Method for producing 3-halopropyltrihalosilane by hydrosilylation

Abstract

The present invention relates to a method for the synthesis of at least one 3-halopropyltrihalosilane compound, the use of a novel catalyst system, and novel compositions.

Description

[Technical field]

[0001] The present invention relates to a method for the synthesis of at least one 3-halopropyltrihalosilane compound, a catalyst composition and its use in hydrosilylation reactions, and a reactive composition.

[0002] 2. Background of the Invention The hydrosilylation reaction, also called catalytic hydrosilylation, is the most important reaction, especially for the production of functional silanes. This reaction represents the addition of Si-H bonds across an unsaturated bond. An important group of silanes produced by this reaction are 3-halopropyltrihalosilane compounds, such as 3-chloropropyltrichlorosilane (also called trichloro(3-chloropropyl)silane). These are traditionally produced by hydrosilylation of allyl halides, such as allyl chloride, with H-silanes, such as trihalosilanes (e.g. trichlorosilane), in the presence of a platinum catalyst. This type of reaction generally suffers from moderate selectivity and yield. A commonly occurring side reaction is the reduction of allyl halides to propene, which is achieved by the reaction of SiCl 4 or SiBr 4 The resulting propene then reacts with one equivalent of H-silane to give a propyltrihalosilane, such as propyltrichlorosilane. Disadvantageously, isomerization of the unsaturated compounds used often occurs.

[0003] Various attempts have been reported in the prior art to improve the selectivity and yield of the aforementioned reactions. In addition to using various sources of metal catalysts, cocatalysts have been employed to improve the yield and selectivity. These cocatalysts include phosphines, oxygen, organic oxo compounds such as ketones and aldehydes, tertiary alcohols, alcoholates, and nitrogen-based compounds, to name a few.

[0004] DE 1 156 073 discloses the use of trialkylamines such as triethylamine and tributylamine as cocatalysts in the above reaction in combination with hexachloroplatinic acid or platinum on charcoal.

[0005] US Patent No. 4,292,434 discloses the synthesis of 3-chloropropyltrichlorosilane using hexachloroplatinic acid or platinum dihalide as the main catalyst and amines as cocatalysts. This method requires the preparation of the catalyst in a step prior to the synthesis of the desired silane. This additional step is naturally undesirable, since it increases the time required to produce the desired silane, unfavorably increasing the cost and time required for its production.

[0006] Examples 3 and 4 of US Pat. No. 3,925,434 disclose the reaction of allyl chloride with trichlorosilane in the presence of a catalytic system consisting of hexachloroplatinic acid and phenothiazine. The selectivity of the reaction is only moderate (see Table I in the cited reference). Many by-products are formed, with the majority of the fraction in the crude mixture constituting propyltrichlorosilane. In particular, the removal of the chlorine atom from the propyl group is undesirable since the alkylsilanes thus obtained cannot be further functionalized.

[0007] DE 10243180 A1 discloses the preparation of 3-chloropropyltrichlorosilane using a platinum catalyst and a ligand selected from aliphatic amides, nitriles and amines. Preferred amides are N,N-dimethylacetamide and N,N-dimethylformamide, and preferred amines are N,N-dimethylbutylamine, tert-butylamine or triethylamine.

[0008] Chinese Patent No. 108069996 reports the use of hexachloroplatinic acid as a platinum catalyst to prepare 3-chloropropyltrichlorosilane using formamide and its N-alkyl derivatives.

[0009] China Patent No. 102127104 discloses the synthesis of 3-chloropropyltrichlorosilane in the presence of n-butylamine, but the selectivity is low when this aliphatic amine is used as a cocatalyst.

[0010] Generally, the prior art proposals suffer from insufficient yields and / or selectivities.

[0011] Objective of the invention Therefore, it is an object of the present invention to overcome the shortcomings of the prior art.A further object of the present invention is to improve the selectivity of the production of 3-halopropyltrihalosilane compounds from allyl halide and H-silane as starting materials.It is further desirable to improve the yield of 3-halopropyltrihalosilane compounds starting from the above-mentioned reactants.

[0012] Summary of the Invention These objectives are: I) at least one unsaturated compound selected from the group consisting of allyl halides and methallyl halides; II) at least one H-silane selected from the group consisting of trihalosilanes, methyldihalosilanes and dimethylhalosilanes; A method for synthesizing at least one 3-halopropyltrihalosilane compound according to the present invention, comprising the reaction of: Reacting at least one unsaturated compound with at least one H-silane III) Karstedt catalyst; IV) Formula (A): [ka] [In the formula, R 1 is an aryl group, Each R 2 are independently an alkyl group, n is selected from 0 and 1; This is achieved by a process characterized in that it is carried out in the presence of

[0013] Components I and II are reacted in the presence of III and IV to provide at least one 3-halopropyltrihalosilane compound.

[0014] The process according to the present invention allows the production of 3-halopropyltrihalosilane compounds in high yields. Moreover, the selectivity of the process according to the present invention is improved, resulting in fewer undesirable by-products such as propyltrihalosilane and silicon tetrahalides. In the context of the present invention, selectivity means the selectivity of 3-halopropyltrihalosilane compounds, especially relative to propyltrihalosilane. The improved selectivity facilitates the purification of the desired 3-halopropyltrihalosilane compounds. The process according to the present invention is also ecologically and environmentally friendly, and more atom-efficient than the prior art processes.

[0015] Preferred embodiments which achieve the above mentioned objects particularly well are set forth in the following description and in the dependent claims.

[0016] Detailed Description of the Invention Percentages throughout this specification are percentages by weight (wt.-% or weight-%) unless otherwise stated. Thus, parts per million (abbreviated as ppm) are also by weight and are equivalent to mg / kg. Concentrations given herein relate to the volume or mass of the entire composition, solution or dispersion unless otherwise stated.

[0017] The term "alkyl" according to the present invention includes branched or unbranched alkyl groups containing cyclic and / or acyclic structural elements, the cyclic structural elements of the alkyl group of course requiring at least 3 carbon atoms. C1-CX alkyl in the present specification and claims refers to alkyl groups having 1 to X carbon atoms, where X is an integer. C1-C8 alkyl includes, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl, tert-pentyl, neopentyl, hexyl, heptyl and octyl. Substituted alkyl groups can theoretically be obtained by replacing at least one hydrogen with a functional group. Unless otherwise stated, the alkyl group is preferably selected from substituted or unsubstituted C1-C8 alkyl, more preferably from substituted or unsubstituted C1-C4 alkyl, due to improved water solubility.

[0018] The term "aryl" according to the present invention refers to a cyclic aromatic hydrocarbon group, for example phenyl or naphthyl, for example benzothiazolyl, in which the individual ring carbon atoms are optionally substituted with N, O and / or S. Preferably, none of said carbon atoms are replaced with other elements as previously described herein. Furthermore, the aryl group is optionally substituted by replacing the hydrogen atoms with respective functional groups. The term C5-CX aryl refers to an aryl group having 5 to X carbon atoms (optionally replaced with N, O and / or S) in a cyclic aromatic group, where X is of course an integer. Unless otherwise stated, C5-C6 aryl is preferred, and C6 aryl is even more preferred.

[0019] Unless otherwise stated, the above groups are substituted or unsubstituted. The functional groups as substituents are preferably halide (chlorine, bromine), ether (-OR), thioether (-SR), amine (-NH 2 , NHR, and NR 2 ), imines, amides, ketones, esters, alkoxysilyl (-Si(OR) 3), alkylsilyl (-SiR 3 ), thiol (-SH), and hydroxyl group (-OH). Preferably, the above groups are unsubstituted.

[0020] When two or more groups are selected from a given group, each group is selected independently of the others, unless otherwise stated below, meaning that each group can be selected to be the same or different members of said group. The methods described herein include named method steps. The named method steps are preferably performed in a given order, unless otherwise stated. The method optionally includes further method steps performed before, after and / or between said method steps. The preferences and details described for one aspect of the invention apply mutatis mutandis to other aspects, unless otherwise stated or technically impracticable.

[0021] The method according to the present invention allows the preparation of 3-halopropyltrihalosilane compounds. 3-halopropyltrihalosilane compounds in the context of the present invention include in particular 3-halopropyltrihalosilane, 3-halopropylmethyldihalosilane or 3-halopropyldimethylhalosilane, and the compounds described below. Preferred 3-halopropyltrihalosilane compounds are selected from the group consisting of 3-chloropropyltrichlorosilane, 3-bromopropyltrichlorosilane, 3-chloro-2-methylpropyltrichlorosilane and 3-bromo-2-methylpropyltrichlorosilane. As the at least one 3-halopropyltrihalosilane compound, 3-chloropropyltrichlorosilane and 3-chloro-2-methylpropyltrichlorosilane are more preferred, and 3-chloropropyltrichlorosilane is most preferred in this context.

[0022] The at least one unsaturated compound is selected from the group consisting of allyl halides such as allyl chloride (also called 3-chloroprop-1-ene, CAS number 107-05-1) and methallyl halides such as methallyl chloride (also called 3-chloro-2-methylprop-1-ene, CAS number 563-47-3). The halide is preferably a chloride. Preferred is an allyl halide. Even more preferred is that the at least one unsaturated compound is allyl chloride.

[0023] The at least one H-silane is selected from the group consisting of trihalosilanes, methyldihalosilanes and dimethylhalosilanes. The H-silane comprises at least one hydrogen atom bonded to the silicon atom by a single bond. The at least one H-silane is preferably selected from the group consisting of trihalosilanes and methyldihalosilanes. Even more preferred is trihalosilanes. The halogen atoms present in the at least one H-silane are preferably independently selected from the group consisting of chlorine and bromine, more preferably the halogen atoms are chlorine atoms. Particularly preferred is the at least one H-silane is trichlorosilane (H-SiCl 3 ).

[0024] The molar ratio of the at least one unsaturated compound to the at least one H-silane is preferably in the range of 2:1 to 0.2:1, more preferably 1.5:1 to 0.5:1, even more preferably 1.2:1 to 0.8:1.

[0025] Karstedt catalysts are known in the art. Karstedt catalysts are platinum complexes of 1,1,3,3-tetramethyl-1,3-divinyldisiloxane (CAS number 68478-92-2). Karstedt catalysts are typically used as alcoholic solutions. The alcohol in this context is preferably selected from the group consisting of methanol, ethanol, n-propanol, isopropanol and mixtures of the aforementioned, with isopropanol being particularly preferred. The weight ratio of the at least one alcohol to the Karstedt catalyst is preferably in the range of 20:1 to 1:10, preferably 10:1 to 1:5, more preferably 5:1 to 1:2.

[0026] The molar ratio of Karstedt catalyst to the at least one unsaturated compound is preferably in the range of 1:10 to 1:10,000,000, more preferably 1:100 to 1:1,000,000, even more preferably 1:1,000 to 1:100,000.

[0027] The at least one cocatalyst has the formula (A): [ka] [In the formula, R 1 is an aryl group, Each R 2 are independently an alkyl group, n is selected from 0 and 1.

[0028] R 1 is preferably an unsubstituted aryl group, more preferably an unsubstituted C5-C12 aryl, even more preferably an unsubstituted C5-C6 aryl, and most preferably an (unsubstituted) phenyl group. 2 is preferably a C1 to C4 alkyl group, and more preferably a methyl group. n is preferably 1.

[0029] Most preferably, the at least one cocatalyst is selected from the group consisting of N,N-dimethylaniline and N,N-dimethylbenzamide.

[0030] The molar ratio of the at least one cocatalyst according to formula (A) to the Karstedt catalyst is preferably in the range of from 1:1 to 100:1, more preferably from 2:1 to 50:1, even more preferably from 5:1 to 25:1.

[0031] Preferably, the reaction of at least one unsaturated compound with at least one H-silane is carried out in at least one solvent, and the solvent is preferably at least one 3-halopropyltrihalosilane compound, to which the priority outlined herein is applied.Other solvents can be selected by those skilled in the art based on routine experimentation.However, by using at least one 3-halopropyltrihalosilane compound as at least one solvent, the yield and selectivity of the reaction are surprisingly improved.

[0032] Preferably, the reaction of the at least one unsaturated compound with the at least one H-silane is carried out at a temperature in the range of 30-250°C, preferably 50-220°C, more preferably 80-200°C.

[0033] The reaction time of at least one unsaturated compound and at least one H-silane is not particularly limited. The reaction can be carried out until at least one unsaturated compound and / or at least one H-silane is consumed. Typically, the reaction of at least one unsaturated compound and at least one H-silane is carried out for 1 minute to 24 hours, preferably 1 to 12 hours, more preferably 2 to 6 hours.

[0034] Preferably, the reaction of at least one unsaturated compound with at least one H-silane is carried out in an inert atmosphere.Various methods of providing an inert atmosphere for this purpose are known to those skilled in the art.A particularly convenient method is to carry out the reaction in an inert gas, such as nitrogen, argon, or a mixture of the aforementioned.

[0035] In one embodiment of the present invention, the at least one unsaturated compound is allyl chloride, the at least one H-silane is trichlorosilane, and the at least one cocatalyst according to formula (A) is selected from the group consisting of N,N-dimethylaniline and N,N-dimethylbenzamide.

[0036] The method according to the invention preferably comprises the steps of: A1) a process step of mixing at least one H-silane, a Karstedt catalyst and at least one complexing agent according to formula (A) to obtain a premixture, A2) a method step of adding at least one unsaturated compound to the premix; and these method steps are performed in a given order.

[0037] The mixture obtained in process step A2 is reacted to obtain a 3-halopropyltrihalosilane compound. In process step A2, it is preferable to add at least one unsaturated compound continuously. Continuous addition in the context of the present invention should be understood as adding at least one unsaturated compound not in one step but over a period of time. A period of time means 1-25%, preferably 2-10% of the total period of the reaction.

[0038] Optionally, the method for the synthesis of at least one 3-halopropyltrihalosilane compound according to the invention then comprises a method step A3: A3) Method steps for purifying 3-halopropyltrihalosilane compounds will be implemented.

[0039] Various purification methods of said compounds are known to those skilled in the art. For example, the obtained mixture is purified by at least one method selected from the group consisting of distillation, filtration, precipitation or a combination of the above, with distillation being the most preferred purification method.

[0040] The present invention further provides a catalyst composition suitable for mediating a hydrosilylation reaction, preferably between at least one unsaturated compound selected from the group consisting of allyl halides and methallyl halides, and at least one H-silane selected from the group consisting of trihalosilanes, methyldihalosilanes and dimethylhalosilanes, to obtain 3-halopropyltrihalosilane compounds, comprising: α) a Karstedt catalyst; β) Formula (A): [ka] [In the formula, R 1 is an aryl group, Each R 2 are independently an alkyl group, n is selected from 0 and 1; The present invention relates to a catalyst composition comprising:

[0041] The catalytic composition according to the invention is capable of mediating (or catalyzing) hydrosilylation reactions, in particular the aforementioned reactions, i.e. in the latter case, converting at least one unsaturated compound and at least one H-silane into a 3-halopropyltrihalosilane compound, without necessarily undergoing any permanent change itself.

[0042] Another aspect of the present invention is directed to the use of the catalyst composition according to the present invention in a hydrosilylation reaction, preferably between at least one unsaturated compound selected from the group consisting of allyl halides and methallyl halides and at least one H-silane selected from the group consisting of trihalosilanes, methyldihalosilanes and dimethylhalosilanes, to obtain 3-halopropyltrihalosilane compounds.

[0043] In a further aspect of the invention, the present invention comprises a) at least one unsaturated compound selected from the group consisting of allyl halides and methallyl halides; b) at least one H-silane selected from the group consisting of trihalosilanes, methyldihalosilanes, and dimethylhalosilanes; c) Karstedt catalyst; d) Formula (A): [ka] [In the formula, R 1 is an aryl group, Each R 2 are independently an alkyl group, n is selected from 0 and 1; The present invention relates to a reactive composition comprising:

[0044] The reactive composition can be used to synthesize at least one 3-halopropyltrihalosilane compound.

[0045] The amount of the at least one unsaturated compound is preferably in the range of 5% to 80% by weight, more preferably 10% to 60% by weight, and even more preferably 15% to 50% by weight, based on the total amount of the reactive composition.

[0046] The amount of the at least one H-silane is preferably in the range of 10% to 90% by weight, more preferably 20% to 85% by weight, even more preferably 30% to 80% by weight, based on the total amount of the reactive composition.

[0047] The amount of Karstedt catalyst is preferably in the range of 0.1 ppm to 10 wt %, more preferably 0.5 ppm to 1 wt %, and even more preferably 1 ppm to 0.1 wt %, based on the total amount of the reactive composition.

[0048] The amount of the at least one cocatalyst according to formula (A) is preferably in the range of 0.1 ppm to 10% by weight, more preferably 0.5 ppm to 5% by weight, even more preferably 1 ppm to 1% based on the total amount of the reactive composition.

[0049] The reactive composition preferably comprises at least one solvent, which is preferably selected from those described hereinbefore. The amount of the at least one solvent in the reactive composition is preferably in the range of 10% to 90% by weight, more preferably 20% to 80% by weight, even more preferably 30% to 70% by weight, based on the total amount of the reactive composition. The amount of the aforementioned components can be optionally reduced by the amount of the solvent.

[0050] The amounts mentioned above preferably refer to the total amounts used before the reaction begins.

[0051] According to the present invention, it is possible to carry out a simple and economical hydrosilylation reaction with high yield and high selectivity.

[0052] The invention will now be described with reference to the following non-limiting examples.

[0053] Working Example Synthetic Procedure I. A 100 ml four-neck flask equipped with a Liebig condenser was placed in an oil bath and then, under nitrogen atmosphere, was charged with 36.5 g of 3-chloropropyltrichlorosilane, 15.0 g of trichlorosilane, Karstedt's catalyst (20% by weight platinum in isopropanol, 64 mg platinum per kg reactive composition), and cocatalyst, if any, in the amounts shown in Table 1. The Liebig condenser itself was connected to a cold trap (isopropanol / dry ice). 8.5 g of allyl chloride was added to this mixture by means of a syringe pump (1 mL / min). After complete addition of allyl chloride, the oil bath was heated to 180° C. until the bottom temperature reached said temperature, but for at least 3 hours. The results are listed in Table 1.

[0054] GC analysis: Restek RTX 200 column (L: 60m, ID: 0.53mm, d fChromatograms were obtained using an Agilent 6890 N gas chromatograph equipped with a column separator (3 μm) and the following temperature program: temperature: 40° C.; initial time: 7.00 min; rate: 15° C. / min; final temperature: 240° C.; final time: 10.00 min; injector temperature: 250° C.; detector temperature: 280° C. Retention times for the compounds of interest were as follows: 8.26 min, trichlorosilane; 9.70 min, tetrachlorosilane; 10.01 min, allyl chloride; 15.53 min, propyltrichlorosilane; 19.45 min, 3-chloropropyltrichlorosilane.

[0055] Selection rate Selectivity was calculated by dividing the GC area of ​​3-chloropropyltrichlorosilane by the GC area of ​​silicon tetrachloride. Because one molecule of silicon tetrachloride produces one molecule of the highly undesirable propyltrichlorosilane in the hydrosilylation reaction, the amount of silicon tetrachloride is a convenient way of assessing the selectivity of 3-chloropropyltrichlorosilane over propyltrichlorosilane.

[0056] [Table 1]

[0057] The process according to the invention using the cocatalyst according to formula (A) showed by far the best selectivity. Although many cocatalysts, such as acetamide and dimethylacetamide, proved to be efficient compared to the reference reaction without cocatalyst, only the compounds according to formula (A), N,N-dimethylaniline and N,N-dimethylbenzamide in our examples, gave selectivities well above 7.

[0058] Synthesis Step II: The synthesis procedure described above (Synthesis Procedure I) was repeated except that Karstedt's catalyst was replaced with hexachloroplatinic acid. The results are shown in Table 2 below.

[0059] [Table 2]

[0060] The results shown in Table 2 show that the platinum source has a significant influence on the reaction outcome. In particular, the yield only slightly decreased when changing from Karstedt catalyst to hexachloroplatinic acid. The most obvious effect is seen in the significantly lower selectivity obtained in the latter case. This observation attests to the uniqueness of the combination of Karstedt catalyst with the cocatalyst of formula (A) in hydrosilylation reactions, especially the combination described herein.

[0061] Other embodiments of the invention will be apparent to those skilled in the art from a consideration of this specification or practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope of the invention being defined only by the following claims.

Claims

1. I) at least one unsaturated compound selected from the group consisting of allyl halides and methallyl halides; II) at least one H-silane selected from the group consisting of trihalosilanes, methyldihalosilanes, and dimethylhalosilanes; 1. A method for synthesizing at least one 3-halopropyltrihalosilane compound, comprising the reaction of: reacting said at least one unsaturated compound with said at least one H-silane, III) Karstedt catalyst; and IV) Formula (A): 【Chemistry 1】 [In the formula, R １ is an aryl group, Each R ２ are independently an alkyl group, n is selected from 0 and 1; and The method is carried out in the presence of

2. R １ 2. The method of claim 1, wherein is a phenyl group.

3. R ２ The method according to claim 1 or 2, characterized in that is a C1 to C4 alkyl group.

4. 3. The process according to claim 1, wherein the molar ratio of said at least one cocatalyst to said Karstedt catalyst is in the range of 1:1 to 100:

1.

5. 3. The process of claim 1, wherein the molar ratio of said at least one unsaturated compound to said at least one H-silane ranges from 2:1 to 0.2:

1.

6. 3. The process according to claim 1, wherein the reaction of the at least one unsaturated compound with the at least one H-silane is carried out in at least one solvent.

7. 3. A process according to claim 1 or 2, characterized in that the reaction of said at least one unsaturated compound with said at least one H-silane is carried out at a temperature ranging from 30 to 250°C.

8. 3. The process according to claim 1, wherein the reaction of the at least one unsaturated compound with the at least one H-silane is carried out in an inert atmosphere.

9. The method comprises: A1) a process step of mixing said at least one H-silane, said Karstedt catalyst and at least one cocatalyst according to formula (A) to obtain a premix; A2) adding said at least one unsaturated compound to said premix; 3. The method according to claim 1, wherein the method steps are carried out in a given order.

10. 3. The method of claim 1, wherein the at least one unsaturated compound is allyl chloride.

11. 3. The method of claim 1, wherein said at least one H-silane is trichlorosilane.

12. 3. The process according to claim 1, wherein the at least one unsaturated compound is allyl chloride, the at least one H-silane is trichlorosilane, and the at least one cocatalyst according to formula (A) is selected from the group consisting of N,N-dimethylaniline and N,N-dimethylbenzamide.

13. 1. A catalyst composition suitable for hydrosilylation reactions, comprising: α) Karstedt catalyst; β) Formula (A): 【Chemistry 2】 [In the formula, R １ is an aryl group, Each R ２ are independently an alkyl group, n is selected from 0 and 1; and A catalyst composition comprising:

14. Use of the catalyst composition of claim 13 in a hydrosilylation reaction.

15. a) at least one unsaturated compound selected from the group consisting of allyl halides and methallyl halides; b) at least one H-silane selected from the group consisting of trihalosilanes, methyldihalosilanes, and dimethylhalosilanes; c) Karstedt catalyst; and d) Formula (A): 【Transformation 3】 [In the formula, R １ is an aryl group, Each R ２ are independently an alkyl group, n is selected from 0 and 1; and A reactive composition comprising:

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