JP2021084881A - Method for producing iodotrialkylsilane compound - Google Patents

Abstract

To provide a method for producing iodotrialkylsilane compounds that can be produced stably even in various organic solvents.SOLUTION: A method for producing an iodotrialkylsilane compound (2A) includes bringing a halogenated trialkylsilane compound (1A) into contact with an alkali iodide metal salt in an organic solvent for a reaction to occur between them (X is F, Cl, or Br).SELECTED DRAWING: None

Description

The present invention relates to a novel method for producing an iodotrialkylsilane compound. More specifically, the present invention relates to a novel method for producing an iodotrialkylsilane compound that can be stably produced even in various organic solvents.

Iodotrialkylsilane compounds such as iodotrimethylsilane are useful reagents that can be used for cleavage of ether bonds, removal of carbamate protecting groups, cleavage of ester groups, and the like. On the other hand, it is known that it is a compound that is sensitive to moisture and light and is extremely difficult to handle (see Non-Patent Document 1).

So far, various methods have been proposed as methods for obtaining an iodotrialkylsilane compound. For example, a method of obtaining an iodidetrimethylsilane compound by the reaction of trimethylsilane chloride and magnesium iodide in tetrahydrofuran (see Non-Patent Document 2), and a method of obtaining an iodotrimethylsilane compound by the reaction of hexamethyldisilane and iodine (Non-Patent Document 3). (See), a method obtained by contacting chlorotrimethylsilane and sodium iodide in an acetonitrile solvent (see Non-Patent Document 4) and the like have been proposed.

Tetrahedron 1982, Vol. 38, No. 15,2225-2277 Chemische Berichte 1962, 95, 174-182 Synthesis 1979 (9), 740-741 The Journal Organic Chemistry 1979, Vol. 44, No. 8,1247-1251

As described above, while the iodotrialkylsilane compound is a reagent used in various reactions, it is an unstable compound in the reaction system, and there is a problem in stably producing the iodotrialkylsilane compound. For example, in the method for obtaining an iodotrialkylsilane compound by the reaction of chlorotrimethylsilane and magnesium iodide in tetrahydrofuran, the produced iodotrialkylsilane compound reacts with tetrahydrofuran which is a solvent, and then reacts with chlorotrimethylsilane. It is known that a mixture of tetramethyldisilane and the like can be obtained, and the method for producing an iodotrialkylsilane compound by this method has a problem in that the conditions such as the substrate to be reacted are greatly restricted. Further, the method for obtaining an iodotrimethylsilane compound by the reaction of hexamethyldisilane and iodine still has a problem in that the reaction rate is very low and an expensive raw material is used. Further, it is known that in the method obtained by contacting chlorotrimethylsilane and sodium iodide in an acetonitrile solvent, the produced iodotrialkylsilane compound becomes a semi-stable state by reaction with acetonitrile as a solvent. Therefore, there is still a problem in terms of application to reactions using other organic solvents.

Therefore, an object of the present invention is to provide a method for producing an iodotrialkylsilane compound capable of stably producing an iodotrialkylsilane compound even in various organic solvents.

The present inventors have made extensive studies to solve the above problems. As a result, a halogenated trialkylsilane compound can be produced by reacting the halogenated trialkylsilane compound with an alkali metal iodide salt in various organic solvents, and in particular, the organic solvent is toluene. , It has been found that a halogenated trialkylsilane compound can be stably produced when a non-polar solvent such as methylene chloride is used. Further, it was confirmed that the obtained trialkylsilane halide compound was not a reaction product with a solvent but a target trialkylsilane halide compound. Further, by allowing the tetra-substituted ammonium salt to be present when the above-mentioned trialkylsilane compound halide is brought into contact with the alkali metal iodide salt, the reaction proceeds in a short time, and the desired halogenation occurs in a high yield. They have found that a trialkylsilane compound can be produced, and have completed the present invention.

That is, the present invention has the following equation (1).

(In the formula, R ^{1 to} R ³ are substituted or unsubstituted alkyl groups having 1 to 4 carbon atoms, and R ^{1 to} R ³ may be the same group or different groups, respectively. Good. X is a group selected from fluorine atom, chlorine atom and bromine atom.)
The halogenated trialkylsilane compound represented by (2) is reacted by contacting it with an alkali metal iodide salt in an organic solvent, and the following formula (2)

(In the formula, R ^{1 to} R ³ are synonymous with those in the above formula (1).)
It is a method for producing an iodotrialkylsilane compound, which produces an iodotrialkylsilane compound represented by.

The present invention preferably adopts the following aspects.

1) The organic solvent is at least one selected from halogenated hydrocarbons, aromatic hydrocarbons, and amides.

2) The organic solvent is a non-polar solvent.

3) The halogenated trialkylsilane compound represented by the above formula (1) is subjected to the following formula (3).

(In the formula, R ^{4 to} R ⁷ are alkyl groups or aralkyl groups, which may be the same group or different groups, respectively. Y is a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. , A hydroxyl group, or a hydrogen sulfate group.)
Contact with alkali metal iodide salt in the presence of the tetra-substituted ammonium salt indicated by.

4) The halogenated trialkylsilane compound represented by the above formula (1) is the following formula (1A).

(In the formula, X is synonymous with that in the formula (1).)
The trimethylsilane halide represented by the above formula (2), and the iodotrialkylsilane compound represented by the above formula (2) is the following formula (2A).

(In the formula, R is synonymous with that in the formula (1A).)
Must be trimethylsilane iodide represented by.

According to the production method of the present invention, a halogenated trialkylsilane compound can be produced in a high yield regardless of the type of organic solvent used in the reaction. Further, the halogenated trialkylsilane compound and the alkali metal iodide salt are relatively inexpensive raw materials, and by using these, the halogenated trialkylsilane compound can be industrially and efficiently produced. In particular, a halogenated trialkylsilane compound can be produced in high yield even when a non-protic solvent is used as the organic solvent, and the range of application of organic synthesis using the halogenated trialkylsilane compound can be expected to be expanded.

Further, by contacting the halogenated trialkylsilane compound with the alkali metal iodide salt and reacting it in the presence of the tetrasubstituted ammonium salt, the halogenated trialkylsilane compound can be produced in a short time and in good yield. As described above, an iodotrialkylsilane compound such as iodotrimethylsilane is a useful reagent that can be used for cleavage of ether bonds, removal of carbamate protecting groups, cleavage of ester groups, etc., and yields in a short time. The production method of the present invention capable of producing a halogenated trialkylsilane compound well is an extremely useful method, and the industrial utility value of the present invention is very high.

In the present invention, the trialkylsilane halide compound represented by the formula (1) is reacted by contacting it with an alkali metal iodide salt in an organic solvent, and the trialkylsilane compound represented by the formula (2) is reacted. Is a method for producing an iodotrialkylsilane compound. Hereinafter, the present invention will be described in detail.

(Halogenated trialkylsilane compound)
In the production method of the present invention, the halogenated trialkylsilane compound is represented by the following formula (1).

It is a compound indicated by. In formula (1), R ^{1 to} R ³ are substituted or unsubstituted alkyl groups having 1 to 4 carbon atoms. Specific examples of such an alkyl group include a methyl group, an ethyl group, an n-butyl group, an n-propyl group, a 1-methylbutyl group and a t-butyl group. R ^{1 to} R ³ may be the same group or different groups, respectively. Among these alkyl groups, R ^{1 to} R ³ are preferably all the same alkyl group from the viewpoint of usefulness as the above-mentioned reagent. That is, the halogenated trialkylsilane compound represented by the formula (1) has the following formula (1A).

The halogenated trimethylsilyl compound represented by is suitable. Further, X is a group selected from a fluorine atom, a chlorine atom and a bromine atom. As these halogenated trialkylsilane compounds, industrially available compounds can be used.

(Organic solvent)
In the production method of the present invention, the iodotrialkylsilane compound represented by the above formula (2) is produced in an organic solvent. The organic solvent is not particularly limited as long as it does not inhibit the reaction, but a low-polarity or non-polar organic solvent is preferable.

Examples of the organic solvent include halogenated hydrocarbons such as chloroform, methylene chloride, chlorobenzene and carbon tetrachloride; aromatic hydrocarbons such as toluene and xylene; N, N-dimethylformamide (DMF), N, N-dimethylacetamide. Examples thereof include amides such as (DMA), N-methyl-2-pyrrolidone (NMP), N, N-dimethylimidazolidine-one (DMI) and the like. Non-polar solvents such as halogenated hydrocarbons and aromatic hydrocarbons are preferable, and toluene and methylene chloride are particularly preferable. These organic solvents can be used alone or as a mixed solvent thereof.

The amount of the organic solvent used is not particularly limited. It is preferable to use 0.5 to 100 times the volume of the organic solvent, and more preferably 1 to 10 times the volume of the halogenated trialkylsilane compound represented by the formula (1). It is particularly preferable to use ~ 3 times the capacity. When a mixed solvent is used as the reaction solvent, the total amount of the mixed solvent may satisfy the above range.

(Alkali metal iodide)
In the present invention, the halogenated trialkylsilane compound represented by the above formula (1) is brought into contact with an alkali metal iodide salt to cause a reaction. Specific examples of the alkali metal iodide salt include lithium iodide (LiI), sodium iodide (NaI), potassium iodide (KI), and cesium iodide (CsI). Among these alkali metal iodide salts, it is preferable to use sodium iodide from the viewpoint of reactivity with the halogenated trialkylsilane compound represented by the above formula (1) and price.

The amount of alkali metal iodide used is not particularly limited. It is preferable to use 1 to 5 mol, and more preferably 1 to 2 mol, with respect to 1 mol of the halogenated trialkylsilane compound represented by the formula (1).

(4-substituted ammonium salt)
The production method of the present invention is characterized in that the halogenated trialkylsilane compound represented by the formula (1) is brought into contact with the alkali metal iodide salt and reacted. 3)

By carrying out the reaction in the presence of the tetra-substituted ammonium salt represented by (2), the iodotrialkylsilane compound represented by the above formula (2) can be produced in a short time with good yield, which is preferable. In the formula (3), R ^{4 to} R ⁷ are alkyl groups or aralkyl groups, which may be the same group or different groups, respectively. Further, it is preferable that at least 3 of ^{R 4 to} R ^{7 are alkyl groups.}

The alkyl group preferably has 1 to 20 carbon atoms, and more preferably 1 to 4 carbon atoms. The aralkyl group preferably has 7 to 20 carbon atoms, and more preferably 7 to 10 carbon atoms.

Y is a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a hydroxyl group, or a hydrogen sulfate group, and is preferably a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a hydrogen sulfate group.

Specific examples of the tetra-substituted ammonium salt represented by the above formula (3) include tetra-n-butylammonium iodide (TBAI), tetramethylammonium iodide (TMAI), and tetra-n-butylammonium bromide (TBAB). Tetra-n-butylammonium chloride (TBAC), tetramethylammonium chloride (TMAC), tetra-n-butylammonium fluoride (TBAF), tetra-n-butylammonium hydrogen sulfate, benzyltrimethylammonium iodide, benzyltrimethylammonium Examples thereof include bromide, benzyltrimethylammonium chloride, benzyltrimethylammonium fluoride, benzyltrimethylammonium hydrogen sulfate, tetraethylammonium iodide, tetraethylammonium bromide, tetraethylammonium chloride, tetraethylammonium fluoride and tetraethylammonium hydrogen sulfate. Among these tetra-substituted ammonium salts, tetra-n-butylammonium bromide (TBAB), tetra, from the viewpoint of the yield of the iodotrialkylsilane compound represented by the above formula (2) and the point of being easily available industrially. It is preferable to use -n-butylammonium chloride (TBAC).

The amount of the tetra-substituted ammonium salt represented by the above formula (3) is not particularly limited. It is preferable to use 0.001 to 1 mol, and more preferably 0.005 to 0.1 mol, with respect to 1 mol of the halogenated trialkylsilane compound represented by the formula (1).

(Manufacture of iodotrialkylsilane compound)
In the production method of the present invention, the halogenated trialkylsilane compound represented by the formula (1) is reacted by contacting it with an alkali metal iodide salt in an organic solvent, and the iodine represented by the formula (2) is reacted. Produces trialkylsilane compounds. The reaction can be carried out by mixing each component.

The method of mixing each component is not particularly limited, and can be carried out in a reaction vessel equipped with a stirrer. The procedure for adding each component into the reaction vessel is to add the halogenated trialkylsilane compound represented by the above formula (1), the tetra-substituted ammonium salt represented by the above formula (3) to be added as needed, and an organic solvent. The halogenated trialkylsilane compound represented by the formula (1) and the tetra-substituted ammonium salt represented by the formula (3) are dissolved in an organic solvent in advance in a reaction vessel, and then the alkali metal iodide is stirred. A method of adding and mixing salts is preferable.

The order in which the halogenated trialkylsilane compound represented by the formula (1), the tetra-substituted ammonium salt represented by the formula (3) added as needed, and the organic solvent are charged into the reaction vessel is not particularly limited, but first. It is preferable that an organic solvent is charged, and then the halogenated trialkylsilane compound represented by the formula (1) and the tetra-substituted ammonium salt represented by the formula (3) are added and dissolved in this order with stirring. The temperature at the time of addition and dissolution is not particularly limited, and can be carried out in the range of 0 to 100 ° C. More specifically, it is preferably 5 to 70 ° C, more preferably 10 to 50 ° C.

The temperature at the time of adding the alkali metal iodide salt is not particularly limited and may be the same as the above temperature range. The reaction temperature after the addition of the alkali metal iodide salt may be appropriately set within a range in which the reaction proceeds sufficiently, and is preferably 0 ° C to 100 ° C, more preferably 10 ° C to 50 ° C. By carrying out the reaction in the temperature range, the reaction can proceed in a high yield and in a short time.

The reaction time is also not particularly limited, and may be appropriately determined while confirming the conversion rate of the product to the iodotrialkylsilane compound represented by the above formula (2), but is usually 1 hour or more and 10 It may be less than an hour, preferably 0.5 hours or more and 5 hours or less.

The reaction atmosphere is also not particularly limited, but is preferably under an inert gas atmosphere and an air atmosphere.

Further, the inside of the reaction system may be under atmospheric pressure, pressurization, or decompression. Above all, it is preferable to carry out under atmospheric pressure.

In the present invention, the following formula (2) is obtained by the above reaction.

The iodotrialkylsilane compound represented by is obtained. In the above formula (2), R ^{1 to} R ³ are synonymous with those in the above formula (1).

Here, when the halogenated trimethylsilane compound represented by the above formula (1A) is used as the halogenated trialkylsilane compound represented by the above formula (1), the following formula (2A) is used.

The iodidetrimethylsilane represented by is can be produced.

The obtained iodine trialkylsilane compound can be used as it is as a reagent in the next reaction without being isolated from the reaction solution.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. The reaction was followed up under the following gas chromatography analysis conditions.

(Gas chromatography analysis conditions)
Equipment: Agilent Technologies 7820A GC System
Column: HP-5 (30m x 0.32mm x 0.25μm) manufactured by Agilent Technologies
Column temperature: 40 ° C for 5 minutes → 10 ° C / min to 110 ° C → 20 ° C / min to 230 ° C → 230 ° C for 5 minutes Injection inlet temperature: 250 ° C
Injection volume: 0.2 μL
Detector: FID
Detector temperature: 300 ° C
Carrier gas: helium, 13.3 mL / min
Split: 30: 1
Retention time: chlorotrimethylsilane 4.62 min, iodotrimethylsilane 8.10 min
Example 1
After dissolving chlorotrimethylsilane (1.0 g, 9.21 mmol) and tetrabutylammonium bromide (TBAB, 148 mg, 0.460 mmol) in dichloromethane (5.0 mL), sodium iodide (1.66 g, 1.66 g,) at 25 ° C. 11.1 mmol) was added, and the mixture was stirred at 40 ° C. for 1 hour.

The reaction solution (100 μL) was diluted with dichloromethane (400 μL), and the obtained sample was analyzed by gas chromatography (GC) to calculate the conversion rate. As a result, the addition rate was 95.4%.

Example 2
After dissolving chlorotrimethylsilane (1.0 g, 9.21 mmol) and tetrabutylammonium bromide (TBAB, 148 mg, 0.460 mmol) in dichloromethane (5.0 mL), mesitylene (1.11 g, 9) at 25 ° C. .21 mmol) and sodium iodide (1.66 g, 11.1 mmol) were added, and the mixture was stirred at 40 ° C. for 1 hour.

^{By measuring 1} H-NMR of the reaction solution after completion of the reaction (internal standard method, internal standard substance: mesitylene), 1.66 g of iodotrimethylsilane (assay yield: 90.00%) was contained in heavy dichloromethane. I found out that.

Examples 3-5
Trimethylsilane was produced in the same manner as in Example 1 except that the amounts of the solvent and tetrabutylammonium bromide were shown in Table 2. The addition rate after the reaction is shown in Table 1.

Claims (5)

The following formula (1)

(In the formula, R ^{1 to} R ³ are substituted or unsubstituted alkyl groups having 1 to 4 carbon atoms, and R ^{1 to} R ³ may be the same group or different groups, respectively. Good. X is a group selected from fluorine atom, chlorine atom and bromine atom.)
The halogenated trialkylsilane compound represented by,
In an organic solvent,
React by contacting with alkali metal iodide,
The following formula (2)

(In the formula, R ^{1 to} R ³ are synonymous with those in the above formula (1).)
A method for producing an iodotrialkylsilane compound, which comprises producing the iodotrialkylsilane compound represented by. The method for producing an iodotrialkylsilane compound according to claim 1, wherein the organic solvent is at least one selected from halogenated hydrocarbons, aromatic hydrocarbons, and amides. The method for producing an iodotrialkylsilane compound according to claim 1 or 2, wherein the organic solvent is a non-polar solvent. The halogenated trialkylsilane compound represented by the above formula (1) is used.
The following formula (3)

(In the formula, R ^{4 to} R ⁷ are alkyl groups or aralkyl groups, which may be the same group or different groups, respectively. Y is a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. , A hydroxyl group, or a hydrogen sulfate group.)
In the presence of the tetra-substituted ammonium salt indicated by
React by contacting with alkali metal iodide,
The method for producing an iodotrialkylsilane compound according to any one of claims 1 to 3, wherein the iodotrialkylsilane compound represented by the formula (3) is produced. The halogenated trialkylsilane compound represented by the formula (1) is the following formula (1A).

(In the formula, X is synonymous with that in the formula (1).)
It is a halogenated trimethylsilane indicated by
The iodotrialkylsilane compound represented by the formula (3) is the following formula (2A).

The method for producing an iodotrialkylsilane compound according to any one of claims 1 to 4, which is trimethylsilane iodide represented by.