JP5019447B2 - Cyanosilylation catalysts for organic carbonyl compounds - Google Patents

Description

  The present invention relates to a novel organic carbonyl compound cyanosilylation catalyst and a method for producing a cyanohydrin silyl ether compound using the same.

  Cyanosilylation of organic carbonyl compounds is widely used in organic synthesis as an important one-carbon carbonization reaction. Cyanohydrin silyl ethers, which are products of cyanosilylation, are useful as intermediates that can be derived into α-amino acids, β-amino alcohols, and the like.

It is known that such cyanohydrin silyl ethers can be produced, for example, by a so-called cyanosilylation reaction in which an organic carbonyl compound is reacted with a trialkylsilyl cyanide compound in the presence of a catalytic amount of Lewis acid or Lewis base ( Non-patent document 1).
Recently, it has also been reported that lithium salts are cyanosilylation catalysts having high catalytic activity (Patent Document 1).
However, when a homogeneous catalyst is used, it is generally difficult to separate and recover the catalyst.

  In order to solve these problems, cyanosilylation reaction of organic carbonyl compounds using solid acid or solid base, which is easy to separate and recover the catalyst, has been reported. On the other hand, it was necessary to use the same or excessive amount of catalyst (Non-patent Document 2).

Further, mesoporous silica modified with an amino group (Non-patent Document 3) and scandium trifluoromethanesulfonate supported on silica gel (Non-patent Document 4) have been reported as cyanosilylation catalysts that can be recovered and reused. Also in this case, when aliphatic aldehydes or ketones are used as raw materials, there are still problems such as low yield or long reaction time.
JP 2006-219457 A Synlett, 2005, p892-899 Bull. Chem. Soc. Jpn., 1993, 66, p892-899 Green Chem., 2000, 2, p47-48 Org. Lett., 2004, 6, p4813-4815

  The present invention has been made in view of such circumstances, and provides a novel solid catalyst for cyanosilylation having high catalytic activity and easy separation and recovery, and cyanohydrin silyl using this catalyst. It aims at providing the method of manufacturing an ether compound easily with a high yield.

  As a result of diligent research to solve the above-mentioned problems, the present inventors have found that mesoporous silica containing aluminum is extremely useful in producing a cyanohydrin silyl ether compound by reacting an organic carbonyl compound and a trialkylsilyl cyanide compound. It was found to be a highly active cyanosilylation catalyst. The present invention has been completed based on the above findings.

  According to the present invention, a cyanohydrin silyl ether compound can be efficiently produced from various organic carbonyl compounds and a trialkylsilyl cyanide compound. In addition, the method of the present invention is advantageous from the viewpoint of the reaction cost in that it uses a solid catalyst that can be easily prepared from an inexpensive raw material and can be recovered and reused. A cyanohydrin silyl ether compound can be obtained in a high yield, and there is no reaction byproduct, and the post-reaction treatment is extremely easy.

（式中、R¹は、置換基を有してもよい、鎖状アルキル基、環状アルキル基、アルケニル基、アルキニル基、アリール基またはヘテロ環；R²は水素、置換基を有してもよい、アルキル基、アリール基またはヘテロ環を示す。ただしR¹とR²は互いに結合して環を形成していてもよい）
で示される化合物であることを特徴とする〈４〉に記載のシアノヒドリンシリルエーテル化合物の製造方法。
〈６〉シアン化トリアルキルシリル化合物が、一般式（２）

（式中、R³, R⁴, R⁵は同じであっても互いに異なっていてもよい、置換基を有してもよいアルキル基またはアリール基を示す）
で示される化合物であることを特徴とする〈４〉に記載のシアノヒドリンシリルエーテル化合物の製造方法。 That is, according to this application, the following invention is provided.
<1> A cyanosilylation catalyst of an organic carbonyl compound mainly composed of mesoporous silica containing aluminum.
<2> The cyanosilylation catalyst according to <1>, wherein the mesoporous silica containing aluminum has regular pores of 2 to 20 nm.
<3> The cyanosilylation catalyst according to <1> or <2>, wherein the molar ratio Si / Al between silicon and aluminum contained in the mesoporous silica containing aluminum is 1 to 100.
<4> A method for producing a cyanohydrin silyl ether compound, comprising reacting an organic carbonyl compound and a cyanide trialkylsilyl compound in the presence of the cyanosilylation catalyst according to any one of <1> to <3>. .
<5> The organic carbonyl compound is represented by the general formula (1)

(Wherein R ¹ may have a substituent, a chain alkyl group, a cyclic alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocycle; R ² may have a hydrogen atom or a substituent. An alkyl group, an aryl group or a heterocyclic ring, wherein R ¹ and R ² may be bonded to each other to form a ring)
<4> The manufacturing method of the cyanohydrin silyl ether compound as described in <4> characterized by the above-mentioned.
<6> The trialkylsilyl cyanide compound has the general formula (2)

(In the formula, R ³ , R ⁴ and R ⁵ may be the same or different from each other, and each represents an optionally substituted alkyl group or aryl group)
<4> The manufacturing method of the cyanohydrin silyl ether compound as described in <4> characterized by the above-mentioned.

  That is, the organic carbonyl cyanosilylation catalyst of the present invention is characterized by containing mesoporous silica containing aluminum as a main component. Here, mesoporous silica is generally prepared by using a surfactant as a template, and is a silica in which mesopores having a uniform pore size distribution and a uniform size are spatially regularly arranged, and mesoporous silica containing aluminum is It means that the aluminum element is introduced into and out of the silica skeleton.

Mesoporous silica containing such aluminum, as well as mesoporous silica, have a regular pore, its average pore diameter, 2 up to 10 nm are good preferable. As a form of aluminum contained, it is preferable that aluminum is present in a 4-coordinate state in the silica skeleton, but a part of aluminum may be present outside the silica skeleton. Mesoporous silica containing aluminum is not particularly limited in its regular structure, and may have a 2d hexagonal structure typified by MCM-41 and SBA-15, and has a cubic structure typified by MCM-48 and SBA-16. You may have. Moreover, 1-100 are preferable and, as for the molar ratio Si / Al of the silicon and aluminum contained in the mesoporous silica containing aluminum, 10-50 are more preferable.

  Examples of the mesoporous silica containing aluminum preferably used in the present invention include, for example, J. Chem. Soc., Chem. Commun., 1995, p711-712 and Micropor. Mesopor. Mater., 2000, 34, p43-54, an aluminum-containing mesoporous silica (Al-MCM-41) obtained by hydrothermal synthesis using an aggregate of surfactants composed of alkyltrimethylammonium as a template. However, as described above, the mesoporous silica containing aluminum is not particularly limited by its raw material, synthesis method, ordered structure, and counter cation.

  The form of the cyanosilylation catalyst of the present invention is not particularly limited, but is usually fine powder or particulate.

  The method for producing a cyanohydrin silyl ether compound of the present invention is characterized in that an organic carbonyl compound and a cyanide trialkylsilyl compound are reacted in the presence of the above-described cyanosilylation catalyst.

（式中、R¹は、置換基を有してもよい、鎖状アルキル基、環状アルキル基、アルケニル基、アルキニル基、アリール基またはヘテロ環；R²は水素、置換基を有してもよい、アルキル基、アリール基またはヘテロ環を示す。ただしR¹とR²は互いに結合して環を形成していてもよい）
で表される有機カルボニル化合物が用いられる。 Although it does not restrict | limit especially as an organic carbonyl compound, Preferably, following General formula (1)

(Wherein R ¹ may have a substituent, a chain alkyl group, a cyclic alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocycle; R ² may have a hydrogen atom or a substituent. An alkyl group, an aryl group or a heterocyclic ring, wherein R ¹ and R ² may be bonded to each other to form a ring)
The organic carbonyl compound represented by these is used.

  Examples of the organic carbonyl compound represented by the general formula (1) include acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, capronaldehyde, enanthaldehyde, caprylaldehyde, pelargonaldehyde, caprinaldehyde, pivalaldehyde, cyclohexanecarbaldehyde and the like. Aliphatic aldehydes and their various substitutes, aromatic aldehydes such as benzaldehyde, tolualdehyde, cuminaldehyde, anisaldehyde, naphthaldehyde, furfural, thiophene aldehyde and their various substitutes, acrolein, crotonaldehyde, cinnamaldehyde, etc. Unsaturated aldehydes and their substitutes, acetone, methyl ethyl ketone, diethyl ketone, methyl propyl ketone, di Aliphatic ketones such as tilketone, cyclohexylmethylketone, diisopropylketone, benzylacetone and various substituted products thereof, cyclic ketones such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone and various substituted products thereof, acetophenone, pro Aromatic ketones such as piophenone, butyrophenone, valerophenone, pivalophenone, caprophenone, caprylophenone, capriphenone, acetonaphthone, benzophenone and various substitutes thereof, unsaturated ketones such as cyclohexenone, benzalacetone, chalcone and the like Various substituents are exemplified.

（式中、R³, R⁴, R⁵は同じであっても互いに異なっていてもよい、置換基を有してもよいアルキル基またはアリール基を示す）
で示される化合物が用いられる。 Further, the trialkylsilyl cyanide compound as the other raw material is not particularly limited, but preferably the following general formula (2)

(In the formula, R ³ , R ⁴ and R ⁵ may be the same or different from each other, and each represents an optionally substituted alkyl group or aryl group)
The compound shown by these is used.

  Examples of the trialkylsilyl cyanide compound represented by the general formula (2) include, for example, trimethylsilyl cyanide, triethylsilyl cyanide, triisopropylsilyl cyanide, dimethylisopropylsilyl cyanide, diethylisopropylsilyl cyanide, tert-cyanide cyanide. Examples include butyldimethylsilyl and tert-butyldiphenylsilyl cyanide.

（式中、R¹, R², R³, R⁴, R⁵は前記と同じ）
で表されるシアノヒドリンシリルエーテル化合物が得られる。 When the organic carbonyl represented by the general formula (1) and the trialkylsilyl cyanide compound represented by the general formula (2) are reacted, as shown in the following synthesis reaction formula (4), the general formula (3)

(In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ are the same as above)
The cyanohydrin silyl ether compound represented by these is obtained.

（式中、R¹, R², R³, R⁴, R⁵は前記と同じ）

(In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ are the same as above)

  The cyanohydrin silyl ether compound represented by the general formula (3) is useful as a synthetic intermediate for α-amino acids, β-aminoalcohols and the like. For example, α-amino acids can be obtained by acid hydrolysis of this compound. Further, β-amino alcohols can be obtained by reacting a cyanohydrin silyl ether compound with lithium aluminum hydride.

  In order to specifically carry out the cyanosilylation reaction of the present invention, for example, the reaction may be carried out by adding a cyanated trialkylsilyl compound and a carbonyl compound to a container containing a cyanosilylation catalyst and stirring. Here, the cyanosilylation catalyst may be suspended in an organic solvent in advance, and the trialkylsilyl cyanide compound and the carbonyl compound may be dissolved in an organic solvent and added.

  The amount of the cyanosilylation catalyst added to the reaction system is not particularly limited, but is preferably in the range of 0.1 to 100% by weight, more preferably 1 to 10% by weight with respect to the organic carbonyl compound. The ratio of the organic carbonyl compound and the trialkylsilyl cyanide compound is not particularly limited. For example, 1 to several moles, preferably 1 to 1.5 moles of trialkylsilyl cyanide can be used with respect to 1 mole of the carbonyl compound.

  The cyanosilylation reaction is preferably carried out at normal pressure under an inert atmosphere such as argon. Further, this cyanosilylation reaction proceeds even in the absence of a solvent or in a solvent. The reaction solvent is not particularly limited as long as it does not participate in the reaction, but aromatic hydrocarbons such as toluene and xylene, and halogen-containing hydrocarbons such as methylene chloride and chloroform are preferable. The reaction temperature is not particularly limited, but the reaction proceeds sufficiently at room temperature. If necessary, the reaction can be carried out under heating or under ice cooling. The reaction time is not particularly limited, but is usually about several minutes.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.

[Reference Example 1]
(Synthesis of aluminum-containing mesoporous silica (Al-MCM-41, Si / Al = 20))
To a mixed solution of hexadecyltrimethylammonium bromide (15.1 g), sodium aluminate (1.14 g), aqueous ammonia (1 mL) and distilled water (100 mL), sodium hydroxide (3.1 g), colloidal silica (56.3 g ) And distilled water (135 mL) were added, and the mixture was stirred at 97 ° C. for 1 day. After cooling to room temperature, the pH was adjusted to 10.2 using an aqueous acetic acid solution. The operation of heating and pH adjustment was further repeated twice. After stirring at 97 ° C. for 1 day, the resulting white solid was collected and washed with distilled water. After drying, firing in air at 550 ° C. yielded Al-MCM-41 (Si / Al = 20). From elemental analysis, the composition of Al-MCM-41 was silicon: 42.5 wt%, aluminum: 1.8 wt%, and sodium: 0.2 wt%. The specific surface area of the Al-MCM-41 determined from the nitrogen adsorption method was 969 m ² / g, the pore volume was 1.14 cm ³ / g, and the average pore diameter was 2.7 nm.

[Reference Example 2]
(Synthesis of mesoporous silica with different aluminum contents (Al-MCM-41, Si / Al = 10))
Al-MCM-41 (Si / Al = 10) was obtained by changing the amount of sodium aluminate by the same operation as in Reference Example 1. From the elemental analysis, the composition of the Al-MCM-41 was silicon: 40.1 wt%, aluminum: 3.5 wt%, sodium: 0.8 wt%. The specific surface area of the Al-MCM-41 determined from the nitrogen adsorption method was 854 m ² / g, the pore volume was 1.19 cm ³ / g, and the average pore diameter was 2.8 nm.

[Reference Example 3]
(Synthesis of mesoporous silica with different aluminum contents (Al-MCM-41, Si / Al = 50))
Al-MCM-41 (Si / Al = 50) was obtained by changing the amount of sodium aluminate by the same operation as in Reference Example 1. From the elemental analysis, the composition of the Al-MCM-41 was silicon: 44.4 wt%, aluminum: 0.7 wt%, and sodium: 0.1 wt%. The specific surface area of the Al-MCM-41 determined from the nitrogen adsorption method was 1039 m ² / g, the pore volume was 1.06 cm ³ / g, and the average pore diameter was 2.9 nm.

[Reference Example 4]
(Synthesis of mesoporous silica containing no aluminum (MCM-41))
MCM-41 was obtained in the same manner as in Reference Example 1 without adding sodium aluminate as an aluminum source. The specific surface area of the MCM-41 determined from the nitrogen adsorption method was 1056 m ² / g, the pore volume was 1.06 cm ³ / g, and the average pore diameter was 2.7 nm.

[Examples 1-3, Comparative Examples 1-2]
(Comparison of catalytic activity)
Al-MCM-41 synthesized in Reference Examples 1 to 3 (Examples 1 to 3) as a catalyst, amorphous silica alumina without regular pores (Reference Catalyst of the Catalytic Society, JRC-SAH-1) (Comparison Using MCM-41 (Comparative Example 2) synthesized in Example 1) and Reference Example 4, the catalytic activity was compared.

  That is, Al-MCM-41 (5.0 mg) synthesized in Reference Example 1 was added to a glass Schlenk flask containing a stirring bar coated with Teflon (registered trademark), and dried at 120 ° C. for 1 hour under reduced pressure. It was. After cooling to room temperature, an argon atmosphere was established, and a solution of phenanthrene (100 mg) in methylene chloride (10 mL) was added as an internal standard substance. Subsequently, trimethylsilyl cyanide (0.68 mL, 5.1 mmol) was added, and after cooling to 0 ° C. with stirring, benzaldehyde (106.6 mg, 1.01 mmol) was added. While stirring at 0 ° C., a part of the reaction mixture was withdrawn at regular intervals, and the yield of the target product, cyanohydrin silyl ether (α-trimethylsiloxy-phenylacetonitrile), was analyzed by gas chromatography (Example 1).

  Also, Al-MCM-41 synthesized in Reference Example 2 (Example 2), Al-MCM-41 synthesized in Reference Example 3 (Example 3), silica alumina having no regular pores (from the Japan Society for Catalysis) Using the reference catalyst, JRC-SAH-1) (5 mg) (Comparative Example 1), and MCM-41 (30 mg) (Comparative Example 2) synthesized in Reference Example 4, the catalytic activity was compared in the same manner. did. Table 1 shows the yield and the pseudo first-order rate constant. In addition, FIG. 1 shows changes with time in yields of Example 1, Comparative Example 1, and Comparative Example 2.

  From the results of Examples 1 to 3 and Comparative Example 1, it is understood that it is important to have regular pores as the cyanosilylation catalyst. Further, the results of Examples 1 to 3 and Comparative Example 2 show that the cyanosilylation catalyst needs to contain aluminum. In other words, it is suggested that the cyanosilylation catalyst of the present invention is a mesoporous silica containing aluminum and having regular pores, thereby expressing high catalytic activity.

[Reference Example 5]
(Synthesis of aluminum-containing mesoporous silica (Al-MCM-41) by another method)
Add a mixed solution of tetraethoxysilane (40.0 g) and aluminum triisopropoxide (2.0 g) to a mixed solution of hexadecyltrimethylammonium bromide (20.8 g), concentrated hydrochloric acid (15.2 g) and distilled water (100 mL). The mixture was further stirred at room temperature for 75 minutes. 2% aqueous ammonia (130 mL) was added, and stirring was continued overnight at room temperature. The resulting white solid was collected and washed with distilled water. After drying, firing in air at 550 ° C. yielded Al-MCM-41.

[Example 4]
In the same manner as in Example 1, the reaction was carried out using Al-MCM-41 (5 mg) synthesized in Reference Example 5. The yield of cyanohydrin silyl ether after 5 minutes was 98%, and the pseudo-first-order rate constant k was 0.75 min ⁻¹ . This result suggests that the cyanosilylation catalyst of the present invention is not restricted by the raw materials and the synthesis method and exhibits high catalytic activity.

[Comparative Example 3]
In the same manner as in Example 1, the reaction was carried out using synthetic zeolite HY (5 mg). The yield of cyanohydrin silyl ether after 1 hour was 4%.

[Comparative Example 4]
In the same manner as in Example 1, the reaction was performed using synthetic zeolite H-ZSM-5 (5 mg). The reaction was carried out for 1 hour, but no cyanohydrin silyl ether was obtained.

[Comparative Example 5]
In the same manner as in Example 1, the reaction was carried out using Nafion-H (registered trademark) (5 mg) which is a solid acid catalyst. The yield of cyanohydrin silyl ether after 5 minutes was 7%, but the product was decomposed over time, and the yield after 1 hour was reduced to 2%.

[Comparative Example 6]
In the same manner as in the method of Example 1, the reaction was performed using Amberlyst-15 (registered trademark) (5 mg) which is an ion exchange resin. The yield of cyanohydrin silyl ether after 1 hour was 6%.

[Comparative Example 7]
In the same manner as in Example 1, the reaction was carried out using triethylamine (5 μL, 5 mol% with respect to benzaldehyde) as a homogeneous base catalyst. The yield of cyanohydrin silyl ether after 1 hour was 14%.

[Example 5]
(Cyanosilylation of benzaldehyde)
To a glass Schlenk flask containing a stirrer coated with Teflon, Al-MCM-41 (5.0 mg) synthesized in Reference Example 1 was added and dried at 120 ° C. under reduced pressure for 1 hour. After cooling to room temperature, an argon atmosphere was established and methylene chloride (1 mL) was added and stirred to form a catalyst suspension. Distilled trimethylsilyl cyanide (158 μL, 1.19 mmol) was added thereto, followed by dropwise addition of benzaldehyde (104.4 mg, 0.98 mmol), followed by stirring at room temperature for 1 minute. After the catalyst was filtered off, the solvent was distilled off to obtain the target product α-trimethylsiloxy-phenylacetonitrile as a single product. Single product was confirmed by ¹ H NMR analysis. As a result of quantification by ¹ H NMR (400 MHz) using 1,1,2,2-tetrachloroethane (20 μL, 0.189 mmol) as an internal standard substance, the yield was 100%.
¹ H NMR (CDCl ₃ , δ): 0.23 (s, 9H), 5.50 (s, 1H), 7.38-7.48 (m, 5H).
¹³ C NMR (CDCl ₃ , δ): -0.31, 63.60, 119.14, 126.31, 128.89, 129.29, 136.21.

[Examples 6 to 19]
In the same manner as in Example 5, cyanosilylation was performed using various organic carbonyl compounds shown in Table 2 below. As a result, even when any organic carbonyl compound was used, the desired cyanohydrin silyl ether compound was quantitatively obtained in a short time as a single product. In addition, from the results of Examples 14 to 19, the cyanosilylation catalyst of the present invention showed a decrease in yield and a significant increase in reaction time for aliphatic aldehydes and ketones, which were difficult in the conventional method. Not suggesting very high catalytic activity.

[Example 20]
(Cyanosilylation of benzaldehyde with tert-butyldimethylsilyl cyanide)
To a glass Schlenk flask containing a stirrer coated with Teflon, Al-MCM-41 (5.1 mg) synthesized in Reference Example 1 was added and dried at 120 ° C. under reduced pressure for 1 hour. After cooling to room temperature, an argon atmosphere was established, a solution of tert-butyldimethylsilyl cyanide (175 mg, 1.24 mmol) in methylene chloride (1.5 mL) was added, and benzaldehyde (105.3 mg, 0.99 mmol) was subsequently added dropwise. After stirring at room temperature for 10 minutes, the catalyst was filtered off and the solvent was distilled off. Separation and purification were performed by silica gel chromatography to obtain the target product α-tert-butyldimethylsiloxy-phenylacetonitrile (239.0 mg). The isolation yield was 97%.
¹ H NMR (CDCl ₃ , δ): 0.15 (s, 3H), 0.23 (s, 3H), 0.94 (s, 9H), 5.52 (s, 1H), 7.39-7.48 (m, 5H).
¹³ C NMR (CDCl ₃ , δ): -5.19, -5.08, 18.16, 25.52, 64.00, 119.26, 126.09, 128.90, 129.23, 136.48.

[Example 21]
(Cyanosilylation of benzylacetone with tert-butyldimethylsilyl cyanide)
In the same manner as in Example 20, the reaction was performed using benzylacetone as the carbonyl compound. The isolated yield of the desired product, 2-tert-butyldimethylsiloxy-4-phenylbutanenitrile, was 97%.
¹ H NMR (CDCl ₃ , δ): 0.24 (s, 3H), 0.29 (s, 3H), 0.92 (s, 9H), 1.62 (s, 1H), 1.98-2.06 (m, 2H), 2.75-2.94 (m, 5H), 7.18-7.32 (m, 5H).
¹³ C NMR (CDCl ₃ , δ): -3.89, -3.18, 18.02, 25.48, 38.92, 30.75, 45.52, 69.30, 121.87, 126.16, 128.35, 128.54, 140.75.

  The present invention can be used extremely effectively as a method for producing a synthetic intermediate (cyanohydrin silyl ether compound) that can be derived into, for example, α-amino acids, β-aminoalcohols, and the like.

Comparative chart of catalytic activity used in Example 1, Comparative Example 1 and Comparative Example 2

Claims (6)

  A cyanosilylation catalyst for an organic carbonyl compound, the main component of which is mesoporous silica containing aluminum. The cyanosilylation catalyst according to claim 1, wherein the mesoporous silica containing aluminum has a regular pore of 2 to 20 nm.   The cyanosilylation catalyst according to claim 1 or 2, wherein the silicon / aluminum molar ratio Si / Al contained in the mesoporous silica containing aluminum is 1 to 100.   A method for producing a cyanohydrin silyl ether compound, comprising reacting an organic carbonyl compound and a cyanide trialkylsilyl compound in the presence of the cyanosilylation catalyst according to any one of claims 1 to 3. The organic carbonyl compound is represented by the general formula (1)

(Wherein, R1 may have a substituent, a chain alkyl group, cyclic alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic; R ² is hydrogen, may have a substituent Represents an alkyl group, an aryl group or a heterocyclic ring, wherein R ¹ and R ² may be bonded to each other to form a ring)
The method for producing a cyanohydrin silyl ether compound according to claim 4, wherein the compound is represented by the formula: The trialkylsilyl cyanide compound has the general formula (2)

(In the formula, R ³ , R ⁴ and R ⁵ may be the same or different from each other, and each represents an optionally substituted alkyl group or aryl group)
The method for producing a cyanohydrin silyl ether compound according to claim 4, wherein the compound is represented by the formula:

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