JP7638510B2 - Method for producing alkynylsilanes - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act "Development of Manufacturing Process Technology for Organosilicon Functional Chemicals / Organosilicon Project" Interim Results Report Meeting Date: December 16, 2020 Organometallics 2020, 39, 2947-2950 Issue Date: August 13, 2020

The present invention relates to a method for producing alkynylsilanes, and more specifically, to a method for producing alkynylsilanes by the decarboxylation reaction of silylalkynnoates.

Alkynylsilanes are useful building blocks in synthetic chemistry (see, for example, Non-Patent Document 1). Usually, (1) a terminal alkyne is reacted with an organolithium reagent or a Grignard reagent to convert it into a metal acetylide, and then a halosilane is reacted with the metal acetylide. In addition, as a catalytic synthesis method of alkynylsilane, (2) a method of reacting a terminal alkyne with a halosilane in the presence of a suitable catalyst (see, for example, Non-Patent Document 2) and (3) a method of dehydrogenative condensation of a terminal alkyne with a hydrosilane are known (see, for example, Non-Patent Document 3). However, (1) has the disadvantage that an unstable and dangerous organolithium reagent or a Grignard reagent must be used, and (1) and (2) have the disadvantage that a halosilane that is very easily hydrolyzed and difficult to handle must be used. In addition, (3) also has the disadvantage that flammable and dangerous hydrogen gas is produced as a by-product.
On the other hand, a method for synthesizing alkynylsilanes by decarboxylation of silylalkynoates has been reported. The by-product of this reaction is usually carbon dioxide, which is harmless and easy to remove, and therefore may be a useful candidate for the synthesis of alkynylsilanes. A method using triethylamine has been reported, but only one applicable substrate, bis(trimethylsilyl)acetylenedicarboxylate, has been shown (see Non-Patent Document 4). In addition, the present inventors have developed a method for synthesizing alkynylsilanes by decarboxylation of silylalkynoates using a catalytic amount of copper complex (see Non-Patent Document 5).

G. Larson, Synthesis, 2018, 50, 2433. I. Kownacki, B. Orwat, B. Marciniec, Organometallics, 2014, 33, 3051. A. A. Toutov, K. N. Betz, D. P. Schuman, W. -B. Liu, A. Fedorov, B. M. Stoltz, R. H. Grubbs, J. Am. Chem. Soc. , 2017, 139, 1668. G. Simchen, H. H. Hergott, Chimia, 1985, 39, 53. T. Kawatsu, K. Aoyagi, Y. Nakajima, J.-C. Choi, K. Sato, K. Matsumoto, Organometallics, 2020, 39, 2947.

The object of the present invention is to provide a simple method for producing alkynylsilanes by decarboxylation of silylalkynates.

＜２＞前記式（ａ）で表されるシリルアルキノエートが下記式（Ａ－１）～（Ａ－３）の何れかで表されるシリルアルキノエートである、＜１＞に記載のアルキニルシランの製造方法。

（式（Ａ－１）～（Ａ－３）中、Ｒ^１およびＲ^２はそれぞれ独立して、水素原子、又は窒素原子、酸素原子、ケイ素原子、及びハロゲン原子からなる群より選択される少なくとも１種の原子を含んでいてもよい炭素原子数１～２０の炭化水素基を、ｎは１～４の整数を、ｍは１～５の整数を表す。）
＜３＞前記５配位のケイ素種を形成し得る求核剤が、フッ化物イオン、塩化物イオン、アルコキシドイオン又はカルボキシラートイオンである、＜１＞又は＜２＞に記載のアルキニルシランの製造方法。
＜４＞前記５配位のケイ素種を形成し得る求核剤がフッ化物イオンであり、前記フッ化物イオン源としてアルカリ金属フッ化物、四級アンモニウムフルオリド又はフルオロシリケートを用いる、＜３＞に記載のアルキニルシランの製造方法。
＜５＞前記５配位のケイ素種を形成し得る求核剤が塩化物イオンであり、前記塩化物イオン源としてアルカリ金属塩化物又は四級アンモニウムクロリドを用いる、＜３＞に記載のアルキニルシランの製造方法。
＜６＞前記５配位のケイ素種を形成し得る求核剤がアルコキシドイオンであり、前記アルコキシドイオン源としてアルカリ金属アルコキシドを用いる、＜３＞に記載のアルキニルシランの製造方法。
＜７＞前記５配位のケイ素種を形成し得る求核剤がカルボキシラートイオンであり、前記カルボキシラートイオン源としてアルカリ金属カルボキシラート又は四級アンモニウムカルボキシラートを用いる、＜３＞に記載のアルキニルシランの製造方法。 Means for Solving the Problems The present inventors have conducted intensive research to solve the above problems and have found that the use of a nucleophile capable of forming a pentacoordinate silicon species causes a decarboxylation reaction of a silylalkynoate to proceed, thereby enabling an alkynylsilane to be easily obtained, thereby completing the present invention.
That is, the present invention includes the following.
<1> A method for producing an alkynylsilane, comprising a reaction step of decarboxylating a silylalkynoate represented by the following formula (a) in the presence of a nucleophile capable of forming a pentacoordinate silicon species to produce an alkynylsilane represented by the following formula (b):

<2> The method for producing an alkynylsilane according to <1>, wherein the silylalkynolate represented by the formula (a) is a silylalkynolate represented by any one of the following formulas (A-1) to (A-3):

(In formulas (A-1) to (A-3), R ¹ and R ² each independently represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom, a silicon atom, and a halogen atom; n represents an integer of 1 to 4; and m represents an integer of 1 to 5.)
<3> The method for producing an alkynylsilane according to <1> or <2>, wherein the nucleophilic agent capable of forming a pentacoordinate silicon species is a fluoride ion, a chloride ion, an alkoxide ion, or a carboxylate ion.
<4> The method for producing an alkynylsilane according to <3>, wherein the nucleophilic agent capable of forming a pentacoordinate silicon species is a fluoride ion, and an alkali metal fluoride, a quaternary ammonium fluoride, or a fluorosilicate is used as the fluoride ion source.
<5> The method for producing an alkynylsilane according to <3>, wherein the nucleophilic agent capable of forming a pentacoordinate silicon species is a chloride ion, and an alkali metal chloride or a quaternary ammonium chloride is used as the chloride ion source.
<6> The method for producing an alkynylsilane according to <3>, wherein the nucleophilic agent capable of forming a pentacoordinate silicon species is an alkoxide ion, and an alkali metal alkoxide is used as a source of the alkoxide ion.
<7> The method for producing an alkynylsilane according to <3>, wherein the nucleophilic agent capable of forming a pentacoordinate silicon species is a carboxylate ion, and an alkali metal carboxylate or a quaternary ammonium carboxylate is used as the carboxylate ion source.

The present invention provides a method for easily producing alkynylsilanes, which are useful in synthetic chemistry as building blocks, by the decarboxylation reaction of silylalkynoates. In addition, the by-product of this reaction is carbon dioxide, which is usually harmless and easy to remove, and therefore does not produce salts as by-products as in existing methods for synthesizing alkynylsilanes using halosilanes, and the resulting alkynylsilanes can be easily purified.

Specific examples will be given to explain the details of the present invention, but the invention is not limited to the following content and can be modified as appropriate without departing from the spirit of the invention.

<Method of Producing Alkynylsilane>
The method for producing an alkynylsilane according to one embodiment of the present invention is characterized by comprising a reaction step (hereinafter sometimes abbreviated as "reaction step") of decarboxylating a silylalkynoate represented by the following formula (a) in the presence of a nucleophile capable of forming a pentacoordinate silicon species to produce an alkynylsilane represented by the following formula (b): The wavy lines in formulas (a) and (b) mean that the structure following them is arbitrary.

The present inventors have conducted extensive investigations into a method for producing alkynylsilanes by decarboxylation of silylalkynoates, and have found that the use of a catalytic amount of a nucleophile capable of forming a pentacoordinate silicon species can cause the decarboxylation of various silylalkynoates to proceed, providing a simple method for synthesizing alkynylsilanes that are useful in synthetic chemistry as building blocks.
Although the detailed mechanism of this reaction has not been fully elucidated, it is speculated that a nucleophile such as a fluoride ion (F ^- ) coordinates to the silicon atom of a silylalkynoate to form a pentacoordinated silicon species, which then undergoes a decarboxylation reaction to produce an alkynylsilane. According to the present invention, it is possible to produce alkynylsilanes by the decarboxylation reaction of not only silylalkynoates having a relatively small substituent on the silicon atom, but also silylalkynoates having a bulky substituent on the silicon atom, and it is possible to produce alkynylsilanes using various silylalkynoates as substrates.

（式（Ａ－１）～（Ａ－３）中、Ｒ^１およびＲ^２はそれぞれ独立して、水素原子、又は窒素原子、酸素原子、ケイ素原子、及びハロゲン原子からなる群より選択される少なくとも１種の原子を含んでいてもよい炭素原子数１～２０の炭化水素基を、ｎは１～４の整数を、ｍは１～５の整数を表す。） (Silyl alkynoates represented by formulas (A-1) to (A-3))
The silyl alkynoate represented by formula (a) used in the reaction step is not particularly limited and should be appropriately selected depending on the alkynylsilane to be produced. Preferred examples of the silyl alkynoate include those represented by any of the following formulae (A-1) to (A-3).

(In formulas (A-1) to (A-3), R ¹ and R ² each independently represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom, a silicon atom, and a halogen atom; n represents an integer of 1 to 4; and m represents an integer of 1 to 5.)

(R ¹ , R ² )
R ¹ and R ² each independently represent a "hydrogen atom" or a "hydrocarbon group having 1 to 20 carbon atoms", and the "hydrocarbon group" may have a branched structure and/or a cyclic structure, and may be any of a saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic hydrocarbon group, etc. In addition, "may contain at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom, a silicon atom, and a halogen atom" means that the hydrogen atom of the hydrocarbon group may be substituted with a monovalent functional group containing a nitrogen atom, an oxygen atom, a silicon atom, or a halogen atom, and that the carbon atom inside the carbon skeleton of the hydrocarbon group may be substituted with a divalent or higher functional group (linking group) containing a nitrogen atom, an oxygen atom, a silicon atom, or the like. Therefore, it means that the carbon skeleton may contain an oxygen atom such as an ether group (-O-), or an oxygen atom and a silicon atom such as a silyloxy group (-O-Si-).

Examples of monovalent functional groups containing a nitrogen atom, an oxygen atom, a silicon atom, or a halogen atom include functional groups containing a nitrogen atom such as an amino group, an ammonium group, an amidino group, a pyrrolyl group, a triazine ring, a triazole ring, a benzotriazolyl group, an imidazolyl group, a benzimidazolyl group, a quinolyl group, a pyridyl group, a pyrimidine group, a pyrazinyl group, a quinazolinyl group, a quinoxalinyl group, a purinyl group, a piperidinyl group, a piperazinyl group, a pyrrolidinyl group, a pyrazolyl group, an aniline group, an azo group, a diazo group, an azide group, and a cyano group; carbonyl groups, keto groups, Examples of the functional groups include functional groups containing oxygen atoms such as an aryl group, an ether group, an alkoxy group, an acyloxy group, and a furanyl group; functional groups containing oxygen atoms and nitrogen atoms such as an amide group, an imide group, a urea group, a group containing an isocyanuric structure, a nitro group, a nitroso group, a cyanate group, an isocyanate group, a morpholino group, and a lactam ring; functional groups containing silicon atoms such as alkylsilyl groups such as a trimethylsilyl group and a tert-butyldimethylsilyl group, and alkylsilyloxy groups such as trimethylsilyloxy; and halogen atoms such as a fluorine atom, a chlorine atom, and a bromine atom. Among these, preferred are amino groups, alkoxy groups, acyloxy groups, nitro groups, and halogen atoms, and more preferred are dimethylamino groups, methoxy groups, acetoxy groups, nitro groups, and chlorine atoms.

Specific examples of R ¹ and R ² include a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-heptadecyl group, an n-octadecyl group, an n-nonadecyl group, or an n-icosyl group; a cycloalkyl group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, or a cyclohexyl group; a phenyl group, a 4-methylphenyl group, a 2,4-dimethylphenyl group, or a 1-naphthyl group. aromatic hydrocarbon groups such as a 2-naphthyl group, a 1-phenanthryl group, a 2-phenanthryl group, a 3-phenanthryl group, a 4-phenanthryl group, a 9-phenanthryl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-pyrenyl group, a 2-pyrenyl group, a 4-pyrenyl group, a 1-triphenylenyl group, and a 2-triphenylenyl group; aralkyl groups such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, and a 2-naphthylmethyl group; alkenyl groups such as a vinyl group and an allyl group; and substituted phenyl groups which may have a substituent containing a nitrogen atom, an oxygen atom, a silicon atom, or a halogen atom, such as a 4-methoxyphenyl group, a 4-acetoxyphenyl group, a 4-chlorophenyl group, a 4-fluorophenyl group, and a 4-nitrophenyl group.

From the viewpoint of availability, ^R1 is preferably a hydrocarbon group having 1 to 20 carbon atoms which may contain at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom, a silicon atom, and a halogen atom, more preferably an alkyl or alkenyl group having 1 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms, which may contain at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom, a silicon atom, and a halogen atom; and even more preferably an alkyl or alkenyl group having 1 to 10 carbon atoms, or a group having a substituent containing a nitrogen atom, an oxygen atom, a silicon atom, or a halogen atom. and particularly preferred are a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, a vinyl group, an allyl group, a phenyl group, a 4-methylphenyl group, a 4-methoxyphenyl group, a 4-acetoxyphenyl group, a 4-chlorophenyl group, a 4-fluorophenyl group, a 4-nitrophenyl group, and a 2,4-dimethylphenyl group; and most preferred are a methyl group, an ethyl group, an n-propyl group, a phenyl group, a 4-methylphenyl group, a 4-methoxyphenyl group, a 4-acetoxyphenyl group, a 4-chlorophenyl group, a 4-fluorophenyl group, and a 4-nitrophenyl group.
From the viewpoint of reactivity, ^R2 is preferably a hydrocarbon group having 1 to 20 carbon atoms which may contain at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom, a silicon atom, and a halogen atom, more preferably an alkyl or alkenyl group having 1 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms, which may contain at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom, a silicon atom, and a halogen atom; and even more preferably an alkyl or alkenyl group having 1 to 10 carbon atoms, or a nitrogen atom. and aromatic hydrocarbon groups having 6 to 10 carbon atoms which may have a substituent containing a carbon atom, an oxygen atom, a silicon atom, or a halogen atom; particularly preferred are a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, a vinyl group, an allyl group, a phenyl group, a 4-methylphenyl group, a 4-methoxyphenyl group, a 4-acetoxyphenyl group, a 4-chlorophenyl group, a 4-fluorophenyl group, a 4-nitrophenyl group, and a 2,4-dimethylphenyl group; and most preferred are a methyl group, an ethyl group, a vinyl group, an allyl group, or a phenyl group.
m represents an integer of 1 to 5. From the viewpoint of reactivity, it is preferably an integer of 1 to 3, and more preferably 1 or 2.
n represents an integer of 1 to 4. From the viewpoint of reactivity, n is preferably an integer of 1 to 3, and more preferably 1 or 2.

Preferred examples of the silylalkynoates represented by the formulae (A-1) to (A-3) include the following compounds 1a to 1r.

(Nucleophiles capable of forming pentacoordinate silicon species)
The reaction step is carried out in the presence of a nucleophile capable of forming a pentacoordinated silicon species. As the nucleophile capable of forming a pentacoordinated silicon species by coordinating with the silicon atom of the silylalkynolate, a nucleophile having high affinity with silicon and small in size is preferred, and a fluoride ion, a chloride ion, an alkoxide ion, or a carboxylate ion is more preferred.

Fluoride ions When the reaction step is carried out in the presence of "fluoride ions," a compound that serves as a source of fluoride ions (F ^- ) is used. The fluoride ion source is preferably an alkali metal fluoride, a quaternary ammonium fluoride, or a fluorosilicate.
The "alkali metal fluoride" is not particularly limited, but preferred examples include cesium fluoride, potassium fluoride, and sodium fluoride.
The "quaternary ammonium fluoride" is not particularly limited, but preferred examples include tetraalkylammonium fluorides such as tetrabutylammonium fluoride, tetraethylammonium fluoride, and tetramethylammonium fluoride.
The "fluorosilicate" is not particularly limited, but preferred examples include tetrabutylammonium difluorotriphenylsilicate and tris(dimethylamino)sulfonium difluorotrimethylsilicate.

When the reaction step is carried out in the presence of "chloride ions", a compound that serves as a source of chloride ions (Cl ^- ) is used. The chloride ion source is not particularly limited, but preferred examples include alkali metal chlorides and quaternary ammonium chlorides.
The "alkali metal chloride" is not particularly limited, but preferred examples include cesium chloride, potassium chloride, and sodium chloride.
The "quaternary ammonium chloride" is not particularly limited, but preferred examples include tetraalkylammonium chlorides such as tetrabutylammonium chloride, tetraethylammonium chloride, tetramethylammonium chloride, didecyldimethylammonium chloride, and hexadecyltrimethyl chloride.

Alkoxide ion When the reaction step is carried out in the presence of "alkoxide ion", a compound that serves as an alkoxide ion (RO ^- ) source is used. The alkoxide ion source is not particularly limited, but metal alkoxides are preferred. In addition, R in the alkoxide ion "RO ^- " is not particularly limited, but preferably has 12 or less carbon atoms, more preferably 10 or less carbon atoms.
The "metal alkoxide" is not particularly limited, but preferred examples include alkali metal alkoxides such as sodium tert-butoxide (NaOtBu), potassium tert-butoxide (KOtBu), sodium phenoxide (NaOPh), and potassium phenoxide (KOPh).

Carboxylate ion When the reaction step is carried out in the presence of "carboxylate ion", a compound that serves as a source of carboxylate ion (R'COO ^- ) is used. The carboxylate ion source is not particularly limited, but preferred examples include alkali metal carboxylates and quaternary ammonium carboxylates. In addition, R' in the carboxylate ion "R'COO ^- " is not particularly limited, but preferably has a carbon number of 20 or less, more preferably 12 or less.
The "alkali metal carboxylate" is not particularly limited, but examples thereof include cesium acetate, potassium acetate, sodium acetate, cesium pivalate, potassium pivalate, sodium pivalate, potassium octylate, sodium octylate, and the like, with potassium acetate being particularly preferred.
The "quaternary ammonium carboxylate" is not particularly limited, but examples thereof include tetrabutylammonium acetate, tetraethylammonium acetate, tetramethylammonium acetate, tetrabutylammonium benzoate, and tetraalkylammonium carboxylates such as the compounds represented by the following formula, with tetrabutylammonium acetate or the compounds represented by the following formula being particularly preferred.

The amount (charge amount) of the nucleophile capable of forming a pentacoordinate silicon species in the reaction step is, in terms of the amount of substance, usually 1 mol% or more, preferably 2 mol% or more, more preferably 5 mol% or more, and usually 50 mol% or less, preferably 20 mol% or less, more preferably 10 mol% or less, relative to the silyl alkynoate having the structure represented by formula (a). Within the above range, alkynylsilane can be produced more efficiently. The nucleophile capable of forming a pentacoordinate silicon species may be used alone or in combination with two or more types. When two or more types are used in combination, the above amount (charge amount) is the total amount.

(solvent)
The reaction step is usually carried out in a solvent. The type of solvent used in the reaction step is not particularly limited, and examples thereof include hydrocarbon solvents such as hexane, octane, toluene, and trifluoromethylbenzene; halogenated hydrocarbon solvents such as 1,2-dichloroethane and o-dichlorobenzene; ether solvents such as diethyl ether, dipropyl ether, dibutyl ether, diethylene glycol dimethyl ether (diglym), tetrahydrofuran (THF), and dioxane; nitrile solvents such as acetonitrile, propionitrile, succinonitrile, butyronitrile, isobutyronitrile, valeronitrile, and benzonitrile; and amide solvents such as N-methylformamide, N,N-dimethylformamide (DMF), N,N-diethylformamide, N,N-diethylformamide, N,N-dimethylacetamide (DMAc), and hexamethylphosphoric triamide (HMPA). From the viewpoint of reactivity, the solvent preferably contains a polar solvent, and among them, it is preferable to contain at least one selected from the group consisting of tetrahydrofuran, diethylene glycol dimethyl ether, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, and hexamethylphosphoric triamide, and more preferably contains at least one selected from the group consisting of acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, and hexamethylphosphoric triamide. One type of solvent may be used, or two or more types may be used in any combination and ratio. In addition, it is preferable to contain 5% by volume or more of the polar solvent with respect to the total amount of the solvent, more preferably 10% by volume or more, and even more preferably 12% by volume or more. By containing the polar solvent in this range, the reaction is more likely to proceed.

(Reaction conditions)
The reaction temperature and reaction time in the reaction step may be appropriately determined depending on the substrate.
The reaction temperature in the reaction step is usually 20° C. or higher, preferably 40° C. or higher, more preferably 60° C. or higher, and usually 200° C. or lower, preferably 180° C. or lower, more preferably 150° C. or lower. Within the above range, alkynylsilane can be produced more efficiently.
The reaction time of the reaction step is usually 10 minutes or more, preferably 30 minutes or more, more preferably 1 hour or more, and usually 48 hours or less, preferably 24 hours or less, more preferably 12 hours or less. When it is within the above range, alkynylsilane can be produced more efficiently.
The reaction step is usually carried out under an inert atmosphere such as nitrogen or argon.
The reaction vessel is not particularly limited as long as it is made of a material stable to the silylalkynylsilane, and may be made of, for example, glass, stainless steel, or a fluororesin such as polytetrafluoroethylene (PTFE). From the viewpoint of suppressing hydrolysis of the generated alkynylsilane, a reaction vessel made of PTFE is preferred.

(Other processes)
The method for producing alkynylsilane according to the present embodiment may include any other step in addition to the reaction step. The optional step may include a purification step for increasing the purity of alkynylsilane. In the purification step, a purification method usually performed in the field of organic synthesis, such as filtration, adsorption, column chromatography, distillation, etc., may be adopted. Specifically, after the reaction step, the reaction mixture may be purified, for example, by silica gel column chromatography.

(Alkynylsilanes represented by formulas (B-1) to (B-3))
The alkynylsilane represented by formula (b) produced by the reaction step is not particularly limited and can be appropriately selected depending on the production purpose. Preferred examples of the alkynylsilane include alkynylsilanes represented by any of the following formulae (B-1) to (B-3).

In formulas (B-1) to (B-3), R ¹ and R ² each independently represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom, a silicon atom, and a halogen atom; n represents an integer of 1 to 4; and m represents an integer of 1 to 5.
R ¹ and R ² have the same meaning as those in the "silyl alkynoate represented by any one of formulas (A-1) to (A-3)."

Alkynylsilanes represented by formulas (B-1) to (B-3) include the following compounds 2a to 2r.

The present invention will be explained in more detail below with reference to examples, but these can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited to the specific examples shown below.

<Examples 1-1 to 1-6>

In a glove box under a nitrogen atmosphere, DMF (1.0 mL) was added to the fluoride (5 mol%) shown in Table 1. Triisopropylsilyl 3-phenylpropiolate (151.2 mg, 0.50 mmol) was added, and the mixture was heated and stirred at 150° C. After 1 hour, a portion of the reaction product was analyzed by ¹ H-NMR (600 MHz). The conversion of silylalkynoate and the yield of alkynylsilane are shown in Table 1.

^＊ＰＴＦＥ製反応容器を使用。その他はガラスバイアルを使用。

^* PTFE reaction vessels are used. Glass vials are used for the rest.

<Examples 2-1 to 2-6, 3-1 to 3-8>

In a glove box under nitrogen atmosphere, DMF (1.0 mL) was added to tetrabutylammonium difluorotriphenylsilicate (13.5 mg, 5 mol%). After adding silylalkynoate (0.50 mmol) shown in Tables 2 and 3, the mixture was heated and stirred at the temperature shown in Tables 2 and 3. After the time shown in Tables 2 and 3 had elapsed, the reaction mixture was diluted with dichloromethane (0.5 mL) and purified with a short silica gel column (eluent: n-hexane). After concentrating with an evaporator, an alkynylsilane was obtained. When the obtained alkynylsilane was analyzed by ¹ H-NMR (600 MHz), it was confirmed that the target compound was produced. The isolation yield of the alkynylsilane is shown in Tables 2 and 3.

¹H NMR (600 MHz, CDCl₃): δ7.48-7.45 (m, 2H), 7.32-7.28 (m, 3H), 0.25 ppm (s, 9H) Trimethyl(phenylethynyl)silane

^1H NMR (600 MHz, CDCl ₃ ): δ7.48-7.45 (m, 2H), 7.32-7.28 (m, 3H), 0.25 ppm (s, 9H)

¹H NMR (600 MHz, CDCl₃): δ7.49-7.47 (m, 2H), 7.32-7.29 (m, 3H), 1.14 ppm (s, 21H) Triisopropyl(phenylethynyl)silane

¹ H NMR (600 MHz, CDCl ₃ ): δ7.49-7.47 (m, 2H), 7.32-7.29 (m, 3H), 1.14 ppm (s, 21H)

¹H NMR (600 MHz, CDCl₃): δ7.51-7.48 (m, 2H), 7.34-7.28 (m, 3H), 1.02 (s, 9H), 0.20 ppm (s, 6H) tert-Butyldimethyl(phenylethynyl)silane

¹ H NMR (600 MHz, CDCl ₃ ): δ7.51-7.48 (m, 2H), 7.34-7.28 (m, 3H), 1.02 (s, 9H), 0.20 ppm (s, 6H)

¹H NMR (600 MHz, CDCl₃): δ7.90-7.86 (m, 4H), 7.64-7.59 (m, 2H), 7.45-7.33 (m, 9H), 1.16 ppm (s, 9H) tert-Butyldiphenyl(phenylethynyl)silane

¹ H NMR (600 MHz, CDCl ₃ ): δ7.90-7.86 (m, 4H), 7.64-7.59 (m, 2H), 7.45-7.33 (m, 9H), 1.16 ppm (s, 9H)

¹H NMR (600 MHz, CDCl₃): δ7.51-7.45 (m, 2H), 7.35-7.27 (m, 3H), 6.20 (dd, J = 20.1, 14.7 Hz, 1H), 6.06 (dd, J = 14.7, 3.8 Hz, 1H), 5.91 (dd, J = 20.1, 3.8 Hz, 1H), 0.32 ppm (s, 6H) Dimethyl(phenylethynyl)(vinyl)silane

¹ H NMR (600 MHz, CDCl ₃ ): δ7.51-7.45 (m, 2H), 7.35-7.27 (m, 3H), 6.20 (dd, J = 20.1, 14.7 Hz, 1H), 6.06 (dd, J = 14.7, 3.8 Hz, 1H), 5.91 (dd, J = 20.1, 3.8 Hz, 1H), 0.32 ppm (s, 6H)

¹H NMR (600 MHz, CDCl₃): δ7.50-7.45 (m, 2H), 7.35-7.28 (m, 3H), 5.94-5.84 (m, 1H), 5.02-4.89 (m, 2H), 1.76-1.69 (m, 2H), 0.25 ppm (s, 6H) Allyldimethyl(phenylethynyl)silane

¹ H NMR (600 MHz, CDCl ₃ ): δ7.50-7.45 (m, 2H), 7.35-7.28 (m, 3H), 5.94-5.84 (m, 1H), 5.02-4.89 (m, 2H), 1.76-1.69 (m, 2H), 0.25 ppm (s, 6H)

¹H NMR (600 MHz, CDCl₃): δ 7.40-7.34 (m, 2H), 7.13-7.08 (m, 2H), 2.35 (s, 3H), 0.26 ppm (s, 9H) Trimethyl(p-tolylethynyl)silane

¹ H NMR (600 MHz, CDCl ₃ ): δ 7.40-7.34 (m, 2H), 7.13-7.08 (m, 2H), 2.35 (s, 3H), 0.26 ppm (s, 9H)

¹H NMR (600 MHz, CDCl₃): δ 7.46-7.35 (m, 2H), 6.85-6.78 (m, 2H), 3.80 (s, 3H), 0.24 ppm (s, 9H) ((4-Methoxyphenyl)ethynyl)trimethylsilane

¹ H NMR (600 MHz, CDCl ₃ ): δ 7.46-7.35 (m, 2H), 6.85-6.78 (m, 2H), 3.80 (s, 3H), 0.24 ppm (s, 9H)

¹H NMR (600 MHz, CDCl₃): δ 7.41-7.37 (m, 2H), 7.29-7.25 (m, 2H), 0.26 ppm (s, 9H) ((4-chlorophenyl)ethynyl)trimethylsilane

¹ H NMR (600 MHz, CDCl ₃ ): δ 7.41-7.37 (m, 2H), 7.29-7.25 (m, 2H), 0.26 ppm (s, 9H)

¹H NMR (600 MHz, CDCl₃): δ7.46-7.40 (m, 2H), 7.34-7.29 (m, 2H), 0.25 ppm (s, 9H) ((4-bromophenyl)ethynyl)trimethylsilane

^1H NMR (600 MHz, CDCl ₃ ): δ7.46-7.40 (m, 2H), 7.34-7.29 (m, 2H), 0.25 ppm (s, 9H)

¹H NMR (600 MHz, CDCl₃): δ8.24-8.08 (m, 2H), 7.66-7.50 (m, 2H), 0.27 ppm (s, 9H) Trimethyl((4-nitrophenyl)ethynyl)silane

¹ H NMR (600 MHz, CDCl ₃ ): δ8.24-8.08 (m, 2H), 7.66-7.50 (m, 2H), 0.27 ppm (s, 9H)

¹H NMR (600 MHz, CDCl₃): δ7.50-7.43 (m, 2H), 7.08-6.99 (m, 2H), 2.29 (s, 3H), 0.24 ppm (s, 9H) 4-((trimethylsilyl)ethynyl)phenylacetate

¹ H NMR (600 MHz, CDCl ₃ ): δ7.50-7.43 (m, 2H), 7.08-6.99 (m, 2H), 2.29 (s, 3H), 0.24 ppm (s, 9H)

¹H NMR (600 MHz, CDCl₃): δ7.58-7.49 (m, 4H), 7.38-7.29 (m, 6H), 1.26-1.15 ppm (m, 14H) Diisopropylbis(phenylethynyl)silane

¹ H NMR (600 MHz, CDCl ₃ ): δ7.58-7.49 (m, 4H), 7.38-7.29 (m, 6H), 1.26-1.15 ppm (m, 14H)

¹H NMR (600 MHz, CDCl₃): δ7.39 (s, 4H), 1.14-1.11 ppm (s, 42H) 1,4-Bis((triisopropylsilyl)ethynyl)benzene

¹ H NMR (600 MHz, CDCl ₃ ): δ7.39 (s, 4H), 1.14-1.11 ppm (s, 42H)

<Examples 4-1 to 4-7>

In a glove box under a nitrogen atmosphere, DMF (1.0 mL) was added to a metal salt or tetrabutylammonium salt (5 mol%) shown in Table 4 as a nucleophile. Triisopropylsilyl 3-phenylpropiolate (151.2 mg, 0.50 mmol) was added, and the mixture was heated and stirred at 150° C. After the time shown in Table 4 had elapsed, a portion of the reaction product was analyzed by ¹ H NMR (600 MHz). The yield of alkynylsilane is shown in Table 4.

As shown in the above Examples 1-1 to 1-6 and Examples 4-1 to 4-7, alkynylsilanes can be easily produced from silylalkynoates using various nucleophiles. Also, as shown in the above Examples 2-1 to 2-6 and 3-1 to 3-8, alkynylsilanes can be easily produced from various silylalkynoates. Also, as shown in Examples 1-5 and 2-2, the yield can be improved by extending the reaction time.

The method of the present invention makes it possible to easily produce alkynylsilanes. The alkynylsilanes produced are useful building blocks in synthetic chemistry and are useful as various functional materials or raw materials thereof.

Claims (6)

The method includes a reaction step of decarboxylating a silylalkynoate represented by the following formula (a) in the presence of a nucleophile capable of forming a pentacoordinate silicon species to produce an alkynylsilane represented by the following formula (b) :
The silyl alkynoate is represented by the following formula (A-1) or (A-3):
the nucleophile capable of forming a pentacoordinate silicon species is a fluoride ion, a chloride ion, an alkoxide ion, or a carboxylate ion;
The fluoride ion source is an alkali metal fluoride, a quaternary ammonium fluoride, or a fluorosilicate;
an alkali metal chloride or a quaternary ammonium chloride is used as the chloride ion source;
An alkali metal alkoxide is used as the alkoxide ion source,
A method for producing alkynylsilanes , wherein an alkali metal carboxylate or a quaternary ammonium carboxylate is used as the carboxylate ion source .

In formulae (A-1) and (A-3), R ¹ is each independently a hydrogen atom or a nitrogen atom.
R 1 represents a hydrocarbon group having 1 to 20 carbon atoms which may contain at least one atom selected from the group consisting of an oxygen atom, a silicon atom, and a halogen atom; R ² each independently represents a hydrocarbon group having 1 to 20 carbon atoms; n represents an integer of 1 to 4; and m represents an integer of 1 to 5. The method for producing an alkynylsilane according to claim 1, wherein the alkynylsilane is an alkynylsilane represented by the following formula (B-1) or (B-3):

(In formulas (B-1) and (B-3), R ¹ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom, a silicon atom, and a halogen atom, ² each independently represents a hydrocarbon group having 1 to 20 carbon atoms, n represents an integer of 1 to 4, and m represents an integer of 1 to 5. the alkali metal fluoride is cesium fluoride, potassium fluoride or sodium fluoride;
The quaternary ammonium fluoride is tetrabutylammonium fluoride, tetraethylammonium fluoride, or tetramethylammonium fluoride;
3. The method for producing alkynylsilanes according to claim 1 or 2, wherein the fluorosilicate is tetrabutylammonium difluorotriphenylsilicate or tris(dimethylamino)sulfonium difluorotrimethylsilicate. the alkali metal chloride is cesium chloride, potassium chloride or sodium chloride;
3. The method for producing alkynylsilanes according to claim 1 or 2, wherein the quaternary ammonium chloride is tetrabutylammonium chloride, tetraethylammonium chloride, tetramethylammonium chloride, didecyldimethylammonium chloride or hexadecyltrimethyl chloride. 3. The method for producing an alkynylsilane according to claim 1, wherein the alkali metal alkoxide is sodium tert-butoxide, potassium tert-butoxide, sodium phenoxide or potassium phenoxide. the alkali metal carboxylate is cesium acetate, potassium acetate, sodium acetate, cesium pivalate, potassium pivalate, sodium pivalate, potassium octoate or sodium octoate;
The method for producing alkynylsilane according to claim 1 or 2, wherein the quaternary ammonium carboxylate is tetrabutylammonium acetate, tetraethylammonium acetate, tetramethylammonium acetate, tetrabutylammonium benzoate, or a tetraalkylammonium carboxylate represented by the following formula: