A method for synthesizing beta (e) type alkenyl silane compounds

Abstract

The application discloses a method for effectively synthesizing β ( E ) type alkenyl silane. The method uses alkyne as a reaction substrate, silane as a silicon source, and a complex [Cp*Ir( μ -Cl)3IrCp*][X] as a catalyst, and in the presence of an organic solvent, at 20-30 DEG C, for a period of time to obtain β ( E ) type alkenyl silane. The method has mild reaction conditions, simple operation, and the catalyst can be recycled and reused, and has good application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for synthesizing β ( E ) type alkenyl silane compounds. BACKGROUND

[0002] Organosilanes are a class of very important synthetic unit compounds [a) Langkopf, E.; Schinzer, D. Chem. Rev. 1995, 95, 1375−1408], which have a wide range of applications in the fields of synthetic chemistry, medicinal chemistry and material chemistry research. Alkenyl silanes are a class of common organosilane compounds, which form alkenyl ion synthons by connecting the carbon-carbon double bond through the silane substituent. At present, the synthesis of alkenyl silanes through the silane hydrosilation reaction of alkynes is the most atom-economical synthesis method [a) Angew. Chem. Int. Ed., 2004, 43, 2749]. The silane hydrosilation reaction of terminal alkynes will produce β ( E ), β ( Z ), α three different stereoisomers of alkenyl silanes. Compared with β ( Z ) 、α , β ( E ) configuration, the β ( Z ) configuration is relatively thermodynamically stable, and it is reported that the β ( E ) configuration can slowly convert into the

[0003] In the current research, the homogeneous catalysts capable of catalyzing the β ( E ) type silane hydrosilation reaction of terminal alkynes are usually mononuclear metal complexes with platinum (Pt), rhodium (Rh) and iridium (Ir) noble metals as active centersa) Faller J. W. et al. Organometallics, 2002, 21, 1743.; b) Salazar V., Suárez A. et al. Organometallics, 2017, 36, 2460.; c) Oro L. A. et al. Organometallics, 2016, 35, 2410.}, and binuclear metal complexes catalyze the silane hydrosilation reaction of terminal alkynes β ( EThere are few reports on the ) type hydrosilylation reaction, and no reports have been found on the recoverable binuclear metal homogeneous catalyst after the catalytic reaction is completed. Summary of the Invention

[0004] The problem this invention aims to solve is to provide an efficient synthesis method. β ( E The synthesis method of )-type alkenylsilanes is based on [Cp*Ir( μ -Cl)3IrCp*][X](Cp*:pentamethylcyclopentadienyl; X:Cl - BF4 - CF3SO3 - Complex-catalyzed hydrosilylation of alkynes enables highly regioselective and stereoselective synthesis. β ( E This method involves compounds of the alkenylsilane type. After the reaction is complete, the catalyst can be recovered by adjusting the solvent polarity.

[0005] This invention is achieved through the following technical solution:

[0006] A synthesis β ( E The method uses alkynes as reaction substrates, silanes as the silicon source, and complexes [Cp*Ir( μ Using -Cl)3IrCp*][X] as a catalyst, the reaction was carried out at 20℃~30℃ for a period of time to obtain β ( E ) type alkenylsilanes, alkynes, silanes, [Cp*Ir( μ The molar ratio of -Cl)3IrCp*][X] is 1:1:0.005~0.01.

[0007] Furthermore, the structure of the alkyne is as follows: R 1 It can be any one of alkyl, aryl, heteroaryl, or substituted aryl.

[0008] Furthermore, the general structural formula of the silane is as follows: , where R 2 R 3 , can be any one of alkyl, aryl, or alkoxy.

[0009] Furthermore, the [Cp*Ir( μ The structural formula of the -Cl)3IrCp*][X] complex is: X is Cl, BF4 - CF3SO3 - Any one of them.

[0010] Furthermore, the synthesis method described in this invention involves an organic solvent, which is selected from any one of chloroform, dichloromethane, acetonitrile, toluene, tetrahydrofuran, benzene, carbon tetrachloride, diethyl ether, petroleum ether, and n-hexane.

[0011] Furthermore, the preferred reaction temperature is 20℃~30℃.

[0012] Furthermore, the reaction time is 0.5 to 1.0 hours.

[0013] Furthermore, the synthesis method of the present invention further includes: after the reaction is completed, adding a weakly polar solvent to the reaction system and then filtering to obtain a filtrate and a solid. The obtained solid is the catalyst, which can be reused after drying. The filtrate obtained by filtration is separated by recrystallization, thin-layer chromatography, column chromatography or vacuum distillation to obtain the alkenylsilane product.

[0014] Furthermore, the weakly polar solvent is selected from at least one of n-hexane, n-pentane, n-heptane, and n-octane. The amount of the weakly polar solvent added is 5 to 10 times the volume of the reaction solvent.

[0015] Furthermore, the synthesis reaction must be carried out under an inert atmosphere.

[0016] Compared with the prior art, the beneficial effects of the method of the present invention are as follows:

[0017] The method of this invention provides an efficient way to use [Cp*Ir( μ -Cl)3IrCp*][X] is used as a catalyst to synthesize from alkyne hydrosilylation reaction. β ( E A method for compounding alkenylsilanes of the type [Cp*Ir(]]. Compared with existing methods, it is applicable to a variety of different types of alkynes and silanes, with mild reaction conditions, simple operation, and 100% atom economy. Compared with mononuclear iridium complexes, the binuclear iridium catalyst [Cp*Ir(]] described in this invention is superior. μ -Cl)3IrCp*][X] fully utilizes the synergistic effect between binary metals, making β ( E The selectivity of alkenylsilanes is higher, achieving a "1+1>2" effect. Furthermore, the catalyst used in this method can be recycled and reused, showing significant potential for practical application. This method exhibits good functional group compatibility, high regioselectivity and stereoselectivity, and the synthesized products contain... β ( E The content of the alkenylsilane compound can reach more than 90 mol%, preferably 96 to 99 mol%. Detailed Implementation

[0018] The method of this invention is an efficient synthesis β ( E) type alkenyl silane. The method is to use complex [Cp*Ir( μ -Cl)3IrCp*][X] as catalyst to synthesize β ( E ) type alkenyl silane with high regioselectivity and high stereoselectivity.

[0019] The molecular general formula of the alkenyl silane compound synthesized by the method of the present application is , R 1 may be any one of alkyl, aryl, heteroaryl, substituted aryl, and X is any one of Cl - , BF4 - , CF3SO3 - . R 2 may be any one of alkyl, aryl, alkoxy.

[0020] The alkenyl silane compound of the present application is obtained by using terminal alkyne and secondary silane as raw materials, [Cp*Ir( μ -Cl)3IrCp*][X] as catalyst, and reacting in a common organic solvent system, which can be represented by the following formula:

[0021] .

[0022] The structural general formula of the alkyne is: , R 1 , R 2 , and X are as described above; and the structural general formula of the catalyst is

[0023] .

[0024] The [Cp*Ir( μ -Cl)3IrCp*][X] complex catalyst described in the present application can be selected from commercially available products or prepared according to conventional knowledge in the art.

[0025] In the present application, the [Cp*Ir( μ -Cl)3IrCp*][X] complex catalyst is synthesized according to the method reported in the literature Rybinskaya M. I., Kudinov A. R., Kaganovich V. S., J. Organometal. Chem., 1983, 246, 279.

[0026] The method of the present application is described in more detail below in conjunction with specific examples.

[0027] Example 1

[0028] Under the protection of inert gas, phenylacetylene ( 1.5 mmol), diphenylsilane (H2SiPh2, Ph is phenyl, 1.5 mmol), [Cp*Ir( μ -Cl)3IrCp*][BF4]( 0.015 mmol) was added to a dry Schlenk flask, and the reaction was carried out at 20°C for 0.5 hours using chloroform (5 mL) as the reaction solvent. The product was treated with n-hexane (40 mL) and then filtered. The resulting solid was used as a catalyst and could be reused after drying. The filtrate was separated by column chromatography to obtain diphenyl(( E )-2-phenylenyl)silane.

[0029]

[0030] A colorless oily substance, in the product β ( E The content of the alkenylsilane configuration is 98 mol. 1 H NMR (CDCl3, δ, ppm, 400 MHz): δ 7.67-7.64 (m, 4H), 7.51-7.47 (m, 2H), 7.45-7.29 (m, 9H), 7.15-7.09 (m, 1H), 6.75 (dd, J = 19.6 Hz, J = 3.2 Hz, CHSi), 5.27 (d, J = 3.2 Hz, SiH).

[0031] Example 2

[0032] Under the protection of an inert gas, phenylacetylene ( , 1.5 mmol), diethylsilane (H2SiEt2, Et is ethyl, 1.5 mmol), [Cp*Ir( μ -Cl)3IrCp*][BF4] ( 0.0075 mmol) was added to a dry Schlenk flask, and chloroform (5 mL) was used as the reaction solvent. The reaction was carried out at 30 °C for 1 hour. The product was treated with n-hexane (40 mL) and then filtered. The resulting solid was used as a catalyst and could be reused after drying. The filtrate was separated by column chromatography to obtain diethyl(( E )-2-phenylenyl)silane.

[0033]

[0034] A colorless oily substance, in the product β ( E The content of the alkenylsilane configuration is 99 mol. 1H NMR (CDCl3, δ, ppm, 400 MHz): 0.72-0.83 (m, 4H, CH3CH2-), 1.02-1.13(m, 6H, CH3CH2-), 4.00 – 4.07(m, 1H, SiH), 6.46 (dd, 1H, JHH = 19.3, 3.4 Hz, =CHSi), 7.06 (d, 1H, JHH =19.2 Hz, =CH), 7.26 – 7.42 (m, 3H, Ph), 7.44 – 7.51 (m, 2H, Ph).

[0035] Example 3

[0036] Under the protection of an inert gas, phenylacetylene ( 1.5 mmol), methylphenylsilane (H2SiMePh, where Me is methyl and Ph is phenyl, 1.5 mmol), [Cp*Ir( μ -Cl)3IrCp*][BF4] ( 0.015 mmol) was added to a dry Schlenk flask, and chloroform (5 mL) was used as the reaction solvent. The reaction was carried out at 30 °C for 0.5 hours. The product was treated with n-hexane (40 mL) and then filtered. The resulting solid was used as a catalyst and could be reused after drying. The filtrate was separated by column chromatography to obtain phenylmethyl(( E )-2-phenylenyl)silane.

[0037]

[0038] A colorless oily substance, in the product β ( E The content of the alkenylsilane configuration is 99 mol. 1 H NMR (CDCl3, δ, ppm, 400 MHz): 0.54 (d, 3H, JHH = 3.8 Hz, CH3), 4.76 (d, 1H, JHH = 3.6 Hz, SiH), 6.58 (dd, 1H, JHH = 19.2, 3.0 Hz, =CHSi), 7.08 (d, 1H, JHH = 19.2 Hz, =CH), 7.28 – 7.42 (m, 6H, Ph), 7.45 – 7.52 (m, 2H, Ph), 7.60 – 7.64 (m, 2H, Ph).

[0039] Example 4

[0040] Under the protection of an inert gas, p-methylphenylacetylene ( 1.5 mmol), diphenylsilane (H2SiPh2, Ph is phenyl, 1.5 mmol), [Cp*Ir( μ -Cl)3IrCp*][BF4] ( 0.015 mmol) was added to a dry Schlenk flask, and chloroform (5 mL) was used as the reaction solvent. The reaction was carried out at 20 °C for 1 hour. The product was treated with n-hexane (40 mL) and then filtered. The resulting solid was used as a catalyst and could be reused after drying. The filtrate was separated by column chromatography to obtain diphenyl(( E )-2-(4-methylphenyl)enyl)silane.

[0041]

[0042] A colorless oily substance, in the product β ( E The content of the alkenylsilane configuration is 98 mol. 1 H NMR (CDCl3, δ, ppm, 400 MHz): δ 7.58-7.62 (m, 4H), 7.34-7.42 (m, 8H), 7.12-7.14 (m, 2H), 7.02 (d,J = 18.8 Hz, 1H), 6.62(dd, J = 18.8 Hz, J = 2.8 Hz, CHSi), 5.21 (d, J = 2.8Hz, SiH), 2.33 (s, 3H).

[0043] Example 5

[0044] Under inert gas protection, 6-chlorohexyne ( , 1.5 mmol), diethylsilane (H2SiEt2, Et is ethyl, 1.5 mmol), [Cp*Ir( μ -Cl)3IrCp*][BF4] ( 0.03 mmol) was added to a dry Schlenk flask, and chloroform (5 mL) was used as the reaction solvent. The reaction was carried out at 30 °C for 1 hour. The product was treated with n-hexane (40 mL) and then filtered. The resulting solid was used as a catalyst and could be reused after drying. The filtrate was separated by column chromatography to obtain diphenyl(( E )-2-(6-chloro)hexenyl)silane.

[0045]

[0046] A colorless oily substance, in the product β( E The content of the alkenylsilane configuration was 96 mol%. ¹H NMR (CDCl₃, δ, ppm, 400 MHz): δ 7.54–7.58 (m, 4H), 7.34–7.44 (m, 6H), 6.26 (dt, J = 18.4 Hz, J = 6.4 Hz, CHCH₂), 5.98–5.93 (m, CHSiH), 5.08 (d, J = 3.2 Hz, SiH), 3.55 (t, J = 7.2 Hz, CH₂Cl), 2.24 (q, J = 7.2 Hz, CH₂CH), 1.82–1.78 (m, 2H), 1.64–1.56 (m, 2H).

[0047] Example 6

[0048] Under the protection of an inert gas, 1-octylene ( 1.5 mmol), diphenylsilane (H2SiPh2, Ph is phenyl, 1.5 mmol), [Cp*Ir( μ -Cl)3IrCp*][BF4] ( 0.03 mmol) was added to a dry Schlenk flask, and chloroform (5 mL) was used as the reaction solvent. The reaction was carried out at 30 °C for 1 hour. The product was treated with n-hexane (40 mL) and then filtered. The resulting solid was used as a catalyst and could be reused after drying. The filtrate was separated by column chromatography to obtain diphenyl(( E )-2-octenyl)silane.

[0049]

[0050] A colorless oily substance, in the product β ( E The content of the alkenylsilane configuration was 97 mol%. ¹H NMR (CDCl₃, δ, ppm, 400 MHz): δ 7.57–7.59 (m, 4H), 7.36–7.42 (m, 6H), 6.32 (dt, J = 18.4 Hz, J = 6.4 Hz, =CHCH₂), 5.90–5.97 (m, =CHSiH), 5.12 (d, J = 2.8 Hz, SiH), 2.22 (q, J = 6.4 Hz, CH₂CH), 1.42–1.46 (m, 2H), 1.26–1.36 (m, 6H), 0.89 (t, J = 6.4 Hz, CH₃).

Claims

1. A method for synthesizing alkenylsilane of formula (I) using alkyne as a reaction substrate, silane as a silicon source, complex [Cp*Ir(Cl)3IrCp*][X] as a catalyst, in the presence of an organic solvent at 20-30°C for a period of time to obtain alkenylsilane of formula (I); the molar ratio of alkyne, silane, [Cp*Ir(Cl)3IrCp*][X] is 1:1:0.005-0.

01. β E μ β E μ ​​​​​​ The structure of the alkyne is , R 1 is any one of alkyl, aryl, heteroaryl, substituted aryl; The general structure of the silane is wherein R 2 , R 3 , is any one of alkyl, aryl, alkoxy; said [Cp*Ir μ -Cl)3IrCp*][X] complex has the structural formula , X is Cl - , BF4 - , CF3SO3 - any one of The organic solvent is selected from any one of trichloromethane, dichloromethane, acetonitrile, toluene, tetrahydrofuran, benzene, carbon tetrachloride, diethyl ether, petroleum ether, n-hexane.

2. The method of claim 1, wherein, The reaction temperature is 20-30°C.

3. The method of claim 1, wherein, The reaction time is 0.5-1.0 hours.

4. The method of claim 1, wherein, Also included are: After the reaction, a weakly polar solvent is added to the reacted system, and then filtered to obtain a filtrate and a solid.

5. The method of claim 4, wherein, The obtained solid is a catalyst, which can be reused after drying.

6. The method of claim 4, wherein, The obtained filtrate is separated by recrystallization, thin layer chromatography, column chromatography or vacuum distillation to obtain an alkenylsilane product.

7. The method of claim 4, wherein, The weakly polar solvent is selected from at least one of n-hexane, n-pentane, n-heptane, n-octane.

8. The method of claim 4, wherein, The weakly polar solvent is added in an amount of 5-10 times the volume of the reaction solvent.

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