Method for producing organic silicon compound

Abstract

To provide a method for producing an organic silicon compound with a trifluoromethanesulfonyloxy group (CF3SO3) that prevents the emission of hazardous HCl gas, is performed without requiring high temperatures, and delivers high yield.SOLUTION: A method for producing an organic silicon compound with a trifluoromethanesulfonyloxy group includes reacting a disubstituted silane compound represented by formula (I) (where each R may be the same or different to represent a C1-C6 linear or branched alkyl group, a C3-C8 cycloalkyl group, a phenyl group or a combination of them) with trifluoromethanesulfonic acid.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a trifluoromethanesulfonyloxy group (CF 3 SO 3 The present invention relates to a method for producing an organosilicon compound having the formula (I). [Background technology]

[0002] As a selective protecting reagent for polyhydroxy compounds, trifluoromethanesulfonyloxy groups (CF 3 SO 3 ) is known (Non-Patent Document 1). For example, di-tert-butylsilyl bis(trifluoromethanesulfonate) is often used as a protecting reagent for diols, such as the 3',5'-dihydroxy groups of nucleosides in amidite synthesis. Trifluoromethanesulfonyloxy groups (CF 3 SO 3 As a method for synthesizing an organosilicon compound having the formula (I), Non-Patent Document 2 describes a method shown in the following reaction scheme. R 2 SiHCl+2CF 3 SO 3 H → R 2 Si(OSO 2 CF 3 ) 2 +H 2 +HCl (wherein R represents an isopropyl group or a t-butyl group). The above reaction is CF at 22°C. 3 SO 3 After adding H dropwise, the mixture was refluxed for 2 hours. CF 3 SO 3Since the boiling point of H is 162°C, it is estimated that reflux was carried out at 160°C or higher. The yields of di-tert-butylsilyl bis(trifluoromethanesulfonate) and diisopropylsilyl bis(trifluoromethanesulfonate) are listed as 71% and 77%, respectively. This method is considered conventional since it is cited in other publications. However, this method has problems in that it generates harmful HCl gas, is carried out at a high temperature similar to the boiling point of trifluoromethanesulfonic acid (162° C.), and the yield is not high. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Greene's Protective Groups in Organic Synthesis, Fifth edition, p456-459, 2014 [Non-Patent Document 2] Tetrahydron Letters, Vol.23, No47, pp4871-4874, 1982 Summary of the Invention [Problem to be solved by the invention]

[0004] It does not generate harmful HCl gas, does not require high temperatures such as the boiling point of trifluoromethanesulfonic acid (162°C), and has a high yield. 3 SO 3 The present invention aims to provide a method for producing an organosilicon compound having the formula (I). [Means for solving the problem]

[0005] As a result of intensive research aimed at solving the above problems, the present inventors have found that by using a di-substituted silane compound such as di-tert-butylsilane as a starting material, it is possible to obtain a trifluoromethanesulfonyloxy group (CF) in a good yield without generating HCl gas or at a high temperature. 3 SO 3 It has been found that it is possible to prepare organosilicon compounds having one or two aryl groups.

[0006] That is, the present invention provides: (1) Formula (I) [ka] (wherein each R may be the same or different and represents a C1-C6 linear or branched alkyl group, a C3-C8 cycloalkyl group, a phenyl group, or a combination thereof) is reacted with trifluoromethanesulfonic acid, Formula (II) [ka] (In the formula, R is defined as in formula (I), and OTf is CF 3 SO 3 The present invention relates to a method for producing an organosilicon compound represented by the formula: (2) The method for producing an organosilicon compound according to (1), wherein the organosilicon compound represented by formula (II) is di-tert-butylsilyl trifluoromethanesulfonate or di-tert-butylsilyl bis(trifluoromethanesulfonate). Effect of the Invention

[0007] The process of the present invention does not generate harmful HCl gas, does not require high temperatures such as the boiling point of trifluoromethanesulfonic acid (162°C), and can efficiently produce trifluoromethanesulfonyloxy groups (CF 3 SO3 It is possible to produce organosilicon compounds having one or two of these groups. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (Di-substituted silane compound represented by formula (I)) The starting material is formula (I) [ka] The di-substituted silane compound represented by the formula (I) may be a commercially available product, or may be obtained by a known method, such as by substituting hydrogen for the chloro group of a di-substituted chlorosilane with a metal hydride such as lithium aluminum hydride.

[0009] In formula (I), each R may be the same or different and represents a C1-C6 linear or branched alkyl group, a C3-C8 cycloalkyl group, a phenyl group, or a combination thereof. Examples of the C1-C6 linear or branched alkyl group include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group. Examples of C3-C8 cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. Groups combining these include groups combining a C1-C6 linear or branched alkyl group, a C3-C8 cycloalkyl group, and a phenyl group. Examples of the group consisting of a C1-C6 linear or branched alkyl group and a C3-C8 cycloalkyl group include a cyclopropylmethyl group, a 2-cyclopropylethyl group, a cyclobutylmethyl group, a cyclohexylmethyl group, a 1-methyl-cyclopropyl group, and a 4-methyl-cyclohexyl group. Examples of the group combining a C1-C6 linear or branched alkyl group with a phenyl group include a benzyl group, a phenethyl group, a 3-phenyl-n-propyl group, a 2-methylphenyl group, and a 4-methylphenyl group. Specific examples include di-tert-butylsilane, di-iso-propylsilane, diphenylsilane, methylcyclohexylsilane, and methylphenylsilane.

[0010] (Organosilicon compound represented by formula (II)) The compound of formula (II)

[0011] [ka] The organosilicon compound represented by the formula 3 SO 3 ) is bonded to the compound, and the compound having two bonded to the compound is also included. Specifically, the trifluoromethanesulfonyloxy group (CF 3 SO 3 Examples of the compound having one trifluoromethanesulfonyloxy group (CF 3 SO 3 Examples of the compound having two bonded silyl groups include di-iso-propylsilyl bis(trifluoromethanesulfonate), di-tert-butylsilyl bis(trifluoromethanesulfonate), dicyclohexylsilyl bis(trifluoromethanesulfonate), and diphenylsilyl bis(trifluoromethanesulfonate).

[0012] (reaction) The reaction in the present invention is carried out by converting a trifluoromethanesulfonyloxy group (CF 3 SO 3 ) is bonded to a compound, which is then converted to a compound with two bonds. [ka] By adjusting the ratio of the di-substituted silane represented by formula (I) and trifluoromethanesulfonic acid used, the reaction temperature, etc., the amount of the compound having one trifluoromethanesulfonyloxy group (OTf) bonded thereto and the amount of the compound having two trifluoromethanesulfonyloxy groups bonded thereto can be adjusted. The conditions for reacting the above di-substituted silane with trifluoromethanesulfonic acid are as follows. When producing a compound in which the organosilicon compound represented by formula (II) is a bis(trifluoromethanesulfonate), the amounts of the di-substituted silane represented by formula (I) and trifluoromethanesulfonic acid used are not particularly limited as long as there are 2 moles or more of trifluoromethanesulfonic acid per mole of the di-substituted silane, but are usually 2 to 3 moles. The reaction temperature is not particularly limited, but a temperature lower than the boiling point of trifluoromethanesulfonic acid (162°C) is sufficient, and is usually 80 to 160°C. When producing a compound in which the organosilicon compound represented by formula (II) is a mono(trifluoromethanesulfonate) compound, the amounts of the di-substituted silane represented by formula (I) and trifluoromethanesulfonic acid used are usually 1 to 2 moles of trifluoromethanesulfonic acid per mole of the di-substituted silane. Alternatively, the compound can be obtained in a mono(trifluoromethanesulfonate) form by reacting at a reaction temperature of 0 to less than 80°C, usually 0 to 60°C, with 2 moles or more of trifluoromethanesulfonic acid per mole of the di-substituted silane.

[0013] The reaction time can be appropriately set depending on the reaction temperature, the amount of the reaction raw materials, etc. The reaction can be carried out under normal pressure. No reaction catalyst is required. The reaction of the present invention can be carried out without a solvent. A solvent can also be used, but in this case, a high-boiling solvent that does not affect the reaction is preferred. For example, aromatic hydrocarbon solvents such as toluene and xylene, and ethers such as butyl ether can be used. The method for mixing the reaction raw materials is not particularly limited. The di-substituted silane represented by formula (I) and trifluoromethanesulfonic acid may be mixed and then heated, or the di-substituted silane represented by formula (I) may be added dropwise to trifluoromethanesulfonic acid, or conversely, trifluoromethanesulfonic acid may be added dropwise to the di-substituted silane represented by formula (I) while heating.

[0014] After the above reaction, the organosilicon compound represented by formula (II) can be isolated by distillation under normal pressure or reduced pressure. The target compound, the organosilicon compound represented by formula (II), can be identified by measuring the NMR spectrum, GC-MS spectrum, or the like. Examples are shown below, but the present invention is not limited to these examples. EXAMPLES

[0015] Example 1 A reaction vessel was charged with 476.4 g (3.17 mol) of trifluoromethanesulfonic acid, and 183.4 g (1.27 mol) of di-tert-butylsilane was added dropwise at an internal temperature of 125±5° C., followed by stirring at the same temperature for 3.5 hours. After the reaction was completed, reduced pressure distillation was performed to obtain 463.1 g of di-tert-butylsilyl bis(trifluoromethanesulfonate) (yield 83% based on the amount of di-tert-butylsilane charged).

[0016] Example 2 A reaction vessel was charged with 100 mg (0.69 mmol) of di-tert-butylsilane and 322 mg (2.15 mmol) of trifluoromethanesulfonic acid, and the mixture was stirred for 4 hours at 40° C. The results are shown in Table 1. Example 3 The procedure of Example 2 was repeated, except that the reaction temperature was 60° C. The results are shown in Table 1. Example 4 The procedure of Example 2 was repeated, except that the reaction temperature was 80° C. The results are shown in Table 1. Example 5 The procedure of Example 2 was repeated, except that the reaction temperature was 100° C. The results are shown in Table 1. Example 6 The procedure of Example 2 was repeated, except that the reaction temperature was 160° C. The results are shown in Table 1.

[0017] The compound numbers in Table 1 correspond to the compound numbers in the reaction scheme below. [ka]

[0018] The abundance ratio of compounds 1 to 3 contained in the reaction solution was calculated by area percentage using GC.

[0019] [Table 1]

[0020] A method using di-tert-butylchlorosilane is shown below as a comparative example. Comparative Example 1 A reaction vessel was charged with 250 mg (1.40 mmol) of di-tert-butylchlorosilane and 651 mg (4.34 mmol) of trifluoromethanesulfonic acid, and the mixture was stirred for 4 hours at 40° C. The results are shown in Table 2.

[0021] Comparative Example 2 The procedure of Comparative Example 1 was repeated, except that the reaction temperature was 100° C. The results are shown in Table 2. Comparative Example 3 The procedure of Comparative Example 1 was repeated, except that the reaction temperature was 140° C. The results are shown in Table 2. Comparative Example 4 The procedure of Comparative Example 1 was repeated, except that the reaction temperature was 160° C. The results are shown in Table 2. Comparative Example 5 The procedure of Comparative Example 1 was repeated, except that the reaction temperature was 170° C. The results are shown in Table 2.

[0022] The compound numbers in Table 2 correspond to the compound numbers in the reaction scheme below. [ka]

[0023] [Table 2]

[0024] As described above, in the method of Example 1 in which di-tert-butylsilane was added dropwise at 125±5° C., di-tert-butylsilyl bis(trifluoromethanesulfonate) could be obtained in high yield. Furthermore, as shown in Examples 2 to 6, the production of the mono-OTf form (compound 2) and the di-OTf form (compound 3) could be separated by controlling the temperature. On the other hand, in the method (Comparative Example) using di-tert-butylchlorosilane described in Non-Patent Document 2, even when the temperature was controlled, a mono-OTf body such as Compound 2 of the present invention was not obtained, and only Compound 5 with a remaining chloro group was obtained. Moreover, in the case of the Comparative Example, even when the temperature was increased, the production rate of the di-OTf body (Compound 3) was low.

Claims

1. Formula (I) 【Chemistry 1】 (wherein each R may be the same or different and represents a C1-C6 linear or branched alkyl group, a C3-C8 cycloalkyl group, a phenyl group, or a combination thereof) is reacted with trifluoromethanesulfonic acid. Formula (II) 【Chemistry 2】 (In the formula, R is defined as in formula (I), and OTf is CF ３ SO ３ wherein W is a hydrogen atom or OTf.

2. 2. The method for producing an organosilicon compound according to claim 1, wherein the organosilicon compound represented by formula (II) is di-tert-butylsilyl trifluoromethanesulfonate or di-tert-butylsilyl bis(trifluoromethanesulfonate).

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