Application of tri (trimethylsilyl) silane in hydrosilicification reaction of disulfide

Abstract

The invention discloses an application of tris (trimethylsilyl) silane in a hydrosilicification reaction of disulfide. The invention finds that TTMSS can realize rapid hydrosilylation reaction of disulfide under mild conditions. Due to a remarkable dynamic stability effect brought by a tri (trimethylsilyl) silicon substituent, the obtained S-Si (TMS) type silicon-based thioether is obviously superior to a reported traditional silicon-sulfur compound in the aspect of hydrolysis resistance stability. Meanwhile, the silicon-based protecting group can be efficiently and controllably removed under the action of fluorine ions. The method is used for orthogonal protection of thiol functional groups in complex molecules and later modification of disulfide bonds, has the advantages of stable yield, wide application range and the like, can be applied to synthesis and modification of cysteine-containing polypeptides, and can also be used for later conversion of disulfide bond-containing functional molecules. The method has been successfully applied to cysteine polypeptide synthesis, polypeptide disulfide bond modification, and later regioselective mercaptan protection, fluorescence labeling and disulfide bond reconstruction of drug molecule lipoic acid.

Description

Technical Field

[0001] This invention relates to tris(trimethylsilyl)silane, and more particularly, to the use of tris(trimethylsilyl)silane in the hydrosilylation reaction of disulfides. Background Technology

[0002] Thiols and disulfide bonds are widely present in peptides, proteins, and various bioactive small molecules, serving as crucial structural units for maintaining molecular conformation, biological activity, and reversible redox processes. In organic synthesis, peptide synthesis, and biomolecular modification, thiol functional groups exhibit high reactivity, readily undergoing oxidation or undesirable side reactions. Therefore, they typically require temporary protection with protecting groups, followed by deprotection or disulfide bond reconstruction at appropriate stages. Currently, commonly used thiol protecting group systems have been widely applied in the synthesis and modification of sulfur-containing amino acids such as cysteine, forming relatively mature technical routes. Different protecting group systems exhibit characteristics in deprotection conditions, selectivity, and applicability. However, when dealing with multifunctional molecules, complex substrate structures, or later-stage modification applications, some deprotection conditions still require further optimization in terms of operating conditions, system compatibility, or application flexibility.

[0003] Silicon-based protecting groups have been widely adopted in the protection of hydroxyl groups due to their ability to be removed under mild conditions, resulting in mature orthogonal protection systems. However, directly applying silicon-based protection strategies to thiol functional groups still faces challenges such as insufficient stability of the silicon-sulfur bond, stringent reaction conditions, and a limited range of applicable substrates. Existing methods for constructing silicon-sulfur bonds typically require high temperatures, metal catalysts, or specific activation conditions, and the resulting silicon-based sulfides are prone to hydrolysis or decomposition during storage or purification, thus limiting their practical application in thiol protection and disulfide bond modification.

[0004] Against this backdrop, tris(trimethylsilyl)silane (TTMSS), a structurally unique silane reagent, has attracted our attention. Due to its highly sterically hindered trisilylated substituent structure, TTMSS exhibits excellent water and oxygen resistance, high chemical stability, and low toxicity. Compared to common silane reagents, TTMSS has a lower Si–H bond energy (approximately 84 kcal·mol⁻¹), making it more prone to breakage and the generation of silane radicals. Simultaneously, its bulky tris(trimethylsilyl)silyl substituent provides significant kinetic stabilization for the generated silane radicals. It is precisely because of these combined thermodynamic activity and kinetic stability that TTMSS has found wide application in radical chemistry, covering multiple fields such as organic synthesis, polymer chemistry, and materials chemistry. Based on these characteristics, we hypothesize that TTMSS may offer new solutions for the protection of thiol functional groups and the selective modification of disulfide bonds. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and discover new applications for tris(trimethylsilyl)silane. This invention discovers that tris(trimethylsilyl)silane can be used in the hydrosilylation reaction of disulfides.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: The structure of tris(trimethylsilyl)silane is shown in Formula I;

[0007] The structure of the tris(trimethylsilyl)silane reagent (CAS: 1873-77-4) is tris(trimethylsilyl)silane (TTMSS) or 1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane (TTMSS).

[0008] Tris(trimethylsilyl)silane can be used in the hydrosilylation of disulfides. These applications include the hydrosilylation of chain-like aromatic disulfides, chain-like aliphatic disulfides, symmetrical cyclic disulfides, and asymmetric cyclic disulfides; its use as a cysteine ​​thiol protecting group in peptide synthesis; selective hydrosilylation and ring-opening of disulfide-containing cyclic peptides; disulfide bond reconstruction; structural expansion of disulfide compounds by combining thiaMichael addition and azidodeacetylation; and fluorescent labeling of disulfide compounds by combining thiaMichael addition.

[0009] The tris(trimethylsilyl)silane-mediated hydrosilylation of disulfides is shown below:

[0010] A kit for disulfide bond ring opening and thiol protection, comprising the above-mentioned tris(trimethylsilyl)silane. Specifically, it includes one or more of the following components: (1) Hydrosilylation ring-opening reagent: tris(trimethylsilyl)silane or deuterated tris(trimethylsilyl)silane or its isotopically labeled analogues; (2) Reaction medium: methyl tert-butyl ether (MTBE) or other organic solvents; or a mixed solvent of DMF and MTBE, used for the dissolution and reaction of peptides or complex substrates; (3) Illumination conditions: Visible blue light source, preferably with a wavelength of about 450 nm (e.g., LED light source), to promote the ring-opening reaction of chain aliphatic disulfide bonds or complex substrates; (4) Deprotection / desiliconization reagents: Fluoride ion source (e.g., tetrabutylammonium fluoride TBAF) is used to convert RS–Si(TMS)3 into the corresponding thiol (RSH); or acidic substances are used for controlled deprotection; (5) Disulfide bond reconstruction reagents: Oxidizing reagents (e.g., NaI / H2O2) are used to oxidize thiols back to disulfide bonds or to achieve disulfide bond reconstruction; or they are used in conjunction with disulfide reagents (e.g., DTDP) to achieve target disulfide bond exchange and reconstruction.

[0011] Compared with the prior art, the present invention has the following beneficial effects: This invention reveals that TTMSS can achieve rapid hydrosilylation of disulfides under mild conditions. More importantly, due to the significant kinetic stabilization effect brought about by the tris(trimethylsilyl)silyl substituent, the resulting S-Si(TMS)3 type silyl sulfide exhibits significantly better hydrolytic stability than previously reported conventional silicon-sulfur compounds. Simultaneously, this silyl protecting group can be efficiently and controllably removed under the action of fluoride ions. We applied this method to the orthogonal protection of thiol functional groups in complex molecules and the late-stage modification of disulfide bonds. This method has advantages such as stable yield and wide applicability, and can be applied to the synthesis and modification of cysteine-containing peptides, as well as the late-stage transformation of functional molecules containing disulfide bonds. As representative examples, this strategy has been successfully applied to the synthesis of cysteine ​​peptides, peptide disulfide bond modification, and the late-stage regioselective thiol protection, fluorescent labeling, and disulfide bond reconstruction of the drug molecule lipoic acid. Detailed Implementation

[0012] Example 1: Application of tris(trimethylsilyl)silane in the hydrosilylation of chain aromatic disulfide compounds (click reaction)

[0013] Experimental Procedure: 0.10 mmol of p-toluene disulfide and 1 mL of methyl tert-butyl ether were added to a 4 mL reaction flask. (The reaction can also be carried out in tetrahydrofuran, acetone, toluene, acetonitrile, ethyl acetate, diethyl ether, 1,2-dichloroethane, N,N-dimethylformamide, and aqueous solutions. The reaction can also be carried out in a closed system at 0.1 M concentration, or under solvent-free conditions.) Tris(trimethylsilyl)silane (TTMSS, 2 equivalents) was added under no inert atmosphere. The reaction mixture was concentrated under reduced pressure at 35°C for 5 minutes, followed by purification by silica gel column chromatography to obtain 1,1,1,3,3,3-hexamethyl-2-(p-toluylthio)-2-(trimethylsilyl)trisilane in 99% yield as a colorless oil. The NMR data are shown below, demonstrating that tris(trimethylsilyl)silane can be used for the hydrosilylation of chain-like aromatic disulfide compounds, yielding the product with the target structure.

[0014] 1H NMR (400 MHz, CDCl3) δ 7.34 (d, J = 8.1 Hz, 2H), 7.00 (d, J = 7.9 Hz, 2H), 2.29 (s, 3H), 0.18 (s, 27H). 13 C NMR (100 MHz, CDCl3) δ 136.2, 134.4, 131.3, 129.5, 21.1, 0.8. 29 Si NMR (79 MHz, CDCl3) δ -11.14, -49.94. HRMS (EI): m / z calcd. for C 16 H 34 SSi4 + [M] + 370.1458, found 370.1452. IR (neat, cm -1 ): 2949, 2893, 1490, 1243, 1088, 806, 826, 687, 622. Example 2: Application of tris(trimethylsilyl)silane in the hydrosilylation of chain aliphatic disulfide compounds

[0015] Experimental Procedure: 1,2-Dicodecyl disulfide (0.10 mmol) and 1 mL methyl tert-butyl ether (MTBE) were added to a 4 mL reaction flask. Tris(trimethylsilyl)silane (TTMSS, 2 equivalents) was then added under an inert atmosphere. The reaction mixture was irradiated at 450 nm (6 W) at room temperature for 12 h. After the reaction was complete, the mixture was purified by silica gel column chromatography to obtain 2-(decylthio)-1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane in 99% yield as a colorless oil. The NMR data are shown below, demonstrating that tris(trimethylsilyl)silane can be used for the hydrosilylation of chain-like aliphatic disulfide compounds, yielding the product with the target structure.

[0016] 1 H NMR (600 MHz, CDCl3) δ 2.50 (t, J = 7.5 Hz, 2H), 1.59 (p, J= 7.5 Hz,2H), 1.40 – 1.34 (m, 2H), 1.30 – 1.21 (m, 12H), 0.88 (t, J = 6.9 Hz, 3H), 0.23(s, 27H). 13 C NMR (100 MHz, CDCl3) δ 33.5, 32.1, 31.0, 29.7, 29.7, 29.5, 29.4,29.1, 22.8, 14.3, 0.9. 29 Si NMR (79 MHz, CDCl3) δ -11.53, -56.05. HRMS (EI): m / z calcd. for C 19 H 48 SSi4 + [M] + 420.2554, found 420.2549. IR (neat, cm -1 ): 2924, 2854, 1244, 1049, 829, 688, 623. Example 3: Application of tris(trimethylsilyl)silane in the hydrosilylation of symmetrical cyclic disulfide compounds

[0017] Experimental Procedure: Trans-4,5-dihydroxy-1,2-dithiane (0.10 mmol) and 1 mL of methyl tert-butyl ether (MTBE) were added to a 4 mL reaction flask. Tris(trimethylsilyl)silane (TTMSS, 2 equivalents) was then added under an inert atmosphere. The reaction mixture was reacted at 35°C for 12 h. After the reaction, the mixture was purified by silica gel column chromatography to obtain ±)-trans-1-((1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)thio)-4-mercaptobutane-2,3-diol, a white solid with a yield of 90%. Its NMR data are shown below, demonstrating that tris(trimethylsilyl)silane can be used for the hydrosilylation of symmetrical cyclic disulfide compounds, yielding the product with the target structure.

[0018] 1 H NMR (400 MHz, CDCl3) δ 3.73 – 3.59 (m, 2H), 2.81 – 2.61 (m, 6H), 1.53 (t, J = 8.6 Hz, 1H), 0.23 (s, 27H). 13 C NMR (100 MHz, CDCl3) δ 73.6, 72.7, 34.7, 28.8, 0.9. 29 Si NMR (79 MHz, CDCl3) δ -11.18, -53.34. HRMS (EI): C generated by trimethylsilyl elimination was detected. 10 H 27 O2S2Si3 + (327.0751) fragment peak (C) 10 H 27 O2S2Si3 + The theoretical mass-to-charge ratio is 327.0760.

[0019] IR (neat, cm -1 ): 3412, 2948, 2893, 1397, 1244, 1044, 826, 688, 622. Example 4: Application of tris(trimethylsilyl)silane in the hydrosilylation of asymmetric cyclic disulfide compounds

[0020] Experimental procedure: Lipoic acid (0.10 mmol) and methyl tert-butyl ether (MTBE) were added to a 4 mL reaction flask. Tris(trimethylsilyl)silane (TTMSS, 4 equivalents) was then added under an inert atmosphere. The reaction mixture was reacted at 35°C for 12 h. After the reaction, the mixture was purified by silica gel column chromatography to obtain 8-((1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)thio)-6-mercaptooctanoic acid, a colorless oil with a yield of 89%. Its NMR data are shown below, demonstrating that tris(trimethylsilyl)silane can be used for the hydrosilylation of asymmetric cyclic disulfide compounds, yielding the product with the target structure.

[0021] 1 H NMR (400 MHz, CDCl3) δ 2.98 – 2.88 (m, 1H), 2.74 – 2.60 (m, 2H), 2.37 (t, J = 7.3 Hz, 2H), 1.97 – 1.84 (m, 1H), 1.77 – 1.62 (m, 4H), 1.55 – 1.40(m, 3H), 1.31 (d, J = 7.5 Hz, 1H), 0.23 (s, 27H). 13 C NMR (100 MHz, CDCl3) δ 179.9, 42.1, 39.9, 38.8, 34.0, 28.4, 26.6,24.5, 0.9. 29 Si NMR (79 MHz, CDCl3) δ -11.43, -55.55. HRMS (EI): Detection of C produced by hydrogen elimination 17 H 41 O2S2Si4 + (453.1625) fragment peak (C) 17 H 41 O2S2Si4 + The theoretical mass-to-charge ratio is 453.1618.

[0022] IR (neat, cm -1 ): 2947, 1708, 1243, 828, 688, 622. Example 5: Tris(trimethylsilyl)silane as a cysteine ​​thiol protecting group for peptide synthesis 1. Preparation of silicon-protected cysteine ​​esters from cysteine ​​esters

[0023] In a 100 mL round-bottom flask, bis(N-tert-butoxycarbonyl-L-cysteine ​​methyl ester) (5.0 mmol, 2.34 g), MTBE (0.1 M, 50 mL), and tris(trimethylsilyl)silane (TTMSS, 2.0 equivalent, 2.48 g, 10 mmol) were added. The reaction system was irradiated with a 450 nm blue LED (30 W) at room temperature for 24 h. After the reaction was completed by TLC monitoring, the solvent was removed by rotary evaporation. The crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 10:1, v / v) to give methyl N-(tert-butoxycarbonyl)-S-(1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)-L-cysteine ​​ester, a white solid with a yield of 90%, 2.16 g, 4.5 mmol. Its NMR data are shown below, demonstrating that tris(trimethylsilyl)silane can be used to prepare silicon-protected cysteine ​​esters from cysteine ​​esters, thus obtaining the product with the target structure.

[0024] 1 H NMR (400 MHz, CDCl3) δ 5.42 (d, J = 8.7 Hz, 1H), 4.57 (dt, J= 8.8, 4.5Hz, 1H), 3.75 (s, 3H), 3.03 (dd, J = 11.9, 4.4 Hz, 1H), 2.88 (dd, J = 11.8, 4.4Hz, 1H), 1.44 (s, 9H), 0.22 (s, 27H). 13 C NMR (100 MHz, CDCl3) δ 171.2, 155.3, 80.1, 54.4, 52.6, 32.8, 28.4,0.9. 29 Si NMR (79 MHz, CDCl3) δ -11.19, -54.00. HRMS (EI): C generated by tert-butoxy elimination was detected. 14 H 34 NO3SSi4 + (408.1331) fragment peak, (C 14 H 34 NO3SSi4 + The theoretical mass-to-charge ratio is 408.1336.

[0025] IR (neat, cm -1 ): 2951, 1717, 1498, 1366, 1244, 1162, 1053, 828, 688,621. 2. Tolerance of thiosilane protecting groups to the removal conditions of Boc groups (a common amine protecting group in peptide synthesis)

[0026] In a dry 10 mL Schlenk flask, N-methylmorpholine (NMM, 30.3 mg, 0.3 mmol, 3 equivalents), methyl N-(tert-butoxycarbonyl)-S-(1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)-L-cysteine ​​ester (48.1 mg, 0.10 mmol), and anhydrous dichloromethane (1 mL) were added. Under nitrogen protection, trimethylsilyl trifluoromethanesulfonate (TMSOTf, 66.7 mg, 0.3 mmol, 3 equivalents) was slowly added dropwise using a syringe at room temperature. The reaction mixture was stirred at room temperature for 6 h (monitored by TLC). After the reaction was completed according to TLC, the mixture was concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 10:1, v / v) to give S-(1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)-L-cysteine ​​methyl ester, a colorless oil with a yield of 60%. This low yield is due to the product's instability and susceptibility to oxidation in air; the color gradually changed from colorless to yellow during the solution's settling process. The NMR data shown below demonstrate the tolerance of the thiosilane protecting group to the removal conditions of the Boc group (a common amine protecting group in peptide synthesis), thus yielding the product with the target structure.

[0027] 1 H NMR (400 MHz, CDCl3) δ 3.73 (s, 3H), 3.63 (dd, J = 7.3, 4.2 Hz, 1H), 2.91 (dd, J = 11.8, 4.3 Hz, 1H), 2.78 (dd, J = 11.8, 7.3 Hz, 1H), 0.22 (s, 27H). 13 C NMR (100 MHz, CDCl3) δ 174.3, 56.4, 52.4, 35.5, 0.9. 29 SiNMR (79 MHz, CDCl3) δ -11.23, -54.24. HRMS (ESI): m / z calcd. for C 12 H 36 NO2SSi4 + [M] + 382.1539, found 382.1545. C. Short peptide synthesis

[0028] Experimental procedure: 0.10 mmol of Boc-L-cysteine ​​and 0.2 mL of methyl tert-butyl ether (MTBE) were added to a 4 mL reaction flask. Tris(trimethylsilyl)silane (TTMSS, 2 equivalents) was then added under an inert atmosphere. The reaction mixture was reacted at 35°C for 8 h. After the reaction was complete, the mixture was purified by silica gel column chromatography to obtain N-(tert-butoxycarbonyl)-S-(1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)-L-cysteine, a white solid with a yield of 86%.

[0029] In a dry 10 mL Schlenk flask, under nitrogen protection, N-tert-butoxycarbonyl-L-valine-L-serine methyl ester (636 mg, 2.0 mmol) and tetrahydrofuran (2 mL) were added. Hydrochloric acid (4 M, 1,4-dioxane solution, 2 mL) was slowly added dropwise using a syringe under ice-water bath conditions, and the mixture was stirred at 0°C for 1 h. After complete deprotection, the reaction mixture was concentrated under reduced pressure to give L-valine-L-serine methyl ester hydrochloride as a white solid (638 mg, 90% yield). In a dry 50 mL Schlenk flask, under nitrogen protection, N-(tert-butoxycarbonyl)-S-(1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilyl-2-yl)-L-cysteine ​​(1.09 g, 2 mmol), N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)hexafluorophosphate urea (HATU, 836 mg, 2.2 mmol, 1.1 equivalents), and anhydrous dichloromethane (10 mL) were added. N-methylmorpholine (NMM, 404 mg, 439 μL, 4 mmol, 2 equivalents) was slowly added dropwise using a syringe at room temperature, and the mixture was stirred for 15 min at room temperature to activate the carboxylic acid. Freshly prepared L-valine-L-serine methyl ester hydrochloride was then added in a single batch. The mixture was then stirred at room temperature for 24 h (monitored by TLC). After the reaction was complete as monitored by TLC, the mixture was concentrated under reduced pressure. The resulting mixture was dissolved in ethyl acetate (20 mL) and washed successively with saturated sodium bicarbonate aqueous solution (10 mL) and water (3 × 10 mL). The combined organic phases were dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 2:1, v / v) to give methyl N-(tert-butoxycarbonyl)-S-(1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)-L-cysteyl-L-valine-L-serine ester, a colorless oil, with an overall yield of 58% for both steps.

[0030] In a dry 10 mL Schlenk flask, under nitrogen protection, methyl N-(tert-butoxycarbonyl)-S-(1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)-L-cysteyl-L-valine-L-serine ester (333.5 mg, 0.5 mmol) and tetrahydrofuran (2 mL) were added. Tetrabutylammonium fluoride (TBAF, 1 M, tetrahydrofuran solution, 0.5 mL, 1 equivalent) was slowly added dropwise using a syringe in an ice-water bath, and the mixture was stirred at 0°C for 20 min. After the desilication reaction was complete, the reaction mixture was concentrated under reduced pressure to give methyl(tert-butoxycarbonyl)-L-cysteyl-L-valine-L-serine ester. This product was used directly in the next reaction without further purification (¹H NMR confirmed a purity of approximately 90%).

[0031] In a dry 10 mL Schlenk flask, under nitrogen protection, the prepared methyl (tert-butoxycarbonyl)-L-cysteyl-L-valine-L-seryl ester, sodium iodide (0.75 mg, 1 mol%), and ethyl acetate (1 mL) were added dropwise. A 30% aqueous hydrogen peroxide solution (1 equivalent) was slowly added dropwise using a syringe under ice-water bath conditions, and the mixture was stirred at 0°C for 20 min. After complete deprotection, the mixture was concentrated under reduced pressure, and the crude product was purified by silica gel column chromatography (dichloromethane / methanol = 20:1, v / v) to give methyl N-(tert-butoxycarbonyl)-S-(((R)-2-((tert-butoxycarbonyl)amino)-3-(((R)-1-(((S)-3-hydroxy-1-methoxy-1-oxopropane-2-yl)amino)-3-methyl-1-oxobutane-2-yl)amino)-3-oxopropyl)thio)-L-cysteyl-L-valine-L-serine salt, a colorless oil in 65% yield. The NMR data are shown below, demonstrating that this method can be applied to peptide synthesis and yields the product with the target structure.

[0032]

[0033] N-(tert-butoxycarbonyl)-S-(1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)-L-cysteine, white solid 40.6 mg, yield 86%.

[0034] 1 H NMR (600 MHz, CDCl3) δ 5.41 (d, J = 8.1 Hz, 1H), 4.56 (s, 1H), 3.08 (d, J = 11.5 Hz, 1H), 2.92 (dd, J = 12.1, 4.6 Hz, 1H), 1.46 (s, 9H), 0.23 (s,27H). 13 C NMR (100 MHz, CDCl3) δ 175.9, 155.5, 80.4, 54.3, 32.4, 28.4, 0.9. 29 Si NMR (79 MHz, CDCl3) δ -11.16, -53.47. HRMS (ESI): m / z calcd. for C 17 H 40 NO4SSi4 - [MH] - 466.1760, found 466.1763. IR (neat, cm -1 ): 2949, 1716, 1500, 1367, 1245, 1163, 831, 689, 623.

[0035] Methyl N-(tert-butoxycarbonyl)-S-(1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)-L-cysteyl-L-valine-L-serine ester, white solid, 773.7 mg, yield 58%.

[0036] 1 H NMR (600 MHz, CDCl3) δ 7.02 (d, J = 7.9 Hz, 1H), 6.76 (d, J = 8.5Hz, 1H), 5.46 – 5.33 (m, 1H), 4.61 (dt, J = 7.5, 3.5 Hz, 1H), 4.30 – 4.16 (m,2H), 3.93 (qd, J = 11.6, 3.5 Hz, 2H), 3.78 (s, 3H), 3.06 (s, 1H), 2.78 (dd, J= 11.9, 6.0 Hz, 1H), 2.35 – 2.12 (m, 1H), 1.45 (s, 9H), 0.99 (dd, J = 15.9,6.8 Hz, 6H), 0.23 (s, 27H). 13C NMR (100 MHz, CDCl3) δ 171.1, 171.0, 170.7, 164.4, 80.9, 62.8, 56.1, 55.0, 52.8, 32.4, 28.4, 19.5, 18.1, 0.9. 29 Si NMR (119 MHz, CDCl3) δ -11.14, -52.98. HRMS (APCI): m / z calcd. for C 26 H 58 N3O7SSi4 + [M+H] + 668.3067, found668.3058. IR (neat, cm -1 ): 3287, 2953, 1643, 1505, 1366, 1244, 1163, 1060, 831,688, 623.

[0037] Methyl N-(tert-butoxycarbonyl)-S-(((R)-2-((tert-butoxycarbonyl)amino)-3-(((R)-1-(((S)-3-hydroxy-1-methoxy-1-oxopropane-2-yl)amino)-3-methyl-1-oxobutane-2-yl)amino)-3-oxopropyl)thio)-L-cysteyl-L-valine-L-serine salt, white solid, 247.8 mg, two-step overall yield 59%.

[0038] 1 H NMR (600 MHz, CDCl3) δ 8.00 (s, 1H), 7.78 (s, 1H), 7.65 (s, 2H), 7.53 (d, J = 7.4 Hz, 1H), 7.43 (s, 1H), 5.81 (s, 1H), 5.57 (s, 1H), 5.44 – 5.34(m, 1H), 4.78 – 4.69 (m, 2H), 4.58 (s, 1H), 4.50 (t, J= 8.1 Hz, 1H), 4.47 –4.38 (m, 2H), 4.36 – 4.31 (m, 1H), 3.93 – 3.84 (m, 2H), 3.77 (s, 3H), 3.76(s, 3H), 3.29 – 3.17 (m, 2H), 3.11 – 3.00 (m, 2H), 2.16 – 2.12 (m, 2H), 1.45 (s, 9H), 1.43 (s, 9H), 1.02 – 0.97 (m, 12H). HRMS (ESI): m / z calcd. for C 34 H 61 N6O 14 S2 + [M+H] + 841.3671, found 841.3682. IR (neat, cm -1 ): 3286, 2959, 1744, 1692, 1637, 1520, 1367, 1226, 1315,1046. Example 6: Selective hydrosilylation and ring-opening of disulfide-containing cyclic polypeptides by tris(trimethylsilyl)silane

[0039] Experimental Procedure: In a 4 mL glass reaction flask, a DMF / MTBE mixed solvent (0.3 mL / 0.1 mL) and eptifibatide (2 mg, 0.0024 mmol) were added. Then, tris(trimethylsilyl)silane (TTMSS, 74 μL, 100 equivalents) was added under an inert atmosphere. The reaction system was stirred at room temperature under 450 nm illumination for 24 h. After the reaction, the system was analyzed by LC-MS using a BaseLine® C18 column (5 μm, 250 × 4.6 mm) with methanol as the mobile phase. The retention times of each component were as follows: eptifibatide 6.9 min, product 7.5 min, DMF 9.4 min, and TTMSS 14.3 min. Based on the percentage of chromatographic peak area, the yield of the product (9S,15S)-15-(((S)-1-((S)-2-(((S)-1-amino-3-mercapto-1-oxopropane-2-yl)carbamoyl)pyrrolidine-1-yl)-3-(1H-indol-3-yl)-1-oxopropane-2-yl)carbamoyl)-9-(4-guanidinobutyl)-2,2-dimethyl-7,10,13-trioxo-3,3-bis(trimethylsilyl)-4-thia-8,11,14-triaza-2,3-disilathaheptadecane-17-acid was 50%.

[0040] HRMS (ESI): m / z calcd. for C 44 H 78 N 11 O9S2Si4 + [M+H] + 1080.4497, found 1080.4483. Example 7: Disulfide bond reconstruction by tris(trimethylsilyl)silane

[0041] Experimental procedure: Methyl lipoate (0.10 mmol) and 1 mL methyl tert-butyl ether (MTBE) were added to a 4 mL reaction flask. Tris(trimethylsilyl)silane (TTMSS, 4 equivalents) was added under no inert atmosphere. The reaction mixture was reacted at 35°C for 12 h. After the reaction was completed, the mixture was purified by silica gel column chromatography to obtain methyl 8-((1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)thio)-6-mercaptooctanoate, a colorless oil with a yield of 93%.

[0042] In a 4 mL glass reaction flask, cesium carbonate (24.4 mg, 1.5 equivalents), 1,2-bis(2-pyridyl)disulfide (DTDP, 5.5 mg, 0.025 mmol, 0.5 equivalents), and dichloromethane (1 mL) were added. Then, under an inert gas atmosphere, methyl 8-((1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)thio)-6-mercaptooctanoate (23.4 mg, 0.05 mmol, 1 equivalent) was added, and the mixture was stirred at room temperature for 4 h. After the reaction was complete, the mixture was concentrated under reduced pressure and purified by silica gel column chromatography (petroleum ether / ethyl acetate = 25:1, v / v) to give dimethyl 6,6'-dithiodiylbis(8-((1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)thio)octanoate, a colorless oil in 90% yield. Its NMR data are shown below, demonstrating that tris(trimethylsilyl)silane can reconstruct disulfide bonds, yielding the product with the target structure.

[0043] 1 H NMR (400 MHz, CDCl3) δ 3.67 (s, 3H), 2.80 – 2.72 (m, 1H), 2.63 (td,J = 7.8, 3.3 Hz, 2H), 2.31 (t, J = 7.5 Hz, 2H), 1.90 – 1.80 (m, 2H), 1.68 –1.59 (m, 4H), 1.49 – 1.41 (m, 2H), 0.23 (s, 27H). 13 C NMR (100 MHz, CDCl3) δ 174.1, 51.6, 51.3, 51.2, 37.5, 34.2, 34.1,28.2, 26.4, 25.0, 0.9. 29 Si NMR (79 MHz, CDCl3) δ -11.49, -55.60. HRMS (ESI): m / z calcd. for C 36 H 86 O4S4Si8Na + [M+Na] + 957.3456, found 957.3455. IR (neat, cm -1 ): 2948, 1740, 1436, 1244, 830, 688, 623, 509. Example 8: Structural extension of disulfide compounds by tris(trimethylsilyl)silane combined with other click chemistry reactions (thia-Michael addition and azido-deacetylation addition).

[0044] Experimental steps: (1) Hydrosilylation reaction to open disulfide bonds: 0.10 mmol of 5-(1,2-dithiopentane-3-yl)valerate hex-5-yn-1-yl ester and 1 mL of methyl tert-butyl ether (MTBE) were added to a 4 mL reaction flask. Tris(trimethylsilyl)silane (TTMSS, 4 equivalents) was added under non-inert atmosphere protection. The reaction mixture was reacted at 35°C for 12 h. After the reaction was completed, it was purified by silica gel column chromatography to obtain 8-((1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)thio)-6-mercaptooctanoate hex-5-yn-1-yl ester, a colorless oil with a yield of 92%.

[0045] (2) Thia-Michael addition to introduce functional groups: In a 4 mL glass reaction flask, cesium carbonate (32.6 mg, 1 equivalent) and 8-((1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)thio)-6-mercaptooctanoic acid hex-5-yn-1-yl ester (53.4 mg, 0.10 mmol) were added, followed by dichloromethane (1 mL). Then, benzyl acrylate (17.8 mg, 0.11 mmol, 1.1 equivalent) was added under no inert gas protection. The mixture was stirred at room temperature for 30 min. After the reaction was completed, the mixture was concentrated under reduced pressure and purified by silica gel column chromatography (petroleum ether / ethyl acetate = 15:1, volume ratio) to give 6-((3-(benzyloxy)-3-oxopropyl)thio)-8-(1,1,1,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)thio)octanoic acid hex-5-yn-1-yl ester, a colorless oil in 85% yield.

[0046] (3) Addition of functional groups to azidoalkynylates: In a dry 15 mL Schlenk flask under nitrogen protection, cuprous thiophene-2-carboxylic acid hydrate (CuTc, 1.9 mg, 0.01 mmol, 20 mol%), 6-((3-(benzyloxy)-3-oxopropyl)thio)-8-(1,1,1,3,3-hexamethyl-2-(trimethylsilyl)trisilyl-2-yl)thio)octanoic acid hex-5-yn-1-yl ester (34.8 mg, 0.05 mmol), and anhydrous toluene (1 mL) were added. A solution of (azidomethyl)benzene (13.3 mg, 0.10 mmol, 2.0 equivalents) was prepared by dissolving it in anhydrous toluene (0.5 mL) and slowly added dropwise using a syringe at room temperature. The mixture was stirred at room temperature for 6 h (monitored by TLC). After the reaction was completed by TLC monitoring, the mixture was concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 3:1, v / v) to give 4-(1-benzyl-1H-1,2,3-triazol-5-yl)butyl6-((3-(benzyloxy)-3-oxopropyl)thio)-8-((1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)thio)octanoate (2z25), a colorless oil in 83% yield. Its NMR data are shown below, demonstrating that tris(trimethylsilyl)silane can be combined with other click chemistry reactions (thia-Michael addition and azido-deacetylation addition) to extend the structure of disulfide compounds, yielding products with the target structure.

[0047] 1 H NMR (400 MHz, CDCl3) δ 7.46 – 7.36 (m, 8H), 7.34 – 7.28 (m, 2H), 5.55 (s, 2H), 5.19 (s, 2H), 4.13 (t, J = 6.1 Hz, 2H), 2.89 – 2.75 (m, 5H), 2.75– 2.64 (m, 4H), 2.33 (t, J = 7.5 Hz, 2H), 1.94 – 1.70 (m, 7H), 1.70 – 1.46 (m,6H), 0.29 (d, J = 0.9 Hz, 27H). 13C NMR (100 MHz, CDCl3) δ 173.74, 171.85, 148.32, 135.94, 135.07,129.21, 128.70, 128.39, 128.12, 120.72, 66.61, 64.13, 54.15, 45.17, 38.17,35.28, 34.85, 34.31, 28.37, 28.10, 26.45, 25.97, 25.44, 25.37, 25.01, 0.93. 29 Si NMR (79 MHz, CDCl3) δ -11.47, -55.48. HRMS (APCI): m / z calcd. for C 40 H 68 N3O4S2Si4 + [M+H] + 830.3723, found 830.3727. IR (neat, cm -1 ): 2943, 2853, 1733, 1456, 1244, 1168, 835, 747, 695,623. Example 9: Fluorescent labeling of disulfide compounds by tris(trimethylsilyl)silane-based thiaMichael addition.

[0048] (1) Hydrosilylation click reaction to break disulfide bonds: 0.10 mmol of 5-(1,2-dithiopentane-3-yl)valerate hex-5-yn-1-yl ester and 1 mL of methyl tert-butyl ether (MTBE) were added to a 4 mL reaction flask. Tris(trimethylsilyl)silane (TTMSS, 4 equivalents) was added under an inert atmosphere. The reaction mixture was reacted at 35°C for 12 h. After the reaction was completed, the mixture was purified by silica gel column chromatography to obtain 8-((1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)thio)-6-mercaptooctanoate hex-5-yn-1-yl ester, a colorless oil with a yield of 92%.

[0049] (2) Introduction of fluorescent labeling by thiaMichael addition: Cesium carbonate (32.6 mg, 1 equivalent) and 2Z7 (53.4 mg, 0.10 mmol) were added to a 4 mL glass reaction flask, followed by dichloromethane (1 mL). Then, pyrene-1-ylmethyl acrylate (31.5 mg, 0.11 mmol, 1.1 equivalent) was added under an inert gas atmosphere. The mixture was stirred at room temperature for 1 h. After the reaction was completed, the mixture was concentrated under reduced pressure and purified by silica gel column chromatography (petroleum ether / ethyl acetate = 15:1, v / v) to give hex-5-yn-1-yl 8-((1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane-2-yl)thio)-6-((3-oxo-3-(pyrene-1-ylmethoxy)propyl)thio)octanoate, a colorless oil with a yield of 65%. The NMR data shown below demonstrate that tris(trimethylsilyl)silane can perform fluorescent labeling of disulfide compounds via thiaMichael addition. 1 H NMR (400 MHz, CDCl3) δ 8.27 (d, J = 9.2 Hz, 1H), 8.23 ​​– 8.18 (m, 2H), 8.17 – 8.13 (m, 2H), 8.07 – 8.00 (m, 4H), 5.86 (s, 2H), 4.07 (t, J = 6.5 Hz,2H), 2.81 – 2.76 (m, 2H), 2.74 – 2.70 (m, 1H), 2.69 – 2.60 (m, 4H), 2.27 –2.19 (m, 4H), 1.96 (t, J = 2.6 Hz, 1H), 1.83 – 1.71 (m, 4H), 1.61 – 1.55 (m,4H), 1.54 – 1.48 (m, 2H), 1.46 – 1.37 (m, 2H), 0.22 (s, 27H). 13C NMR (100 MHz, CDCl3) δ 173.6, 171.9, 131.9, 131.3, 130.8, 129.6,128.8, 128.3, 127.9, 127.9, 127.4, 126.2, 125.6, 125.6, 125.0, 124.7, 123.0,84.0, 68.9, 65.0, 63.8, 45.1, 38.1, 35.3, 34.8, 34.2, 28.0, 27.8, 26.4, 25.4,25.0, 25.0, 18.2, 0.9. 29 Si NMR (79 MHz, CDCl3) δ -11.48, -55.49. HRMS (ESI): m / z calcd. for C 43 H 64 O4S2Si4Na + [M+Na] + 843.3216, found843.3214. IR (neat, cm -1 ): 2946, 2851, 1733, 1244, 1165, 834, 689, 623.。

Claims

1. The application of tris(trimethylsilyl)silane in the hydrosilylation reaction of disulfides, wherein the structure of the tris(trimethylsilyl)silane is shown in Formula I; 。 2. The application as described in claim 1, characterized in that it is applied to the hydrosilylation of chain-like aromatic disulfide compounds, the hydrosilylation of chain-like aliphatic disulfide compounds, the hydrosilylation of symmetrical cyclic disulfide compounds, the hydrosilylation of asymmetric cyclic disulfide compounds, as a cysteine ​​thiol protecting group for peptide synthesis, selective hydrosilylation and ring-opening of disulfide-containing cyclic peptides, disulfide bond reconstruction, structural extension of disulfide-bonded compounds by combining thia-Michael addition and azido-deacetylation, and fluorescent labeling of disulfide-bonded compounds by combining thia-Michael addition.

3. A kit for disulfide bond ring opening and thiol protection, characterized in that... Contains the tris(trimethylsilyl)silane as described in claim 1.

4. The kit for disulfide bond ring opening and thiol protection as described in claim 1, characterized in that... It contains one or more of the following components: (1) Hydrosilylation ring-opening reagent: tris(trimethylsilyl)silane or deuterated tris(trimethylsilyl)silane or its isotopically labeled analogues; (2) Reaction medium: methyl tert-butyl ether or other organic solvents; or a mixed solvent of DMF and MTBE; (3) Illumination conditions: Visible light and blue light source; (4) Deprotection / desiliconization reagents: fluoride ion source or acidic substance; (5) Disulfide bond reconstruction reagents: oxidizing reagents or disulfide reagents.

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