Method for synthesizing indole derivative by palladium-catalyzed aryl sulfonium salt

Abstract

The invention relates to the technical field of organic synthesis, and particularly discloses a method for synthesizing an indole derivative by palladium-catalyzed aryl sulfonium onium salt, which comprises the following steps: adding aryl sulfonium onium salt, diazacyclopropyridinone, an alkyne derivative or norbornadiene into a reaction container, adding a palladium catalyst, a ligand, alkali and a solvent, and reacting in inert gas at 110-140 DEG C to obtain the indole derivative. And removing the solvent after the reaction is finished, and separating to obtain the indole derivative. According to the method, aryl sulfonium onium salt, diazacyclopropyridinone, an alkyne derivative or norbornadiene are used as initial raw materials, and under the action of palladium catalysis, the indole derivative can be prepared through one-step reaction.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing indole derivatives by palladium-catalyzed arylsulfonium salt. BACKGROUND

[0002] Indole and its derivatives play a variety of important physiological functions in the human body. Tryptophan, as an essential amino acid for the human body, not only participates in protein synthesis, but also can derive melatonin and serotonin. Melatonin is responsible for regulating the biological clock, while serotonin is a neurotransmitter related to happiness. Due to its unique biological activity, indole and its derivatives have attracted much attention in the pharmaceutical field, showing a wide application prospect and important research value. According to the review report of “Ring in Drugs”, there are currently 24 drugs on the market containing indole ring structure, which fully embodies the important value of indole in drug research and development. The synthesis method of indole compounds has been one of the hot topics of chemical researchers.

[0003] The traditional method for synthesizing indole derivatives mainly uses arylhydrazines, arylamines, aryl nitroxides and other aryl nitrogen-containing compounds as raw materials to construct various substituted indole derivatives. The existing method is difficult to synthesize highly functionalized indole derivatives due to problems such as pre-functionalization of raw materials, complex substrates, difficulty in separation of catalysts and low yield. Therefore, it is still challenging to develop an efficient method for synthesizing indole derivatives.

[0004] In order to solve the problem of poor positional selectivity when introducing active functional groups (such as halogen -Cl, -Br, -I or boron group) into aromatic hydrocarbons, Ritter, Procter, Alcarazo and Yorimitsu research groups developed a highly position-selective preparation method of arylsulfonium salt in 2019. This method can realize the functionalization of C-H bond with extremely high positional selectivity to generate arylsulfonium salt, in which the ratio of para-product to ortho-product is as high as 500:1, and the ratio of para-product to meta-product is as high as 200:1. The arylsulfonium salt strategy can directly introduce arylsulfonium salt into complex natural products and drug molecules due to its excellent positional selectivity, so the source of arylsulfonium salt is very wide.

[0005] Although the source of arylsulfonium salt is very wide, there is no report on the direct synthesis of indole from arylsulfonium salt. SUMMARY

[0006] The first object of the present application is to solve the problem of complex synthesis method of indole derivatives in the prior art, and to provide a method for synthesizing indole derivatives by palladium-catalyzed arylsulfonium salt.

[0007] The second object of the present application is to provide indole derivatives obtained by the above method.

[0008] The objective of this invention is specifically achieved through the following technical solutions: A method for synthesizing indole derivatives from arylsulfonium salts catalyzed by palladium catalysis involves using arylsulfonium salts, diazapyridine ketones, and alkyne derivatives. or norbornene Add the mixture to a reaction vessel, along with a palladium catalyst, ligand, base, and solvent. After mixing, the mixture is reacted under an inert gas atmosphere at 110-140 °C. After the reaction is complete, the solvent is removed, and the indole derivative is obtained. The arylsulfonium salt is or In the formula, R is one or more different groups, including but not limited to alkyl, trifluoromethyl, nitro, acyl, cyano, halogen, alkoxy, oxyester, aryl, and hydrogen, and X is sulfur or oxygen. The alkyne derivatives In the middle, R 1 R 2 Including but not limited to aryl or alkyl groups that are not hydrogen.

[0009] Preferably, the solvent includes, but is not limited to, one of toluene, acetonitrile, 1,4-dioxane, N,N-dimethylformamide, dichloroethane, and ethylene glycol dimethyl ether; The inert gas includes, but is not limited to, argon.

[0010] Preferably, the palladium catalyst is one of palladium chloride, palladium acetate, palladium dichloride of bis(triphenylphosphine), palladium tetra(triphenylphosphine), and palladium dichloride of bis(acetonitrile).

[0011] Preferably, the ligand is one of triphenylphosphine derivatives or bidentate phosphine ligands.

[0012] Preferably, the alkali includes, but is not limited to, one of potassium carbonate, cesium carbonate, potassium bicarbonate, sodium bicarbonate, potassium acetate, and sodium acetate.

[0013] Preferably, the molar ratio of arylsulfonium salt: diazacyclopropidone: alkyne derivative or norbornene in the reaction raw materials is 1:2:1-2; the palladium catalyst is 10 mol% of the reaction raw materials; the ligand is 20 mol% of the reaction raw materials; and the molar ratio of arylsulfonium salt: base is 1:4.

[0014] Preferably, the separation is performed using column chromatography, wherein the mobile phase used in column chromatography has a composition of petroleum ether / ethyl acetate with a volume ratio of 100:1-15:1.

[0015] Preferably, the reaction also includes additives such as carboxylic acid, metal salt, or phase transfer catalyst; the carboxylic acid includes, but is not limited to, pentanoic acid, benzoic acid, and acetic acid, and the metal salt includes, but is not limited to, sodium iodide and sodium bromide. The reaction can also be carried out without additives, but the yield is slightly lower. The reaction mechanism is to promote the activation of C–H bonds—a synergistic metallization deprotonation (CMD) process.

[0016] Preferably, the reaction time is 24 to 36 hours.

[0017] Indole derivatives obtained by any of the above methods.

[0018] Compared with the prior art, the present invention has the following advantages: (1) The conversion process of the synthesis reaction has significant step economy, and indole derivatives can be efficiently constructed in one step through arylsulfonium salts; (2) Arylsulfonium salts are widely available and can be directly prepared from aromatic hydrocarbons through highly selective C–H activation. They are suitable for the late-stage scaffold modification and editing of complex natural products and drug molecules. (3) The operation steps are simple; (4) The synthesis method has the advantages of mild reaction conditions, high yield, low cost and simple post-processing, and can realize the simple synthesis of highly functionalized indole derivatives. Attached Figure Description

[0019] Figure 1 The proton NMR spectrum of the product of Example 1; Figure 2 The carbon-13 nuclear magnetic resonance spectrum of the product of Example 1; Figure 3 The proton NMR spectrum of the product of Example 2; Figure 4 The carbon-13 NMR spectrum of the product of Example 2; Figure 5 The 1H NMR spectrum of the product of Example 3; Figure 6 The carbon-13 NMR spectrum of the product of Example 3; Figure 7 The 1H NMR spectrum of the product of Example 4; Figure 8 The carbon-13 NMR spectrum of the product of Example 4 is shown. Detailed Implementation

[0020] The preferred embodiments of the present invention are described below. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0021] This invention provides a method for synthesizing indole derivatives from palladium-catalyzed arylsulfonium salts, the synthetic route being as follows: ;

[0022] The reaction formula is as follows: ;

[0023] This synthetic method uses arylsulfonium salts, diazacyclopropidone, alkyne derivatives, or norbornadiene as starting materials to prepare indole derivatives through a one-step reaction under palladium catalysis. Among them, arylsulfonium salts are or In the formula, R is one or more different groups, including but not limited to alkyl, trifluoromethyl, nitro, acyl, cyano, halogen, alkoxy, oxyester, aryl, and hydrogen, and X is sulfur or oxygen. Diazapyridinone is di-tert-butyldiazapyridinone ; The structural formula of norbornene is ; Alkyne derivatives In the middle, R 1 R 2 Including but not limited to aryl or alkyl groups that are not hydrogen; The structural formula of the indole derivative is as follows: or .

[0024] The general experimental synthesis steps for some of the raw materials in the examples are as follows: 1. General Synthetic Procedures for Arylthiaanthium Salts [1] ;

[0025] Thioxane (21.6 g, 100 mmol, 1.0 equiv.), ferric nitrate nonahydrate (40.4 g, 100 mmol, 1.0 equiv.), and sodium bromide (408 mg, 4 mmol, 4.0 mol%) were added to a 500 mL round-bottom flask. Then, dichloromethane (200 mL) and acetic acid (4.0 mL) were added to the flask using a plastic syringe. The reaction mixture was stirred overnight at room temperature. After the reaction was complete, the mixture was extracted with dichloromethane and water. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain a grayish-white solid, thioxane-S-oxide.

[0026] ;

[0027] Under argon protection, aromatic hydrocarbons (10 mmol, 1.0 equiv.), dichloromethane (25.0 mL), and thioxanthracene-S-oxide (10 mmol, 1.0 equiv.) were added dropwise to a 50 mL round-bottom flask. The reaction mixture was cooled to -40 °C, and at this temperature, trifluoromethanesulfonic anhydride (12 mmol, 1.2 equiv.) was added dropwise. The mixture was stirred at this temperature for 30 min, and then allowed to react at room temperature for 12 h. After the reaction was complete, the mixture was quenched with saturated sodium bicarbonate solution, extracted with dichloromethane, and the combined organic layers were dried over anhydrous sodium sulfate. The solvent was removed by rotary evaporation under reduced pressure. The crude product was purified by recrystallization from a dichloromethane / ether system or by silica gel column chromatography to give a white solid.

[0028] 2. General synthetic steps of pyriproxypyridine thiaanthraium salt [2] ;

[0029] Under argon protection, thioanthracene S-oxide (10 mmol, 1.0 equiv.), dichloromethane (15.0 mL), and pyriproxyfen (10 mmol, 1.0 equiv.) were added sequentially to a 50 mL round-bottom flask. The reaction system was cooled to -40 °C and stirred at this temperature. Then, trifluoroacetic anhydride (TFAA, 6 mmol, 3.0 equiv.) and trifluoroacetic acid (TFA, 6 mmol, 3.0 equiv.) were added dropwise. The reaction mixture was stirred at -40 °C for 30 min, then brought to room temperature and stirred for 12 h. After the reaction was complete, the mixture was quenched with saturated sodium bicarbonate solution and extracted with dichloromethane. The combined organic phases were washed with an aqueous solution of sodium trifluoromethanesulfonate (3 × 20 mL, 5% w / w), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was purified by recrystallization from a dichloromethane / ethyl ether system to give a white solid.

[0030] 3. General synthetic steps of diazacyclopropidone [3] ;

[0031] In a 500 mL round-bottom flask, tert-butylamine (6.6 equiv.), triethylamine (7.5 equiv.), and toluene (200.0 mL) were added sequentially. The mixture was then cooled to 0 °C, and triphosgene (1.0 equiv.) was added in small amounts several times over one hour. The mixture was brought to room temperature and stirred for 24 h. After the reaction was complete, the mixture was quenched with water and transferred to a separatory funnel to separate the phases. The organic layer was washed with saturated brine, and the white solid was collected by vacuum filtration. The combined white solids were washed with water and dried to obtain a white solid, di-tert-butylurea.

[0032] ;

[0033] Di-tert-butylurea (1.0 equiv.) and diethyl ether (200.0 mL) were added to a 500 mL round-bottom flask. The reactor was protected from light, and tert-butyl hypochlorite (1.1 equiv.) was added to the mixture over 10 min. The resulting pale yellow solution was stirred for another 30 min. The mixture was cooled to 0 °C, and then potassium tert-butoxide (1.3 equiv.) was added in portions over 20 min. The resulting solution was heated to room temperature and stirred for 5 h. After the reaction was complete, the solution was diluted with n-hexane (200.0 mL), transferred to a separatory funnel, washed with water, and the organic layer was dried with anhydrous potassium carbonate (30.0 g). After stirring for 5 h, the solution was filtered, concentrated by rotary evaporation, and purified by silica gel column chromatography (ethyl acetate / petroleum ether) to obtain a colorless liquid product.

[0034] References [1] Zhe Zhang, Xi Chen, Zhi-Jie Niu, Zhuo-Mei Li, Qiao Li, Wei-YuShi, Tian Ding, Xue-Yuan Liu, Yong-Min Liang. A Practical and Regioselective Strategy for Aromatic C–H Difunctionalization via Site-Selective C–HThianthrenation [J], Org. Lett. 2024, 26 , 1813-1818. [2] Binlin Zhao, Qiuzhu Wang, Tianxiang Zhu, Bin FengMengtao Ma.Palladium-Catalyzed Synthesis of C-1 Deuterated Aldehydes from (Hetero)Arenes Mediated by C (sp 2 )–H Thianthrenation [J], Org. Lett. 2022, 24 , 5608-5613. [3] Haifeng Du, Baoguo Zhao, Yian Shi, Pd(0)-catalyzed diamination oftrans-1-phenyl-1,3-butadiene with di-tert-butyldiaziridinone as nitrogen source [J], Org. Synth 2009, 86 , 315-324. Unless otherwise stated, all commercially available reagents can be used without further purification. The commercially available vials and reagents are as follows: Diphenylacetylene (Model: D080021, Manufacturer: Anaiji), Palladium acetate (Model: E060087, Manufacturer: Anaiji), Bistriphenylphosphine palladium dichloride (Model: E060080, Manufacturer: Anaiji), Tris(m-fluorophenyl)phosphine (Model: D051345, Manufacturer: Anaiji), 1,6-Bis(diphenylphosphino)hexane (Model: BD19166, Manufacturer: Bide Pharmaceutical), Norbornene (Model: N0346, Manufacturer: TCI).

[0035] Example 1 ;

[0036] Add the following to a 20 mL thick-walled ground glass tube: thiaanthraquinone salt of pyriproxyfen (0.2 mmol, 1.0 equiv, 137.2 mg), diphenylacetylene (0.2 mmol, 1.0 equiv, 35.6 mg), diazacyclopropidone (0.4 mmol, 2.0 equiv, 68.1 mg), palladium acetate (10 mol%, 4.5 mg), tris(m-fluorophenyl)phosphine (20 mol%, 12.7 mg), potassium carbonate (0.8 mmol, 4.0 equiv, 110.6 mg), potassium bromide (0.2 mmol, 1.0 equiv, 23.8 mg), and terpentine (30 mol%, 6.1 mg). Seal the tube with a stopper, evacuate, and replace with argon gas at least three times. Then, inject N,N-dimethylformamide (3... Add 1 mL of the mixture to the reaction tube and secure the stopper with tape. Stir the reaction mixture at room temperature for 15 minutes, then place it in an oil bath at 110 °C and react for 24 hours. After the reaction is complete, cool the reaction mixture to room temperature, dilute with ethyl acetate (EtOAc) (15 mL), wash with brine (2 × 15 mL), dry the organic phase with anhydrous sodium sulfate, filter and concentrate under vacuum. The residue is purified by silica gel column chromatography (petroleum ether / ethyl acetate = 15:1 v / v) to give a white solid (61.4 mg, yield 54%).

[0037] The product test data are as follows: 1 H NMR (600 MHz, CDCl3) δ 8.15 – 8.13 (m, 1H), 7.56 – 7.52 (m, 2H),7.42 (d, J = 1.9 Hz, 1H), 7.32 – 7.30 (m, 2H), 7.27 – 7.23 (m, 3H), 7.18-7.15(m, 2H), 7.12 – 7.07 (m, 3H), 6.99 (d, J = 9.1 Hz, 2H), 6.91 (d, J = 9.1 Hz,2H), 6.85 – 6.81 (m, 2H), 6.73 (d, J = 8.3 Hz, 1H), 5.60 – 5.57 (m, 1H), 4.19– 4.17 (m, 1H), 4.07 (d, J = 5.0 Hz, 1H), 1.56 (s, 9H), 1.48 (d,J = 6.4 Hz, 3H). See Figure 1 .

[0038] 13 C NMR (151 MHz, CDCl3) δ 163.1, 154.4, 152.5, 152.4, 146.7, 138.6, 137.9, 136.8, 136.3, 135.0, 131.8, 130.2, 127.7, 127.6, 127.4, 125.4, 124.9, 120.2, 119.1, 117.7, 116.7, 115.7, 112.2, 111.6, 105.6, 71.1, 69.3, 59.3, 32.0, 17.0. See Figure 2 .

[0039] HRMS (ESI) m / z: [M + H] + Calcd for C 38 H 36 N2O3 569.2799; Found 569.2800.

[0040] Example 2 ;

[0041] Add biphenylthiamium salt (0.2 mmol, 1.0 equiv, 103.7 mg), diazacyclopropidone (0.4 mmol, 2.0 equiv, 68.1 mg), bis(triphenylphosphine)palladium dichloride (10 mol%, 14.0 mg), 1,6-bis(diphenylphosphine)hexane (20 mol%, 18.2 mg), and potassium carbonate (0.8 mmol, 4.0 equiv, 110.6 mg) to a 20 mL thick-walled ground glass tube. Seal the tube with a stopper, evacuate the air, and replace the gas with argon gas at least three times. Add ethylene glycol dimethyl ether (3 mL) to the reaction tube using a plastic syringe. Add norbornene (0.4 mmol, 2.0 equiv, 36.9 mg) using a microsyringe. Finally, reinforce the stopper with adhesive tape and medical tape. After stirring the reaction mixture at room temperature for 15 minutes, it was placed in an oil bath at 140 °C and reacted for 36 hours. After the reaction was completed, the mixture was concentrated under reduced pressure and purified by silica gel column chromatography (petroleum ether / ethyl acetate = 100:1 volume ratio) to finally obtain a yellow oil (33.4 mg, yield 67%).

[0042] The product test data are as follows: 1 H NMR (600 MHz, CDCl3) δ 7.82 (s, 1H), 7.68 – 7.65 (m, 3H), 7.45 (t, J = 7.8 Hz, 2H), 7.35 – 7.30 (m, 3H), 6.46 (d, J = 3.3 Hz, 1H), 1.76 (s, 9H). See Figure 3 .

[0043] 13 C NMR (151 MHz, CDCl3) δ 143.0, 135.4, 134.3, 129.7, 128.6, 127.6, 126.4, 125.9, 121.2, 118.9, 112.1, 100.0, 55.9, 29.9. See Figure 4 .

[0044] HRMS (ESI) m / z: [M + H] + Calcd for C 18 H 19 N 250.1590; Found 250.1591.

[0045] Example 3 ;

[0046] Add (3-chloropropyl)benzianthiamonium salt (0.2 mmol, 1.0 equiv, 103.8 mg), diazacyclopropidone (0.4 mmol, 2.0 equiv, 68.1 mg), bis(triphenylphosphine)palladium dichloride (10 mol%, 14.0 mg), 1,6-bis(diphenylphosphine)hexane (20 mol%, 18.2 mg), and potassium carbonate (0.8 mmol, 4.0 equiv, 110.6 mg) to a 20 mL thick-walled ground glass tube. Seal the tube with a stopper, evacuate the air, and replace the gas with argon gas at least three times. Add ethylene glycol dimethyl ether (3 mL) to the reaction tube using a plastic syringe. Add norbornene (0.4 mmol, 2.0 equiv, 36.9 mg) using a microsyringe. Finally, reinforce the stopper with adhesive tape and medical tape. After stirring the reaction mixture at room temperature for 15 minutes, it was placed in an oil bath at 140 °C and reacted for 36 hours. After the reaction was completed, the mixture was concentrated under reduced pressure and purified by silica gel column chromatography (petroleum ether / ethyl acetate = 100:1 volume ratio) to finally obtain a yellow oil (31.0 mg, yield 62%).

[0047] The product test data are as follows: 1 H NMR (600 MHz, CDCl3) δ 7.54 (d, J = 8.0 Hz, 1H), 7.46 (s, 1H), 7.23(d, J = 3.3 Hz, 1H), 6.93 (d, J = 8.1 Hz, 1H), 6.40 (d, J = 3.2 Hz, 1H), 3.55(t, J = 6.5 Hz, 2H), 2.91 (t, J = 7.3 Hz, 2H), 2.14 (p, J = 6.6 Hz, 2H), 1.73 (s, 9H). See Figure 5 .

[0048] 13 C NMR (151 MHz, CDCl3) δ 135.2, 133.0, 128.7, 125.0, 121.0, 119.8, 113.2, 99.9, 55.7, 44.4, 34.7, 33.4, 29.8. See [reference needed] Figure 6 .

[0049] HRMS (ESI) m / z: [M + H] + Calcd for C 15 H 20 ClN 250.1357; Found 250.1360.

[0050] Example 4 ;

[0051] Add to a 20 mL thick-walled ground glass tube the following substances: toluenethiazide (0.2 mmol, 1.0 equiv, 91.3 mg), diphenylacetylene (0.2 mmol, 1.0 equiv, 35.6 mg), diazacyclopropidone (0.4 mmol, 2.0 equiv, 68.1 mg), palladium acetate (10 mol%, 4.5 mg), tris(m-fluorophenyl)phosphine (20 mol%, 12.7 mg), potassium carbonate (0.8 mmol, 4.0 equiv, 110.6 mg), potassium bromide (0.2 mmol, 1.0 equiv, 23.8 mg), and terpentine (30 mol%, 6.1 mg). Seal the tube with a stopper, evacuate the tube, and replace with argon gas at least three times. Then, inject N,N-dimethylformamide (3... Add 1 mL of the solution to the reaction tube and secure the stopper with tape. Stir the reaction mixture at room temperature for 15 minutes, then place it in an oil bath at 110 °C and react for 24 hours. After the reaction is complete, cool the reaction mixture to room temperature, dilute with EtOAc (15 mL), wash with brine (2 × 15 mL), dry the organic phase with anhydrous sodium sulfate, filter and concentrate under vacuum. The residue is purified by silica gel column chromatography (petroleum ether / ethyl acetate = 100:1 v / v) to give a white solid (56.4 mg, yield 83%).

[0052] The product test data are as follows: 1 H NMR (600 MHz, CDCl3) δ 7.57 (s, 1H), 7.50 (d, J = 8.1 Hz, 1H), 7.29(dd, J = 7.8, 1.6 Hz, 2H), 7.24 (dd, J = 9.9, 7.0 Hz, 3H), 7.17-7.14 (m, 2H),7.11 – 7.06 (m, 3H), 6.96 (d, J = 8.1 Hz, 1H), 2.53 (s, 3H), 1.61 (s, 9H). See Figure 7 .

[0053] 13C NMR (151 MHz, CDCl3) δ 137.4, 136.9, 136.5, 135.3, 131.8, 130.6, 130.3, 127.6, 127.5, 127.3, 126.6, 125.3, 121.1, 119.3, 117.7, 115.0, 59.1, 32.1, 22.3. See [reference needed] Figure 8 .

[0054] HRMS (ESI) m / z: [M + H] + Calcd for C 25 H 25 N 340.2060; Found 340.2059. As can be seen from the examples, the method of the present invention uses arylsulfonium salts, diazacyclopropidone, alkyne derivatives or norbornene as raw materials to prepare indole derivatives through a one-step reaction under palladium catalysis. The method is simple to operate, has mild reaction conditions, and features low cost and simple post-processing.

[0055] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for the synthesis of indole derivatives from arylsulfonium salts catalyzed by palladium, characterized in that, Arylsulfonium salts, diazirine ketones, acetylenic derivatives or norbornadiene are added to a reaction vessel, a palladium catalyst, a ligand, a base and a solvent are added, after mixing, the reaction is carried out under inert gas at 110-140 °C, after the reaction is completed, the solvent is removed, and an indole derivative is separated. The aryl sulfonium salt is or where R is one or more different groups including, but not limited to, alkyl, trifluoromethyl, nitro, acyl, cyano, halogen, alkoxy, oxyester, aryl, hydrogen, and X is sulfur or oxygen; The acetylenic derivatives R 1 R 2 include, but are not limited to, aryl or alkyl groups and are not hydrogen.

2. The method of synthesizing indole derivatives from a palladium-catalyzed arylsulfonium salt according to claim 1, characterized in that, The solvent includes but is not limited to one of toluene, acetonitrile, 1,4-dioxane, N,N-dimethylformamide, dichloroethane, ethylene glycol dimethyl ether; The inert gas includes but is not limited to argon.

3. The method of synthesizing indole derivatives from a palladium-catalyzed arylsulfonium salt according to claim 1, characterized in that, The palladium catalyst is one of palladium chloride, palladium acetate, bis-triphenylphosphine palladium dichloride, tetraphenylphosphine palladium, bis-acetonitrile palladium dichloride.

4. The method of synthesizing indole derivatives from a palladium-catalyzed arylsulfonium salt according to claim 1, characterized in that, The ligand is one of triphenylphosphine derivative, bidentate phosphine ligand.

5. The method of synthesizing indole derivatives from a palladium catalyzed arylsulfonium salt according to claim 1, wherein, The base includes but is not limited to one of potassium carbonate, cesium carbonate, potassium bicarbonate, sodium bicarbonate, potassium acetate, sodium acetate.

6. The method of synthesizing indole derivatives from a palladium catalyzed arylsulfonium salt according to claim 1, wherein, The molar ratio of arylsulfonium salt, diaziridine ketone, acetylene derivative or norbornadiene in the reaction raw material is 1:2:1-2; the palladium catalyst is 10 mol% of the reaction raw material; the ligand is 20 mol% of the reaction raw material; the molar ratio of arylsulfonium salt to base is 1:

4.

7. The method of synthesizing indole derivatives from a palladium-catalyzed arylsulfonium salt according to claim 1, characterized in that, The separation uses column chromatography, and the composition of the mobile phase used in the column chromatography is petroleum ether / ethyl acetate with a volume ratio of 100:1-15:

1.

8. The method of synthesizing indole derivatives from a palladium catalyzed arylsulfonium salt according to claim 1, wherein, An additive carboxylic acid, metal salt or phase transfer catalyst is also added in the reaction; the carboxylic acid includes but is not limited to pivalic acid, benzoic acid, acetic acid, and the metal salt includes but is not limited to sodium iodide, sodium bromide.

9. The method of synthesizing indole derivatives from a palladium catalyzed arylsulfonium salt according to claim 1, wherein, The reaction time is 24-36 hours.

10. The indole derivative obtained by any one of the methods of claims 1-9.

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