A method for preparing a siloxane catalyst and its use in the synthesis of siloxanes

Abstract

The application discloses a preparation method of a silicic ether catalyst and application of the silicic ether catalyst in synthesis of silicic ether, and the preparation method comprises the following steps: a) preparation of a tungsten sulfide precursor; and b) preparation of the silicic ether catalyst. The application also provides application of the silicic ether catalyst prepared by any one of the preparation methods in synthesis of silicic ether. The application uses tungsten compounds as a tungsten source and sulfides as a sulfur source, uniformly disperses the tungsten compounds and the sulfides in deionized water, and obtains a tungsten sulfide solution by drying; the tungsten sulfide solution is dried and calcined in a microwave tube furnace to obtain the silicic ether catalyst; and the catalyst can be used in a silane and alcohol dehydrogenation coupling reaction to catalyze preparation of different types of silicic ethers. The application provides a fast and efficient preparation method of the silicic ether catalyst, the synthesized catalyst can catalyze a plurality of silane and alcohol dehydrogenation coupling reactions, the experimental operation is simple, the reaction condition is mild, and the catalyst has potential application value in the catalytic synthesis of silicic ethers.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic chemical synthesis, and particularly relates to a preparation method of a silicic ether catalyst and application of the silicic ether catalyst in synthesis of a silicic ether. BACKGROUND

[0002] Silicon is abundant in the earth's crust, and silicon and oxygen coexist in nature to form compounds such as silicon dioxide. The compounds of silicon and oxygen are not only abundant in reserves but also have special properties. Organic silicon products have always been a research hotspot (CN113754889B). As an important organic silicon product, the main chain structure of silicic ether is similar to R-O-Si-R1R2R3 (wherein R is an alkyl substituent or an aryl substituent), and silicic ether has similar properties, such as good biocompatibility and excellent thermal stability, and is widely used in the cosmetics, medical, electronic, and silicone oil industries. Silicic ether is initially synthesized by halosilane and alcohol under the catalysis of strong base, and the synthesis process is energy-consuming and easy to produce excessive halide, which pollutes the environment. With the exploration of the synthesis mechanism of silicic ether, researchers found that the dehydrogenative coupling of silane and alcohol is a more environmentally friendly and energy-saving method for synthesizing silicic ether (ACS Omega 2022, 7, 11939-11945).

[0003] The performance of the catalyst greatly affects the yield and purity of the catalytic preparation of silicic ether, so researchers have explored a series of catalysts for the effect of silicic ether preparation yield and purity. Noble metal catalysts have excellent catalytic effect on the dehydrogenative coupling of silane and alcohol, but there are problems such as poor recycling stability of noble metals, low product purity, high purification cost, low reserves of noble metals, and high price. With the in-depth research, a series of transition metal catalysts have been gradually used in the dehydrogenative coupling reaction of silane and alcohol. The Cu ZIF-8 catalyst prepared by Zhang Xianming's team (Dalton Transactions, 2019, 48(44): 16562-16568) exhibits low catalytic activity at 70℃ for 65h, and good catalytic effect can be exhibited only when the reaction temperature reaches 110℃. Therefore, it is an important research direction to select a non-noble metal catalyst with simple synthesis steps and low price to catalytically synthesize silicic ether at a temperature of 0-60℃. Therefore, there is an urgent need to provide a technical solution to improve the above technical problems. SUMMARY

[0004] In view of the deficiencies and problems in the prior art, the present application aims to provide a preparation method of a silicic ether catalyst and application of the silicic ether catalyst in synthesis of a silicic ether.

[0005] The present application is implemented by the following technical solutions:

[0006] In a first aspect, the present application provides a preparation method of a silicic ether catalyst, comprising the following steps:

[0007] a) Preparation of tungsten sulfide precursor: after tungsten compound and sulfide are uniformly dispersed in deionized water, ultrasonic treatment is performed for 10-120 min, stirring reaction is performed at 30-80 °C for 0.5-5 h, vacuum drying is performed, and grinding is performed to obtain tungsten sulfide precursor;

[0008] b) Preparation of silylether catalyst: the tungsten sulfide precursor obtained in step a) is purged with nitrogen for 10-120 min, microwave calcination is performed for 2-10 h, cooling is performed, grinding is performed, a mixed solution of ethanol and deionized water is added, suction filtration is performed, and freeze drying is performed to obtain the silylether catalyst.

[0009] Preferably, the tungsten compound is one or more of tungsten chloride, tungstic acid, ammonium tungstate, tungsten oxide, sodium tungstate, blue tungsten, tungsten boride, tungsten carbide, tungsten ethoxide, tungsten dioxide and oxo tungsten chloride. The tungsten compound is a tungsten source.

[0010] Preferably, the sulfide is one or more of thiourea, diaryl thiourea, potassium thiocyanate, sulfur, thiophene, benzene thiol, phenothiazine, ethyl mercaptan, benzyl mercaptan, dithizone, rhodanine, ammonium sulfide and octyl sulfide. The sulfide is a sulfur source.

[0011] Preferably, the mass ratio of the tungsten compound to the sulfide is 1:0.1-1:5.

[0012] Preferably, the microwave calcination power is 100-500 W; and the volume ratio of ethanol to deionized water in the mixed solution is 1:1.5-1:5.

[0013] In a second aspect, the present application also provides a use of the silylether catalyst prepared by any of the above preparation methods in silylether synthesis, characterized in that it comprises the following steps: under the silylether catalyst WS2, a compound represented by formula (I) and a compound represented by formula (II) react at 0-60 °C to obtain a silylether represented by formula (III).

[0014] ;

[0015] wherein R is C1-C 12 alkyl or aryl, R1 is C1-C 18 alkyl, alkenyl, aryl or alkylaryl or C1-C 18 alkyl, alkenyl, aryl or alkylaryl substituted by amino, R2 is C1-C 18 alkyl, alkenyl, aryl or alkylaryl or C1-C 18 alkyl, alkenyl, aryl or alkylaryl substituted by amino, and R3 is C1-C 18 alkyl, alkenyl, aryl or alkylaryl or C1-C 18 alkyl, alkenyl, aryl or alkylaryl substituted by amino.

[0016] Preferably, the silicon ether synthesis reaction time is controlled for 2-72h.

[0017] Compared with the prior art, the beneficial effects are: the present application uses tungsten compound as tungsten source and sulfide as sulfur source, uniformly disperses in deionized water, ultrasonic, stirring reaction to obtain tungsten sulfide solution, vacuum drying, grinding to obtain tungsten sulfide precursor, then the tungsten sulfide precursor is purged in nitrogen atmosphere, microwave calcination, cooling, grinding, adding the mixed solution of ethanol and deionized water, filtering, freeze-drying to obtain silicon ether catalyst, which is put into silane and alcohol dehydrogenation coupling reaction to prepare different types of silicon ether, providing a fast and efficient preparation method for preparing silicon ether catalyst, the synthesized silicon ether catalyst can catalyze various silane and alcohol dehydrogenation coupling reactions, the experimental operation is simple, the reaction condition is mild, and the method has potential application value in the industry of catalytic preparation of silicon ether, and is suitable for large-scale promotion in industry. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The XRD graph of the silicon ether catalyst one prepared by taking tungsten chloride as tungsten source, thiourea as sulfur source and the mass ratio of tungsten chloride to thiourea being 1:0.25 in example 1 of the present application.

[0019] Figure 2 The XRD graph of the silicon ether catalyst two prepared by taking tungsten chloride as tungsten source, thiourea as sulfur source and the mass ratio of tungsten chloride to thiourea being 1:0.5 in example 2 of the present application.

[0020] Figure 3 The XRD graph of the silicon ether catalyst three prepared by taking tungsten chloride as tungsten source, thiourea as sulfur source and the mass ratio of tungsten chloride to thiourea being 1:1 in example 3 of the present application.

[0021] Figure 4 The XRD graph of the silicon ether catalyst four prepared by taking tungsten chloride as tungsten source, thiourea as sulfur source and the mass ratio of tungsten chloride to thiourea being 1:2 in example 4 of the present application.

[0022] Figure 5 The XRD graph of the silicon ether catalyst five prepared by taking tungsten chloride as tungsten source, thiourea as sulfur source and the mass ratio of tungsten chloride to thiourea being 1:4 in example 5 of the present application.

[0023] Figure 6 The XRD graph of the silicon ether catalyst six prepared by taking tungsten acid as tungsten source, thiourea as sulfur source and the mass ratio of tungsten acid to thiourea being 2:1 in example 6 of the present application.

[0024] Figure 7The XRD pattern of the silicic ether catalyst seven prepared in Example 7 of the present application is obtained under the condition that tungstic acid is used as a tungsten source and sulfur is used as a sulfur source, and the mass ratio of tungstic acid to sulfur is 2:1.

[0025] Figure 8 The XRD pattern of the silicic ether catalyst eight prepared in Example 8 of the present application is obtained under the condition that tungsten oxide is used as a tungsten source and thiourea is used as a sulfur source, and the mass ratio of tungsten oxide to thiourea is 5:2.

[0026] Figure 9 The XRD pattern of the silicic ether catalyst nine prepared in Example 9 of the present application is obtained under the condition that blue tungsten is used as a tungsten source and benzyl mercaptan is used as a sulfur source, and the mass ratio of blue tungsten to benzyl mercaptan is 2:3.

[0027] Figure 10 The XRD pattern of the silicic ether catalyst ten prepared in Example 10 of the present application is obtained under the condition that ethanoltungsten is used as a tungsten source and ammonium sulfide is used as a sulfur source, and the mass ratio of ethanoltungsten to ammonium sulfide is 1:0.7.

[0028] Figure 11 The XRD pattern of the silicic ether catalyst eleven prepared in Example 11 of the present application is obtained under the condition that tungsten dioxide is used as a tungsten source and thiourea is used as a sulfur source, and the mass ratio of tungsten dioxide to thiourea is 1:0.4.

[0029] Figure 12 The XRD pattern of the silicic ether catalyst twelve prepared in Example 12 of the present application is obtained under the condition that tungsten carbide is used as a tungsten source and potassium thiocyanate is used as a sulfur source, and the mass ratio of tungsten carbide to potassium thiocyanate is 1:1.3.

[0030] Figure 13 The XRD pattern of the silicic ether catalyst thirteen prepared in Example 13 of the present application is obtained under the condition that ammonium tungstate is used as a tungsten source and ammonium sulfide is used as a sulfur source, and the mass ratio of ammonium tungstate to ammonium sulfide is 1:0.8.

[0031] Figure 14 The scanning electron microscope pattern of the silicic ether catalyst one prepared in Example 1 of the present application is obtained under the condition that tungsten chloride is used as a tungsten source and thiourea is used as a sulfur source, and the mass ratio of tungsten chloride to thiourea is 1:0.25.

[0032] Figure 15 The scanning electron microscope pattern of the silicic ether catalyst two prepared in Example 2 of the present application is obtained under the condition that tungsten chloride is used as a tungsten source and thiourea is used as a sulfur source, and the mass ratio of tungsten chloride to thiourea is 1:0.5.

[0033] Figure 16 The scanning electron microscope pattern of the silicic ether catalyst three prepared in Example 3 of the present application is obtained under the condition that tungsten chloride is used as a tungsten source and thiourea is used as a sulfur source, and the mass ratio of tungsten chloride to thiourea is 1:1.

[0034] Figure 17The scanning electron microscope image of the silane catalyst four prepared in Example 4 of the present application is shown in Figure 4.

[0035] Figure 18 The scanning electron microscope image of the silane catalyst five prepared in Example 5 of the present application is shown in Figure 5.

[0036] Figure 19 The scanning electron microscope image of the silane catalyst six prepared in Example 6 of the present application is shown in Figure 6.

[0037] Figure 20 The scanning electron microscope image of the silane catalyst seven prepared in Example 7 of the present application is shown in Figure 7.

[0038] Figure 21 The scanning electron microscope image of the silane catalyst eight prepared in Example 8 of the present application is shown in Figure 8.

[0039] Figure 22 The scanning electron microscope image of the silane catalyst nine prepared in Example 9 of the present application is shown in Figure 9.

[0040] Figure 23 The scanning electron microscope image of the silane catalyst ten prepared in Example 10 of the present application is shown in Figure 10.

[0041] Figure 24 The scanning electron microscope image of the silane catalyst eleven prepared in Example 11 of the present application is shown in Figure 11.

[0042] Figure 25 The scanning electron microscope image of the silane catalyst twelve prepared in Example 12 of the present application is shown in Figure 12.

[0043] Figure 26 The scanning electron microscope image of the silane catalyst thirteen prepared in Example 13 of the present application is shown in Figure 13. DETAILED DESCRIPTION

[0044] The application aims to provide a preparation method of a silicic ether catalyst and application of the silicic ether catalyst in synthesis of a silicic ether.

[0045] The technical solutions in the embodiments of the application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0046] The application will be further described in conjunction with the embodiments without departing from the spirit or essential characteristics of the application.

[0047] The application provides a preparation method of a silicic ether catalyst, comprising the following steps:

[0048] a) Preparation of a tungsten sulfide precursor: after uniformly dispersing a tungsten compound and a sulfide in deionized water, ultrasonic treatment is performed for 10-120 min, and then the mixture is stirred and reacted at 30-80 ℃ for 0.5-5 h, vacuum drying is performed, and grinding is performed to obtain the tungsten sulfide precursor;

[0049] b) Preparation of a silicic ether catalyst: the tungsten sulfide precursor obtained in step a) is purged with nitrogen for 10-120 min, microwave calcination is performed for 2-10 h, cooling is performed, grinding is performed, a mixed solution of ethanol and deionized water is added, suction filtration is performed, and freeze drying is performed to obtain the silicic ether catalyst.

[0050] Further, the tungsten compound is one or more of tungsten chloride, tungstic acid, ammonium tungstate, tungsten oxide, sodium tungstate, blue tungsten, tungsten boride, tungsten carbide, tungsten ethoxide, tungsten dioxide and oxo tungsten chloride. The tungsten compound is a tungsten source.

[0051] Further, the sulfide is one or more of thiourea, diaryl thiourea, potassium thiocyanate, sulfur, thiophene, benzene thiol, phenothiazine, ethyl mercaptan, benzyl mercaptan, dithizone, rhodanine, ammonium sulfide and octyl sulfide. The sulfide is a sulfur source.

[0052] Further, the mass ratio of the tungsten compound to the sulfide is 1:0.1-1:5.

[0053] Further, the microwave calcination power is 100-500 W; and the volume ratio of ethanol to deionized water in the mixed solution is 1:1.5-1:5.

[0054] The application also provides application of the silicic ether catalyst prepared by any one of the preparation methods in synthesis of a silicic ether, and the application comprises the following steps: under the silicic ether catalyst WS2, a compound shown in formula (I) and a compound shown in formula (II) react at 0-60 ℃ to obtain a silicic ether shown in formula (III).

[0055] ;

[0056] wherein R is C1-C 12 alkyl or aryl, R1 is C1-C 18 alkyl, alkenyl, aryl or alkylaryl or C1-C 18 alkyl, alkenyl, aryl or alkylaryl, R2 is C1-C 18 alkyl, alkenyl, aryl or alkylaryl or C1-C 18 alkyl, alkenyl, aryl or alkylaryl, R3 is C1-C 18 alkyl, alkenyl, aryl or alkylaryl or C1-C 18 alkyl, alkenyl, aryl or alkylaryl.

[0057] Further, the reaction time of the siloxane synthesis is controlled to be 2-72h. Example 1

[0058] a) 2.0g of tungsten chloride was weighed, 0.5g of thiourea was added, 100ml of deionized water was added, and it was uniformly dispersed, ultrasonic treatment was performed for 25min, stirring was performed at 30℃ for 1h, a tungsten sulfide solution was obtained, vacuum drying was performed, and grinding was performed to obtain a tungsten sulfide precursor;

[0059] b) 1.5g of the tungsten sulfide precursor described in step a) was taken, nitrogen atmosphere purging was performed for 15min, 200W microwave calcination was performed for 8h, natural cooling was performed to 30℃, grinding was performed, 120ml of an ethanol and 300ml of deionized water mixture was added for washing, suction filtration was performed, and freeze drying was performed to obtain a siloxane catalyst one;

[0060] c) 200mg of the siloxane catalyst one in step b), 10ml of ethanol, and 2ml of dimethylphenylsilane were taken, and reaction was performed at 30℃ for 48h to prepare a siloxane, and the yield was measured to be 53%;

[0061] Please refer to Figure 1 and Figure 14 , Figure 1 and Figure 14 are an XRD (X-ray diffraction) diagram and a scanning electron microscope diagram of the siloxane catalyst one, respectively. Example 2

[0062] a) 2.0g of tungsten chloride was weighed, 1g of thiourea was added, 180ml of deionized water was added, and it was uniformly dispersed, ultrasonic treatment was performed for 40min, stirring was performed at 30℃ for 2h, a tungsten sulfide solution was obtained, vacuum drying was performed, and grinding was performed to obtain a tungsten sulfide precursor;

[0063] b) Take 1.5 g of the tungsten sulfide precursor in step a), purge with nitrogen atmosphere for 15 min, microwave calcination at 200 W for 8 h, naturally cool to 30°C, grind, add 100 ml of ethanol and 300 ml of deionized water mixed solution, wash, suction filter, freeze-drying to obtain the silylether catalyst 2;

[0064] c) Take 200 mg of the silylether catalyst 2 in step b), 10 ml of ethanol, 2 ml of dimethylphenylsilane, react at 30°C for 48 h to prepare a silylether, and the yield is measured to be 59%;

[0065] Please refer to Figure 2 and Figure 15 , Figure 2 and Figure 15 are the XRD (X-ray diffraction) and scanning electron microscope images of the silylether catalyst 2, respectively. Example 3

[0066] a) Take 2.0 g of tungsten chloride, add 2.0 g of thiourea, add 200 ml of deionized water, uniformly disperse, ultrasonic for 60 min, stir at 30°C for 1 hour to obtain a tungsten sulfide solution, vacuum drying, grinding to obtain a tungsten sulfide precursor;

[0067] b) Take 1.5 g of the tungsten sulfide precursor in step a), purge with nitrogen atmosphere for 15 min, microwave calcination at 200 W for 8 h, naturally cool to 30°C, grind, add 100 ml of ethanol and 300 ml of deionized water mixed solution, wash, suction filter, freeze-drying to obtain the silylether catalyst 3;

[0068] c) Take 200 mg of the silylether catalyst 3 in step b), 10 ml of ethanol, 2 ml of dimethylphenylsilane, react at 30°C for 48 h to prepare a silylether, and the yield is measured to be 64%;

[0069] Please refer to Figure 3 and Figure 16 , Figure 3 and Figure 16 are the XRD (X-ray diffraction) and scanning electron microscope images of the silylether catalyst 3, respectively. Example 4

[0070] a) Take 2.0 g of tungsten chloride, add 4.0 g of thiourea, add 250 ml of deionized water, uniformly disperse, ultrasonic for 80 min, stir at 30°C for 1 hour to obtain a tungsten sulfide solution, vacuum drying, grinding to obtain a tungsten sulfide precursor;

[0071] b) Take 1.5 g of the tungsten sulfide precursor in step a), purge with nitrogen atmosphere for 15 min, microwave calcination at 200 W for 8 h, naturally cool to 30°C, grind, add 100 ml of ethanol and 300 ml of deionized water mixed solution, wash, suction filter, freeze-drying to obtain the silylether catalyst 4;

[0072] c) 200 mg of the silyl ether catalyst four in step b), 10 ml of ethanol, 2 ml of dimethylphenylsilane, 30 °C, reaction for 48 h, to prepare the silyl ether, the yield is 66%;

[0073] See Figure 4 and Figure 17 , Figure 4 and Figure 17 are the XRD (X-ray diffraction) and scanning electron microscope images of the silyl ether catalyst four, respectively. Example 5

[0074] a) Take 1.0 g of tungsten chloride, add 4.0 g of thiourea, add 350 ml of deionized water, uniformly disperse, ultrasonic for 15 min, stir at 30 °C for 1 hour, to obtain a tungsten sulfide solution, vacuum drying, grinding to obtain a tungsten sulfide precursor;

[0075] b) Take 1.5 g of the tungsten sulfide precursor in step a), nitrogen atmosphere purging for 15 min, 200 W microwave calcination for 8 h, natural cooling to 30 °C, grinding, adding 100 ml of ethanol and 300 ml of deionized water mixture, washing, suction filtration, freeze drying, to obtain the silyl ether catalyst five;

[0076] c) 200 mg of the silyl ether catalyst five in step b), 10 ml of ethanol, 2 ml of dimethylphenylsilane, 30 °C, reaction for 48 h, to prepare the silyl ether, the yield is 72%;

[0077] See Figure 5 and Figure 18 , Figure 5 and Figure 18 are the XRD (X-ray diffraction) and scanning electron microscope images of the silyl ether catalyst five, respectively.

[0078] The silyl ether catalyst for catalytic synthesis of silyl ether is prepared quickly and efficiently using cheap and readily available tungsten chloride and thiourea as raw materials through a simple process, solving the problems of expensive raw materials for noble metal catalysts and complicated preparation of non-noble metal catalysts, and the silyl ether catalyst can catalyze the reaction of silane and alcohol to generate silyl ether at 30 °C, reducing the temperature for the preparation of silyl ether by non-noble metal silyl ether catalysts. The synthesis process is simple, a large amount of silyl ether catalyst can be prepared quickly and efficiently, and it has a broad application prospect in silyl ether synthesis. Example 6

[0079] a) Take 2.0 g of tungstic acid, add 1.0 g of thiourea, add 250 ml of deionized water, uniformly disperse, ultrasonic for 45 min, stir at 30 °C for 2 hours, to obtain a tungsten sulfide solution, vacuum drying, grinding to obtain a tungsten sulfide precursor;

[0080] b) Take 2 g of the tungsten sulfide precursor in step a), purge with nitrogen atmosphere for 15 min, microwave calcination at 200 W for 5 h, naturally cool to 30℃, grind, add 200 ml of ethanol and 500 ml of deionized water mixture, wash, filter, freeze-dry to obtain the silane catalyst six;

[0081] c) Take 200 mg of the silane catalyst six in step b), 10 ml of ethanol, 2 ml of dimethylphenylsilane, react at 30℃ for 48 h to prepare a silane, and the yield is 98%;

[0082] See Figure 6 and Figure 19 , Figure 6 and Figure 19 are the XRD (X-ray diffraction) and scanning electron microscope images of the silane catalyst six, respectively.

[0083] The silane catalyst prepared by the reaction of tungstic acid and thiourea has good catalytic effect. The prepared silane catalyst has low addition amount and good catalytic effect, and can efficiently catalyze the preparation of silane at 30℃, thereby further reducing the production cost of the silane catalyst and improving the economic benefit. Example 7

[0084] a) Take 2.0 g of tungsten oxide, add 1.0 g of sulfur, add 200 ml of deionized water, disperse uniformly, ultrasonic for 30 min, stir at 30℃ for 1 hour to obtain a tungsten sulfide solution, vacuum dry, grind to obtain a tungsten sulfide precursor;

[0085] b) Take 1.5 g of the tungsten sulfide precursor in step a), purge with nitrogen atmosphere for 30 min, microwave calcination at 300 W for 2 h, naturally cool to 30℃, grind, add 100 ml of ethanol and 300 ml of deionized water mixture, wash, filter, freeze-dry to obtain the silane catalyst seven;

[0086] c) Take 200 mg of the silane catalyst seven in step b), 10 ml of ethanol, 2 ml of dimethylphenylsilane, react at 60℃ for 2 h to prepare a silane, and the yield is 92%;

[0087] See Figure 7 and Figure 20 , Figure 7 and Figure 20 are the XRD (X-ray diffraction) and scanning electron microscope images of the silane catalyst seven, respectively. Example 8

[0088] a) Take 5.0 g of tungsten oxide, add 2.0 g of thiourea, add 400 ml of deionized water, disperse uniformly, ultrasonic for 60 min, stir at 30℃ for 2.5 hours to obtain a tungsten sulfide solution, vacuum dry, grind to obtain a tungsten sulfide precursor;

[0089] b) Take 3 g of the tungsten sulfide precursor in step a), purge with nitrogen atmosphere for 15 min, microwave calcination at 400 W for 5 h, naturally cool to 30 °C, grind, wash with 300 ml of ethanol and 900 ml of deionized water mixed solution, suction filtration, freeze-drying to obtain the silane catalyst eight;

[0090] c) Take 200 mg of the silane catalyst eight in step b), 10 ml of ethanol, 2 ml of dimethylphenylsilane, react at 30 °C for 48 h to prepare a silane, and the yield is measured to be 56%;

[0091] Please refer to Figure 8 and Figure 21 , Figure 8 and Figure 21 , which are the XRD (X-ray diffraction) pattern and the scanning electron microscope pattern of the silane catalyst eight, respectively. Example 9

[0092] a) Take 2.0 g of blue tungsten, add 3.0 g of benzyl mercaptan, add 280 ml of deionized water, uniformly disperse, ultrasonic for 45 min, stir at 30 °C for 2 hours to obtain a tungsten sulfide solution, vacuum drying, grinding to obtain a tungsten sulfide precursor;

[0093] b) Take 2.0 g of the tungsten sulfide precursor in step a), purge with nitrogen atmosphere for 20 min, microwave calcination at 250 W for 7 h, naturally cool to 30 °C, grind, wash with 100 ml of ethanol and 300 ml of deionized water mixed solution, suction filtration, freeze-drying to obtain the silane catalyst nine;

[0094] c) Take 200 mg of the silane catalyst nine in step b), 10 ml of ethanol, 2 ml of dimethylphenylsilane, react at 30 °C for 48 h to prepare a silane, and the yield is measured to be 43%;

[0095] Please refer to Figure 9 and Figure 22 , Figure 9 and Figure 22 , which are the XRD (X-ray diffraction) pattern and the scanning electron microscope pattern of the silane catalyst nine, respectively. Example 10

[0096] a) Take 2.0 g of tungsten ethoxide, add 1.4 g of ammonium sulfide, add 150 ml of deionized water, uniformly disperse, ultrasonic for 15 min, stir at 30 °C for 1 hour to obtain a tungsten sulfide solution, vacuum drying, grinding to obtain a tungsten sulfide precursor;

[0097] b) Take 1.8 g of the tungsten sulfide precursor in step a), purge with nitrogen atmosphere for 15 min, microwave calcination at 300 W for 5 h, naturally cool to 30 °C, grind, wash with 100 ml of ethanol and 300 ml of deionized water mixed solution, suction filtration, freeze-drying to obtain the silane catalyst ten;

[0098] c) Take 200 mg of the silyl ether catalyst ten in step b), 10 ml of ethanol, 2 ml of dimethylphenylsilane, and react at 30°C for 48 h to prepare a silyl ether, and the yield is measured to be 18%;

[0099] See Figure 10 and Figure 23 , Figure 10 and Figure 23 are the XRD (X-ray diffraction) and scanning electron microscope images of the silyl ether catalyst ten, respectively. Example 11

[0100] a) Take 2.0 g of tungsten dioxide, add 0.8 g of thiourea, add 100 ml of deionized water, uniformly disperse, ultrasonic for 20 min, stir at 30°C for 1.2 hours to obtain a tungsten sulfide solution, vacuum drying, and grinding to obtain a tungsten sulfide precursor;

[0101] b) Take 1.5 g of the tungsten sulfide precursor in step a), purge for 15 min under nitrogen atmosphere, microwave calcine at 280 W for 7 h, naturally cool to 30°C, grind, add 100 ml of an ethanol and 300 ml of deionized water mixture, wash, suction filter, and freeze-dry to obtain a silyl ether catalyst eleven;

[0102] c) Take 200 mg of the silyl ether catalyst eleven in step b), 10 ml of ethanol, 2 ml of dimethylphenylsilane, and react at 30°C for 48 h to prepare a silyl ether, and the yield is measured to be 92%;

[0103] See Figure 11 and Figure 24 , Figure 11 and Figure 24 are the XRD (X-ray diffraction) and scanning electron microscope images of the silyl ether catalyst eleven, respectively.

[0104] Using tungsten dioxide as a tungsten source can greatly reduce the amount of thiourea, prepare a high-efficiency silyl ether catalyst under a low-sulfur content condition, reduce the synthesis difficulty of the silyl ether catalyst, reduce the cost of the synthesis of the silyl ether catalyst, and have a broad application prospect. Example 12

[0105] a) Take 2.0 g of tungsten carbide, add 2.6 g of potassium thiocyanate, add 280 ml of deionized water, uniformly disperse, ultrasonic for 30 min, stir at 30°C for 1.5 hours to obtain a tungsten sulfide solution, vacuum drying, and grinding to obtain a tungsten sulfide precursor;

[0106] b) Take 1.5 g of the tungsten sulfide precursor in step a), purge with nitrogen atmosphere for 15 min, microwave calcination at 200 W for 8 h, naturally cool to 30°C, grind, add 100 ml of ethanol and 250 ml of deionized water mixed solution, filter, freeze-dry, to obtain the silylether catalyst twelve;

[0107] c) Take 200 mg of the silylether catalyst twelve in step b), 10 ml of ethanol, 2 ml of dimethylphenylsilane, react at 30°C for 48 h, to obtain the silylether, and the yield is measured to be 61%.

[0108] Please refer to Figure 12 and Figure 25 , Figure 12 and Figure 25 are the XRD (X-ray diffraction) and scanning electron microscope images of the silylether catalyst twelve, respectively. Example 13

[0109] a) Take 2.0 g of ammonium tungstate, add 1.6 g of ammonium sulfide, add 300 ml of deionized water, uniformly disperse, ultrasonic for 50 min, stir at 30°C for 3 hours, to obtain a tungsten sulfide solution, vacuum dry, grind to obtain a tungsten sulfide precursor;

[0110] b) Take 1.5 g of the tungsten sulfide precursor in step a), purge with nitrogen atmosphere for 30 min, microwave calcination at 400 W for 2 h, naturally cool to 30°C, grind, add 200 ml of ethanol and 500 ml of deionized water mixed solution, filter, freeze-dry, to obtain the silylether catalyst thirteen;

[0111] c) Take 200 mg of the silylether catalyst thirteen in step b), 10 ml of ethanol, 2 ml of dimethylphenylsilane, react at 0°C for 64 h, to obtain the silylether, and the yield is measured to be 19%.

[0112] Please refer to Figure 13 and Figure 26 , Figure 13 and Figure 26 are the XRD (X-ray diffraction) and scanning electron microscope images of the silylether catalyst thirteen, respectively.

[0113] The above merely illustrates the preferred embodiments of the present application, and the description is relatively specific and detailed, but should not be understood as a limitation on the patent scope of the present application. It should be noted that for ordinary skilled persons in the art, several modifications, improvements and substitutions can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims. The above merely illustrates the preferred embodiments of the present application, and the description is relatively specific and detailed, but should not be understood as a limitation on the patent scope of the present application. It should be noted that for ordinary skilled persons in the art, several modifications, improvements and substitutions can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. Use of a siloxane catalyst in the synthesis of a siloxane, characterized in that The method comprises the following steps: The compound shown as formula (I) and the compound shown as formula (II) are reacted under a silylether catalyst WS2 at 0-60℃ to obtain a silylether shown as formula (III); ； wherein R is C1-C 12 alkyl or aryl, R1is C1-C 18 alkyl, alkenyl, aryl or alkylaryl or C1-C 18 alkyl, alkenyl, aryl or alkylaryl substituted with amino, R2is C1-C 18 alkyl, alkenyl, aryl or alkylaryl or C1-C 18 alkyl, alkenyl, aryl or alkylaryl substituted with amino, R3is C1-C 18 alkyl, alkenyl, aryl or alkylaryl or C1-C 18 alkyl, alkenyl, aryl or alkylaryl substituted with amino; The preparation method of the silylether catalyst comprises the following steps: a) Preparation of tungsten sulfide precursor: after uniformly dispersing a tungsten compound and a sulfide in deionized water, ultrasonic treatment is performed for 10-120 min, and then the mixture is stirred at 30-80℃ for 0.5-5 h, vacuum drying, and grinding to obtain the tungsten sulfide precursor; b) Preparation of the silylether catalyst: the tungsten sulfide precursor obtained in step a) is purged with nitrogen for 10-120 min, microwave calcination is performed for 2-10 h, cooling, grinding, washing with a mixture of ethanol and deionized water, suction filtration, and freeze drying to obtain the silylether catalyst; The mass ratio of the tungsten compound to the sulfide is 1:0.1-1:

5.

2. Use of a siloxane catalyst according to claim 1 in the synthesis of siloxanes, characterized in that: The tungsten compound is one or more of tungsten chloride, tungstic acid, ammonium tungstate, tungsten oxide, sodium tungstate, blue tungsten, tungsten boride, tungsten carbide, tungsten ethoxide, tungsten dioxide, and oxo-tungsten chloride.

3. Use of a siloxane catalyst according to claim 1 in the synthesis of siloxanes, characterized in that: The sulfide is one or more of thiourea, diaryl thiourea, potassium thiocyanate, sulfur, thiophene, benzene thiol, phenothiazine, ethyl mercaptan, benzyl mercaptan, dithizone, rhodanine, ammonium sulfide, and octyl sulfide.

4. Use of a siloxane catalyst according to claim 1 in the synthesis of siloxanes, characterized in that: The microwave calcination power is 100-500 W; and the volume ratio of ethanol to deionized water in the mixture is 1:1.5-1:

5.

5. Use of a siloxane catalyst according to claim 1 in the synthesis of siloxanes, characterized in that: The silylether synthesis reaction time is controlled to be 2-72 h.

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