Method for producing organosilicon compound
By reacting disubstituted silane with trifluoromethanesulfonic acid, an organosilicon compound with a trifluoromethanesulfonyloxy group is prepared, which solves the problems of HCl gas generation, high temperature reaction and low yield in the existing technology, and achieves high efficiency. , low temperature preparation process.
Patent Information
- Application Number
- CN202410918755.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-07-21
- Filing Date
- 2024-07-10
- Publication Date
- 2025-01-21
AI Technical Summary
In the prior art, when producing an organic silicon compound having a trifluoromethanesulfonyloxy group (CF3SO3), there are problems such as producing harmful HCl gas, high temperature reactions and low yields.
By reacting disubstituted silanes with trifluoromethanesulfonic acid, organosilicon compounds with 1 or 2 trifluoromethanesulfonyloxy groups are prepared, avoiding the generation of HCl gas, and conducting the reaction at a lower temperature, thereby increasing the yield. Rate.
A reaction that does not produce harmful HCl gas is achieved, high-temperature treatment is avoided, and the yield of organosilicon compounds is improved.
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Figure CN119331003A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for producing an organic silicon compound having a trifluoromethanesulfonyloxy group (CF3SO3). Background Art
[0002] As a selective protecting agent for polyhydroxy compounds, an organosilicon compound having a trifluoromethanesulfonyloxy group (CF3SO3) such as di-tert-butylsilyl bis(trifluoromethanesulfonate) is known (Non-Patent Document 1).
[0003] For example, di-tert-butylsilyl bis(trifluoromethanesulfonate) is often used as a protecting agent for 3',5'-dihydroxy and other diols of nucleosides in the synthesis of amidites.
[0004] As a method for synthesizing an organosilicon compound having a trifluoromethanesulfonyloxy group (CF 3 SO 3 ) such as di-tert-butylsilyl bis(trifluoromethanesulfonate), Non-Patent Document 2 describes a method represented by the following reaction formula.
[0005] R2SiHCl+2CF3SO3H→R2Si(OSO2CF3)2+H2+HCl
[0006] (wherein R represents isopropyl or tert-butyl)
[0007] In the above reaction, CF3SO3H was added dropwise at 22°C and then refluxed for 2 hours. The boiling point of CF3SO3H is 162°C, from which it is inferred that the reflux was performed at 160°C or above. Regarding the yield, it is recorded that di-tert-butylsilyl bis(trifluoromethanesulfonate) is 71% and diisopropylsilyl bis(trifluoromethanesulfonate) is 77%.
[0008] This method has also been cited in other literature and can be considered a commonly used method.
[0009] However, this method has the following problems: it generates harmful HCl gas; it is carried out at a high temperature around the boiling point of trifluoromethanesulfonic acid (162° C.); and the yield is not high.
[0010] Prior art literature
[0011] Non-patent literature
[0012] Non-patent document 1: Greene's Protective Groups in Organic Synthesis, Fifth edition, p456-459, 2014
[0013] Non-patent document 2: Tetrahydron Letters, Vol. 23, No. 47, pp. 4871-4874, 1982 Summary of the invention
[0014] Problems to be solved by the invention
[0015] The object of the present invention is to provide a method for preparing organic silicon compounds having a trifluoromethanesulfonyloxy group (CF3SO3) such as di-tert-butylsilyl bis(trifluoromethanesulfonate), wherein the method does not generate harmful HCl gas, can be carried out at a high temperature other than around the boiling point of trifluoromethanesulfonic acid (162°C), and has a good yield.
[0016] Means for solving problems
[0017] The inventors of the present application have conducted in-depth research to solve the above-mentioned problems and found that by using a di-substituted silane compound such as di-tert-butylsilane as a starting material, no HCl gas will be generated, there is no need to operate at high temperature, and an organic silicon compound having one or two trifluoromethanesulfonyloxy groups (CF3SO3) can be produced in good yield.
[0018] That is, the present invention relates to:
[0019] (1) A method for producing an organosilicon compound represented by formula (II), wherein a disubstituted silane compound represented by formula (I) is reacted with trifluoromethanesulfonic acid,
[0020] [Chemical formula 1]
[0021]
[0022] (In the formula, each R may be the same or different and represents a C1-C6 straight chain or branched chain alkyl, a C3-C8 cycloalkyl, a phenyl group, or a group formed by combining them)
[0023] [Chemical formula 2]
[0024]
[0025] (wherein, R is the same as defined in formula (I), OTf represents a CF3SO3 group, and W represents a hydrogen atom or OTf);
[0026] Specifically, it involves:
[0027] (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).
[0028] Effects of the Invention
[0029] According to the preparation method of the present invention, no harmful HCl gas is generated, and the process can be carried out at a high temperature other than the boiling point of trifluoromethanesulfonic acid (162° C.), and an organic silicon compound having one or two trifluoromethanesulfonyloxy groups (CF3SO3) such as di-tert-butylsilyl bis(trifluoromethanesulfonate) can be produced in good yield. DETAILED DESCRIPTION
[0030] (Disubstituted silane compound represented by formula (I))
[0031] The disubstituted silane compound represented by the formula (I) as a starting material may be a commercially available compound, or may be obtained by a known method such as substituting hydrogen for the chlorine group of disubstituted chlorosilane with a metal hydride such as lithium aluminum hydride.
[0032] [Chemical formula 3]
[0033]
[0034] In formula (I), each R may be the same or different and represents a C1-C6 straight-chain or branched alkyl group, a C3-C8 cycloalkyl group, a phenyl group, or a group composed of a combination thereof.
[0035] Examples of the C1-C6 straight-chain or branched alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, and n-hexyl.
[0036] Examples of the C3-C8 cycloalkyl group include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl.
[0037] The group formed by combining these is a group formed by combining a C1-C6 straight-chain or branched alkyl group, a C3-C8 cycloalkyl group and a phenyl group.
[0038] Examples of the group formed by combining a C1-C6 straight-chain or branched alkyl group with a C3-C8 cycloalkyl group include a cyclopropylmethyl group, a 2-cyclopropylethyl group, a cyclobutylmethyl group, a cyclohexylmethyl group, a 1-methylcyclopropyl group, and a 4-methylcyclohexyl group.
[0039] Examples of the group formed by combining a C1-C6 straight-chain or branched alkyl group and 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.
[0040] Specific examples thereof include di-tert-butylsilane, diisopropylsilane, diphenylsilane, methylcyclohexylsilane, and methylphenylsilane.
[0041] (Organosilicon compound represented by formula (II))
[0042] The produced organic silicon compound represented by the formula (II) includes a compound to which one trifluoromethanesulfonyloxy group (CF3SO3) is bonded and a compound to which two trifluoromethanesulfonyloxy groups (CF3SO3) are bonded.
[0043] [Chemical formula 4]
[0044]
[0045] Specifically, as the compound having one trifluoromethanesulfonyloxy group (CF3SO3) bonded thereto, there are mentioned diisopropylsilyl trifluoromethanesulfonate, di-tert-butylsilyl trifluoromethanesulfonate, dicyclohexylsilyl trifluoromethanesulfonate, diphenylsilyl trifluoromethanesulfonate, and the like; as the compound having two trifluoromethanesulfonyloxy groups (CF3SO3) bonded thereto, there are mentioned diisopropylsilyl bis(trifluoromethanesulfonate), di-tert-butylsilyl bis(trifluoromethanesulfonate), dicyclohexylsilyl bis(trifluoromethanesulfonate), diphenylsilyl bis(trifluoromethanesulfonate), and the like.
[0046] (reaction)
[0047] The reaction in the present invention is as shown in the following reaction formula, and a compound having two trifluoromethanesulfonyloxy groups (CF3SO3) bonded thereto is generated via a compound having one trifluoromethanesulfonyloxy group (CF3SO3) bonded thereto.
[0048] [Chemical formula 5]
[0049]
[0050] The production amounts of the compound having one trifluoromethanesulfonyloxy group (OTf) bonded thereto and the compound having two trifluoromethanesulfonyloxy groups (OTf) bonded thereto can be adjusted by adjusting the ratio of the disubstituted silane represented by formula (I) to trifluoromethanesulfonic acid, the reaction temperature, and the like.
[0051] The conditions for reacting the above-mentioned disubstituted silane with trifluoromethanesulfonic acid are as follows.
[0052] When the organosilicon compound represented by formula (II) is a bis(trifluoromethanesulfonate) compound, the amount of disubstituted silane represented by formula (I) and trifluoromethanesulfonic acid used is not particularly limited as long as the amount of trifluoromethanesulfonic acid is 2 mol or more per 1 mol of disubstituted silane, and is usually 2 to 3 mol.
[0053] The reaction temperature is not particularly limited, and may be a temperature lower than the boiling point of trifluoromethanesulfonic acid (162°C), and is usually 80 to 160°C.
[0054] When the organosilicon compound represented by formula (II) is produced as a mono(trifluoromethanesulfonate) compound, the amount of disubstituted silane represented by formula (I) and trifluoromethanesulfonic acid used is set as follows: the amount of trifluoromethanesulfonic acid is usually 1 to 2 moles per 1 mole of disubstituted silane. Alternatively, the amount of trifluoromethanesulfonic acid is set to 2 moles or more per 1 mole of disubstituted silane, and the reaction temperature is set to 0°C or more and lower than 80°C, usually at 0 to 60°C, thereby obtaining a mono(trifluoromethanesulfonate) compound.
[0055] The reaction time can be appropriately set depending on the reaction temperature, the amount of the reaction raw materials, etc. In addition, the reaction can be carried out under normal pressure.
[0056] No reaction catalyst is required.
[0057] The reaction of the present invention can be carried out in the absence of a solvent. A solvent may also be used, but in this case, a high boiling point solvent that does not affect the reaction is preferably used. For example, aromatic hydrocarbon solvents such as toluene and xylene, and ethers such as butyl ether may be used.
[0058] The mixing method of the reaction raw materials is not particularly limited. The disubstituted silane represented by formula (I) and trifluoromethanesulfonic acid may be mixed and then heated, or the disubstituted silane represented by formula (I) may be added dropwise to trifluoromethanesulfonic acid, or conversely, trifluoromethanesulfonic acid may be added dropwise to the disubstituted silane represented by formula (I) while heating.
[0059] After the above reaction, the organosilicon compound represented by formula (II) can be taken out by distillation under normal pressure or reduced pressure.
[0060] The organosilicon compound represented by the formula (II) as the target compound can be identified by measuring an NMR spectrum, a GC-MS spectrum, or the like.
[0061] Although Examples are shown below, the present invention is not limited to these Examples.
[0062] [Example 1]
[0063] (Example 1)
[0064] 476.4 g (3.17 mol) of trifluoromethanesulfonic acid was charged into a reaction vessel, and 183.4 g (1.27 mol) of di-tert-butylsilane was added dropwise at an internal temperature of 125±5° C., and stirred at the same temperature for 3.5 hours. After the reaction was completed, vacuum distillation was performed to obtain 463.1 g of di-tert-butylsilyl bis(trifluoromethanesulfonate) (yield of 83%, based on the charge of di-tert-butylsilane).
[0065] (Example 2)
[0066] 100 mg (0.69 mmol) of di-tert-butylsilane and 322 mg (2.15 mmol) of trifluoromethanesulfonic acid were placed in a reaction container, and the mixture was stirred at 40° C. for 4 hours.
[0067] (Example 3)
[0068] The operation of Example 2 was repeated except that the reaction temperature was 60°C. The results are shown in Table 1.
[0069] (Example 4)
[0070] The operation of Example 2 was repeated except that the reaction temperature was 80°C. The results are shown in Table 1.
[0071] (Example 5)
[0072] The results are shown in Table 1.
[0073] (Example 6)
[0074] The operation of Example 2 was repeated except that the reaction temperature was 160°C. The results are shown in Table 1.
[0075] The compound numbers in Table 1 correspond to the compound numbers of the following reaction formulas.
[0076] [Chemical formula 6]
[0077]
[0078] The abundance ratios of Compounds 1 to 3 contained in the reaction solution were calculated by area percentage using GC.
[0079] [Table 1]
[0080]
[0081] A method using di-tert-butylchlorosilane is shown below as a comparative example.
[0082] (Comparative Example 1)
[0083] 250 mg (1.40 mmol) of di-tert-butylchlorosilane and 651 mg (4.34 mmol) of trifluoromethanesulfonic acid were placed in a reaction container, and the mixture was stirred at 40° C. for 4 hours.
[0084] (Comparative Example 2)
[0085] The results are shown in Table 2.
[0086] (Comparative Example 3)
[0087] The operation of Comparative Example 1 was repeated except that the reaction temperature was 140°C.
[0088] (Comparative Example 4)
[0089] The results are shown in Table 2, except that the reaction temperature was 160°C.
[0090] (Comparative Example 5)
[0091] The operation of Comparative Example 1 was repeated except that the reaction temperature was 170°C.
[0092] The compound numbers in Table 2 correspond to the compound numbers of the following reaction formulas.
[0093] [Chemical formula 7]
[0094]
[0095] [Table 2]
[0096]
[0097] As described above, in the method of adding di-tert-butylsilane dropwise at 125±5° C. in Example 1, di-tert-butylsilyl bis(trifluoromethanesulfonate) can be obtained in high yield.
[0098] In addition, as shown in Examples 2 to 6, the production of a single OTf body (Compound 2) and a di-OTf body (Compound 3) can be separated by controlling the temperature.
[0099] On the other hand, in the method using di-tert-butylchlorosilane described in Non-Patent Document 2 (Comparative Example), even if the temperature is controlled, a single OTf body such as the compound 2 of the present invention is not obtained, and only a compound 5 with a residual chlorine group is obtained. In addition, in the case of the comparative example, even if the temperature is increased, the generation rate of the di-OTf body (compound 3) is low.
Claims
1. A method for producing an organosilicon compound represented by formula (II), wherein the method comprises reacting a disubstituted silane compound represented by formula (I) with trifluoromethanesulfonic acid, [Chemical formula 1] In formula (I), each R may be the same or different and represents a C1-C6 straight-chain or branched alkyl group, a C3-C8 cycloalkyl group, a phenyl group, or a group composed of a combination thereof; [Chemical formula 2] In formula (II), R is the same as defined in formula (I), OTf represents a CF3SO3 group, and W represents a hydrogen atom or OTf.
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).