JPH03150382A - Preparation of organosilicone compound - Google Patents

Abstract

PURPOSE: To make it possible to electrochemically synthesize an organosilicon compd. by electrically reducing a compd. having carbon atoms subjected to halogen substitution in the presence of a silane having a substituting which is a silicon-bonded halogen atom.

CONSTITUTION: The compd. I having the substituent of general formula -RX (R is bivalent carbon or a (substd.) hydrocarbon, X is a halogen atom) is electrically reduced in the presence of the silane II expressed by the formula R'_4-a-bSiX_a(RX)_b. In the formula, R' is hydrogen, a hydrocarbon, etc., (a) is 1 to 4, (b) is 0 to 3, a+b is 2 to 4. Reaction is preferably effected in an electrolytic cell having two cells by using silver or stainless steel for a cathode and carbon or Al for an anode.

COPYRIGHT: (C)1991,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an electrochemical method for synthesizing organosilicon compounds, particularly polycarbosilane compounds.

[Conventional technology and issues]

The term organosilicon compound as used herein refers to a compound in which at least one organic group is attached to a silicon atom via a Si--C bond.

These compounds have a silane with one silicon atom and at least one organic group bonded to the silicon atom via a silicon-carbon bond and at least two silicon atoms bonded via an R group. including carbosilane compounds, provided that R is divalent carbon or substituted or Si-
The carbosilane, which represents a hydrocarbon group that may be attached to each silicon atom via a C bond, has the general formula -Si-R-Si
- and polycarbosilanes having at least two units of the general tR structure -(R-Si-)-, where R is defined as above.

Si-C and Si-CH2-Si bonds are usually formed via Grignard or Wurtz reactions involving the use of metals such as magnesium, sodium and lithium. These methods are complex and expensive; Furthermore, it is necessary to protect any functional groups that may be present from the reagent.

electrochemical synthesis
hesis) is known and has been practiced in organic chemistry for quite some time. Recently, it has been shown that the silylation of compounds using trimethylchlorosilane is possible via electrosynthesis. Shono et al. (Chemical Letters 1985, pp. 463-466)
We have shown that reduction of benzyl and allyl halides in the presence of trimethylchlorosilane gives the corresponding benzylsilanes and allylsilanes. They are also 1, 4
It is shown that electrolytic reduction of dichlorobutene gives 1.4 bis(trimethylsilyl)butene. Pons et al. (Journal of Organometallic Chemistry, 1988.31-37)
page) is carbon tetrachloride using trimethylchlorosilane,
By electroreduction of chloroform and methylene chloride,
sacrificial electrode
rode) to give the corresponding trimethylsilyl-substituted compounds. They also illustrate the electroreduction of trimethylchloromethylsilane using trimethylchlorosilane to give hexamethylsilymethylene.

[Means to solve the problem]

We have now found that it is possible to use electrosynthesis for the production of organosilicon compounds as defined above by using dihalosilanes, trihalosilanes, tetrahalosilanes, or octalocarbohalosilanes. Ta.

According to the present invention, a compound (I) having a substituent of the general formula -RX (wherein R represents a divalent carbon or an optionally substituted hydrocarbon compound, and X is a halogen atom), General formula % formula %) (wherein R' is hydrogen, a hydrocarbon group, a group containing H, C and 0 atoms, S atom and/or P atom, and C,
a group consisting of H and N atoms and optionally O atoms (provided that N does not form part of an amino group), X and R are as defined above, and a has a value of 1.2.3 or 4; , b has a value of 0.1.2 or 3, and a
+ b has a value of 2.3 or 4) silane(II)
A method is provided for producing organosilicon compounds having at least one silicon-bonded organic group attached to a silicon atom via a Si-C bond by subjecting the compound to electroreduction in the presence of .

The compound (I) used in the process of the invention may be any compound with a halogen-substituted carbon atom, the halogen atom being preferably chlorine, bromine or iodine, the latter being the most reactive. . However, for industrial availability and cost purposes chlorine and bromine are preferred; halogen atoms are used in compounds which may be purely organic or which may have both organic and inorganic parts, e.g. Bonded to silicon or organogermanium compounds. The R group to which the halogen atom is attached is a binary carbon or substituted hydrocarbon group. Carbon groups include, for example, acetylene and 1.
Contains 3 butadiene.

Hydrocarbon R groups can vary from methylene groups to very large hydrocarbon groups. These are saturated alkylene groups, e.g.
Ethylene, isopropylene, hexylene and octadecylene, unsaturated aliphatic groups such as alkenylene or alkynylene such as vinylene, propenylene, butadienylene, hexynylene, vinylene and 1.4 octadecylene, aromatic groups such as phenylene, benzylene, tolylene and phenyl A substituted hydrocarbon group, which may be ethylene, has one or more substituents, which may be any group in which the carbon atom does not react with the halogen group of compound (l[) under the reaction conditions. It is.

These substituents include fluorine, cyano, nitro, oxyethylene, silyl, siloxane, carbosilyl; examples of such substituted hydrocarbon groups are hexafluoro-10pyrene, oxyethyleneoxypropylene substituents,
The R group, including acetyl substituents, ether substituents and ester substituents, can be aromatically unsaturated, aliphatically unsaturated or aliphatically saturated hydrocarbons such as benzylene, propenylene, Preferably isopentylene, butylene, propylene, ethylene or phenylene, most preferably methylene and vinylene, the R group may be attached oppositely to any atom or group,
These include, for example, halogen atoms, hydrocarbon groups, organosilicon groups, organofunctional groups such as sulfur-containing, phosphorus-containing groups and even halogen atoms, with the R group opposite from the X group relative to the hydrogen or halogen atom. Examples of compounds (I) which are preferably combined are carbohalides such as methyl halides, such as methyl chloride, methane dichloride,
Benzyl halides, such as benzyl chloride, phenyl halide, vinyl halide, 1.4 dichloro-2-butene, dibromoethylene, 1.2. and suchloromethylbenzene, silanes such as trimethylchloromethylsilane, dimethylchloromethylchlorosilane, siloxanes such as general formula 04--FSiRx(CHzX)? (
where R' is as defined above but is preferably hydrogen, a hydrocarbon such as an alkyl, aryl, alkenyl or alkaryl or a group containing (,H and optionally N or 0 atoms, is 0.1 or 2
, y has a value of l, 2, or 3, and x + y is less than 3) and, if present, the average formula and 2 has the value O, It is preferred to avoid siloxanes as it is difficult to control the properties of the reaction products, including siloxanes having at least - units of (as described above).

Compound (II) used in the method of the present invention is a silane having a substituent containing at least two halogens, at least one of which is a silicon-bonded halogen atom. Iodine is the most reactive halogen, but chlorine and bromine atoms are preferred for industrial availability and cost reasons.
Any silicon-bonded halogen atom is compound (I)
Examples of these halogen-containing substituents which are not bonded to the silicon via an R group as defined above for are haloalkyl, such as chloromethyl,
Bromoheptyl, octoalkenyl such as chlorovinyl, bromopropenyl, octoaryl groups such as chlorophenyl and bromobenzyl. The halogen-free substituents R′, if present, include hydrogen, hydrocarbon groups such as alkyl, aryl, alkaryl, aralkyl,
Arkeni.

alkynyl, C, H and O atom-containing groups such as carboxyl group-containing groups, C=0-containing groups, aldehyde-containing groups and epoxy-containing groups, ether-containing groups, sulfur-containing groups or C, H and N atom-containing groups (but , N does not form part of an amino group), e.g. cyano group-containing substituents and N
Examples of such groups containing O group-containing substituents are methyl,
Ethyl, propyl, phenyl, phenylethyl, tolyl, vinyl, allyl, hexenyl, ethynyl, butadienyl, stearyl, lauryl, ethoxy, methoxy, polyoxyethyl and benzyl. Preferably R' is hydrogen, alkyl or aryl, most preferably methyl or phenyl.

Preferably, the value of a+b is equal to 2, provided that the two R' groups independently represent substituents as mentioned above, and the values for a and b are 1 and 1 or separately i and 0. Examples of compound (II) which is preferably dimethyldichlorosilane, dimethylchloromethylchlorosilane,
Methyltrichlorosilane, carboxymethyltrichlorosilane, phenylmethyldichlorosilane, diphenyldichlorosilane, methylcyanopropyldichlorosilane,
Methyldichlorosilane, dichlorosilane, methylbis(
chloromethyl)chlorosilane and methylglycidoxyprobylchloromethylchlorosilane.

Depending on the organosilicon compound one wishes to synthesize, certain types of compounds (I) and (II) should be selected. Additional compounds may also be added, if the organosilicon compounds made by the method of the invention contain silanes, or if [) is a purely organic compound without silicon atoms in its structure, and if one -If only RX groups are present in (I), or if more than one RX group
group is present in (I) and only the excess of (n) is 1 of (I)
If fed to react with -RX groups, silanes will be produced; the resulting silanes are e.g. Carbosilanes as defined above, including chloromethyldimethylbutylsilane, dibromovinyldimethylsilane, etc.
11(I) or a compound (I) of formula XRX with an amount of compound (II) sufficient to react with at least two of these -RX groups or with the Alternatively, the compound (I) having only one -RX group is converted into a compound (I) having two or more silicon-bonded halogen atoms.
I) containing, for example, one -RX group and one SiX group for reaction with a compound (ff) which may be supplied together with or identical to It is produced by supplying compound (I). In general, the value of a+b in compound (II) will determine in most cases the general properties of the resulting carbosilane, a
If +b is 2, the use of such a compound (II) will increase the chain length of the resulting organosilicon compound, while if a + has a value of 3 or 4, then A mixture of a compound (II) with a + b of 2 and a compound (II) with a + b of 3 or 4, which in some cases will give rise to some branching in the organosilicon compound leading to a three-dimensional #I structure, is basically becomes a linear carbosilane with some branching. On the other hand, increasing the amount of compound (II) with a value of 3 or 4 will increase the amount of branching and ultimately result in a resin-type carbosilane reaction product.

Depending on the properties of the desired carbosilane compound, the compound (I
) and (II) may be reacted together, or mixtures of different types of compound (I) and/or compound (II) may be reacted together. It is also possible to use the same reagents for and compound (n), for example silanes with one or more silicon-bonded halogen atoms and one or more -RX groups. For example, the compound (
Chloromethylchlorosilanes falling under both definitions I) and (II) can react with each other. Such a reaction produces a polycarbosilane having repeating units of the general formula [S i (R)z CHt ]-. These compounds may be linear or cyclic or mixtures of linear and cyclic organosilicon compounds; when linear polycarbosilanes are desired, other compounds, such as formula R3Si
X (where R' and X are as defined above)
It is preferred to add an end-capping agent, which may be a silane of, for example, the general formula R[Si(R''>2-R],
To obtain a linear polymer with S ; It should include a silane of the formula R'', SiX.

However, it is possible to make relatively low molecular weight ones, such as polycarbosilanes with two or three silicon atoms, which may be used as precursors for higher molecular weight materials using conventional polymerization techniques. preferable.

The reaction may be carried out in any manner using an electrolytic cell having a cathode and an anode; the electrolytic cell may be a single-chamber cell, but preferably has two chambers separated by a membrane, e.g. The bath is equipped with a potentiostat and/or a calvastat to adjust the potential or intensity of the current.

The electrodes which may be used as cathodes or practical electrodes are preferably made of inert metals such as gold, silver or platinum, most preferably of silver or other fairly inert metals or alloys, such as stainless steel. However, the counter electrode (anode) may also be inert or sacrificial to some extent.

The choice of counter electrode sometimes depends on the desired reaction. In some cases a sacrificial inert counter electrode is preferred, while in other cases a sacrificial electrode works well. The metals used for manufacturing the counter electrode are, for example, C, A1. pt-Ni-Zn and M, with C being particularly preferred as an inert electrode;
And Al is particularly preferable as an electrode for cathodic protection.

Preferably, the complexing agent is used together with the sacrificial electrode,
The use of a complexing agent counteracts the catalytic activity of the resulting Lewis acid,
Lewis acids, such as AICI, are known catalysts for the ring opening of eg tetramethylsilacyclobutane and even tetrahydrofuran, which are suitable as solvents for the process according to the invention. Suitable complexing agents are known to those skilled in the art and include tris(dioxa-3,6 hebutyl)amine and hexamethylphosphoramide.

The electrolytic cell is filled with a solution of any electrolyte that is commercially available and soluble in the solvent used for the reagents. These electrolytes have the general formula MY-(
In the formula, M is, for example, Li, Na, NBu, NM e
4, represents NEtn, and Y is, for example, CIO,, CI-
Br, I, NO3, BF,, AsF,, BPh,, P
F,, AIC1,, CF, So3, and SCN (where Bu, Me, Et, and ph are butyl,
1 representing methyl, ethyl, and phenyl groups. Examples of suitable electrolytes include tetrabutylammonium-P-)luenesulfonic acid, tetrabutylammonium hexafluorophosphate, tetrabutylammonium bromide, tetraethylammonium tetrafluoroborate, lithium chloride and magnesium chloride.

Solvents that dissolve both reagents and electrolytes are typically used. Suitable solvents are those in which the reagents are at least partially soluble under the operating conditions of concentration and temperature. These include tetrahydrofuran, acetonitrile, gamma-butyrolactone, dimethoxyethane with nitromethane, 1.3 dioxolane, liquid S02, trimethylurea and dimethylformamide.

The electrolytic reaction may be carried out by keeping the intensity constant at a predetermined level or by maintaining a constant potential determined by cyclic voltammetry; standard electrolytic techniques are applicable to the method of the invention. It is possible.

〔Example〕

A number of examples are presented below to illustrate the invention.

All parts and percentages herein are by weight, unless otherwise specified.

1) A one-compartment electrolytic cell equipped with a nitrogen supply port, stirring and air cooling system was charged with 50 iZ of a solution of 0.2 mol of tetrabutylammonium hexafluorophosphate in tetrahydrofuran and 8.5 g of chloromethyldimethylchlorosilane. A constant current density of 125 mA was applied via a galvanostat/potentiostat using an aluminum foil as the anode and a silver wire as the cathode.

This current was applied for 22 hours to provide 1.9 Faradays per mole of CZC82. A mixture of reaction products was obtained which was analyzed by gas chromatography/mass spectrometry and showed that about 65% had the formula [(CH3)2S
i CHz]z, and about 35% have the formula [(CH,)
, Si-CI,], about 50% cyclic compound,
Formula % Formula %] (where 84% is waiting for a value where n is equal to 3, and about 5
~8% were the respective compounds where n had values of 2.4 and 5, and a trace amount of the compound where n had a value of 1) consisted of approximately 50% linear compounds. It was discovered that

A 250 x flask was equipped with a nitrogen purge, magnetic stirring bar, condenser and air cooling system. 100 zl of a 0.2 molar solution of tetrabutylammonium hexafluorophosphate in tetrahydrofuran and 1511 F of 3-chloropropyldimethylchlorosilane were added.

Electrolytic reactions were carried out using a 362 potentiostat-galvanostat. The cathode was a silver wire (5 cm length and 0.25 mid diameter) and the anode was 4 pieces of aluminum (3.5 x O, 01 cm). A constant current is applied for 25 hours at a temperature of 23°C (2 per mole of Giraffe).
．． 5 Faraday) applied. The resulting reaction mixture was analyzed by gas chromatography/mass spectrometry. 83.7% was 1.1-dimethyl-1-silacyclobutane, 8.1% was unreacted 3-chloropropyldimethylchlorosilane, and 7.9% was propyldimethylchlorosilane.

A 250 ml flask was equipped with a nitrogen purge, magnetic stirring bar, condenser, and air cooling system. 150 ml of a 0.2 molar solution of tetrabutylaluminum hexafluorophosphate in tetrahydrofuran and 25.52 ml of chloromethyldimethylchlorosilane were added. The electrolytic reaction was carried out as in the previous example, except that 2.8 Faradays were applied per mole of silane at a temperature of 30°C. The resulting reaction mixture was analyzed as above. 62
．． 6% is 1.1.3.3-tetramethyl-1,3-disilanecyclobutane and 31.4% is 1.1.3.
It was 3.5°5-hexamethyl-1,3,5-)lysilacyclohexane.

A 250i+f flask was equipped with a nitrogen purge, magnetic stirring bar, condenser, and air cooling system. Tetrabutylammonium hexafluorophosphate) 0.2 molar tetrahydrofuran solution 10011 and 2,2.
5.24 sr of 0-dichloroxylene and 43 sr of dichlorodimethylsilane were added.

The electrolytic reaction was carried out as in the previous example, except that 4.87 Faradays were applied per mole of 0-dichloroxylene. The resulting reaction product was washed with water, extracted with diethyl ether, dried and analyzed as above. 65% Formula % Formula % A 250 iN flask was equipped with a nitrogen purge, magnetic stirring bar, condenser, and air cooling system. 100xl of a 0.2 molar solution of tetrabutylammonium hexafluorophosphate in tetrahydrofuran, 3.70 g of cis-dichlorobutane and 4 g of dichlorodimethylsilane were added. In the electrolytic reaction, 2113 Faraday is cis-
It was carried out as in the previous example, except that it was applied per mole of dichlorobutane. Analysis of the resulting reaction mixture showed 15% dimethylsilacyclopentene.

A 250 ml flask was equipped with a nitrogen purge, magnetic stirring bar, condenser, and air cooling system. 100 wl of a 0-2 molar solution of tetrabutylammonium hexafluorophosphate, 12.5 g of chloromethyltrimethylsilane and 6.5 g of dichloromethylsilane were added. The electrolytic reaction was carried out as in the previous example except that 2.3 Faradays were applied per mole of chloromethyltrimethylsilane. The resulting reaction mixture was analyzed to show 25% bis(trimethylsilane)methylsilane.

E11d An aluminum rod (99 purity) as an anode for the Schlenk tube.
．． 5%, diameter 6.3511) and a stainless steel case (20 meshes 30 cm) as cathode. Tetrahydrofuran 14-3 ml, tetraethylammonium tetrafluorophosphate O-
08y, a solution of 3.6 ml hexamethylphosphoramide and 0.1 wl trimethylchlorosilane is Loom^
Electrolyzed 2 hours ago. 2.28y of chloromethyldimethylchlorosilane was added. The electrolytic reaction was carried out at a temperature of 23 °C for 10 hours at a constant current (2.3 molar per mole of silane).
Faraday). The resulting reaction mixture was filtered and stripped under reduced pressure.
It gave 1.68g of distillate.

Analysis by gas chromatography/mass spectrometry yielded 69% of 1.1.3.3-tetramethyl-1,3-disilacyclobutane.

and 1''1 Using the apparatus of Example 7, 4.24 g of chloropropyltrichlorosilane was added to the reaction product of the previous example. Electrolysis was then continued for 0 hours in 2001^. After 3.5 hours, a maximum conversion of 45% to dichlorosilacyclobutane was observed.

Large 111'' - The apparatus of Example 7 was used, except that a solid carbon dioxide cooled condenser was added to minimize reagent loss. Tetrahydrofuran 8-45wl Tetraethylammonium Tetrafluoroborate 0.08#
, hexamethylphosphoramide 2.1i+J! , 6.4 ml of dichloromethane and 0.0 ml of trimethylchlorosilane.
1 ml of solution was added at 50 x^, 3-03 yzl of pre-electrolyzed \chloromethyldimethylchlorosilane for 2 hours. The electrolytic reaction was carried out by applying a constant current (giving 4 Faradays per mole of silane) for 53 hours at a temperature of 23°C. The resulting reaction mixture was analyzed by gas chromatography/mass spectrometry to give 74% dimethyldichloromethylsilane.

Support 1''J The apparatus of Example 9 was used. Tetora Dorofuran 9.
16zZ, tetraethylammonium tetrafluoroborate 0.08g, hexamethylphosphoramide2.
29d, a solution of 1.28 ml dichloromethane and 1 ml trimethylchlorosilane O was preelectrolyzed at 50 mA for 2 hours. 7.27 ml of dimethyldichlorosilane were added and the electrolysis was continued at 501^ for 24 hours (giving 2.2 Faradays per mole of silane). The resulting reaction mixture was analyzed by gas chromatography/it quantitative analysis to give 81% (based on reacted silane) chlorodimethylchloromethylsilane.

Dog 11[''''2 Tetrahydrofuran 12 in which the device of Example 9 was used
．． A solution of 0.08 g of 67zN, tetraethylammonium tetrafluorobole), 3.12d of hexamethylphosphoramide, 0.85Ill of dichloromethane and OAxl of trimethylchlorosilane was pre-electrolyzed at 50Z for 2 hours. 4.48 ml of methyltrichlorosilane were added and the electrolysis was continued at 501^ for 12.5 hours (giving 2.2 faradays per mole of silane). The resulting reaction mixture was analyzed by gas chromatography/mass spectrometry to reveal 62% methyldichlorochloromethylsilane and 1% methylchlorodichloromethylsilane.
I gave 3%.

The apparatus of Example 9 was used. Tetrahydrofuran 11
．． 8 ml, tetraethylammonium tetrafluoroborate 0.08 g, hexamethylpho.

Sphoramide 2.95ml, dichloromethane 0.64ml
A solution of 1 ml and trimethylchlorosilane O, L ml is 5
9 f of a loaf of tetrachlorosilane, previously electrolyzed for 2 hours at 0 g^, is added and the electrolysis is carried out for 12.5 hours at 50 m^ (giving 2.2 Faradays per mole of silane).
I could continue. The resulting reaction mixture was subjected to chromatography/
Analyzed by mass spectrometry to give 58% trichlorochloromethylsilane, 15% dichlorodichloromethylsilane and 3% chlorotrichloromethylsilane.

The apparatus of Example 9 was used. Tetora Dorofuran 12
-37mZ, tetraethylammonium tetrafluoroborate 0.08y, hexamethylphosphoramide 3
．． 09xl, phenyl chloride 1-12zjl and trimethylchlorosilane OAxl were preelectrolyzed for 2 hours at 5011^. 4.48 g of methyltrichlorosilane were added and electrolysis was continued at 501^ for 12 hours (giving 2.2 faradays per mole of silane). The resulting reaction mixture was analyzed by gas chromatography/mass spectrometry to give 65% dichlorophenylmethylsilane, 10% methylchlorodiphenylsilane and 6% dichloromethylsilphenylene.

The apparatus of Example 9 was used. Tetora Dorofuran 11
．． 52 mN, tetraethylammonium tetrafluoroborate 0.08f, hexamethylphosphoramide 2
．． A solution of 88 mN, phenyl chloride 1-12zf and trimethylchlorosilane Q4d was preelectrolyzed at 50i+^ for 2 hours. 6.79 g of methyltrichlorosilane was added and the electrolysis was continued at 501^ for 12.5 hours (giving 2.2 Faradays per mole of silane). The resulting reaction mixture gave 68% trichlorophenylsilane, 10% dichlorodiphenylsilane and 8% trichlorosilphenylene analyzed by gas chromatography/mass spectrometry.

Claims (1)

[Claims] 1. A method for producing an organosilicon compound having at least one silicon-bonded organic group bonded to a silicon atom via a Si-C bond, wherein
A compound (I) having a substituent (R represents a divalent carbon or an optionally substituted hydrocarbon compound, and X is a halogen atom) has the general formula R'_4_-_a_-_bSiX_a(RX)_b (wherein, R is hydrogen, a hydrocarbon group, a group containing H, C and O atoms, S atom and/or P atom, and C, H and N atoms, and optionally O atom (however, N is an amino group). X and R are as defined above, a has a value of 1, 2, 3 or 4, b is 0, 1, 2 or 3, and a+b is 2 , having a value of 3 or 4) A method for producing an organosilicon compound 2, characterized in that the R group of the compound (I) is an aromatic is an aliphatically unsaturated, aliphatically unsaturated, or aliphatically saturated hydrocarbon, and in compound (II), R' is hydrogen, alkyl or aryl. , a method according to claim 1. 3. Process according to claim 1 or 2, characterized in that in compound (II) the value of a+b is equal to 2. 4.Claim, characterized in that the cathode is made of silver or stainless steel and the anode is made of carbon or aluminum, and that the electrolysis is carried out in an electrolytic cell with two compartments separated by a membrane. Method according to any one of paragraphs 1 to 3. 5. Claim 1, characterized in that a complexing agent is used.
Method according to any of paragraphs from paragraphs to paragraphs 4.