A method for photocatalytic synthesis of silanols or siloxanes from silanes

Abstract

The application relates to the field of organic chemistry, in particular to a method for photocatalytic synthesis of silanol or silyl ether. The application provides a method for photocatalytic synthesis of silanol or silyl ether compound, in which, under the condition of existence of an iridium catalyst and an organic solvent, hydrosilane is reacted with any one of water, alcohol or phenol under light to obtain silanol or silyl ether. The synthesis method has high yield and selectivity, low catalyst consumption, mild reaction condition and high environmental protection and efficiency.

Description

Technical Field

[0001] This application relates to the field of organic chemistry, and in particular to a method for the photocatalytic synthesis of silanols or silyl ethers. Background Technology

[0002] Silicon is abundant on Earth and possesses a variety of fundamental properties and excellent characteristics, playing a vital role in materials science and synthetic chemistry. Silica ethers and silanols, as typical representatives of organosilicon compounds, are important. Silica ethers are commonly used as protecting groups and are widely applied in organic synthesis and the total synthesis of natural products; related compounds have been shown to enhance the pharmacokinetic properties of drugs. Silanols are often used in cross-coupling reactions as nucleophilic partners, directing groups for C-H functionalization, and catalysts for activating carbonyl compounds. Furthermore, silanols are studied in medicinal chemistry as equivalents of enzyme inhibitors and pheromones. Given their application value and central role, exploring and optimizing their synthetic strategies is essential. Traditionally, the synthesis of silica ethers mainly relies on the reaction of silanizing reagents such as halosilanes or hexamethyldisilazane with alcohols or carbonyl compounds. However, these traditional methods have many drawbacks, such as harsh reaction conditions, high-temperature requirements, and the potential release of corrosive hydrogen halide gases. Traditional methods for synthesizing silanols typically involve the hydrolysis of chlorosilanes. However, this conversion often generates large quantities of useless chlorine-containing wastewater or condensation byproducts, which does not meet the requirements of green development. Therefore, directly oxidizing the Si-H bonds in hydrosilanes under oxidizing conditions provides another possible route for the synthesis of silanols. It should be noted that the use of strong oxidants (such as silver salts, KMnO4, ozone, etc.) inevitably leads to functional group tolerance issues.

[0003] With the increasing awareness of environmental protection, low-content processes will be gradually phased out, making it urgent to develop a method for synthesizing silanols or silanes that is environmentally friendly and efficient with mild reaction conditions. Summary of the Invention

[0004] To address the shortcomings of the prior art, this application aims to provide a highly active, highly selective, mild, green, environmentally friendly, and efficient method for synthesizing silanols and silane ethers with industrial production potential. Through screening and optimization of reaction conditions, the yield of the products has been improved.

[0005] This application provides a method for photocatalytic synthesis of silanols or silane ethers, characterized in that, in the presence of an iridium catalyst and an organic solvent, a hydrosilane of formula I reacts with water, an alcohol, or a phenol under light irradiation to obtain a silanol or silane ether of formula II. The synthetic route is as follows:

[0006]

[0007] R is independently selected from any one of hydrogen, alkyl, phenyl, benzyl, substituted phenyl, and substituted benzyl.

[0008] R 1 It is independently selected from any one of hydrogen, alkyl, phenyl, benzyl, substituted phenyl, and substituted benzyl.

[0009] R 2 It is independently selected from any one of hydrogen, alkyl, phenyl, benzyl, substituted phenyl, and substituted benzyl.

[0010] R 3 It is independently selected from any one of hydrogen, alkyl, phenyl, benzyl, substituted phenyl, and substituted benzyl.

[0011] The substituents in the substituted phenyl and / or substituted benzyl groups are selected from any one of hydrogen, alkyl, alkoxy, halogen, or hydrosilyl.

[0012] The alkyl group is a C1-C4 alkyl group, and the alkoxy group is a C1-C4 alkoxy group.

[0013] The iridium catalyst is a complex with iridium as the central atom, and its structural formula is shown in Formula III below:

[0014]

[0015] The organic solvent is a polar solvent.

[0016] Preferably, the organic solvent is selected from tetrahydrofuran, dimethylformamide, and acetonitrile.

[0017] More preferably, the solvent is tetrahydrofuran.

[0018] The light source is visible light.

[0019] Preferably, the wavelength of the visible light is 395–420 nm.

[0020] The power of the visible light is 10-15W.

[0021] The beneficial effects of this application are as follows:

[0022] 1. This application provides a method for photocatalytic synthesis of silanols and silanes, using a complex with iridium as the central atom as the catalyst. After optimization of reaction conditions, the method exhibits high catalytic activity and selectivity, for example, a yield of over 98% for triphenylsilane and a selectivity of approximately 100%. There are virtually no other byproducts generated, the catalyst dosage is low, the damage to equipment is significantly reduced, and the corrosiveness is controlled, which is beneficial for mass production.

[0023] 2. The photocatalytic synthesis method for silanols provided in this application is simple to operate and has mild conditions. It is an atom-economical and environmentally friendly method for synthesizing silanols. Due to the high selectivity of synthesizing silanols and the green, efficient and easy-to-recycle characteristics of the catalyst, it has the value of promotion and application. Attached Figure Description

[0024] Figure 1 The hydrogen spectrum of the triphenylsilanol synthesized in Example 1 is shown.

[0025] Figure 2 This is the carbon spectrum of the triphenylsilanol synthesized in Example 1.

[0026] Figure 3 The photon spectrum of (benzyloxy)triethylsilane synthesized in Example 8 is shown.

[0027] Figure 4 The carbon spectrum of (benzyloxy)triethylsilane synthesized in Example 8 is shown.

[0028] Figure 5 The photon spectrum of (3,4-dimethylphenoxy)triphenylsilane synthesized in Example 16 is shown.

[0029] Figure 6 The carbon spectrum of (3,4-dimethylphenoxy)triphenylsilane synthesized in Example 16 is shown. Detailed Implementation

[0030] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application.

[0031] Before further describing the specific embodiments of this application, it should be understood that the scope of protection of this application is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of this application is for describing specific embodiments and not for limiting the scope of protection of this application; in the specification and claims of this application, unless otherwise expressly stated in the text, the singular forms "a", "an" and "this" include the plural forms.

[0032] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in this application, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description in this application, any prior art methods, apparatus, and materials similar to or equivalent to those described, used, and materials in the embodiments of this application may be used to implement this application.

[0033] This invention discovers that complexes with iridium as the central atom can catalytically oxidize hydrosilanes to silanols or silane ethers under visible light induction, exhibiting high activity and high selectivity. Based on the optimization of reaction conditions such as visible light, iridium catalyst dosage, and organic solvent selection, this invention was completed.

[0034] This application provides a method for the photocatalytic synthesis of silanols or silane ethers. In the presence of an iridium catalyst and an organic solvent, a hydrosilane of Formula I reacts with water, an alcohol, or a phenol under light irradiation to obtain a silanol or silane ether of Formula II. The synthetic route is as follows:

[0035]

[0036] R is independently selected from any one of hydrogen, alkyl, phenyl, benzyl, substituted phenyl, and substituted benzyl.

[0037] R1 is independently selected from any one of hydrogen, alkyl, phenyl, benzyl, substituted phenyl, and substituted benzyl.

[0038] R2 is independently selected from any one of hydrogen, alkyl, phenyl, benzyl, substituted phenyl, and substituted benzyl.

[0039] R3 is independently selected from any one of hydrogen, alkyl, phenyl, benzyl, substituted phenyl, and substituted benzyl.

[0040] In specific embodiments of this application, the substituents in the substituted phenyl and / or substituted benzyl groups are selected from any one of hydrogen, alkyl, alkoxy, halogen, or hydrosilyl.

[0041] In specific embodiments of this application, the alkyl group is a C1 to C4 alkyl group.

[0042] In specific embodiments of this application, the alkoxy group is a C1-C4 alkoxy group.

[0043] The alkyl group usually refers to a saturated aliphatic group, which can be straight-chain or branched.

[0044] The C1 to C4 alkyl groups typically refer to alkyl groups comprising 1, 2, 3, or 4 carbon atoms. Specifically, the alkyl groups can be methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, etc., or they can be hydrogen.

[0045] The phenyl group usually refers to the part remaining after removing one hydrogen atom from the benzene ring, and is usually represented by Ph.

[0046] The benzyl group usually refers to a group formed by a benzene ring and a methyl group (-CH2-) linked together. It consists of a benzene ring and a methyl group linked by a single bond to form a C-C bond, and is also known as benzyl group.

[0047] The substituted phenyl group usually refers to the group formed when the hydrogen atom on the benzene ring of a phenyl group is replaced by other atoms or groups of atoms.

[0048] The substituted benzyl group usually refers to the group formed when the hydrogen atom on the benzyl group is replaced by other atoms or groups of atoms.

[0049] The alkoxy group typically refers to an alkyl-O- group, wherein the alkyl group is as defined above, for example, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, and heptoxy. The bond with the parent moiety is via an ether oxygen.

[0050] The C1 to C4 alkoxy groups generally refer to alkyl groups containing 1 to 4 carbon atoms connected by oxygen atoms, such as methoxy, ethoxy, propoxy, and butoxy.

[0051] The halogen usually refers to F, Cl, Br or I.

[0052] The silane group referred to typically refers to a monovalent group formed by removing one hydrogen atom from an organosilicon, and may have at least one hydrogen atom. Examples include -SiHMe2 and -SiHEt2.

[0053] In a specific embodiment of this application, the iridium catalyst is an iridium complex, which refers to a complex with iridium as the central atom and has the molecular formula C. 43 H 27 F6Ir2N4O2, the structural formula is shown in equation III below:

[0054]

[0055] The iridium complex is a phosphorescent metal complex. Phosphorescent metal complexes have a heavy metal chelate structure, which can increase spin-orbit coupling through the heavy atom effect, making it possible to attenuate the light radiation of forbidden triplet excitons. Theoretically, the internal quantum efficiency can reach 100%. Due to its high luminous efficiency, good thermal stability, and wide emission range, the iridium complex is used as a photocatalyst in this application.

[0056] In a specific embodiment of this application, the organic solvent is a good solvent for the reaction system, thereby ensuring that the reactants are fully dispersed and at a certain concentration so that the reaction can proceed smoothly.

[0057] In specific embodiments of this application, the organic solvent is selected from tetrahydrofuran, dimethylformamide, and acetonitrile.

[0058] In a preferred embodiment of this application, the organic solvent is tetrahydrofuran, which is beneficial for improving the yield of the product.

[0059] In a specific embodiment of this application, when hydrosilane reacts with water, the feed ratio of hydrosilane to water is 1 mmol:(1.1–2) mmol, for example, 1 mmol:(1.1–1.2) mmol, 1 mmol:(1.2–1.3) mmol, 1 mmol:(1.3–1.4) mmol, 1 mmol:(1.4–1.5) mmol, 1 mmol:(1.5–1.6) mmol, or 1 mmol:(1.6–1.7) mmol. In a preferred embodiment of this application, when hydrosilane reacts with water, the feed ratio of hydrosilane to water is 1 mmol:1.1 mmol. If the feed ratio of hydrosilane to water is lower than 1 mmol:1.1 mmol, the hydrosilane will be incompletely converted and the product yield will decrease. If the feed ratio of hydrosilane to water is too high, it will easily lead to waste of substrate.

[0060] In a specific embodiment of this application, when hydrosilane reacts with alcohol, the feed ratio of hydrosilane to alcohol is 1 mmol:(1.1-1.5) mmol, for example, 1 mmol:(1.1-1.2) mmol, 1 mmol:(1.2-1.3) mmol, 1 mmol:(1.3-1.4) mmol, 1 mmol:(1.4-1.5) mmol. In a preferred embodiment of this application, when hydrosilane reacts with alcohol, the feed ratio of hydrosilane to alcohol is 1 mmol:1.1 mmol. If the feed ratio of hydrosilane to alcohol is lower than 1 mmol:1.1 mmol, the hydrosilane will be incompletely converted, and the product yield will decrease. If the feed ratio of hydrosilane to alcohol is too high, it will easily lead to substrate waste.

[0061] In a specific embodiment of this application, when hydrosilane reacts with phenol, the feed ratio of hydrosilane to phenol is 1 mmol:(1-1.5) mmol, for example, it can be 1 mmol:(1-1.1) mmol, 1 mmol:(1.1-1.2) mmol, 1 mmol:(1.2-1.3) mmol, 1 mmol:(1.3-1.4) mmol, 1 mmol:(1.4-1.5) mmol. In a preferred embodiment of this application, when hydrosilane reacts with phenol, the feed ratio of hydrosilane to phenol is 1 mmol:1 mmol. If the feed ratio of hydrosilane to phenol is lower than 1 mmol:1 mmol, the hydrosilane will be incompletely converted, and the product yield will decrease. If the feed ratio of hydrosilane to water is too high, it will easily lead to waste of substrate.

[0062] The feed ratio refers to the proportion of different raw materials added. Under the feed ratio of this application, it is beneficial to the reaction and saves raw materials.

[0063] In a specific embodiment of this application, the amount of iridium catalyst used, based on the Si-H bonds in the hydrosilane, is 0.1–1.0 mol% of the Si-H bonds in the hydrosilane, for example, 0.1–0.2 mol%, 0.2–0.3 mol%, 0.3–0.4 mol%, 0.4–0.5 mol%, 0.5–0.6 mol%, 0.6–0.7 mol%, 0.7–0.8 mol%, 0.8–0.9 mol%, and 0.9–1.0 mol%. Under the conditions of the iridium catalyst in this application, the iridium catalyst has the best catalytic effect, which is beneficial to improving the yield of the product.

[0064] The use of iridium catalyst, calculated based on the amount of Si-H bonds in the hydrosilane, refers to calculating the amount of iridium catalyst based on the amount of Si-H bonds in the hydrosilane. For example, when R1 in the silane is H, since 1 mol of hydrosilane contains 2 mol of Si-H bonds, the amount of iridium catalyst used is 0.1 mol of the 2 mol of Si-H bonds.

[0065] In a specific embodiment of this application, the ratio of the organic solvent to the hydrosilane is (2-15) mL:1 mmol, which can be (2-3) mL:1 mmol, (3-4) mL:1 mmol, (4-5) mL:1 mmol, (5-6) mL:1 mmol, (6-7) mL:1 mmol, (7-8) mL:1 mmol, (8-9) mL:1 mmol, (9-10) mL:1 mmol, (10-11) mL:1 mmol, (11-12) mL:1 mmol, (12-13) mL:1 mmol, (13-14) mL:1 mmol, or (14-15) mL:1 mmol. The amount of organic solvent used in this application is beneficial for the reactants to be fully dispersed and to ensure a certain concentration so that the reaction can proceed smoothly.

[0066] In a specific embodiment of this application, the light source is visible light, that is, the reaction takes place under visible light.

[0067] Visible light refers to a portion of the electromagnetic spectrum that the human eye can perceive, located between ultraviolet and infrared radiation, with a wavelength range of approximately 380 nm to 750 nm.

[0068] In a specific embodiment of this application, the wavelength of the visible light is 395–420 nm, for example, it can be 395–396 nm, 396–398 nm, 398–400 nm, 400–402 nm, 402–404 nm, 404–406 nm, 406–408 nm, 408–410 nm, 410–412 nm, 412–414 nm, 414–416 nm, 416–418 nm, or 418–420 nm. In a preferred embodiment of this application, the wavelength of the visible light is 395 nm.

[0069] In a specific embodiment of this application, the power of the visible light is 10-15W, for example, it can be 10-11W, 11-12W, 12-13W, 13-14W, or 14-15W. In a preferred embodiment of this application, the power of the visible light is 15W.

[0070] Under the aforementioned visible light conditions, the photocatalytic reaction is more likely to proceed, resulting in the highest product yield.

[0071] In a specific embodiment of this application, the reaction temperature is room temperature.

[0072] The reaction temperature is the temperature condition that allows the reaction to proceed fully in the positive direction. The room temperature refers to the actual temperature of the current environment, which is usually between 20°C and 25°C.

[0073] In the specific embodiments of this application, the reaction time is 3 to 8 hours, for example, it can be 3 to 3.5 hours, 3.5 to 4 hours, 4 to 4.5 hours, 4.5 to 5 hours, 5 to 5.5 hours, 5.5 to 6 hours, 6 to 6.5 hours, 6.5 to 7 hours, 7 to 7.5 hours, or 7.5 to 8 hours.

[0074] In specific embodiments of this application, the reaction process may include stirring to accelerate the reaction. The stirring is not particularly limited and may be mechanical or magnetic stirring, preferably magnetic stirring.

[0075] In a specific embodiment of this application, the method further includes filtering the reactants after the reaction to obtain a filtrate, and separating and purifying the filtrate to obtain the silanol or silane.

[0076] The filtration method is not limited, as long as it can separate the filtrate. For example, it can be atmospheric pressure filtration, vacuum filtration, membrane filtration technology, or filtration aided by adsorbent.

[0077] The separation and purification methods include distillation, crystallization, extraction, filtration, chromatography, washing, conjugate method, mass spectrometry, evaporation, and gas phase extraction, wherein the chromatography methods include thin-layer chromatography and column chromatography.

[0078] In a specific embodiment of this application, the separation and purification method is column chromatography and collection of the target product.

[0079] Column chromatography separates substances based on their different adsorption capacities on the stationary phase. Highly polar substances are easily adsorbed by the stationary phase, while less polar substances are not. Through repeated adsorption and desorption processes, the components are separated. The steps include: 1) Preparing the chromatography column: Select a suitable chromatography column, usually a glass tube or plexiglass tube. Load a certain amount of thin-layer chromatography silica gel into an enamel dish, activate it in an oven, and then remove it to room temperature. Next, load the silica gel into the chromatography column using a dry packing method, ensuring the entire column is filled without dead volume, and seal it tightly. 2) Sample loading: Dissolve the sample to be separated in a suitable solvent, such as acetone or ethanol. Pump the sample solution into the top of the chromatography column, ensuring the sample is evenly distributed on the stationary phase. 3) Elution: Select a suitable eluent, usually a mixture of petroleum ether and acetone. Elute at a certain flow rate. As the eluent passes through the stationary phase, the components are separated according to their different partition coefficients in the stationary and mobile phases. During elution, highly polar components are easily adsorbed by the stationary phase and retain for a longer time, while less polar components are easily eluted. 4) Collecting components: During elution, each component will elute sequentially from the chromatography column. A fraction collector can be used to collect the eluent, and each component can be further analyzed or purified as needed.

[0080] In a specific embodiment of this application, the eluent used in the column chromatography is petroleum ether or a mixture of petroleum ether and ethyl acetate.

[0081] In a specific embodiment of this application, the volume ratio of petroleum ether to ethyl acetate in the mixture of petroleum ether and ethyl acetate is (100-200):1, for example, it can be (100-110):1, (110-120):1, (120-130):1, (130-140):1, (140-150):1, (150-160):1, (160-170):1, (170-180):1, (180-190):1, (190-200):1. In one embodiment of this application, the volume ratio of petroleum ether to ethyl acetate in the mixture of petroleum ether and ethyl acetate is 100:1.

[0082] In a specific embodiment of this application, the method further includes removing the solvent from the target product.

[0083] The method for removing organic solvents is not limited, as long as it can remove the organic solvents. For example, it can be vacuum distillation, solvent evaporation, freeze drying, adsorption-desorption, membrane separation, fractionation, or chromatography.

[0084] In a specific embodiment of this application, the method for removing the solvent is vacuum distillation, specifically, using a rotary evaporator to evaporate the solvent.

[0085] The following specific examples provide further details. Unless otherwise stated, all reaction materials are commercially available products.

[0086] Example 1: Synthesis of Triphenylsilanol

[0087] Triphenylsilane (52.02 mg, 0.2 mmol), water (3.96 mg, 0.22 mmol), and 0.1 mol% iridium catalyst PC-1 were dissolved in 3 mL of tetrahydrofuran and placed in a 25 mL reaction tube. The mixture was stirred at room temperature under 395 nm illumination for 6 h, and the reaction was monitored by TLC. After the reaction was complete, the filtrate was concentrated and separated by column chromatography. The product was eluted with a mixture of petroleum ether / ethyl acetate (v:v) = 100:1. The solvent was collected, and the product was evaporated by rotary evaporation to obtain 54.12 mg of product, with a yield of 98%.

[0088] The synthesis route is as follows:

[0089]

[0090] Where R 1 R 2 R 3 R is a phenyl group, and R is hydrogen.

[0091] The structural formula of iridium catalyst PC-1 is as follows:

[0092]

[0093] The product structure is as follows:

[0094]

[0095] 1 H NMR (600MHz, Chloroform-d) δ7.51–7.47(m,6H),7.34–7.30(m,3H),7.30–7.25(m,7H),5.39(s,1H); 13 C NMR(151MHz,Chloroform-d)δ134.76,132.26,128.77,127.00ppm.HRMS m / z(ESI)calcd for C 18 H 16 OSi[M+H] + :277.1049,found: 277.1048.

[0096] Example 2 Synthesis of triisopropylsilanol

[0097] The synthesis method described in Example 1 was followed, except that the substrates used were triisopropylsilane (31.67 mg, 0.2 mmol) and water (3.96 mg, 0.22 mmol). The reaction was carried out under 395 nm light and stirred at room temperature for 8 h to obtain 32.43 mg of product, with a yield of 93%.

[0098] The product structure is as follows:

[0099]

[0100] 1 H NMR(600MHz,Chloroform-d6)δ1.04(s,21H),1.49(brs,1H); 13 C NMR(151MHz,Chloroform-d6)δ12.2,17.6ppm.HRMS m / z(ESI)calcd for C9H 22 OSi[M+H] + :175.1518, found: 175.1520.

[0101] Example 3 Synthesis of diphenylsilanediol

[0102] The synthesis method described in Example 1 was followed, except that the substrates used were diphenyldihydrosilane (36.46 mg, 0.2 mmol) and water (3.96 mg, 0.22 mmol), yielding 42.34 mg of product in a yield of 70%.

[0103] The product structure is as follows:

[0104]

[0105] 1 H NMR (600MHz, Chloroform-d6) δ7.45 (dd, J=8.0, 1.4Hz, 4H), 7.33 (ddd, J=7.1, 4.2, 1.4Hz, 2H), 7.16 (t, J=7.6Hz, 4H), 13 C NMR(151MHz,Chloroform-d6)δ134.4,134.3,130.0,127.6ppm.HRMS m / z(ESI)calcd for C 12 H 12 O2Si[M+H] + :217.0685, found: 217.0687.

[0106] Example 4: Synthesis of benzyldimethylsilanol

[0107] The synthesis method described in Example 1 was followed, except that the substrates used were benzyldimethylsilane (30.06 mg, 0.2 mmol) and water (3.96 mg, 0.22 mmol), yielding 31.22 mg of product with a yield of 94%.

[0108] The product structure is as follows:

[0109]

[0110] 1 H NMR(600MHz,Chloroform-d6)δ0.15(s,6H),1.71(brs,1H),2.19(s,2H),7.06–7.12(m,3H),7.23–7.26ppm(m,2H). 13 C NMR(151MHz,Chloroform-d6)δ-0.7,28.0,124.2,128.1,128.4,138.9ppm.HRMS m / z(ESI)calcd for C9H 14 OSi[M+H] + :167.0892,found:167.0890.

[0111] Example 5 Synthesis of 1,4-Phenylidene bis(dimethylsilanol)

[0112] The synthesis method described in Example 1 was followed, except that the substrate used was 1,4-bis(dimethylsilyl)benzene (38.88 mg, 0.2 mmol) and water (3.96 mg, 0.22 mmol), yielding 42.96 mg of product with a yield of 95%.

[0113] The product structure is as follows:

[0114]

[0115] 1 H NMR(DMSO-d6): δ0.24(s,12H),5.89(s,2H),7.53(s,4H). 13 C NMR(DMSO-d6):δ1.0,132.5,141.7ppm.HRMS m / z(ESI)calcd for C 10 H 18 O2Si2[M+H] + :195.1385,found:195.1388.

[0116] Example 6 Synthesis of Methyldiphenylsilanol

[0117] The synthesis method described in Example 1 was followed, except that the substrates used were diphenylmethylsilane (39.67 mg, 0.2 mmol) and water (3.96 mg, 0.22 mmol), yielding 39.82 mg of product with a yield of 93%.

[0118] The product structure is as follows:

[0119]

[0120] 1 H NMR(600MHz,Chloroform-d6)δ7.60-7.40(m,4H),7.39-7.36(m,6H),6.55(br,1H),0.54(s,3H). 13 C NMR(151MHz,Chloroform-d6)δ=-1.1,128.1,130.0,134.1,137.2ppm.HRMS m / z(ESI)calcd for C 13 H 14 OSi[M+H] + :215.0892, found 215.0893.

[0121] Example 7 Synthesis of (4-fluorophenyl)dimethylsilanol

[0122] The synthesis method described in Example 1 was followed, except that the substrate used was (4-fluorophenyl)dimethylsilane (31.81 mg, 0.2 mmol) and water (3.96 mg, 0.22 mmol), yielding 30.60 mg of product in 90% yield.

[0123] The product structure is as follows:

[0124]

[0125] 1 H NMR (400MHz, Chloroform-d): δ = 7.51 (t, J = 7.1Hz, 2H), 7.02 (t, J = 8.8Hz, 2H), 2.56 (br s, 1H), 0.34 (s, 6H). 13 C NMR (101MHz, Chloroform-d): δ = 165.20, 162.73, 135.11, 135.03, 115.07, 114.88, 0.03.; HRMS (ESI)calcd for C8H 11 FOSi[M+H] + :171.0641,found:171.0645.

[0126] Example 8: Synthesis of (benzyloxy)triethylsilane

[0127] The synthesis method described in Example 1 was followed, except that the substrates used were triethylsilane (23.25 mg, 0.2 mmol) and benzyl alcohol (23.79 mg, 0.22 mmol), yielding 40.17 mg of product with a yield of 98%.

[0128] The product structure is as follows:

[0129]

[0130] 1 H NMR (400MHz, Chloroform-d) δ7.28–7.21(m,4H),7.18–7.13(m,1H),4.66(d,J=2.8Hz,2H),0.91(td,J=7.8,3.4Hz,9H),0.58(qd,J=7.9,3.3Hz,6H). 13C NMR(101MHz,Chloroform-d)δ141.37,128.26,126.99,126.26,64.77,6.82,4.56.HRMS(APCI)m / z:calculated for C 13 H 22 OSi[M+H] + 223.1518, found 223.1515.

[0131] Example 9: Triethyl((4-methoxybenzyl)oxy)silane

[0132] The synthesis method described in Example 1 was followed, except that the substrates used were triethylsilane (23.25 mg, 0.2 mmol) and p-methoxybenzyl alcohol (30.39 mg, 0.22 mmol), yielding 46.91 mg of product in 93% yield.

[0133] The product structure is as follows:

[0134]

[0135] 1 H NMR (400MHz, Chloroform-d) δ7.24 (d, J = 8.7Hz, 2H), 6.85 (d, J = 8.7Hz, 2H), 4.65 (s, 2H), 3.76 (s, 3H), 0.97 (t, J = 7.9Hz, 9H), 0.63 (q, J = 7.9Hz, 6H). 13 C NMR(101MHz,Chloroform-d)δ158.82,133.52,127.80,113.68,64.52,6.83,4.60.HRMS(APCI)m / z:calculated for C 14 H 24 O2Si[M+H] + 252.1946, found 252.1943.

[0136] Example 10 ((4-(tert-butyl)benzyl)oxy)triethylsilane

[0137] The synthesis method described in Example 1 was followed, except that the substrates used were triethylsilane (23.25 mg, 0.2 mmol) and p-tert-butylbenzyl alcohol (39.67 mg, 0.22 mmol), yielding 53.05 mg of product in 95% yield.

[0138] The product structure is as follows:

[0139]

[0140] 1 H NMR (400MHz, Chloroform-d) δ7.38(d,J=8.4Hz,2H),7.29(d,J=7.9Hz,2H),4.73(s,2H),1.34(s,9H),1.00(t,J=8.0Hz,9H),0.72–0.61(m,6H). 13 C NMR(101MHz,Chloroform-d)δ148.85,137.26,125.07,124.11,63.52,30.37,5.77,3.48.HRMS(APCI)m / z:calculated for C 17 H 30 OSi[M+H] + 279.2144, found 279.2141.

[0141] Example 11 (triethyl((4-fluorobenzyl)oxy)silane)

[0142] The synthesis method described in Example 1 was followed, except that the substrates used were triethylsilane (23.25 mg, 0.2 mmol) and p-fluorobenzyl alcohol (27.75 mg, 0.22 mmol), yielding 43.89 mg of product with a yield of 91%.

[0143] The product structure is as follows:

[0144]

[0145] 1 H NMR (400MHz, Chloroform-d) δ7.32–7.25(m,2H),6.99(t,J=8.7Hz,2H),4.69(s,2H),0.97(t,J=7.9Hz,9H),0.64(q,J=7.9Hz,6H). 13 C NMR(101MHz,Chloroform-d)δ137.06,127.86,127.78,115.10,114.89,64.10,6.72,4.50.HRMS(APCI)m / z:calculatedfor C 13 H 21 FOSi[M+H] + 241.1424, found 241.1427.

[0146] Example 12 (4-chlorobenzyl)oxy)triethylsilane

[0147] The synthesis method described in Example 1 was followed, except that the substrates used were triethylsilane (23.25 mg, 0.2 mmol) and p-chlorobenzyl alcohol (31.37 mg, 0.22 mmol), yielding 47.31 mg of product with a yield of 92%.

[0148] The product structure is as follows:

[0149]

[0150] 1 H NMR (400MHz, Chloroform-d) δ7.34–7.21 (m, 4H), 4.69 (s, 2H), 0.97 (t, J = 7.9Hz, 10H), 0.64 (q, J = 7.9Hz, 7H). 13 C NMR(101MHz,Chloroform-d)δ139.87,132.61,128.36,127.51,64.03,6.77,4.50.HRMS(APCI)m / z:calculated for C 13 H 21 ClOSi[M+H] + 257.1128, found 257.1131.

[0151] Example 13 ([1,1'-biphenyl]-4-ylmethoxy)triethylsilane

[0152] The synthesis method described in Example 1 was followed, except that the substrates used were triethylsilane (23.25 mg, 0.2 mmol) and p-phenylbenzyl alcohol (40.50 mg, 0.22 mmol), yielding 53.85 mg of product in 90% yield.

[0153] The product structure is as follows:

[0154]

[0155] 1 H NMR (400MHz, Chloroform-d) δ7.61–7.53(m,4H),7.42(t,J=7.7Hz,4H),7.32(t,J=7.3Hz,1H),4.77(s,2H),1.00(t,J=7.9Hz,9H),0.67(q,J=7.9Hz,6H). 13C NMR(101MHz,Chloroform-d)δ141.14,140.46,139.98,128.77,127.16,127.12,127.06,126.72,64.54,6.86,4.58.HRMS(APCI)m / z:calculated for C 19 H 26 OSi[M+H] + 299.1831, found 299.1831.

[0156] Example 14 4-(((triethylsilyl)oxy)methyl)benzonitrile

[0157] The synthesis method described in Example 1 was followed, except that the substrates used were triethylsilane (23.25 mg, 0.2 mmol) and p-cyanobenzyl alcohol (29.29 mg, 0.22 mmol), yielding 36.23 mg of product in a yield of 73%.

[0158] The product structure is as follows:

[0159]

[0160] 1 H NMR (400MHz, Chloroform-d) δ7.62(d,J=8.3Hz,2H),7.44(d,J=8.5Hz,2H),4.78(s,2H),0.98(t,J=8.0Hz,9H),0.67(dd,J=8.4,7.6Hz,6H). 13 C NMR(101MHz,Chloroform-d)δ145.94,131.08,125.38,118.03,109.62,62.86,5.71,3.40.HRMS(APCI)m / z:calculated for C 14 H 21 NOSi[M+H] + 248.1471, found 248.1477.

[0161] Example 15 Triethyl((3-nitrobenzyl)oxy)silane

[0162] The synthesis method described in Example 1 was followed, except that the substrates used were triethylsilane (23.25 mg, 0.2 mmol) and m-nitrobenzyl alcohol (31.37 mg, 0.22 mmol), yielding 51.48 mg of product with a yield of 96%.

[0163] The product structure is as follows:

[0164]

[0165] 1 H NMR(400MHz,Chloroform-d)δ8.21(s,1H),8.11(d,J=7.3Hz,1H),7.67(d,J=7.7Hz,1 H),7.50(t,J=7.9Hz,1H),4.82(s,2H),1.00(t,J=8.0Hz,9H),0.68(q,J=7.9Hz,6H). 13 C NMR(101MHz,Chloroform-d)δ147.34,142.61,130.94,128.12,120.97,119.90,62.58,5.71,3.41.HRMS(APCI)m / z:calculated for C 13 H 21 NO3Si[M+H] + 268.1369, found268.1362.

[0166] Example 16 (3,4-Dimethylphenoxy)triphenylsilane

[0167] The synthesis method described in Example 1 was followed, except that the substrates used were triphenylsilane (52.08 mg, 0.2 mmol) and 3,4-dimethylphenol (24.43 mg, 0.2 mmol), yielding 47.26 mg of product in a yield of 62%.

[0168] The product structure is as follows:

[0169]

[0170] 1 H NMR(400MHz,Chloroform-d)δ7.65(ddd,J=12.8,8.0,1.5Hz,6H),7.45–7.33(m,9H),6.83(d,J=8.1Hz, 1H), 6.69 (d, J = 2.6Hz, 1H), 6.57 (dd, J = 8.1, 2.7Hz, 1H), 2.10 (d, J = 10.6Hz, 3H), 1.18 (d, J = 6.0Hz, 2H). 13C NMR(101MHz,Chloroform-d)δ134.48,134.41,133.96,132.79,129.16,129.04,128.80,1 26.86,126.72,120.17,115.81,65.30,24.63,18.77,17.79.HRMS(APCI)m / z:calculated for C 26 H 24 OSi[M+H] + 381.1675, found 381.1688.

[0171] Example 17 Triphenyl(m-tolyloxy)silane

[0172] The synthesis method described in Example 1 was followed, except that the substrates used were triphenylsilane (52.08 mg, 0.2 mmol) and m-methylphenol (21.63 mg, 0.2 mmol), yielding 49.20 mg of product in a yield of 67%.

[0173] The product structure is as follows:

[0174]

[0175] 1 H NMR (400MHz, Chloroform-d) δ7.69–7.65(m,6H),7.45–7.37(m,4H),7.34(d,J=6.7Hz,5H),6.97(t,J=7.7Hz,1H),6.74–6.61(m,3H),2.17(s,3H). 13 C NMR(101MHz,Chloroform-d)δ153.91,138.26,134.45,134.39,132.64,129.20,128.79,127.8 8,126.87,126.71,121.31,119.81,115.82,65.28,24.63,20.24.HRMS(APCI)m / z:calculated forC 25 H 22 OSi[M+H] + 367.1518, found 367.1523.

[0176] Example 18 Triphenyl(o-tolyloxy)silane

[0177] The synthesis method described in Example 1 was followed, except that the substrates used were triphenylsilane (52.08 mg, 0.2 mmol) and o-methylphenol (21.63 mg, 0.2 mmol), yielding 38.92 mg of product in a yield of 53%.

[0178] The product structure is as follows:

[0179]

[0180] 1 H NMR (400MHz, Chloroform-d) δ7.68–7.61 (m, 10H), 7.36 (t, J = 7.5Hz, 10H), 2.27 (s, 3H). 13 C NMR(101MHz,Chloroform-d)δ134.42,134.02,132.85,129.87,129.22,128.80,126.92,126.73,125.49,120.44,117.83,24.64.HRMS(APCI)m / z:calculated forC 25 H 22 OSi[M+H] + 367.1518, found 367.1518.

[0181] Example 19 (4-Fluorophoxy)triphenylsilane

[0182] The synthesis method described in Example 1 was followed, except that the substrates used were triphenylsilane (52.08 mg, 0.2 mmol) and p-fluorophenol (22.42 mg, 0.2 mmol), yielding 51.96 mg of product in a yield of 70%.

[0183] The product structure is as follows:

[0184]

[0185] 1 H NMR(400MHz,Chloroform-d)δ7.66–7.61(m,9H),7.48–7.34(m,14H). 13 C NMR(101MHz,Chloroform-d)δ134.48,134.44,134.03,132.31,129.39,128.81,126.98,126.74,119.93,119.85,114.75,114.52.HRMS(APCI)m / z:calculated for C 24H 19 FOSi[M+H] + 371.1267, found371.1261.

[0186] Example 20 (4-bromophenoxy)triphenylsilane

[0187] The synthesis method described in Example 1 was followed, except that the substrates used were triphenylsilane (52.08 mg, 0.2 mmol) and p-bromophenol (34.60 mg, 0.2 mmol), yielding 53.44 mg of product in a yield of 62%.

[0188] The product structure is as follows:

[0189]

[0190] 1 H NMR (400MHz, Chloroform-d) δ7.64(dd,J=8.0,1.3Hz,6H),7.48–7.43(m,3H),7.38(t,J=7.2Hz,6H),7.21(d,J=8.9Hz,2H),6.72(d,J=8.9Hz,2H). 13 C NMR(101MHz,Chloroform-d)δ134.45,132.11,131.21,129.46,127.03,120.84.HRMS(APCI)m / z:calculated for C 24 H 19 BrOSi[M+H] + 431.0467, found 431.0472.

[0191] Example 21 Optimization of Reaction Conditions

[0192] This embodiment employs the following synthetic route: the substrates are triethylsilane (1.0 mmol, 1.0 equiv), benzyl alcohol (1.1 mmol, 1.1 equiv), and iridium catalyst PC-1 (1.0 mol%) with the following structural formula. These were dissolved in 2 mL of the organic solvents shown in Table 1 below and placed in a 25 mL reaction tube. The reaction was carried out under the light conditions shown in Table 1 below, with stirring at room temperature for 3 h, and monitored by TLC. After the reaction was complete, the filtrate was concentrated and separated by column chromatography. The product was eluted with a mixture of petroleum ether / ethyl acetate (v:v) = 100:1, and the target product was collected. The solvent was evaporated using a rotary evaporator to obtain the product.

[0193]

[0194] PC-1 structural formula:

[0195]

[0196] The results are shown in Table 1.

[0197] Table 1 Reaction conditions and yield

[0198]

[0199]

[0200] Note: a. Reaction substrates and reaction conditions for the samples: 1a (1.1 mmol, 1.1 equiv), 2a (1.0 mmol, 1.0 equiv), PC-1 (1.0 mol%), Solvent (2.0 mL), reaction time was 3 h (monitored by TLC).

[0201] b.Isolated yields.nd = not detected, meaning no product was detected.

[0202] c. The conditions for changing the iridium catalyst in this sample were PC-1 (5.0 mol%).

[0203] d. No iridium catalyst was added to this sample.

[0204] Sample 1 shows that no product can be detected when the reaction lacks visible light, indicating that the product cannot be synthesized. Samples 2-9 show that higher yields are achieved when the visible light wavelength is between 395 and 420 nm (samples 4 and 5). Samples 4 and 10-13 show that higher yields are achieved when the organic solvent is tetrahydrofuran, dimethylformamide, or acetonitrile, with tetrahydrofuran showing the highest yield (sample 4). Samples 4 and 14-15 show that higher yields are achieved when the visible light power is between 10 and 15 W (samples 4 and 14). Samples 4 and 16 show that the product yield increases when the amount of iridium catalyst is 1 mol%, and decreases when the amount of iridium catalyst is 5.0 mol%. Samples 4 and 17 show that the product cannot be synthesized when the reaction lacks iridium catalyst.

[0205] In summary, the method provided in this application has mild reaction conditions, low catalyst dosage, high selectivity, no byproducts, high yield, and is environmentally friendly. It effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0206] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A method for photocatalytic synthesis of silanols or silane ethers, characterized in that, Under light irradiation, the hydrosilane represented by Formula I reacts with any of water, alcohol, or phenol in the presence of an iridium catalyst and an organic solvent to yield the silanol or silane ether represented by Formula II. The synthetic route is as follows: Among them, R, R 1 R 2 R 3 Each is independently selected from any one of hydrogen, alkyl, phenyl, benzyl, substituted phenyl, or substituted benzyl.

2. The method according to claim 1, characterized in that, The substituents in the substituted phenyl and / or substituted benzyl groups are selected from any one of hydrogen, alkyl, alkoxy, halogen, or hydrosilyl.

3. The method according to any one of claims 1 to 2, characterized in that, The alkyl group is a C1-C4 alkyl group, and the alkoxy group is a C1-C4 alkoxy group.

4. The method according to claim 1, characterized in that, The iridium catalyst is a complex with iridium as the central atom, and its structural formula is shown in Formula III below:

5. The method according to claim 1, characterized in that, The organic solvent is a polar solvent; preferably, the organic solvent is selected from at least one of tetrahydrofuran, dimethylformamide, or acetonitrile; more preferably, the solvent is tetrahydrofuran.

6. The method according to claim 1, characterized in that, When hydrosilane reacts with water, the ratio of hydrosilane to water is 1 mmol: 1.1 to 2 mmol. When hydrosilane reacts with alcohol, the feed ratio of hydrosilane to alcohol is 1 mmol: 1.1 to 1.5 mmol; When hydrosilane reacts with phenol, the ratio of hydrosilane to phenol is 1 mmol: 1 to 1.5 mmol.

7. The method according to claim 1, characterized in that, The amount of the iridium catalyst used is 0.1 to 1.0 mol% of the Si-H bonds in the hydrosilane, based on the Si-H bonds in the hydrosilane. And / or, the ratio of the organic solvent to the hydrosilane is 2-15 mL: 1 mmol.

8. The method according to claim 1, characterized in that, The light source is visible light; preferably, the wavelength of the visible light is 395-420nm and the power of the visible light is 10-15W. And / or, the reaction temperature is room temperature and the reaction time is 3 to 8 hours.

9. The method according to claim 1, characterized in that, The method further includes filtering the reactants after the reaction to obtain a filtrate, and separating and purifying the filtrate to obtain the silanol or silane ether; Preferably, the separation and purification method is column chromatography followed by collection of the target product.

10. The method according to claim 9, characterized in that, The column chromatography uses petroleum ether or a mixture of petroleum ether and ethyl acetate as the eluent, wherein the volume ratio of petroleum ether to ethyl acetate in the mixture is 100 to 200:

1. And / or, the method further includes removing the solvent from the target product; Preferably, the method for removing the solvent is vacuum distillation.

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