bis (2-methylbenzo [e] indenyl) zirconium dichloride. In particular, the present invention relates to a method for racemoselective synthesis of the above compound via the racemoselective synthesis of dimethylsilylbis (2-methylbenzo [e] indenyl) zirconium bis (3,5-di-tert-butylphenolate).

For the stereospecific Olefin polymerization is becoming increasingly chiral metallocene complexes of metals of the third to sixth subgroups of the periodic table used the elements. Correspondingly substituted ansa metallocene complexes are generally as described in the prior art processes Diastereomeric mixture consisting of the racemic and the meso form the metallocene produced. For the stereospecific olefin polymerization is generally the Use of the metallocene complex in its racemic form, i. without the mirror-symmetric meso compounds needed. Therefore, must in the metallocene synthesis of the prior art, the meso-form be separated from the diastereomer mixture.

There the meso-form of isomerization is usually inaccessible, This form must be destroyed or removed after the synthesis, which is why the yield of racemic metallocene complexes in synthetic procedures of the prior art is low.

In WO 99/15538 and the DE 100 30 638 describes a general multi-step process for the preparation of racemic metal complexes via an intermediate of biphenolate or bisphenolate-substituted metallocenes.

The synthesis of ansa zirconocene dichloride complexes according to the prior art generally starts from a general route of ZrCl ₄ or its solvent adducts. The cyclopentadienyl ligand is usually dissolved or suspended in toluene, optionally with the addition of small amounts of THF or DME, deprotonated by strong bases and subsequently reacted with zirconium tetrachloride to give the corresponding ansa-metallocene dichlorides and two equivalents of alkali / alkaline earth metal chloride. The ansa metallocene dichloride is separated from the alkali or alkaline earth metal salts by filtration and isolated by crystallization.

This classical reaction path has two major problems. Instead of of the desired Racemates are almost equivalent in most cases Quantities of the mirror-symmetric meso-diastomeres formed. Further the yields of the rac / meso mixture are relative by this method low and are in the range of about 30 to 40%. Since, as mentioned above, for the catalytic Applications of ansa metallocene compounds Only the racemate form can be used, follows below the synthesis of the rac / meso mixture of ansa metallocene compounds either a complicated Diastereomentrennung or the destruction of Meso-form, which halves the yield again approximately. The total yield pure racansa metallocene is therefore usually no longer as 15 to 20%.

One Another disadvantage is the efficiency of the synthesis route. There, how described, the ansa metallocene compound from the alkali or alkaline earth metal halides formed in parallel must be separated, which in some cases due to the low solubility the ansa metallocene compound, especially in toluene, difficult proves, as well as the alkali or alkaline earth metal halides practical insoluble in organic solvents are, will be for This separation step therefore large amounts of solvent needed which in turn is productivity and effectiveness affected the synthesis route.

A Object of the present invention was therefore to provide a method for selective production of racemic and almost meso-isomer free To find metallocene complexes.

The solution The above object is apparent from the independent method claim. Preferred embodiments The present invention is achieved by combining the features of the main claim with the features of the dependent subclaims.

umfassend die folgenden Schritte:

• a) Umsetzen einer Verbindung der Formel II mit einem Zirkoniumbisphenolatkomplex der Formel III zum ansa-Zirkonocenbisphenolatkomplex der Formel IV,
  
• b) Substitution der Phenolatgruppen aus IV mit X unter Verwendung geeigneter Abspaltungsreagenzien, um die Verbindung der Formel I zu erhalten; wobei die Substituenten X gleich oder verschieden sein können und für F, Cl, Br, I, sowie lineares, cyclisches oder verzweigtes C_1-10-Alkyl stehen; und die Substituenten R gleich oder verschieden sein können und für lineares, cyclisches oder verzweigtes C_1-10-Alkyl oder C_6-10-Aryl stehen; und LB eine geeignete Lewis-Base ist, sowie M₁ und M₂ einwertig positive Alkalimetallionen sind oder M₁ und M₂ zusammen ein zweiwertig positives Erdalkalimetallion sind.

According to the present invention there is provided a specific process for the diastereoselective synthesis of rac-diorganosilyl-bis (2-methylbenzo [e] indenyl) zirconium compounds according to formula I,

comprising the following steps:

• a) reacting a compound of the formula II with a zirconium bisphenolate complex of the formula III to the ansa-zirconocene bisphenolate complex of the formula IV,
  
• b) Substitution of the phenolate groups from IV with X using suitable cleavage reagents to obtain the compound of formula I; wherein the substituents X may be the same or different and are F, Cl, Br, I, as well as linear, cyclic or branched C _1-10 alkyl; and the substituents R may be the same or different and represent C _1-10 linear, cyclic or branched alkyl or C _6-10 aryl; and LB is a suitable Lewis base, and M ₁ and M _{2 are} monovalent positive alkali metal ions, or M ₁ and M ₂ together are a divalent alkaline earth metal alkaline ion.

umfasst die folgenden Schritte:

• a) Deprotonierung von 2-Methylbenzo[e]inden mittels eines geeigneten Deprotonierungsmittels;
• b) Umsetzen des deprotonierten 2-Methylbenzo[e]indens mit einer Diorganosilylverbindung R₂SiY₂, wobei die Substituenten R gleich oder verschieden sein können und für lineares, cyclisches oder verzweigtes C_1-10-Alkyl oder C_6-10-Aryl stehen, und die Abgangsgruppen Y gleich oder verschieden sein können und für F, Cl, Br oder I stehen, und anschließende nochmalige Deprotonierung mittels eines geeigneten Deprotonierungsmittels, wobei eine Verbindung gemäß Formel II erhalten wird:
  
  wobei M₁ und M₂ einwertig positive Alkalimetallionen sind, oder M₁ und M₂ zusammen ein zweiwertig positives Erdalkalimetallion sind;
• c) Umsetzung der Verbindung gemäß Formel II mit einem Zirkoniumbisphenolat-komplex gemäß Formel III:
  
  wobei LB eine geeignete Lewis-Base ist, wodurch eine Verbindung der Formel IV erhalten wird:
  
• d) Umsetzen der Verbindung gemäß Formel IV mit geeigneten Abspaltungsreagenzien unter Substitution der Phenolatgruppen aus IV mit X um die Verbindung der Formel I zu erhalten, wobei die Substituenten X gleich oder verschieden sein können und für F, Cl, Br, I, sowie lineares, cyclisches oder verzweigtes C_1-10-Alkyl stehen.

A particularly preferred embodiment of the process according to the invention for the diastereoselective synthesis of rac-diorganosilylbis (2-methylbenzo [e] indenyl) zirconium compounds of the formula I,

includes the following steps:

• a) deprotonation of 2-methylbenzo [e] inden by means of a suitable deprotonating agent;
• b) reacting the deprotonated 2-methylbenzo [e] indene with a diorganosilyl compound R ₂ SiY ₂ , where the substituents R may be the same or different and are linear, cyclic or branched C _1-10 -alkyl or C _6-10 -aryl and the leaving groups Y can be identical or different and stand for F, Cl, Br or I, and subsequent deprotonation by means of a suitable deprotonating agent, a compound according to formula II being obtained:
  
  wherein M ₁ and M _{2 are} monovalent alkali metal positive ions, or M ₁ and M ₂ together are a divalent alkaline earth metal alkaline ion;
• c) Reaction of the compound according to formula II with a zirconium bisphenolate complex according to formula III:
  
  wherein LB is a suitable Lewis base, whereby a compound of formula IV is obtained:
  
• d) reacting the compound according to formula IV with suitable cleavage reagents substituting the phenolate groups of IV with X to obtain the compound of formula I, wherein the substituents X may be the same or different and for F, Cl, Br, I, and linear, cyclic or branched C _1-10 alkyl.

Especially the process according to the invention is preferred performed in such a way that the formed intermediate compound IV in the same reaction vessel by Substitution of the phenolate groups in the complex compound I is transferred.

Furthermore, it is preferred according to the invention that the substituents R are selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and phenyl and combinations thereof. The substituents X are preferably selected from F, Cl, Br, I, methyl, ethyl, n-propyl, isopropyl, n-butyl and isobutyl, more preferably Cl and / or methyl. It is further preferred that M ₁ and M _{2 are selected} from lithium, sodium, potassium, rubidium or cesium ions or together denote magnesium. Most preferably, R is methyl or ethyl, X is Cl and LB is THF or DME, and M ₁ and M ₂ are Li. As the Lewis base LB, tetrahydrofuran (THF), dimethoxyethane (DME) or tetramethylethanediamine (TMEDA) is preferably used ,

Possibly is in the process of the invention in the substitution of the phenolate groups from the complex IV again a Lewis base, preferably THF or DME.

The Terms "meso-form", "racemate" and thus also "diastereomers" and "enantiomers" are in combination known with metallocene complexes and, for example, pure gold et al., Organometallics 11 (1992), pages 1869-1876. The term "nearly meso-free" or "racemoselective" is present understood that more than 80%, preferably at least 90%, one Compound in the form of the racemate, more preferably at least 95%.

in the It has surprisingly been found, within the scope of the present invention, that diorganosilyl-bis- (2-methylbenzo [e] indenyl) zirconocene compounds I racemoselective the corresponding diorganosilyl-bis (2-methylbenzo [e] indenyl) zirconium bis (3,5-di-tert-butylphenolate) in a simple manner IV can be obtained. This exploits the fact that the reaction of the diorganosilyl bis (2-methylbenzo [e] indenyl) metal salt with zirconium bis (3,5-di-tert-butylphenolate) compounds diastereoselective to a high surplus the racemate form of complex IV lead.

It has also shown that the inventive method without isolation of intermediates, in a so-called "one-pot" process, starting from the 2-methylbenzo [e] inden, the process being racemoselective with high overall yields. Especially It is therefore preferred if the inventive method, starting from 2-methylbenzo [e] indene without isolation of intermediates after the individual process steps carried out becomes.

The diastereoselectivity the synthesis of the invention with this ligand system seems, without being bound by theory to be in the steric claim of tert-butyl substituents at positions three and five of phenolate to lie.

The Synthesis strategy according to the invention leads in the Compared to the methods of the prior art significantly improved Overall yields of the racemate form of the resulting metallocene. Further, the intermediate IV complex may be due to its good solubility in aliphatic and aromatic solvents in a simple manner separated from the alkali or alkaline earth metal salts formed in parallel become. Furthermore allows the good solubility of the complex IV an execution the synthesis in high concentrations, resulting in increased productivity of the synthesis method of the invention leads. According to one preferred embodiment the procedure is carried out in such a way that complex IV in a concentration of 5-30% by weight, preferably 10-25 wt .-%, particularly preferably 15-25% by weight and especially preferably about 20% by weight, based on the amount used Solvent, is present.

The according to the inventive method As a rule, the metallocene complexes I obtained contain 1 to 4 equivalents a Lewis base, which is usually introduced via the synthesis route becomes. Examples of such Lewis bases are ethers, such as diethyl ether or tetrahydrofuran (THF) but also amines such as TMEDA. It is also possible to obtain the metallocene complexes I Lewis bases-free, for example by drying in vacuo or selection of other solvents in the synthesis. Such measures are known in the art.

According to the method of the invention becomes silyl-bridged Alkali or alkaline earth metal bis-benzo [e] indenyl salt II with the zirconium bis (3,5-di-tert-butylphenolate) base adduct III converted to metallocene complex IV.

The Ligand salts II can be by literature methods, under Use of suitable deprotonating, for example through the, preferably stoichiometric, Reaction of an organometallic compound or a hydride of a Alkali or alkaline earth metal with the 2-methylbenzo [e] inden. Suitable organometallic compounds deprotonating the methylbenzo [not] include strong bases, for example N-butyllithium, tert-butyllithium, sodium hydride, potassium tert-butoxide, Grignard reagents of magnesium or suitable compounds of magnesium such as di-n-butylmagnesium or (n, s) -dibutylmagnesium or other suitable alkali or alkaline earth metal alkyl compounds.

Two moles of the deprotonated indene are subsequently reacted with Diorganosilandihalogenverbindungen the formula R ₂ SiY ₂ , wherein the substituents R may be identical or different and are linear, cyclic or branched C _1-10 alkyl or C _6-10 aryl, and the Leaving groups Y may be the same or different and stand for F, Cl, Br or I.

Preferred compounds R ₂ SiY ₂ are in this case dialkylsilane dichlorides such as dimethylsilane dichloride, diethylsilane dichloride or dipropylsilane dichloride, or else diarylsilane dichlorides such as diphenylsilane dichloride or alkylarylsilane dichlorides such as phenylmethylsilane dichloride.

following the reaction products obtained are again with the deprotonating agents such mentioned above deprotonated to ansa Ligandsalz II.

Selected examples of compounds of the formula II which can be used according to the invention are:
Dimethylsilanediyl-bis (2-methylbenzo [e] indenyl) di-lithium
Diethylsilanediyl-bis (2-methylbenzo [e] indenyl) di-lithium
Diphenylsilanediyl-bis (2-methylbenzo [e] indenyl) di-lithium
Phenylmethylsilanediyl-bis (2-methylbenzo [e] indenyl) di-lithium
Dimethylsilanediyl-bis (2-methylbenzo [e] indenyl) magnesium
Diethylsilanediyl-bis (2-methylbenzo [e] indenyl) magnesium
Diphenylsilanediyl-bis (2-methylbenzo [e] indenyl) magnesium
Phenylmethylsilanediyl-bis (2-methylbenzo [e] indenyl) magnesium
and the respective Lewis base adducts of these compounds with, for example, THF, DME or TMEDA.

Besides be in the literature known manner two equivalents of 3,5-di-tert-butylphenol also with suitable strong bases as mentioned above, preferably with butyllithium or Grignard compounds or other alkyl lithium compounds deprotonated and then with zirconium tetrachloride or other zirconium halides such as Zirconium tetrafluoride, bromide and iodide in suitable solvents optionally in the presence of suitable Lewis bases, to the zirconium bisphenolate compound III implemented.

suitable solvent therefor are aliphatic hydrocarbons, such as pentane, hexane, heptane, aromatic Hydrocarbons such as toluene, ortho-, meta- or para-xylene or Isopropylbenzene (cumene), as well as ethers, such as tetrahydrofuran (THF), Diethyl ether, methyl tert-butyl ether or dimethoxyethane (DME), Amines such as diisopropylamine, tetramethylethanediamine (TMEDA) or pyridine, the latter also being suitable Lewis bases.

suitable Lewis bases for the stabilization of zirconium bisphenolate complexes (III) in the form of the Lewis base adduct are, for example, THF, 1,2-dimethoxyethane (DME), TMEDA, ethers, amines, cyclic ethers, pyridine and the like. Suitable according to the invention are all Lewis bases that adduct to the zirconium complexes to lead.

Well suitable solvent mixtures or solvent / Lewis base mixtures for the Synthesis of III are those of toluene and THF, toluene and DME or toluene and TMEDA, wherein the Lewis base is generally in one Amount of 0.1 to 50 mol%, preferably 1 to 20 mol%, based on the solvent mixture, is present.

The reaction of the ligand salt II with the zirconium bis (3,5-di-tert-butylphenolate) base adduct III to the ansa metallocene complex IV usually takes place in an organic solvent or suspending agent, preferably in a solvent mixture which is a Lewis basic solvent contains, in the temperature range of -78 ° C to 250 ° C, preferably in the temperature range of 0 to 110 ° C instead. Suitable solvents are aliphatic hydrocarbons such as pentane, hexane, heptane, aromatic hydrocarbons such as toluene, ortho-, meta- or para-xylene or isopropylbenzene (cumene), ethers such as tetrahydrofuran (THF), diethyl ether, methyl tert-butyl ether or Dimethoxyethane (DME), amines such as diisopropylamine, Tertrame thylethanediamine (TMEDA) or pyridine. Highly suitable solvent mixtures are those of toluene and THF, toluene and DME or toluene and TMEDR, the Lewis base generally in an amount of 0.1 to 50 mol%, preferably 1 to 20 mol%, based on the solvent mixture , is present. The molar ratio of the complex III to the alkali metal or alkaline earth metal ligand salt II is usually in the range from 0.8: 1 to 1: 1.2, preferably 1: 1.

By the reaction of the invention of ligand salt II with zirconium bisphenolate complex III racemoselectively the corresponding diorganosilyl bis (2-methylbenzo [e] indenyl) zirconium bisphenolate complex IV obtained, the ratio of rac: meso of this compound at least 4: 1, preferably about 5: 1, and more preferably 6-10: 1 lies. By appropriate leadership the reaction conditions can also rac / meso ratios of 11: 1 and more can be obtained.

in the last step of the synthesis are preferably carried out at room temperature a suitable cleavage agent, in particularly preferred embodiments acetyl chloride or ethylaluminum dichloride, the phenolate groups cleaved to give the racemic metallocene complex I becomes. It has been shown that in this cleavage step in usually no isomerization of the complex occurs.

The Phenolatgruppen of the racemic complex IV can essentially without a completely eliminated rac / meso isomerization in a simple manner or substituted and optionally reused.

Suitable cleavage (substitution) methods are the reaction of the racemic metallocene complexes of the formula IV with corresponding cleavage reagents such as SOCl ₂ , silicon tetrachloride, methylaluminum dichloride, dimethylaluminum chloride, aluminum trichloride, dialkylaluminum chlorides, aluminum sesquichlorides, particularly preferably ethylaluminum dichloride, or else inorganic Brönsted acids such as hydrogen halides, ie HF, HBr, HI, preferably HCl, which are usually used in bulk or as a solution in water or organic solvents such as diethyl ether, THF. Suitable solvents for this purpose are aliphatic hydrocarbons, such as pentane, hexane, heptane, aromatic hydrocarbons, such as toluene, ortho, meta or para-xylene or isopropylbenzene (cumene), ethers, such as tetrahydrofuran (THF), diethyl ether, methyl tert-butyl ether or dimethoxyethane (DME), amines such as diisopropylamine, tetramethylethanediamine (TMEDA) or pyridine. Also very suitable are Lewis base-containing solvent mixtures of hydrocarbons and ethers or amines or both, for example those of toluene and THF, toluene and DME or toluene and TMEDA, wherein the Lewis base is generally used in an amount of 0.01%. 50 mol%, preferably 0.1-10 mol%, based on the solvent mixture, is present.

Especially Also suitable are aliphatic and aromatic carboxylic acid halides such as acetyl chloride, phenylacetyl chloride, 2-thiopheneacetyl chloride, Trichloroacetyl chloride, trimethylacetyl chloride, O-acetylmandelic acid chloride, 1,3,5-benzenetricarboxylic, 2,6-pyridinecarboxylic acid chloride, tert-butylacetyl chloride, chloroacetyl chloride, 4-chlorobenzacetyl chloride, dichloroacetyl chloride, 3-methoxyphenylacetyl chloride, acetyl bromide, bromoacetyl bromide, acetyl fluoride, Benzoylfluorid, as a cleavage reagent, these usually in the o.g. solvents or used in substance. This usually arises the di-halide analogous to the compound of formula IV (X = F, Cl, Br, I).

Another well-suited substitution method is the reaction of the racemic metallocene complexes, preferably those of formula IV with organoaluminum compounds such as tri-C ₁ - to C ₁₀ -alkylaluminum, ie trimethylaluminum, triethylaluminum, tri-n-butylaluminum, tri-iso-butylaluminum replacement reagent. In this case, according to the current state of knowledge, the organo compound analogous to compound IV (X = organic radical, eg C ₁ - to C ₁₀ -alkyl, such as methyl, ethyl, n-butyl, isobutyl) is generally formed.

at the cleavage reactions, the components are usually in the stoichiometric Ratio used, optionally also an excess can be used on cleavage reagent.

The Cleavage reactions generally take place with retention of stereochemistry the metallocene complexes, that means it finds particular essentially no conversion of the racemic form to the meso form the metallocene complexes. Rather, in many cases, in particular with the chlorination methods described above, the rac selectivity even further increased However, the stereochemistry of the starting bisphenolate complexes IV in the Usually maintained.

Particularly preferred cleavage agents according to the invention are acetyl chloride, ethylaluminum dichloride and MeAlCl ₂ .

The formed substitution products of target complex I are relative easily separated as the formed diorganosilyl (2-methylbenzo [e] indenyl) zirconium compounds generally relatively poorly soluble are and while the cleavage reaction from the solvent precipitate. These can therefore obtained in pure form by filtration and appropriate washing operations become.

Either the 3,5-di-tert-butylphenol used as the auxiliary ligand and those used Cleavage or substitution agents can usually be simple Recovered and in a corresponding synthesis process optionally recycled and be recycled. About that In addition, the auxiliary ligands and cleavage agents used are easy-to-handle, non-toxic and non-mutagenic substances, which the inventive method in terms of make the requirements for the security measures unproblematic.

The inventive method is characterized by being very selective in the rac form of the metallocene complexes the formula I accessible power.

The following rac-metallocene compounds of the formula I are particularly preferably obtained by the process according to the invention:
Dimethylsilylbis (2-methylbenzo [e] indenyl) zirconium dichloride
Diethylsilyl-bis- (2-methylbenzo [e] indenyl) zirconium dichloride
Diphenylsilyl-bis- (2-methylbenzo [e] indenyl) zirconium dichloride
Phenylmethylsilyl-bis (2-methylbenzo [e] indenyl) zirconium dichloride
Phenylethylsilyl-bis (2-methylbenzo [e] indenyl) zirconium dichloride.

wobei die Substituenten R gleich oder verschieden sein können und für lineares, cyclisches oder verzweigtes C_1-10-Alkyl oder C_6-10-Aryl stehen, und bevorzugt aus Methyl, Ethyl, n-Propyl, iso-Propyl, n-Butyl, iso-Butyl und Phenyl sowie Kombinationen davon ausgewählt sind.The process according to the invention can also be used to obtain the racemic transition metal compound according to formula IV by omitting the cleavage step,

where the substituents R may be identical or different and represent a linear, cyclic or branched C _1-10 -alkyl or C _6-10 -aryl, and preferably from methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl and phenyl, as well as combinations thereof.

The racemic complexes I obtained according to the invention, as well as those according to formula IV, can be used as catalysts or in catalyst systems for the polymerization and copolymerization of olefinically unsaturated compounds such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, styrene, use. They are particularly advantageous for the stereoselective polymerization of prochiral, olefinically unsaturated compounds, such as propylene and styrene. Suitable catalysts or catalyst systems in which the racemic metallocene complexes of this invention can function as the "metallocene component" will usually contain metallocenium ion-forming compounds such as in EP-A-0 700 935, page 7, line 34 to page 8, line 21 and formulas (IV) and (V) Further compounds forming metallocenium ions are aluminoxanes (RA10) _s, such as methylaluminoxane, or else boron activators.

The racemic according to the invention Metallocene complexes of the formulas I and IV can furthermore be described as Reagents or as catalysts or in catalyst systems in use the stereoselective, especially organic synthesis. For example, be the stereoselective reductions or stereoselective alkylations of C = C double bonds or C = O, C = N double bonds.

The resulting complex compounds I and IV are obtained by the process according to the invention a yield of about 30-80% rac based on used indene compound.

One Another significant advantage is that the inventive method racemoselectively be carried out in a so-called one-pot process can. Eintopfverfahren is understood in the present case that after the individual process steps no interconnections specifically be isolated. The further reaction can be carried out directly with the reaction product mixtures of the previous step.

Especially the formed intermediate compound IV can be subsequently in the same reaction vessel in a further process step by cleavage of the phenolate radicals in the target compound I are transferred.

The The present invention will be described below with reference to specific Examples closer described.

Example 1:

Preparation of dimethylsilylbis (2-methylbenzo [e] indenyl) zirconium bis (3,5-di-tert-butylphenolate) (IV):

a) Preparation of ZrCl ₄ (THF) ₂

6.4 g (27.46 mmol) of ZrCl _{4 are} suspended in 100 ml of toluene in a dry, inert gas-purged 500 ml three-necked flask with magnetic stirring bar, dropping funnel and vacuum pump connection with tap. The suspension was cooled to about 4 ° C in an ice bath. To this was added dropwise over 15 minutes 4.5 g of THF slowly via a dropping funnel. Then allowed to warm to room temperature and stirred for about 1 hour.

b) Preparation of Li (3,5- (t-Bu) ₂ -C ₆ H ₂ O)

In a dry 500 ml three-necked flask with magnetic stir bar, Dropping funnel and vacuum pump connection with tap are under inert gas 11.33 g (54.91 mmol) of 3,5-di-tert-butylphenol in 120 ml of toluene and 4.5 g of THF dissolved. The colorless solution was at 4 ° C cooled in an ice bath and subsequently, 21.5 ml of a 2.5 molar solution of BuLi in toluene (20% by weight) slowly add the dropping funnel. The formed suspension is allowed warm to room temperature and stir at room temperature for 1.5 hours.

c) Preparation of Cl ₂ Zr (3,5- (t-Bu) ₂ -C ₆ H ₃ O) ₂ (THF) ₂

The Suspension from step b) was added under nitrogen by means of a cannula in the Suspension from step a) within a few minutes at room temperature brought in. Residual Residues of lithium phenolate were washed with 10 ml of toluene and added. The resulting suspension was further 4 hours at room temperature touched.

d) Preparation of Me ₂ Si (2-Me-benzo [e] ind) ₂ Li ₂

In a dry 100 ml three-necked flask with magnetic stir bar, dropping funnel and vacuum connection with tap 11.0 g (26.40 mmol) of Me ₂ Si (2-Me-benzo [e] ind) ₂ in 120 ml of toluene and 6 g under inert gas THF suspended. To the suspension was added dropwise 20.5 ml of a 2.6 molar solution of BuLi in toluene at room temperature. The resulting suspension was heated to 80 ° C and stirred for 2 hours at this temperature.

e) Preparation of Me ₂ Si (2-Me-benzo [e] ind) ₂ Zr (3,5- (t-BU) ₂ -C ₆ H ₃ O) ₂ (IV)

The suspension from step c) was introduced via a cannula under nitrogen into the suspension from step d). Remaining residues of the zirconium bisphenolate THF adduct were washed with 10 ml of toluene and added. The resulting suspension was stirred for 12 hours at room temperature. A ¹ H NMR spectrum of the reaction mixture indicated the formation of complex IV with a rac / meso ratio of about 5: 1. The suspension was heated to 85 ° C and stirred for a further 4.5 hours, then cooled to room temperature. The ¹ H NMR spectrum showed no change in the rac / meso ratio. The suspension was again heated to 85 ° C and filtered at this temperature via a cannula over a glass frit under nitrogen. The filtrate was concentrated strongly under reduced pressure and then allowed to stand at room temperature. The complex IV fell after several hours as a fine pulse ver out. The precipitate was filtered off and dried in vacuo to give 14.7 g of complex IV with a rac / meso ratio of about 8: 1 (determined by means of ¹ H-NMR). Yield 61% (14.7 g).

recrystallization of complex IV from toluene gave the complex in pure rac form.

Example 2:

Preparation of rac-dimethylsilylbis (2-methylbenzo [e] indenyl) zirconium dichloride (I)

3.4 g of rac-dimethylsilylbis (2-methylbenzo [e] indenyl) zirconium bis (3,5-di-tert-butylphenolate) (IV) from Example 1 were placed in a dry, inert gas-purged round bottom flask suspended with cock and magnetic stir bar in 35.8 g of toluene. To this suspension, 7.5 g of a 10% strength by weight solution of acetyl chloride in toluene were added rapidly at room temperature via a dropping funnel. The mixture was stirred at room temperature. After 4 hours, the reaction mixture was filtered under inert gas over a number 3 glass filter frit. The filter cake was washed twice with 10 g of heptane and then dried in vacuo. There were obtained 1.7 g of the compound I as a yellowish powder. The ¹ H NMR spectrum of the compound showed the pure rac form. Elemental analysis: C% (calculated) 62.48 C% (found) 61.9 H% (calculated) 4,54 H% (found) 4.6 Cl% (calculated) 12.29 Cl% (found) 12.2 Zr% (calculated) 15.82 Zr% (found) 15.8

Example 3:

Preparation of rac-dimethylsilylbis (2-methylbenzo [e] indenyl) zirconium dichloride (I) by cleavage of the phenolate from IV with 2.5 equivalents Acetyl chloride and one equivalent THF

3.4 g (3.71 mmol) of the complex IV from Example 1 were suspended in 33.6 g of toluene and 0.7 g of THF in a dry round-bottomed flask with tap and magnetic stir bar, which had been purged with inert gas. To this suspension, 7.3 g of a 10% by weight solution of acetyl chloride in toluene (9.30 mmol) was added rapidly at room temperature via a dropping funnel. The mixture was stirred at room temperature. After 4.5 hours, the reaction mixture was filtered on a number 3 glass filter frit purged with inert gas. The filter cake was washed twice with 10 g of heptane and dried in vacuo. There was obtained 1.9 g of the compound I as a yellow powder. The ¹ H-NMR spectrum showed the presence of the pure rac form of I. Elemental analysis: C% (calculated) 62.48 C% (found) 62.6 H% (calculated) 4,54 H% (found) 4.6 Cl% (calculated) 12.29 Cl% (found) 12.2 Zr% (calculated) 15.82 Zr% (found) 16.0

Example 4:

Preparation of rac-dimethylsilylbis (2-methylbenzo [e] indenyl) zirconium dichloride (I) by cleavage of the phenates from dimethylsilyl-bis (2-methylbenzo [e] indenyl) zirconium bis (3,5-di-tert-butyl-phenolate) (IV) with 2.6 equivalents Acetyl chloride and two equivalents DME.

4.1 g of the complex IV (4.47 mmol) from Example 1 were suspended in 40.6 g of toluene and 0.9 g (9.98 mmol) of DME in a dry round-bottom flask, which had been flushed with inert gas, with a cock and magnetic stir bar. To this suspension, 9.1 g (11.59 mmol) of a 10% by weight solution of acetyl chloride in toluene was added rapidly at room temperature via a dropping funnel. The reaction mixture was stirred at room temperature. After 4.5 hours, the reaction mixture was filtered with a number 4 glass filter frit purged with inert gas. The filter cake was washed twice with 10 g of heptane and then dried in vacuo. There was obtained 2.1 g of Compound I as a yellow powder. The ¹ H NMR spectrum showed the presence of the pure rac form. Elemental analysis: C% (calculated) 62.48 C% (found) 62.8 H% (calculated) 4,54 H% (found) 4.6 Cl% (calculated) 12.29 Cl% (found) 12.3 Zr% (calculated) 15.82 Zr% (found) 15.7

Example 5:

Preparation of rac-dimethylsilylbis (2-methylbenzo [e] indenyl) zirconium dichloride (I) via racemoselective synthesis of dimethylsilylbis (2-methylbenzo [e] indenyl) zirconium bis (3,5-di-tert-butylphenolate) (IV) with THF as Lewis base

a) Preparation of ZrCl ₄ (THF) ₂

10.0 g (42.91 mmol) of ZrCl ₄ in 130 g of toluene were suspended in a dry 500 ml round-bottom flask with tap and magnetic stir bar flushed with inert gas and a dropping funnel. The suspension was cooled in an ice bath to approximately 4 ° C. 3.10 g of THF in 38 g of toluene were then added dropwise via the dropping funnel dropwise over 15 minutes. The resulting suspension was allowed to warm to room temperature and stirred for one hour.

b) Preparation of Li (3,5- (t-Bu) ₂ -C ₆ H ₂ O)

In a dry, rinsed with inert gas 500 ml round bottom flask with Cock and magnetic stir bar and a dropping funnel were added 17.9 g (86.75 mmol) of 3,5-di-tert-butylphenol in 130 g of toluene and 6.4 g of THF dissolved. The solution was in an ice bath at about Cooled to 4 ° C and subsequently were during 29.0 g of a 20 wt .-% BuLi solution was added via the dropping funnel for 10 minutes. To Termination of the additive was left The reaction mixture was warmed to room temperature and stirred for about an hour.

c) Preparation of Cl ₂ Zr (3,5- (t-Bu) ₂ -C ₆ H ₃ O) ₂ (THF) ₂

The Suspension from step b) was added under nitrogen by means of a cannula in the Suspension of step a) at room temperature within several Minutes transferred. The Suspension was for stirred for a further 2.5 hours at room temperature.

d) Preparation of Me ₂ Si (2-Me-benzo [e] ind) ₂ Li ₂

In a dry 1000 ml three-necked round bottomed flask with magnetic stirring bar, dropping funnel and vacuum connection with tap, 16.7 g (40.08 mmol) of the ligand Me ₂ Si (1-H-2-Mebenz [e] indenyl) ₂ suspended in 157 g of toluene and 6.1 g of THF. To the suspension, 27.1 g of a 20% by weight BuLi solution was slowly added dropwise over 10 minutes at room temperature. The reaction mixture was heated to 80 ° C and stirred at this temperature for 2 hours. It was then cooled to room temperature.

e) Preparation of complex IV

The suspension from step c) was transferred under nitrogen by means of a cannula into the suspension from step d) within 5 minutes at room temperature. The suspension was stirred for 12 hours at room temperature. The ¹ H NMR spectrum of the reaction mixture showed that the complex IV had formed with a rac / meso ratio of about 5: 1. The suspension was filtered by cannula under nitrogen at room temperature over a number 4 glass filter frit rinsed with inert gas and slowly into a round bottomed flask. The filtrate was concentrated under reduced pressure to approximately half, whereby the complex partially crystallized. The suspension obtained contained about 200 ml of solvent and theoretically 40 mmol of complex IV.

f) Preparation of complex I

To the suspension from step e) was added 3.0 g (0.258 mmol) of THF. Subsequently, at room temperature, 99.7 g (100.1 mmol) of a 7.95% strength by weight solution of acetyl chloride in toluene were added via the dropping funnel. The mixture was stirred at room temperature. After an hour showed up yellow precipitate, whereupon the reaction mixture was stirred for a further 60 hours at room temperature. The ¹ H-NMR spectrum of the mixture indicated the formation of the metallocene compound I. The yellow precipitate was filtered and washed twice with 15 ml of toluene and then dried in vacuo. There were obtained 11.2 g of the object compound I. The ¹ H NMR spectrum showed the presence of the pure racemate form with only minor traces of impurities. Yield 47% based on ligands used. Elemental analysis: C% (calculated) 62.48 C% (found) 57.7 H% (calculated) 4,54 H% (found) 5.0 Cl% (calculated) 12.29 Cl% (found) 15.3 Zr% (calculated) 15.82 Zr% (found) 15.0

Example 6:

Preparation of rac-dimethylsilylbis (2-methylbenzo [e] indenyl) zirconium dichloride (I) via racemoselective synthesis of dimethylsilylbis (2-methylbenzo [e] indenyl) zirconium bis (3,5-di-tert-butylphenolate) (IV) with DME as Lewis base

a) Preparation of ZrCl ₄ (DME)

10.6 g (45.48 mmol) of ZrCl ₄ in 44 g of toluene were suspended in a dry, inert-gas purged 500 ml round bottom flask with a tap and magnetic stir bar and a dropping funnel. The suspension was cooled to approximately 4 ° C in an ice bath. Subsequently, 5.3 g of DME were added dropwise slowly over the dropping funnel over 15 minutes. The suspension was warmed to room temperature and stirred for one hour.

b) Preparation of Li (3,5- (t-Bu) ₂ -C ₆ H ₂ O)

In a dry, rinsed with inert gas 250 ml round bottom flask with Cock and magnetic stir bar and a dropping funnel were 18.9 g (91.60 mmol) of 3,5-di-tert-butylphenol in 55 g of toluene and 9.2 g of DME dissolved. The solution was at about 4 ° C in an ice bath cooled. Subsequently were during 28.3 g of a 20 wt .-% BuLi solution was added via the dropping funnel for 20 minutes. After completion of the addition, the mixture was allowed to reach room temperature heat and stirred another 50 minutes at room temperature.

c) Preparation of Cl ₂ Zr (3,5- (t-Bu) ₂ -C ₆ H ₃ O) ₂ (DME)

The Suspension from step a) was injected under nitrogen through a cannula into the solution from step b) within several minutes at room temperature. The resulting suspension was further 2.5 hours at room temperature touched and subsequently at 80 ° C heated.

d) Preparation of Me ₂ Si (2-Me-benzo [e] ind) ₂ Li ₂

Into a dry 1000 ml round bottom flask purged with inert gas, equipped with magnetic stirrer bar, dropping funnel and vacuum connection with tap, were added 15.8 g (37.92 mmol) of ligand Me ₂ Si (1-H-2-Me-benzo [e] ind). ₂ suspended in 52 g of toluene and 6.1 g of DME. To the suspension was added dropwise 26.0 g of a 20% by weight BuLi solution rapidly at room temperature. The mixture was heated to 80 ° C and stirred for 2.5 hours at this temperature.

e) Preparation of complex IV

The suspension from step c) was added under nitrogen to the suspension of step d) by means of a cannula at 80 ° C within a few minutes. The mixture was slowly cooled to room temperature and stirred at room temperature for a further 60 hours. The ¹ H NMR spectrum showed the formation of complex IV with a rac meso ratio of about 10: 1. The suspension was then filtered at room temperature on a number 4 glass filter frit. The filter cake was washed three times with 100 g of warm toluene and once with 200 g of 80 ° C hot toluene. The filtrate was concentrated under reduced pressure at 40 ° C to about 150 ml, whereby the complex partially crystallized.

f) Preparation of complex I

3.4 g of THF were added to the suspension obtained in step e). Then, at room temperature, 7.2 g of acetyl chloride in 200 g of toluene were added via the dropping funnel. The mixture was stirred for 12 hours at room temperature. Subsequently, the reaction mixture was filtered under inert gas through a number 3 glass frit filter. The yellowish precipitate was washed twice with 20 g of toluene and then dried in vacuo. 12.2 g of the target compound I were obtained. The ¹ H NMR spectrum showed the formation of the pure rac form of I with only traces of impurities. Yield 56% based on ligand. Elemental analysis: C% (calculated) 62.48 C% (found) 61.8 H% (calculated) 4,54 H% (found) 4.8 Cl% (calculated) 12.29 Cl% (found) 11.9 Zr% (calculated) 15.82 Zr% (found) 15.5

Comparative Example A:

Preparation of rac-dimethylsilylbis (2-methylbenzo [e] indenyl) zirconium dichloride (I) via recemo-selective synthesis of dimethylsilylbis (2-methylbenzo [e] indenyl) zirconium bis (3,5-dimethylphenolate) (IV) with THF as Lewis base.

a) Preparation of ZrCl ₄ (THF) ₂

In a dry, inertized 500 ml three-necked round bottom flask with magnetic stir bar, dropping funnel and vacuum connection with tap, 10.6 g ZrCl _{4 were} suspended in 50 g toluene. The suspension was cooled to about 4 ° C and slowly added dropwise over 15 minutes with 6.6 g of THF via a dropping funnel. The white suspension was warmed to room temperature and stirred for 1 h.

b) Preparation of Li (3,5-Me ₂ -C ₆ H ₂ O)

In a dry, inerted 250 ml three-neck round bottom flask with magnetic stir bar, Dropping funnel and vacuum connection with Hahn were 11.2 g of 3,5-dimethylphenol in 50 g of toluene and 6.6 g of THF solved. The red solution was at about 4 ° C chilled and over a dropping funnel with 29 g of a BuLi solution. It formed a blue suspension. Upon completion of the addition, the white suspension became warmed to room temperature and stirred for 1 h at room temperature.

c) Preparation of Cl ₂ Zr (3,5-Me ₂ -C ₆ H ₃ O ₂ ) ₂ (THF) ₂

The Suspension from reaction step b) was carried out under nitrogen using a cannula into the suspension from reaction step a) within several Minutes at room temperature. Left over Residues of the lithium phenolate were washed with 10 g of toluene. The brown suspension was stirred for 2.5 hours at room temperature.

d) Preparation of Me ₂ -Si (2-Me-benz [e] ind) ₂ Li ₂

15.9 g of the ligand Me ₂ Si (1-H-2-Mebenz [e] ind) ₂ in 50 g of toluene and 3.9 were placed in a dry, inerted 1000 ml three-necked round bottom flask with magnetic stir bar, dropping funnel and vacuum tap g THF suspended. 25.6 g of a BuLi solution were added dropwise to the suspension at room temperature. The yellow suspension was heated to 80 ° C and stirred at this temperature for 1.5 hours.

e) Preparation of Me ₂ -Si (2-Me-benz [e] ind) ₂ Zr (3,5-Me ₂ -C ₆ H ₃ O) ₂ and Reaction to Me ₂ Si (2-Me-benz [e ] ind) ₂ ZrCl ₂

The suspension obtained in reaction step c) was transferred under nitrogen by means of a cannula into the suspension from reaction step d) at 80 ° C. in each case. From the reaction mixture, a yellow colored suspension formed. Remaining residues of Cl ₂ Zr (3,5-Me ₂ -C ₆ H ₃ O ₂ ) ₂ (THF) ₂ were washed with 10 g of toluene. The suspension was stirred for 2 h at 80 ° C. It was treated with 250 g of toluene. The suspension was transferred at 80 ° C under nitrogen via cannula into an inert gas protected glass filter frit # 4 leads. The suspension was slowly filtered into a round bottom flask with a tap. The filter cake was washed with 50 g of toluene. The filtrate was strongly concentrated under reduced pressure, whereby 80% of the solvents evaporated, and then allowed to stand at room temperature. At room temperature, 7.3 g of acetyl chloride were injected and the reaction mixture was stirred for 12 h at room temperature. The yellow precipitate was filtered and dried in vacuo. 5.2 g of Me ₂ Si (2-Me-benz [e] ind) ₂ ZrCl _{2 were obtained} in pure rac form. Yield: 24%, based on indenyl ligands used.

Example 7:

Preparation of rac-dimethylsilylbis (2-methylbenzo [e] indenyl) zirconium dichloride (I) in a one-pot reaction

a) Preparation of Me ₂ Si (2-Me-benzo [e] ind) ₂ Li ₂

Into a dry 1000 ml round bottom flask with tap flushed with inert gas were charged 22.5 g of a 60% solution (in toluene) of 2-Me-benzindene (74.90 mmol). In addition, 290 g of toluene and 8.3 g of THF were added. At room temperature, 25.7 g of a 20 wt .-% solution of BuLi in toluene were added via a dropping funnel with stirring. Subsequently, the reaction mixture was stirred for one hour at 60 ° C and then cooled to room temperature. Thereafter, 5.0 g of Me ₂ SiCl _{2 was} added via the dropping funnel. After complete addition, the reaction mixture was heated to 80 ° C and stirred for 1.5 hours at this temperature. It was then allowed to cool to room temperature and put 25.7 g of a 20% BuLi solution in toluene to. After complete addition, the reaction mixture was heated to 80 ° C and stirred for a further 2 hours at this temperature. Then allowed to cool to room temperature.

b) Preparation of ZrCl ₄ (THF) ₂

In a 500 ml round bottom flask with tap 10.5 g of ZrCl _{4 were} suspended in 50 g of toluene. The suspension was cooled to about 4 ° C in an ice bath and then 8.0 g of THF were added slowly via a dropping funnel. The resulting suspension was allowed to warm to room temperature with stirring.

c) Preparation of Li (3,5- (t-Bu) ₂ -C ₆ H ₂ O)

In A 1000 ml round bottomed flask with a tap was added with 18.9 g of 3,5-di-tert-butylphenol (91.60 mmol) dissolved in 50 g of toluene and 8 g of THF. The solution was cooled in an ice bath and then added 29 g of a 20 wt .-% BuLi solution in Toluene added slowly. The reaction mixture was allowed to settle stir warm to room temperature.

d) Preparation of Cl ₂ Zr (3,5- (t-Bu) ₂ -C ₆ H ₃ O) ₂ (THF) ₂

at Room temperature was the suspension from step c) by cannula and under Nitrogen added to the suspension from step b) and at room temperature touched.

e) Preparation of complex IV

The suspension from step d) was added at room temperature to the suspension from step a). The mixture was then stirred at room temperature for 12 hours. The ¹ H-NMR spectrum of the reaction mixture showed a rac / meso ratio of about 11: 1. The mixture was stirred for 40 minutes at 80 ° C and then filtered under nitrogen on a glass filter frit. The round bottom flask was washed with 20 ml of toluene and the filter cake was washed twice with 20 ml of toluene. The ¹ H NMR spectrum of the filtrate showed a rac / meso ratio of about 9: 1. The filtrate had a mass of 614.6 g and was concentrated under reduced pressure at 40 ° C to 123.5 g. The theoretical concentration of IV is 20%.

f) Preparation of rac-dimethylsilylbis (2-methylbenzo [e] indenyl) zirconium dichloride (I)

Via a dropping funnel, 8.9 g of acetyl chloride in 25 g of toluene were added dropwise slowly at room temperature to the concentrated filtrate from step e). After completion of the addition, the mixture was stirred for a further 12 hours at room temperature. This formed a precipitate. To this suspension was added a further 100 ml of toluene and stirred for a further 2 hours. The resulting suspension was filtered, the round bottom flask was washed with 20 ml of toluene. The filter cake was washed twice with 20 ml of toluene and then dried in vacuo. There were obtained 9.3 g of the target Compound I in pure rac form with minor trace impurities.
Yield 43% based on the amount of indenyl ligand used.

Claims (18)

Process for the diastereoselective synthesis of rac-diorganosilyl-bis- (2-methylbenzo [e] indenyl) zirconium compounds according to formula I,

comprising the following steps: a) reacting a compound of the formula II with a zirconium bisphenolate complex of the formula III to the ansa-zirconocene bisphenolate complex of the formula IV,

b) Substitution of the IV phenolate groups with X using cleavage reagents to give the compound of Formula I; wherein the substituents X may be the same or different and represent F, Cl, Br, I and also linear, cyclic or branched C _1-10 -alkyl; and the substituents R may be the same or different and represent C _1-10 linear, cyclic or branched alkyl or C _6-10 aryl; and LB is a Lewis base, and M ₁ and M _{2 are} monovalent positive alkali metal ions or M ₁ and M ₂ together are a divalent positive alkaline earth metal ion. Process according to claim 1 for the diastereoselective synthesis of rac-diorganosilyl-bis- (2-methylbenzo [e] indenyl) zirconium compounds according to formula I,

comprising the following steps: a) deprotonation of 2-methylbenzo [e] inden by means of a deprotonating agent; b) reacting the deprotonated 2-methylbenzo [e] indene with a diorganosilyl compound R ₂ SiY ₂ , where the substituents R may be the same or different and are linear, cyclic or branched C _1-10 -alkyl or C _6-10 -aryl and the leaving groups Y can be the same or different and are F, Cl, Br or I, and subsequent deprotonation by means of a deprotonating agent, a compound according to formula II is obtained:

wherein M ₁ and M _{2 are} monovalent positive alkali metal ions or M ₁ and M ₂ together are a divalent positive alkaline earth metal ion; c) Reaction of the compound according to formula II with a zirconium bisphenolate complex according to formula III:

wherein LB is a Lewis base, whereby a compound of formula IV is obtained:

d) reacting the compound of formula IV with cleavage reagents substituting the phenolate groups of IV with X to obtain the compound of formula I wherein the substituents X are the same or ver may be different and stand for F, Cl, Br, I and linear, cyclic or branched C _1-10 alkyl. Method according to claim 2, characterized in that that the deprotonating agent is prepared from n-butyllithium, tert-butyllithium, Sodium hydride, potassium t-butoxide, Grignard reagents of magnesium, magnesium compounds such as in particular Di-n-butylmagnesium, (n, s) -Dibutylmagnesium or other suitable alkaline earth or alkali metal alkyl compounds selected is. Method according to claim 2 or 3, characterized that the process without isolation of intermediates after individual Process steps performed becomes. Method according to one of the preceding claims, characterized characterized in that the cleavage reagent aliphatic and aromatic acyl halides such as acetyl chloride, phenylacetyl chloride, 2-thiopheneacetyl chloride, trichloroacetyl chloride, Trimethylacetyl chloride, O-acetylmandelic acid chloride, 1,3,5-benzenetricarboxylic acid chloride, 2,6-pyridinecarboxylic acid chloride, tert-butylacetyl chloride, chloroacetyl chloride, 4-chlorobenzacetyl chloride, Dichloroacetyl chloride, 3-methoxyphenylacetyl chloride, acetyl bromide, Bromoacetyl bromide, acetyl fluoride, benzoyl fluoride, in solvents or used in substance. Method according to one of claims 1-4, characterized in that are used as cleavage reagent SOCl ₂ , silicon tetrachloride, methylaluminum dichloride, dimethylaluminum chloride, aluminum trichloride or ethylaluminum dichloride. Method according to one of claims 1-4, characterized that as elimination reagent HF, HBr, HI, preferably HCl, in substance or as a solution in water or organic solvents such as diethyl ether, DME or THF. A process as claimed in any of claims ₁ to 4, wherein the elimination reagent used is organoaluminum compounds such as tri-C ₁ -C ₁₀ -alkylaluminum, ie trimethylaluminum, triethylaluminum, tri-n-butylaluminum, triisobutylaluminum or dialkylaluminum chlorides or aluminum sesquichlorides be used. Method according to one of the preceding claims, characterized characterized in that the reaction in Lewis base-containing solvent mixtures of hydrocarbons and ethers or amines or both, preferably toluene and THF, Toluene and DME or toluene and TMEDA is performed. Method according to claim 9, characterized in that the Lewis base is used in an amount of 0.01-50 mol%, preferably 0.1-10 mol%, based on the solvent mixture, is present. Method according to one of the preceding claims, characterized characterized in that LB in formula III is selected from tetrahydrofuran (THF), Dimethoxyethane (DME) or tetramethylethanediamine (TMEDA). Method according to one of the preceding claims, characterized in that M ₁ and M _{2 are selected} from lithium, sodium, potassium, rubidium or cesium ions or together are magnesium. Method according to one of the preceding claims, characterized in that the substituents R are selected from methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl and phenyl, as well as combinations thereof selected are. Method according to one of the preceding claims, characterized characterized in that the substituents X are selected from F, Cl, Br, I, methyl, Ethyl, n-propyl, iso-propyl, n-butyl and iso-butyl, preferably Cl and / or methyl are. Method according to one of the preceding claims, characterized characterized in that R is methyl or ethyl, X is Cl and LB is THF or DME. Racemic transition metal compound according to formula IV:

wherein the substituents R may be the same or different and are C _1-10 linear, cyclic or branched alkyl or C _6-10 aryl. Connection according to claim 16, characterized in that the substituents R are selected from methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl and phenyl, and combinations thereof are selected. Use of racemic compounds according to the claims 16 or 17, as catalysts or as part of catalysts for the Polymerization of olefinically unsaturated compounds or as reagents or catalysts in stereoselective synthesis.