2N type cobalt complex and preparation method thereof, and silylation reaction of hydrogen-containing silane and alcohol

Abstract

The invention relates to a 2N-type cobalt complex and a preparation method thereof. The 2N-type cobalt complex is used for a silylation reaction of hydrogen-containing silane and alcohol. The invention relates to a 2N type cobalt complex, and the 2N type cobalt complex is one of Co < 1 >-Co < 6 >. According to the 2N type cobalt complex, the preparation method thereof and the silylation reaction of the hydrogen-containing silane and the alcohol, the 2N type cobalt complex can be used for catalyzing the silylation reaction of the hydrogen-containing silane and the alcohol to synthesize the triphenyl silyl ether, and has the advantages of mild conditions, simple synthesis steps, lower cost, higher catalytic activity, good substrate universality, no need of an active auxiliary agent and the like; and a new method is provided for constructing the silicon-oxygen bond.

Description

Technical Field

[0001] This invention belongs to the field of organic chemical catalysis technology, specifically relating to a 2N type cobalt complex and its preparation method, and the silanization reaction of hydrogen-containing silanes with alcohols. Background Technology

[0002] Organosilicon ethers (Si-O bonds) are an important class of chemicals that play a vital role in the chemical industry because they are used in the production of adhesives, adhesion promoters, lubricants, waterproofing agents, etc. In addition, the dehydrogenation coupling of hydrosilanes with alcohols produces hydrogen as a byproduct, which has also led to increasing interest in using hydrosilanes as hydrogen storage materials.

[0003] The traditional method for synthesizing silyl ethers involves the alcoholysis of chlorosilanes. However, this method requires a large amount of base to neutralize the HCl gas produced during the reaction, thus necessitating a more environmentally friendly and sustainable approach. Therefore, hydrosilanes have replaced traditional chlorosilanes. From an atom economy perspective, dehydrogenation coupling is the most attractive route, forming H2 as the sole byproduct to generate silyl ethers. This process avoids the unnecessary generation of acids. These reactions are primarily driven by the formation of stable Si-O bonds, a chemically advantageous but kinetically slow method. Designing sustainable methods for synthesizing organosilanes largely requires the development of efficient catalysts that can operate under mild conditions. However, almost all methods for producing silyl ethers through dehydrogenation coupling require noble metal catalysts or strong base catalysis.

[0004] More importantly, the direct dehydrogenation coupling of triphenylsilanes, which are sterically hindered and have low activity, with alcohols remains a challenge. Existing non-noble metal catalytic systems (such as some iron catalysts) often suffer from one or more of the following drawbacks: high catalyst loading (>5 mol%), resulting in poor economic efficiency; narrow substrate universality, especially with a sharp drop in catalytic efficiency for sterically hindered secondary alcohols, tertiary alcohols, or long-chain aliphatic alcohols; harsh reaction conditions, requiring high temperatures (>150℃) or strong base additives; and poor chemoselectivity, easily leading to side reactions such as self-dehydrogenation polymerization of triphenylsilane, resulting in low yields of the target silane ether. Therefore, developing inexpensive, highly efficient, and universally applicable metal catalysts is essential for the dehydrogenation coupling reaction of silanes.

[0005] In view of this, the present invention proposes a 2N type cobalt complex and its preparation method, and a catalytic reaction of hydrogen-containing silanes with alcohols to prepare triphenylsilanes. The 2N type cobalt complex is inexpensive and has the advantages of high reactivity and good substrate universality in the dehydrogenation coupling reaction of triphenylsilanes with alcohols. Moreover, the silanization reaction does not require the addition of an activator. Summary of the Invention

[0006] The purpose of this invention is to provide a 2N type cobalt complex that can catalyze the silanization reaction of triphenylsilane and alcohol to prepare triphenylsilyl ether under additive-free conditions.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A 2N type cobalt complex, wherein the 2N type cobalt complex is one of Co1-Co6;

[0009] The structural formulas of Co1-Co6 are shown below:

[0010]

[0011] Another objective of this invention is to provide a method for preparing the above-mentioned 2N type cobalt complex, which is simple and uses inexpensive and readily available raw materials.

[0012] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0013] The preparation method of the above-mentioned 2N type cobalt complex is as follows: dissolve the ligand and cobalt acetylacetonate in tetrahydrofuran solution, and react at 60-70℃ for 10-14h to obtain the 2N type cobalt complex.

[0014] The ligand is one of 2-(1H-pyrazol-1-yl)pyridine, 2-(3-methyl-1H-pyrazol-1-yl)pyridine, o-phenanthroline, bipyridine, or 4,4'-dimethyl-2,2'-bipyridine, 4,4'-di-tert-butyl-2,2'-bipyridine.

[0015] Furthermore, the molar ratio of the ligand to cobalt acetylacetone is 1:0.5-0.7.

[0016] Furthermore, the synthesis method of 2-(1H-pyrazole-1-yl)pyridine is as follows: 2-bromopyridine, pyrazole, potassium carbonate, and cuprous iodide are added to a dimethyl sulfoxide solution and reacted at 110-130℃ for 20-28h.

[0017] The method for synthesizing 2-(3-methyl-1H-pyrazole-1-yl)pyridine is as follows: 2-bromopyridine, 3-methylpyrazole, potassium carbonate, and cuprous iodide are added to a dimethyl sulfoxide solution and reacted at 110-130℃ for 20-28 h.

[0018] Another objective of this invention is to provide a silanization reaction of hydrogen-containing silanes and alcohols, which is a method for preparing triphenylsilane. This preparation method uses the above-mentioned 2N-type cobalt complex to catalyze the dehydrogenation coupling reaction of triphenylsilanes and alcohols, and has the advantages of low cost, good universality, good stability, mild reaction conditions, and high yield.

[0019] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0020] A silanization reaction of a hydrogen-containing silane with an alcohol, wherein the silanization reaction is carried out by mixing the hydrogen-containing silane, alcohol, catalyst and organic solvent, and then carrying out the silanization reaction under an inert gas atmosphere to obtain a dehydrogenation coupling product, namely triphenylsilyl ether.

[0021] The catalyst is the aforementioned 2N-type cobalt complex.

[0022] Furthermore, the hydrogen-containing silane is triphenylsilane;

[0023] The chemical structural formula of the alcohol used is: In the formula, R is a benzene ring substituent or an aliphatic chain group.

[0024] Furthermore, the alcohol used is at least one of benzyl alcohol, 4-methylbenzyl alcohol, 3-methylbenzyl alcohol, 2-methylbenzyl alcohol, 4-methoxybenzyl alcohol, 4-isopropylbenzyl alcohol, 2,4,6-trimethylbenzyl alcohol, p-ethylbenzyl alcohol, 2-(methylthio)ethanol, cyclohexanol, 4-chlorobenzyl alcohol, 4-trifluoromethylbenzyl alcohol, 3-nitrobenzyl alcohol, and 2-phenylethanol.

[0025] Furthermore, the organic solvent is tetrahydrofuran.

[0026] Furthermore, the molar ratio of the hydrogen-containing silane, alcohol, and catalyst is 1:0.5-2:0.005-0.02;

[0027] The siliconization reaction is carried out at a temperature of 40-80℃ for 8-20 hours.

[0028] Furthermore, the molar ratio of the hydrogen-containing silane, alcohol, and catalyst is 1:2:0.02;

[0029] The siliconization reaction was carried out at a temperature of 70°C for 12 hours.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] 1. The technical solution of this invention uses a 2N-type cobalt complex as the catalyst. This catalyst is cheaper and more readily available than precious metal catalysts such as palladium, platinum, and rhodium, and its preparation method is simple. Compared with existing inexpensive metal catalysts, it does not require the use of an activator and can catalyze the silanization reaction of triphenylsilane and alcohol under additive-free conditions, with milder conditions and better results.

[0032] 2. The technical solution of the present invention uses a 2N type cobalt complex as a catalyst, which simplifies the synthesis steps of the reaction between triphenylsilane and alcohol silylation and yields products that are all triphenylsilyl ethers with good stability.

[0033] 3. The technical solution of the present invention uses a 2N type cobalt complex as a catalyst, which has good substrate versatility in the reaction of triphenylsilane with alcohols and can be applied to aromatic alcohols and aliphatic alcohols with different substituents, including electron-withdrawing groups, electron-donating groups, short chains and long chains.

[0034] 4. The technical solution of this invention uses a 2N type cobalt complex as a catalyst. The dehydrogenation coupling reaction has the characteristics of mild conditions and high yield, which breaks the traditional characteristics of using precious metals to produce silicon ethers and provides a new experimental idea for realizing the production of cheap and efficient silicon chemical products. Attached Figure Description

[0035] Figure 1 The single-crystal structure of the 2N-type cobalt complex [Co1] is characterized.

[0036] Figure 2 The single-crystal structure of the 2N-type cobalt complex [Co2] is characterized. Detailed Implementation

[0037] To further illustrate the 2N-type cobalt complex and its preparation method, as well as the silanization reaction of hydrogen-containing silanes with alcohols according to the present invention, and to achieve the intended objectives of the invention, the following detailed description, in conjunction with preferred embodiments, details the specific implementation methods, structures, features, and effects of the 2N-type cobalt complex and its preparation method, as well as the silanization reaction of hydrogen-containing silanes with alcohols proposed in this invention. In the following description, different "an embodiment" or "an embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable manner.

[0038] The following will provide a more detailed description of the 2N-type cobalt complex and its preparation method, as well as the silanization reaction of hydrogen-containing silanes with alcohols, using specific embodiments:

[0039] Siloxane sequences are ubiquitous structural units in chemical synthesis and industry. Due to their unique properties, they are highly valuable and used in numerous diverse fields, including medicine, cosmetics, and textiles. In this invention, a novel 2N-type cobalt complex is synthesized using a ligand and cobalt acetylacetonate as the metal salt. After the reaction, a high-purity cobalt catalyst can be obtained by filtration without column chromatography purification.

[0040] After obtaining the cobalt complex, the dehydrogenation coupling reaction of triphenylsilane with alcohols of different substituents can be achieved using the cobalt complex, yielding relatively high yields of the dehydrogenation coupling product. This reaction procedure is simple, uses inexpensive and readily available raw materials, and exhibits good stability. Furthermore, the dehydrogenation coupling reaction catalyzed by the 2N-type cobalt complex of this invention has the advantages of mild conditions, high reactivity, and broad substrate universality, breaking away from the traditional use of precious metals to produce organosilicon products and providing a new experimental approach for the production of inexpensive and efficient organosilicon reagents.

[0041] The technical solution of this invention is as follows:

[0042] A 2N type cobalt complex, wherein the 2N type cobalt complex is one of Co1-Co6;

[0043] The structural formulas of Co1-Co6 are shown below:

[0044]

[0045] The preparation method of the above-mentioned 2N type cobalt complex is as follows: dissolve the ligand and cobalt acetylacetonate in tetrahydrofuran solution, and react at 60-70℃ for 10-14h to obtain the 2N type cobalt complex.

[0046] The ligand is one of 2-(1H-pyrazol-1-yl)pyridine, 2-(3-methyl-1H-pyrazol-1-yl)pyridine, o-phenanthroline, bipyridine, or 4,4'-dimethyl-2,2'-bipyridine, 4,4'-di-tert-butyl-2,2'-bipyridine.

[0047] Preferably, the molar ratio of the ligand to cobalt acetylacetonate is 1:0.5-0.7.

[0048] Preferably, the synthesis method of 2-(1H-pyrazole-1-yl)pyridine is as follows: 2-bromopyridine, pyrazole, potassium carbonate, and cuprous iodide are added to a dimethyl sulfoxide solution and reacted at 110-130°C for 20-28 hours.

[0049] The method for synthesizing 2-(3-methyl-1H-pyrazole-1-yl)pyridine is as follows: 2-bromopyridine, 3-methylpyrazole, potassium carbonate, and cuprous iodide are added to a dimethyl sulfoxide solution and reacted at 110-130℃ for 20-28 h.

[0050] In the above technical solution, pyrazole and 2-bromo-pyridine, which are inexpensive and commercially available, are used as reactants to synthesize 2-(1H-pyrazole-1-yl)pyridine and 2-(3-methyl-1H-pyrazole-1-yl)pyridine ligands. The method is low-cost and simple.

[0051] A silanization reaction of a hydrogen-containing silane with an alcohol is described as follows: after mixing the hydrogen-containing silane, alcohol, catalyst, and organic solvent, a silanization reaction is carried out under an inert gas atmosphere to obtain a dehydrogenation coupling product, namely triphenylsilyl ether.

[0052] The catalyst is the aforementioned 2N-type cobalt complex.

[0053] In the above technical solution, the triphenylsilane, alcohol, catalyst and solvent are mixed in the following manner: a dehydrogenation coupling reaction is carried out in an inert gas atmosphere. First, the catalyst and triphenylsilane are added, then the alcohol is added, and finally the organic solvent is added to obtain the silanized product, namely the triphenylsilyl ether.

[0054] Preferably, the hydrogen-containing silane is triphenylsilane;

[0055] The chemical structural formula of the alcohol used is: In the formula, R is a benzene ring substituent or an aliphatic chain group.

[0056] More preferably, the alcohol used is at least one selected from benzyl alcohol, 4-methylbenzyl alcohol, 3-methylbenzyl alcohol, 2-methylbenzyl alcohol, 4-methoxybenzyl alcohol, 4-isopropylbenzyl alcohol, 2,4,6-trimethylbenzyl alcohol, p-ethylbenzyl alcohol, 2-(methylthio)ethanol, cyclohexanol, 4-chlorobenzyl alcohol, 4-trifluoromethylbenzyl alcohol, 3-nitrobenzyl alcohol, and 2-phenylethanol, with the following structural formula:

[0057]

[0058] Preferably, the organic solvent is tetrahydrofuran.

[0059] Preferably, the molar ratio of the hydrogen-containing silane, alcohol, and catalyst is 1:0.5-2:0.005-0.02;

[0060] The siliconization reaction is carried out at a temperature of 40-80℃ for 8-20 hours.

[0061] More preferably, the molar ratio of the hydrogen-containing silane, alcohol, and catalyst is 1:2:0.02;

[0062] The siliconization reaction was carried out at a temperature of 70°C for 12 hours.

[0063] A further preferred embodiment of the silanization reaction is:

[0064] .

[0065] All pharmaceuticals are commercially available and require no further processing. This invention does not have special requirements for alcohols, as long as an alcohol-like structure that meets the above requirements can be obtained. In the above technical solutions, the hydrogen-containing silanes, ligands, and pharmaceuticals required for synthesizing the ligands can be commercially available products well-known in the art.

[0066] Example 1: Synthesis of 2N-type cobalt complexes

[0067] The structural formula of the 2N type cobalt complex is shown below:

[0068]

[0069] The reaction formula is shown below:

[0070]

[0071]

[0072]

[0073]

[0074]

[0075] The specific operating steps are as follows:

[0076] (1) 2-bromopyridine (12 mmol), pyrazole compound (20 mmol), potassium carbonate (30 mmol), and cuprous iodide (3 mmol) were added to 10 mL of dimethyl sulfoxide solution and reacted at 120 °C for 24 h to obtain the ligand.

[0077] The pyrazole compounds are pyrazole and 3-methylpyrazole, and their synthesized ligands 1-2 are 2-(1H-pyrazole-1-yl)pyridine and 2-(3-methyl-1H-pyrazole-1-yl)pyridine, respectively. The structural formulas of the ligands are shown below:

[0078] , .

[0079] The results of NMR analysis of ligands 1-2 are as follows:

[0080] NMR data for ligand 1:2-(1H-pyrazole-1-yl)pyridine:

[0081] 1 H NMR (400 MHz, ) δ 8.57 (d, J = 2.6 Hz, 1H), 8.41 (d, J = 4.2Hz, 1H), 7.98 (d, J = 8.2 Hz, 1H), 7.81 (td, J = 7.9, 1.9 Hz, 1H), 7.74 (s,1H), 7.18 (ddd, J = 7.3, 4.9, 1.0 Hz, 1H), 6.46 (t, J = 2.1 Hz, 1H).

[0082] 13 C NMR (100 MHz, ) δ 151.6, 148.0, 142.1, 138.7, 127.0, 121.4,112.4, 107.8.

[0083] NMR data for ligand 2: 2-(3-methyl-1H-pyrazole-1-yl)pyridine:

[0084] 1 H NMR (400 MHz, ) δ 8.43 (d, J = 2.6 Hz, 1H), 8.36 (d, J = 4.0Hz, 1H), 7.90 (d, J = 8.3 Hz, 1H), 7.78 – 7.73 (m, 1H), 7.11 (ddd, J = 7.3,4.9, 1.1 Hz, 1H), 6.24 (d, J = 2.5 Hz, 1H), 2.37 (s, 3H).

[0085] 13 C NMR (100 MHz, ) δ 151.8, 151.6, 148.1, 138.6, 127.8, 120.9,112.2, 108.1, 14.0.

[0086] Ligands 3, 4, 5, and 6 were purchased directly and did not require synthesis.

[0087] (2) Ligands 1-6 (5 mmol), (3 mmol) was dissolved in tetrahydrofuran solution and reacted at 70 °C for 12 h to obtain [Co] ([Co1]-[Co6]).

[0088] [Co1] and [Co2] were characterized by single-crystal diffraction, and were respectively... Figure 1 , 2 As shown in the figure, 2N-type cobalt complexes with [Co1] and [Co2] structures were formed.

[0089] Example 2.

[0090] The specific operating steps are as follows:

[0091] (1) 2-bromopyridine (12 mmol), pyrazole compound (20 mmol), potassium carbonate (30 mmol), and cuprous iodide (3 mmol) were added to 10 mL of dimethyl sulfoxide solution and reacted at 110 °C for 28 h to obtain the ligand.

[0092] The pyrazole compounds are pyrazole and 3-methylpyrazole, and their synthetic ligands 1-2 are 2-(1H-pyrazole-1-yl)pyridine and 2-(3-methyl-1H-pyrazole-1-yl)pyridine, respectively.

[0093] (2) Add ligands 1-2 (5 mmol), (2.5 mmol) was dissolved in tetrahydrofuran solution and reacted at 60 °C for 14 h to obtain [Co]([Co1]-[Co2]).

[0094] The single-crystal diffraction characterization results of [Co1] and [Co2] are the same as those in Example 1.

[0095] Example 3.

[0096] The specific operating steps are as follows:

[0097] (1) 2-bromopyridine (12 mmol), pyrazole compound (20 mmol), potassium carbonate (30 mmol), and cuprous iodide (3 mmol) were added to 10 mL of dimethyl sulfoxide solution and reacted at 130 °C for 20 h to obtain the ligand.

[0098] The pyrazole compounds are pyrazole and 3-methylpyrazole, and their synthetic ligands 1-2 are 2-(1H-pyrazole-1-yl)pyridine and 2-(3-methyl-1H-pyrazole-1-yl)pyridine, respectively.

[0099] (2) Add ligands 1-2 (5 mmol), (3.5 mmol) was dissolved in tetrahydrofuran solution and reacted at 65 °C for 10 h to obtain [Co] ([Co1]-[Co2]).

[0100] The single-crystal diffraction characterization results of [Co1] and [Co2] are the same as those in Example 1.

[0101] In Examples 4-19, the catalyst used was the complex [Co1] prepared in Example 1, and the process was carried out under an inert gas atmosphere.

[0102] In the examples, the triphenylsilane, alcohol and catalyst were mixed by first adding the catalyst and triphenylsilane, then adding the alcohol, and finally adding the organic solvent.

[0103] Example 4.

[0104] The reaction formula is as follows:

[0105]

[0106] The specific operating steps are as follows:

[0107] 0.5 mmol triphenylsilane, 1.0 mmol benzyl alcohol, and 2 mol% catalyst were added to a THF solution and heated to 70 °C, then reacted for 12 h. After the reaction was complete, the product was obtained by column chromatography with a yield of 90%.

[0108] NMR data for the product benzyloxytriphenylsilane:

[0109] 1 H NMR (400 MHz, ) δ 7.70 – 7.67 (m, 6H), 7.49 – 7.40 (m, 9H), 7.39 – 7.33 (m, 5H), 4.92 (s, 2H).

[0110] 13 C NMR (100 MHz, ) δ 140.7, 135.6, 134.1, 130.2, 128.4, 128.1,127.2, 126.5, 65.7.

[0111] Example 5.

[0112] The reaction formula is as follows:

[0113]

[0114] The specific operating steps are as follows:

[0115] 0.5 mmol triphenylsilane, 1.0 mmol 4-methylbenzyl alcohol, and 2 mol% catalyst were added to a THF solution and heated to 70 °C, then reacted for 12 h. After the reaction was complete, the product was obtained by column chromatography with a yield of 87%.

[0116] NMR data for the product ((4-tolyl)methoxy)triphenylsilane):

[0117] 1 H NMR (400 MHz, ) δ 7.75 – 7.72 (m, 6H), 7.53 – 7.49 (m, 3H), 7.47 – 7.43 (m, 6H), 7.30 (d, J = 7.9 Hz, 2H), 7.20 (d, J = 7.8 Hz, 2H), 4.93(s, 2H), 2.41 (s, 3H).

[0118] 13 C NMR (100 MHz, ) δ 137.7, 136.8, 135.6, 134.2, 130.2, 129.0,128.0, 126.6, 65.6, 21.3.

[0119] Example 6.

[0120] The reaction formula is as follows:

[0121]

[0122] The specific operating steps are as follows:

[0123] 0.5 mmol of triphenylsilane, 1.0 mmol of 3-methylbenzyl alcohol, and 2 mol% catalyst were added to a THF solution and heated to 70 °C, then reacted for 12 h. After the reaction was complete, the product was obtained by column chromatography in 75% yield.

[0124] NMR data for the product ((3-tolyl)methoxy)triphenylsilane:

[0125] 1 H NMR (400 MHz, ) δ 7.77 – 7.75 (m, 6H), 7.54 – 7.50 (m, 3H), 7.49 – 7.46 (m, 6H), 7.30 – 7.28 (m, 1H), 7.24 (d, J = 7.8 Hz, 1H), 7.22 (s,1H), 7.15 (d, J = 7.3 Hz, 1H), 4.96 (s, 2H), 2.41 (s, 3H).

[0126] 13 C NMR (100 MHz, ) δ 140.6, 137.9, 135.9, 135.6, 134.2, 130.2,128.3, 128.0, 127.4, 123.7, 65.8, 21.6.

[0127] Example 7.

[0128] The reaction formula is as follows:

[0129]

[0130] The specific operating steps are as follows:

[0131] 0.5 mmol triphenylsilane, 1.0 mmol 2-methylbenzyl alcohol, and 2 mol% catalyst were added to a THF solution and heated to 70 °C, then reacted for 12 h. After the reaction was complete, the product was obtained by column chromatography in 67% yield.

[0132] NMR data for product ((2-tolyl)methoxy)triphenylsilane:

[0133] 1 H NMR (400 MHz, ) δ 7.70 – 7.67 (m, 6H), 7.51 – 7.44 (m, 4H), 7.43 – 7.38 (m, 6H), 7.23 – 7.17 (m, 2H), 7.14 (dd, J = 5.7, 3.2 Hz, 1H), 4.89 (s, 2H), 2.23 (s, 3H).

[0134] 13 C NMR (100 MHz, ) δ 138.6, 135.6, 135.4, 134.2, 130.2, 130.0,128.1, 127.2, 127.0, 126.0, 64.0, 18.8.

[0135] Example 8.

[0136] The reaction formula is as follows:

[0137]

[0138] The specific operating steps are as follows:

[0139] 0.5 mmol of triphenylsilane, 1.0 mmol of 4-methoxybenzyl alcohol, and 2 mol% catalyst were added to a THF solution and heated to 70 °C, then reacted for 12 h. After the reaction was complete, the product was obtained by column chromatography in 86% yield.

[0140] NMR data for the product ((4-methoxy)benzyloxy)triphenylsilane:

[0141] 1 H NMR (400 MHz, ) δ 7.69 – 7.66 (m, 6H), 7.49 – 7.44 (m, 4H), 7.42 – 7.40 (m, 5H), 7.27 – 7.25 (m, 2H), 6.89 – 6.86 (m, 2H), 4.85 (s, 2H), 3.82 (s, 3H).

[0142] 13 C NMR (100 MHz, ) δ 158.9, 135.6, 134.2, 132.9, 130.2, 128.1,128.0, 113.8, 65.5, 55.4.

[0143] Example 9.

[0144] The reaction formula is as follows:

[0145]

[0146] The specific operating steps are as follows:

[0147] 0.5 mmol of triphenylsilane, 1.0 mmol of 4-isopropylbenzyl alcohol, and 2 mol% catalyst were added to a THF solution and heated to 70 °C, then reacted for 12 h. After the reaction was complete, the product was obtained by column chromatography with a yield of 93%.

[0148] NMR data for the product ((4-isopropyl)benzyloxy)triphenylsilane:

[0149] 1 H NMR (400 MHz, ) δ 7.69 – 7.65 (m, 6H), 7.48 – 7.43 (m, 3H), 7.42 – 7.37 (m, 6H), 7.28 (d, J = 8.2 Hz, 2H), 7.21 – 7.18 (m, 2H), 4.88 (s, 2H), 2.91 (p, J = 6.9 Hz, 1H), 1.26 (d, J = 6.9 Hz, 6H).

[0150] 13 C NMR (100 MHz, ) δ 147.9, 138.1, 135.6, 134.2, 130.2, 128.0,126.7, 126.4, 65.6, 34.0, 24.2.

[0151] Example 10.

[0152] The reaction formula is as follows:

[0153]

[0154] The specific operating steps are as follows:

[0155] 0.5 mmol of triphenylsilane, 1.0 mmol of 2,4,6-trimethylbenzyl alcohol, and 2 mol% catalyst were added to a THF solution and heated to 70 °C, then reacted for 12 h. After the reaction was complete, the product was obtained by column chromatography with a yield of 61%.

[0156] NMR data for the product ((2,4,6-trimethyl)benzyloxy)triphenylsilane:

[0157] 1 H NMR (400 MHz, ) δ 7.70 – 7.67 (m, 6H), 7.49 – 7.46 (m, 2H), 7.45 (t, J = 1.6 Hz, 1H), 7.43 – 7.40 (m, 5H), 7.39 (d, J = 1.5 Hz, 1H), 6.85(s, 2H), 4.85 (s, 2H), 2.30 (s, 3H), 2.26 (s, 6H).

[0158] 13 C NMR (100 MHz, ) δ 137.6, 137.4, 135.6, 134.4, 133.6, 130.1,129.0, 128.0, 60.2, 21.1, 19.6.

[0159] Example 11.

[0160] The reaction formula is as follows:

[0161]

[0162] The specific operating steps are as follows:

[0163] 0.5 mmol of triphenylsilane, 1.0 mmol of p-ethylbenzyl alcohol, and 2 mol% catalyst were added to a THF solution and heated to 70 °C, then reacted for 12 h. After the reaction was complete, the product was obtained by column chromatography with a yield of 84%.

[0164] NMR data for the product ((4-ethyl)benzyloxy)triphenylsilane:

[0165] 1 H NMR (400 MHz, ) δ 7.72 – 7.68 (m, 6H), 7.50 – 7.45 (m, 3H), 7.44 – 7.40 (m, 6H), 7.30 (d, J = 7.9 Hz, 2H), 7.19 (d, J = 7.9 Hz, 2H), 4.91(s, 2H), 2.68 (q, J = 7.6 Hz, 2H), 1.27 (t, J = 7.6 Hz, 3H).

[0166] 13 C NMR (100 MHz, ) δ 143.2, 138.0, 135.6, 134.2, 130.2, 128.0,127.9, 126.7, 65.7, 28.7, 15.8.

[0167] Example 12.

[0168] The reaction formula is as follows:

[0169]

[0170] The specific operating steps are as follows:

[0171] 0.5 mmol of triphenylsilane, 1.0 mmol of 2-(methylthio)ethanol, and 2 mol% catalyst were added to a THF solution and heated to 70 °C, then reacted for 12 h. After the reaction was complete, the product was obtained by column chromatography in 56% yield.

[0172] NMR data for product 2-methylthioethoxytriphenylsilane:

[0173] 1 H NMR (400 MHz, ) δ 7.66 – 7.62 (m, 6H), 7.47 – 7.43 (m, 3H), 7.41 – 7.37 (m, 6H), 3.95 (t, J = 7.1 Hz, 2H), 2.67 (t, J = 7.1 Hz, 2H), 2.01(s, 3H).

[0174] 13 C NMR (100 MHz, ) δ 135.5, 134.1, 130.3, 128.1, 63.3, 36.3,16.1.

[0175] Example 13.

[0176] The reaction formula is as follows:

[0177]

[0178] The specific operating steps are as follows:

[0179] 0.5 mmol triphenylsilane, 1.0 mmol cyclohexanol, and 2 mol% catalyst were added to a THF solution and heated to 70 °C, then reacted for 12 h. After the reaction was complete, the product was obtained by column chromatography with a yield of 62%.

[0180] NMR data for product (cyclohexyloxy)triphenylsilane:

[0181] 1 H NMR (400 MHz, ) δ 7.65 (dt, J = 6.7, 1.6 Hz, 6H), 7.46 – 7.36 (m, 9H), 3.85 (tt, J = 9.2, 3.6 Hz, 1H), 1.80 – 1.68 (m, 4H), 1.51 – 1.12 (m,6H).

[0182] 13 C NMR (100 MHz, ) δ 135.6, 135.3, 129.9, 127.9, 71.9, 35.7, 25.8, 24.1.

[0183] Example 14.

[0184] The reaction formula is as follows:

[0185]

[0186] The specific operating steps are as follows:

[0187] 0.5 mmol of triphenylsilane, 1.0 mmol of 4-chlorobenzyl alcohol, and 2 mol% catalyst were added to a THF solution and heated to 70 °C, then reacted for 12 h. After the reaction was complete, the product was obtained by column chromatography in 90% yield.

[0188] NMR data for the product (4-chlorobenzyloxy)triphenylsilane:

[0189] 1 H NMR (400 MHz, ) δ 7.72 – 7.70 (m, 6H), 7.53 – 7.43 (m, 10H), 7.32 (d, J = 2.2 Hz, 3H), 4.92 (s, 2H).

[0190] 13 C NMR (100 MHz, ) δ 139.2, 135.5, 133.9, 132.9, 130.3, 128.5,128.1, 127.9, 65.1.

[0191] Example 15.

[0192] The reaction formula is as follows:

[0193]

[0194] The specific operating steps are as follows:

[0195] 0.5 mmol of triphenylsilane, 1.0 mmol of 4-trifluoromethylbenzyl alcohol, and 2 mol% catalyst were added to a THF solution and heated to 70 °C, then reacted for 12 h. After the reaction was complete, the product was obtained by column chromatography in 67% yield.

[0196] NMR data for product (4-(trifluoromethyl)benzyloxy)triphenylsilane:

[0197] 1H NMR (400 MHz, ) δ 7.70 – 7.66 (m, 6H), 7.59 (d, J = 8.0 Hz, 2H), 7.50 – 7.46 (m, 5H), 7.42 (t, J = 7.1 Hz, 6H), 4.97 (s, 2H).

[0198] 13 C NMR (100 MHz, ) δ 144.7, 135.5, 133.8, 130.4, 128.2, 126.5,125.3 (q, J = 3.7 Hz), 123.1, 65.1.

[0199] 19 F NMR (376 MHz, ) δ -62.34.

[0200] Example 16.

[0201] The reaction formula is as follows:

[0202]

[0203] The specific operating steps are as follows:

[0204] 0.5 mmol of triphenylsilane, 1.0 mmol of 3-nitrobenzyl alcohol, and 2 mol% catalyst were added to a THF solution and heated to 70 °C, then reacted for 12 h. After the reaction was complete, the product was obtained by column chromatography in 58% yield.

[0205] NMR data for the product ((3-nitro)benzyloxy)triphenylsilane:

[0206] 1 H NMR (400 MHz, ) δ 8.19 (t, J = 2.0 Hz, 1H), 8.10 (dd, J =8.6, 2.2 Hz, 1H), 7.67 (dt, J = 6.6, 1.5 Hz, 6H), 7.50 – 7.39 (m, 11H), 4.98 (s, 2H).

[0207] 13 C NMR (100 MHz, ) δ 148.4, 142.8, 135.5, 133.5, 132.4, 130.5,129.3, 128.2, 122.3, 121.4, 64.7.

[0208] Example 17.

[0209] The reaction formula is as follows:

[0210]

[0211] The specific operating steps are as follows:

[0212] 0.5 mmol of triphenylsilane, 1.0 mmol of 2-phenylethanol, and 2 mol% catalyst were added to a THF solution and heated to 70 °C, then reacted for 12 h. After the reaction was complete, the product was obtained by column chromatography with a yield of 84%.

[0213] NMR data for the product phenylethoxytriphenylsilane:

[0214] 1 H NMR (400 MHz, δ 7.57 (dt, J = 6.7, 1.5 Hz, 6H), 7.44 – 7.40 (m, 3H), 7.35 (dd, J = 7.9, 6.4 Hz, 6H), 7.26 – 7.22 (m, 2H), 7.20 – 7.16 (m,1H), 7.15 – 7.11 (m, 2H), 3.98 (t, J = 7.1 Hz, 2H), 2.88 (t, J = 7.1 Hz, 2H).

[0215] 13 C NMR (100 MHz, ) δ 138.9, 135.5, 134.3, 130.1, 129.3, 128.4,128.0, 126.3, 65.2, 39.4.

[0216] Example 18.

[0217] Condition optimization:

[0218]

[0219] The specific operating steps are the same as in Example 4, except for the type and amount of catalyst, reaction temperature, time, and the amount of alcohol added relative to triphenylsilane. See Table 1 for details.

[0220] Table 1

[0221]

[0222] Note: In the table It is cobalt acetylacetonate.

[0223] Based on Table 1, we can see that:

[0224] (1) As can be seen from treatments 1-7, compared to The ligand Co1-Co2 of this invention can significantly improve the product yield.

[0225] (2) As can be seen from treatments 8-11, the yield increases further with increasing temperature, that is, temperature can increase the yield.

[0226] (3) As can be seen from treatments 12-15, the yield further increases with the increase of alcohol content.

[0227] (4) As can be seen from treatments 16-18, the yield further increases with the increase of catalyst dosage.

[0228] Example 19.

[0229] Compared with the current literature (Table 2), the catalyst and dehydrogenation coupling reaction of the present invention have a cheaper and simpler catalyst synthesis step, milder reaction conditions, and can efficiently synthesize triphenylsilyl ether.

[0230] Table 2

[0231]

[0232] As can be seen from the above embodiments, the present invention provides a 2N-type cobalt complex and its preparation method, as well as a catalytic reaction of hydrogen-containing silanes with alcohols. By reacting triphenylsilane with different alcohols, corresponding silanized products were obtained. The yield and configuration of the products obtained vary depending on the cobalt complex used for the catalytic reaction. Overall, the silanization yield obtained using [Co1] catalysis ranges from 69% to 93%, exhibiting a very high yield.

[0233] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A 2N-type cobalt complex, characterized in that, The 2N-type cobalt complex is one of Co1-Co6; The structural formulas of Co1-Co6 are shown below: 。 2. The method for preparing the 2N-type cobalt complex according to claim 1, characterized in that, The preparation method is as follows: the ligand and cobalt acetylacetone are dissolved in tetrahydrofuran solution and reacted at 60-70℃ for 10-14h to obtain the 2N type cobalt complex. The ligand is one of 2-(1H-pyrazol-1-yl)pyridine, 2-(3-methyl-1H-pyrazol-1-yl)pyridine, o-phenanthroline, bipyridine, or 4,4'-dimethyl-2,2'-bipyridine, 4,4'-di-tert-butyl-2,2'-bipyridine.

3. The preparation method according to claim 2, characterized in that, The molar ratio of the ligand to cobalt acetylacetone is 1:0.5-0.

7.

4. The preparation method according to claim 2, characterized in that, The method for synthesizing 2-(1H-pyrazol-1-yl)pyridine is as follows: 2-bromopyridine, pyrazole, potassium carbonate, and cuprous iodide are added to a dimethyl sulfoxide solution and reacted at 110-130℃ for 20-28 h. The method for synthesizing 2-(3-methyl-1H-pyrazole-1-yl)pyridine is as follows: 2-bromopyridine, 3-methylpyrazole, potassium carbonate, and cuprous iodide are added to a dimethyl sulfoxide solution and reacted at 110-130℃ for 20-28 h.

5. A silanization reaction of a hydrogen-containing silane with an alcohol, characterized in that, The silanization reaction is as follows: after mixing hydrogen-containing silane, alcohol, catalyst and organic solvent, the silanization reaction is carried out under an inert gas atmosphere to obtain the dehydrogenation coupling product, namely triphenylsilyl ether. The catalyst is the 2N-type cobalt complex as described in claim 1.

6. The silanization reaction according to claim 5, characterized in that, The hydrogen-containing silane is triphenylsilane; The chemical structural formula of the alcohol used is: In the formula, R is a benzene ring substituent or an aliphatic chain group.

7. The silanization reaction according to claim 6, characterized in that, The alcohol used is at least one of benzyl alcohol, 4-methylbenzyl alcohol, 3-methylbenzyl alcohol, 2-methylbenzyl alcohol, 4-methoxybenzyl alcohol, 4-isopropylbenzyl alcohol, 2,4,6-trimethylbenzyl alcohol, p-ethylbenzyl alcohol, 2-(methylthio)ethanol, cyclohexanol, 4-chlorobenzyl alcohol, 4-trifluoromethylbenzyl alcohol, 3-nitrobenzyl alcohol, and 2-phenylethanol.

8. The silanization reaction according to claim 5, characterized in that, The organic solvent is tetrahydrofuran.

9. The silanization reaction according to claim 5, characterized in that, The molar ratio of the hydrogen-containing silane, alcohol, and catalyst is 1:0.5-2:0.005-0.02; The siliconization reaction is carried out at a temperature of 40-80℃ for 8-20 hours.

10. The silanization reaction according to claim 4, characterized in that, The molar ratio of the hydrogen-containing silane, alcohol, and catalyst is 1:2:0.02; The siliconization reaction was carried out at a temperature of 70°C for 12 hours.

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