DE4009910A1 - Ethenolytic metathesis of olefin(s) - using organo-rhenium oxide catalyst on oxidic carrier - Google Patents

Abstract

The use is claimed of an organorhenium oxide cpd. of formula (I) as the catalyst on an oxidic carrier for the metathesis of olefinic cpds. as per the parent patent EP appln. 89122437 (DE 3940196), the novel feature in this patent of addn. being that the metathesis is an ethenolytic one. (I) is (R1)a (e)b (O)c where a = 1-6; b = 1-4; c = 1-14 with the provisos that a+b+c is such that the 5-7 valency of Re is fulfilled and that c is not greater than 3-b; R1 = 1-9C alkyl, 5-10C cycloalkyl or 7-9C aralkyl and R1 is opt. at least partly fluorinated, with the provisos that (i) there are no more than 3 gps. with more than 6C per Re atom and (ii) the C atom in the alpha position is still bonded to an H atom. Specifically the olefin is of formula (II) and it is reacted with ethylene YCZ=CZ-(CX2)n R2 (II) n = 1-28; x = H or F; Y = H or 1-10 alkyl; Z = H or a non-aromatic 1-6 hydrocarbon with the proviso that Y and Z are not simultaneously H; R2 = H, alkyl, halogen, COOR3 or OR4; R3 and R4 = 1-15(pref. 1-6)C hydrocarbon or phenyl (opt. carrying 1-3 substits. on the ring or R4 = (R5)3 Si where R5 = 1-5(pref. 1-3)C alkyl. USE/ADVANTAGE - (I) catalyses the ethenolytic splitting of chain or cyclic non-functional or functionalised olefins such as cis/trans-3-heptene, 2,4,4-trimethyl -2-pentene, 1,3-cyclohexadiene, cyclooctene, Me oleate, 2-norbornene, alpha, alpha'-diphenylstilbene, geranyl acetone or 1,6-di(perfluoro -n-hexyl)-hexene-3.

Description

The present invention relates to a method for the so-called ethenolytic metathesis (ethenolysis) of non-functionalized and functionalized olefins using organic derivatives of Rhenium oxides, as well as on the use of such Derivatives as catalysts for this ethenolysis.

The term ethenolysis denotes the cleavage of olefinic compounds in the presence of the olefin Basic body ethylene, in such a way that the Double bonds of the olefin and ethylene in question be broken apart and the resulting ones Statistically broken fragments to new olefinic ones Unite connections. This creates a single product if you use a symmetrical mono-olefin. Out an asymmetrical monoolefin gives two different products. When using di and oligo olefins the number of products increases accordingly. To Ethenolysis of olefins also belongs in the broader sense Ring opening of cycloolefins, with one Cycloolefin with n ring members by ethenolysis ω, ω′-diolefin with n + 2 chain links.

Ethenolytic olefin cleavages are for the manufacture of fine and large chemicals for some time industrial interest. This is how the Phillips process is Production of neohexene (3,3-dimethyl-1-butene) and that Shell process for the preparation of ω, ω′-diolefins, which as Crosslinker in olefin polymerization or for production bifunctional connections are technically important, industrial examples of catalytic olefin ethenolysis.  

While in conventional olefin metathesis, mostly Called "self-metathesis", the purpose is a unbalanced olefin into two other olefins with shorter or longer carbon atom chain to convert or a cyclic To differentiate or polymerize olefin ring opening the ethenolysis is such that one basically final olefins (α-olefins) generated, the fragments, by breaking the starting olefin on the double bond arise, each extended by a CH₂ group. The Ethenolysis of internal olefins is therefore the counterpart for self-metathesis of α-olefins.

Ethenolysis is almost always a pressure reaction and in terms of process technology from conventional Differentiated olefin metathesis. As a rule, you also have different catalysts for the two processes used.

Of the numerous catalysts for olefin metathesis are suitable, have been described in the main patent so-called organorhenium oxides through special activity expelled. This class of catalysts is even in the Location, without adding the required by older procedures Cocatalysts also catalyze functionalized olefins convert into metathesis products.

The subject of the main patent is u. a. the use of Compounds of the general formula

R¹ _a Re _b O _c (I)

wherein a are 1 to 6, b are 1 to 4 and c are 1 to 14 and the sum of a, b and c is such that it corresponds to the 5- to 7-valence of the Rheniums does justice with the proviso that c is not greater than 3xb, and wherein R¹ is an alkyl group of 1 to 9 C atoms, a cycloalkyl radical having 5 to 10 C atoms or represents an aralkyl radical having 7 to 9 carbon atoms, where R1 may be at least partially fluorinated, the Connections no more than three groups with more than Contain 6 carbon atoms per rhenium atom and attached to the carbon atom in  α position still bound at least one hydrogen atom which are applied to oxidic substrates, as catalysts for the metathesis of olefinic compounds.

The main patent also relates to a process for Metathesis of olefins, which is characterized in that type olefins

YCZ = CZ- (CX₂) _n R² (II)

where n is a integer from 1 to 28, X is H or F, Y is H or alkyl with 1 to 10 C atoms and Z is H or one is not aromatic hydrocarbon radical with 1 to 6 carbon atoms represents and the substituent R² H, alkyl, halogen, COOR³ or OR⁴, wherein R³ and R⁴ are alkyl of 1 to 15, preferably 1 to 6, carbon atoms or phenyl, which is still on the ring Can contain 1 to 3 substituents or wherein R⁴ trialkyl is silyl R⁵₃Si, wherein R⁵ is alkyl with 1 to 5, preferably 1 to 3, represents carbon atoms on catalysts, which converts oxide support materials exist on the compounds of the aforementioned type are applied.

With this procedure, it was possible for the first time to choose from many For reasons of disadvantageous use of additional activators ("Cocatalysts") are dispensed with. The effectiveness such catalysts on ethylene itself was not described. It was because of the mentioned Differences between traditional metathesis and Ethenolysis also not to be expected.

It has now surprisingly been found that the mentioned methods of the main patent used Catalysts also as catalysts for ethenolysis for splitting chain and cyclic, non- functionalized and functionalized olefins suitable are.

The invention thus relates to the use of those compounds of rhenium that have the general formula

R¹ _a Re _b O _c (I)

in which a is 1 to 6, b is 1 to 4 and c is 11 to 14 and the sum of a, b and c is such that it is the 5- to 7 valence of the rhenium, with the proviso that c is not greater than 3 · b, and that on oxidic Carrier materials are applied as Heterogeneous catalysts for ethenolytic metathesis. Here R¹ is an organic group which has a Carbon atom, at least one more Hydrogen atom is bound to the metal rhenium is bound, namely alkyl radicals with 1 to 9 carbon atoms, Cycloalkyl with 5 to 10 carbon atoms, such as cyclohexyl or 1-norbornyl, or aralkyl with 7 to 9 carbon atoms, such as Benzyl, but preferably methyl. The terms alkyl and Cycloalkyl naturally involve that these groups are none Multiple bonds included. R1 can at least partially be fluorinated. However, comes out in the connections steric reasons the presence of more than three groups not considered with more than 6 carbon atoms per rhenium atom; the compounds expediently contain at most one such group. The term metathesis closes here ring opening of cycloolefins.

The complex compounds of the aforementioned formula (I) are known, but the catalytic activity of these compounds in ethenolysis, that is to say in pressure reactions of ethylene, was not known and was not to be expected. The catalytic effect is all the more surprising since the (trimethylstannoxy) rhenium trioxide [(CH₃) ₃SnO] ReO₃ is catalytically ineffective like all other oxidic rhenium compounds, such as the dirhenium heptoxide Re₂O₇, various perrhenates with the anion [ReO₄] ^- , the rhenium trioxide ReO₃ and the other rhenium oxides Re₂O₅ and ReO₂.

Those used in accordance with the present invention Catalysts can be found in the main application manufacture as specified. Especially come into consideration  Catalysts that are easy as a rhenium compound accessible methylrhenium trioxide contain CH₃ReO₃. As Carrier materials are particularly suitable for aluminum oxide and combinations thereof with silica, however other oxides such as titanium, zirconium, niobium, tantalum and Chromium oxides by themselves or in combination with aluminum and / or silicon dioxide.

The oxidic used according to the invention Carrier materials are applied rhenium compounds highly active catalysts for non-ethenolysis functionalized as well as functionalized olefins of Type

YCZ = CZ- (CX₂) _n R² (II)

where n is an integer from 1 to 28, X is H or F, Y is H or alkyl with 1 to 10 C atoms and Z is H or a non-aromatic Represents hydrocarbon radical with 1 to 6 carbon atoms (where however, Y and Z should not be hydrogen at the same time), the z. B. is cyclohexyl, but preferably is open-chain alkyl having 1 to 4 carbon atoms, and the R² is H, alkyl, halogen, COOR³ or OR⁴, wherein R³ alkyl or aryl and R⁴ alkyl, aryl or trialkylsilyl R⁵₃Si is. The alkyl groups in R⁵ contain 1 to 5, preferably 1 to 3 carbon atoms. In R³ and R⁴ alkyl stands for 1 to 15, preferably 1 to 6 carbon atoms and aryl for Phenyl, which has one to three substituents on the ring may contain, such as halogen, e.g. B. fluorine, chlorine or bromine, NO₂, NR⁶R⁷, OR⁸ and / or alkyl. The residues R⁶, R⁷ and R⁸ are the same or different and can be hydrogen or Be alkyl with 1 to 4 carbon atoms. R² as halogen can be fluorine, Chlorine, bromine or iodine. The two Z can be the same or to be different. When Z is hydrogen and R² is halogen, this is preferably bromine. Connections in which at least an X = F, z. B. 1,6-di- (perfluoro-n-hexyl) hexene (3) of the formula

(n-C₆F₁₃) -CH₂-CH₂-CH = CH-CH₂-CH₂- (n-C₆F₁₃)

and Perfluoropropene C₃F₆. The number of links n preferably varies in the range from 1 to 12 and in particular to 8.  

The catalysts are therefore not only included in olefins Z = H, but also partially in the case of ethenolysis fluorinated olefins effective. They are also suitable for the Ethenolysis of internal, functionalized olefins formula

R⁹CH = CH- (CH₂) _n R¹⁰ (III)

wherein R⁹ is a branched or expediently unbranched alkyl radical having 1 to 12 carbon atoms, R¹⁰ is a carboxylalkyl radical, wherein the alkyl radical expediently has 1 to 4 carbon atoms and n is an integer of 1 to 10. Methyl oleate may be mentioned as an example (R⁹ = n-octyl, R¹⁰ = CO₂CH₃, n = 7).

Catalyze the catalysts used according to the invention but not only the ethenolysis of open chain compounds, but also the ring-opening ethenolysis of cycloolefins and cyclic hydrocarbons with several olefinic structural elements. Examples are cyclooctene, 1,5-cyclooctadiene and cycloolefins with up to 20 Chain links, also cyclic di- and oligo-olefins, which still carry heteroatom-containing functions.

The catalytically active rhenium compound is used for the present methods advantageously at room temperature a solvent, preferably a dichloromethane Solution, on the catalyst support, advantageously silica gel / Alumina, applied, with only the carrier in front its use for 2 h at 550 to 800 ° C in a nitrogen stream is freed of moisture so that the catalyst system afterwards its full activity unfolds.

In the case of ethenolysis with those used according to the invention It is important to ensure that air and Moisture can be excluded. Even the ones used Before use, olefins are expediently good too dry. Ethenolysis is generally at 3 to 30 preferably 5 to 20 bar ethylene pressure and a temperature from -25 to + 70 ° C, expediently carried out +20 to 65 ° C.  

The possibility of being relatively mild Working reaction conditions is a particular advantage of the method according to the invention. But it is also possible even higher temperatures, e.g. B. up to 100 ° C or with less, e.g. B. atmospheric pressure to work. However there are usually no advantages associated with this.

Examples 1 to 13 - ethenolysis with (CH₃) ReO₃

In a 250 ml laboratory autoclave, the temperature given in Table 1 a solution of 13 mg (0.052 mmol) of methyl rhenium trioxide CH₃ReO₃ in 0.5 ml Dichloromethane in a suspension of 2000 mg Catalyst carrier SiO₂ / Al₂O₃ (weight ratio 87: 13, Grain size below 15 µm; Kept at 550 ° C for 2 h) in 50 ml Dichloromethane (dried over calcium hydride and under Nitrogen atmosphere saved) entered. To For 5 minutes stirring 2.5 mmol olefin were injected (t = 0) and an ethylene pressure shown in Table 1 pressed on. After a reaction time of 5 h Liquid phase the products listed in Table 1 proven by gas chromatography.

Examples 14 to 17 - ethenolysis with (CH₃) ₄Re₂O₄

When using this compound as a catalyst for the Olefin metathesis was carried out in the same way as in the Examples 1 to 13 for methyl rhenium trioxide CH₃ReO₃ is described, only that instead of the solution of 13 mg Methyl rhenium trioxide now a solution of 25.4 mg (0.052 mmol) Tetramethyltetraoxodirhenium (CH₃) ₄Re₂O₄ in 0.5 ml Dichloromethane in a suspension of 2000 mg of Catalyst carrier entered. After a response time of 5 h in the liquid phase were given in Table 2 Products detected by gas chromatography (Examples 14 to 17).  

Table 1

Ethenolysis of non-functionalized and functionalized open-chain and cyclic olefins with (CH₃) RO₃

Table 2

Ethenolysis of olefins with (CH₃) ₄Re₂O₄ on Al₂O₃ / SiO₂

Claims (5)

1. Use of compounds of the general formula R 1 _a Re _b O _c (I) in which a is 1 to 6, b 1 to 4 and c 1 to 14 and the sum of a, b and c is such that it is the 5- to 7-valence of the rhenium is justified with the proviso that c is not greater than 3 · b, and in which R¹ is an alkyl radical with 1 to 9 carbon atoms, a cycloalkyl radical with 5 to 10 carbon atoms or an aralkyl radical with 7 to 9 represents carbon atoms, where R¹ can be at least partially fluorinated, the compounds contain no more than three groups with more than 6 carbon atoms per rhenium atom and at least one hydrogen atom is bonded to the carbon atom in the α-position oxidic support materials are applied as catalysts for the metathesis of olefinic compounds according to the patent. . . (European patent application 8 91 22 437.0), characterized in that the catalysts are intended for the ethenolytic metathesis of olefinic compounds. 2. Process for the metathesis of olefins, in which olefins of the type YCZ = CZ- (CX₂) _n R² (II) wherein n is an integer from 1 to 28, XH or F, YH or alkyl with 1 to 10 C- Is atoms and represents ZH or a non-aromatic hydrocarbon radical having 1 to 6 carbon atoms and the substituent R² is H, alkyl, halogen, COOR³ or OR⁴, where R³ and R⁴ are alkyl having 1 to 15, preferably 1 to 6, carbon atoms or Phenyl, which may contain 1 to 3 substituents on the ring or wherein R⁴ is trialkylsilyl R⁵₃Si, wherein R⁵ is alkyl having 1 to 5, preferably 1 to 3, C atoms, on catalysts which consist of oxidic support materials on which Compounds of the type defined in claim 1 are applied, characterized in that the olefins are subjected to a reaction with ethylene and in the olefins of the formula II Y and Z are not simultaneously hydrogen. 3. The method according to claim 2, characterized in that the catalyst carrier made of aluminum oxide, silicon dioxide, Titanium, zirconium, niobium, tantalum, chromium oxide or Combinations of these exist. 4. The method according to claim 2 or 3, characterized characterized in that at an ethylene pressure of 3 to 30, preferably works from 5 to 20 bar. 5. The method according to one or more of the claims 2 to 4, characterized in that one Temperature from -25 to +70, preferably from +20 to + 65 ° C is working.