Method for preparing aryl or heteroaryl nitrile compound through photo-induced polyacid catalysis

Abstract

The invention belongs to the technical field of compound preparation, and discloses a method for preparing aryl or heteroaryl nitrile compounds through photo-induced polyacid catalysis, which comprises the following steps: taking halogenated aromatic hydrocarbon or halogenated heteroaromatic hydrocarbon and potassium ferrocyanide as raw materials, under the condition of existence of a polyacid catalyst and alkali, carrying out photoinduced polyacid catalysis on the aryl or heteroaryl nitrile compounds to obtain aryl or heteroaryl nitrile compounds. And carrying out photocatalytic reaction at room temperature to synthesize the aryl or heteroaryl nitrile compound. According to the method, fluorine or chlorobenzene is activated under mild conditions by using a polyacid catalysis system, efficient cyanidation of fluorine or chlorobenzene is successfully promoted, a feasible synthesis path is provided for a substrate which is difficult to utilize in the past, the application range of the method is widened, and the method has higher universality.

Description

Technical Field

[0001] The present invention belongs to the technical field of compound preparation, and relates to a method for preparing aryl or heteroaryl nitrile compounds by photoinduced polyoxometalate catalysis. Background Art

[0002] Aryl nitrile compounds are important organic synthesis intermediates and are widely used in many fields such as medicine, pesticides, dyes, and materials science. In addition, aryl nitriles can be further converted into nitrogen-containing heterocyclic compounds, carboxylic acid derivatives, amine compounds, etc. with biological activity, which are of great value in drug research and development and pesticide manufacturing.

[0003] Currently, the synthesis of aryl nitrile compounds mainly uses the coupling reaction of haloarenes with cyanating reagents. Among them, relatively expensive iodobenzene or bromobenzene is usually used as the raw material for haloarenes, and cyanating reagents (such as NaCN, CuCN, etc.) are highly toxic, which is not conducive to environmental protection. In recent years, potassium ferrocyanide (K4Fe(CN)6) with lower toxicity has gradually become an emerging cyanide source for aryl nitrile synthesis (Tetrahedron Letters, 2016, (57): 337 - 339). However, most of the existing methods require the use of precious metal palladium catalysts and are carried out under high temperature or ultraviolet light conditions (Adv. Synth. Catal., 2017, 359: 2345 - 2351), and they have poor applicability to more economically available chlorobenzene and fluorobenzene. In addition, traditional methods (such as Rosenmund-von Braun reaction and Sandmeyer reaction) also face problems such as high temperature (150 - 250 °C), generation of heavy metal wastes, and low raw material utilization rate, which limit their wide application. Therefore, it is urgent to develop an efficient, green and economical method for synthesizing aryl nitriles.

[0004] In recent years, photocatalytic technology has attracted wide attention in organic synthesis. In particular, visible light photocatalytic reactions have been favored because they can efficiently utilize solar energy and are environmentally friendly. However, aryl halides such as chlorobenzene and fluorobenzene are difficult to directly absorb visible light, which limits their application in photocatalytic conversion.

[0005] As a photocatalytic material, polyoxometalates (POMs, simply referred to as polyacids) have strong redox ability, photostability and environmental friendliness, can effectively absorb visible light and excite highly active photogenerated electrons and holes, and promote the activation of difficult-to-react substrates. By loading polyacids on magnetic nanoparticles or oxide carriers, the reuse of the catalyst can also be realized, improving economic benefits. Therefore, using polyoxometalates to catalyze the coupling reaction of potassium ferrocyanide with chlorobenzene or fluorobenzene has broad application prospects. Summary of the Invention

[0006] In view of the technical problem that it is difficult for chlorobenzene and fluorobenzene in aryl halides to directly absorb visible light, which limits their photocatalytic conversion reactions, the present invention provides a method for preparing aryl or heteroaryl nitrile compounds by photoinduced polyoxometalate catalysis. Using polyoxometalate as a catalyst, the efficient cyanation of halo(hetero)arenes is achieved at room temperature under light irradiation. This method activates fluorobenzene and chlorobenzene under visible light conditions, providing a new way for the green synthesis of (hetero)aryl nitriles and their derivatives.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention provides a method for preparing aryl or heteroaryl nitrile compounds by photoinduced polyoxometalate catalysis, comprising the following steps: using haloarene or haloheteroarene and potassium ferrocyanide as raw materials, under the conditions of the presence of a polyoxometalate catalyst and a base, photocatalytically reacting at room temperature to synthesize aryl or heteroaryl nitrile compounds;

[0009] The reaction equation is:

[0010]

[0011] Wherein, Ar is an aryl or heteroaryl group; R is a substituent, and the substituent is hydrogen, an electron-donating group or an electron-withdrawing group; X is a halogen.

[0012] Preferably, the aryl group is selected from phenyl, naphthyl, biphenyl, phenanthryl; the heteroaryl group is selected from pyridyl, indolyl, thienyl, 2,3-dihydrobenzo[b][1,4]dioxanyl.

[0013] Preferably, the electron-donating group is at least one of C1-C4 alkyl, C1-C4 alkoxy, hydroxyl, methylthio or amino.

[0014] Preferably, the electron-withdrawing group is at least one of nitro, cyano, aldehyde or halogen.

[0015] Preferably, the molar ratio of the haloarene or haloheteroarene to potassium ferrocyanide is 1:1-3, preferably 1:2.

[0016] Preferably, the polyoxometalate catalyst is selected from H3[PMo 12 O 40 , Na 10 [α-SiW9O 34 ·18H2O, H6[P2W 18 O 62 , Na2H[α-PMo 12 O 40 ·14H2O, H5[PMo 10 V2O 40 ·32.5H2O or H3[α-PW 12 O40 one of those in

[0017] Preferably, the addition amount of the polyoxometalate catalyst is 1-5 mol%, preferably 5 mol%, based on the haloarene or haloheteroarene.

[0018] Preferably, there is also a base in the reaction system, and the base is selected from one of lithium tert-butoxide, cesium carbonate, potassium phosphate, sodium hydroxide or sodium carbonate.

[0019] Preferably, the molar ratio of the base to the haloarene or haloheteroarene is 1-2:1, preferably 2:1.

[0020] Preferably, there is also an additive in the reaction system, and the additive is selected from one of aluminum fluoride, zinc sulfide, zinc chloride, tin chloride, aluminum chloride or aluminum oxide.

[0021] Preferably, the molar ratio of the additive to the haloarene or haloheteroarene is 1-1.5:1, preferably 1.5:1.

[0022] Preferably, there is also a solvent in the reaction system, and the solvent is selected from one of dimethyl sulfoxide, acetonitrile, dichloromethane, toluene, tetrahydrofuran or N,N-dimethylformamide.

[0023] Preferably, the addition amount ratio of the solvent to the haloarene or haloheteroarene is 2 mL:0.3 mmol.

[0024] Preferably, the reaction is carried out in an atmosphere of air, oxygen or inert gas, and the inert gas is preferably nitrogen.

[0025] Preferably, the reaction light source can be red light (640 nm), blue light (455 nm), green light (520 nm), ultraviolet light (254 nm), incandescent light, xenon lamp (400 nm - 780 nm), preferably green light and xenon lamp, and most preferably blue light.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] 1. In traditional methods for synthesizing benzonitrile, due to the high bond energy and electronic effect of the carbon-halogen bond in fluorobenzene or chlorobenzene substrates, it is often difficult to achieve efficient conversion, which limits their application scope. The present invention uses a polyoxometalate catalytic system to activate fluorobenzene or chlorobenzene under mild conditions, successfully promoting its efficient cyanation, providing a feasible synthesis route for substrates that were difficult to utilize in the past, broadening the applicable scope of the method, and making it more universal.

[0028] 2. Compared with the traditional methods that rely on substrates such as bromobenzene and iodobenzene, the method of the present invention can be applied to fluoro- or chloro-benzene compounds. The raw material sources are more abundant and the prices are lower, making the industrial synthesis cost more advantageous. In addition, the method of the present invention uses polyoxometalates as catalysts, abandoning the dependence on precious metals, further reducing the economic cost and improving the feasibility of industrial promotion.

[0029] 3. The present invention realizes the cyanation reaction of haloarenes or haloheteroarenes through a photo-promoted polyoxometalate-catalyzed process under mild conditions through radical coupling. Compared with the traditional methods driven by high temperature, high pressure or ultraviolet light, the energy consumption and safety risks are significantly reduced. At the same time, it also exhibits excellent functional group compatibility, making it applicable to the fields of drug molecule and fine chemical synthesis, showing broad application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is the 1H NMR spectrum of benzonitrile in Example 1.

[0031] Figure 2 It is the 13C NMR spectrum of benzonitrile in Example 1.

[0032] Figure 3 It is the 1H NMR spectrum of 3,5-dimethylbenzonitrile in Example 15.

[0033] Figure 4 It is the 13C NMR spectrum of 3,5-dimethylbenzonitrile in Example 15.

[0034] Figure 5 It is the 1H NMR spectrum of naphthalene-2-carbonitrile in Example 16.

[0035] Figure 6 It is the 13C NMR spectrum of naphthalene-2-carbonitrile in Example 16.

[0036] Figure 7 It is the 1H NMR spectrum of 3-ethylbenzonitrile in Example 17.

[0037] Figure 8 It is the 13C NMR spectrum of 3-ethylbenzonitrile in Example 17. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The following examples are used to illustrate the present invention, but are not used to limit the protection scope of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. The test methods in the following examples are all conventional methods unless otherwise specified.

[0039] Example 1: Preparation of Benzonitrile

[0040] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40 (5 mol%), aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were separately added into a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and chlorobenzene (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was detected by thin-layer chromatography (TCL). Then, the organic solvent was removed under reduced pressure, and the product was separated and purified by column chromatography and dried to obtain the final product benzonitrile with a yield of 86%.

[0041] The reaction equation is as follows:

[0042]

[0043] Figure 1 This is the 1H NMR spectrum of benzonitrile in Example 1.

[0044] The 1H NMR characterization of benzonitrile is as follows: 1 H NMR (400 MHz, CDCl3) δ 7.55 (m, J = 10.4, 7.6, 4.3 Hz, 3H), 7.41 (dt, J = 9.8, 4.9 Hz, 2H).

[0045] Figure 2 This is the 13C NMR spectrum of benzonitrile in Example 1.

[0046] The 13C NMR characterization of benzonitrile is as follows: 13 C NMR (100 MHz, CDCl3) δ 132.8, 132.0, 129.1, 118.8, 112.2.

[0047] Example 2: Preparation of 4-methylbenzonitrile

[0048] First, potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[PMo 12 O 40(5 mol %), aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were respectively added into a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and 4-methylchlorobenzene (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, the final product was detected by thin-layer chromatography (TCL), then the organic solvent was removed under reduced pressure, and it was separated, purified, and dried by column chromatography to obtain the final product 4-methylbenzonitrile with a yield of 85%.

[0049] The reaction equation is as follows:

[0050]

[0051] The 1H NMR characterization of 4-methylbenzonitrile is as follows: 1 H NMR (400 MHz, CDCl3) δ 7.52 (d, J = 8.2 Hz, 2H), 7.26 (d, J = 8.2 Hz, 2H), 2.41 (s, 3H).

[0052] The 13C NMR characterization of 4-methylbenzonitrile is as follows: 13 C NMR (100 MHz, CDCl3) δ 143.4, 131.6, 129.5, 118.8, 108.9, 21.5.

[0053] Example 3: Preparation of 4-methoxybenzonitrile

[0054] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40 (5 mol %), aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were respectively added into a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and 4-methoxyfluorobenzene (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, the final product was detected by thin-layer chromatography (TCL), then the organic solvent was removed under reduced pressure, and it was separated, purified, and dried by column chromatography to obtain the final product 4-methoxybenzonitrile with a yield of 73%.

[0055] The reaction equation is as follows:

[0056]

[0057] The 1H NMR characterization of 4-methoxybenzonitrile is as follows: 1 H NMR(400MHz,CDCl3)δ7.57(d,J=8.8Hz,2H),6.95(d,J=8.8Hz,2H),3.86(s,3H).

[0058] The 13C NMR characterization of 4-methoxybenzonitrile is as follows: 13 C NMR(100MHz,CDCl3)δ162.6,133.7,119.0,114.5,103.5,55.3.

[0059] Example 4: Preparation of 1-naphthonitrile

[0060] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40 (5 mol%), zinc sulfide (1.5 equiv.), and cesium carbonate (2 equiv.) were separately added to a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and 1-chloronaphthalene (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, the final product was detected by thin-layer chromatography (TCL), and then the organic solvent was removed under reduced pressure. It was separated and purified by column chromatography and dried to obtain the final product 1-naphthonitrile with a yield of 85%.

[0061] The reaction equation is as follows:

[0062]

[0063] 1H NMR of 1-naphthonitrile: 1 HNMR(400MHz,CDCl3)δ8.19(d,J=8.4Hz,1H),8.03(d,J=8.4Hz,1H),7.86(dd,J=10.2Hz,4.2Hz,2H),7.67 - 7.56(m,2H),7.50 7.46(m,1H).

[0064] The 13C NMR characterization of 1-naphthonitrile is as follows: 13 C NMR(100MHz,CDCl3)δ133.2,132.8,132.6,132.3,128.6,128.5,127.5,125.1,124.9,117.8,110.1.

[0065] Example 5: Preparation of 4-hydroxybenzonitrile

[0066] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H6[P2W 18 O 62 (5 mol%), zinc chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were separately added to a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and 4-fluorophenol (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was detected by thin-layer chromatography (TCL). Then, the organic solvent was removed under reduced pressure, and the product was separated, purified by column chromatography, and dried to obtain the final product 4-hydroxybenzonitrile with a yield of 78%.

[0067] The reaction equation is as follows:

[0068]

[0069] The 1H NMR characterization of 4-hydroxybenzonitrile is as follows: 1 1H NMR (400 MHz, DMSO-d6) δ 6.86 (d, J = 8 Hz, 2H), 7.59 (d, J = 8 Hz, 2H), 10.57 (s, 1H).

[0070] The 13C NMR characterization of 4-hydroxybenzonitrile is as follows: 13 13C NMR (100 MHz, DMSO-d6) δ 101.5, 116.9, 120.1, 134.8, 162.1.

[0071] Example 6: Preparation of 4-aminobenzonitrile

[0072] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40 (5 mol%), zinc sulfide (1.5 equiv.), and cesium carbonate (2 equiv.) were separately added to a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and 4-fluoroaniline (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was detected by thin-layer chromatography (TCL). Then, the organic solvent was removed under reduced pressure, and the product was separated, purified by column chromatography, and dried to obtain the final product 4-aminobenzonitrile with a yield of 73%.

[0073] The reaction equation is as follows:

[0074]

[0075] The 1H NMR characterization of 4-aminobenzonitrile is as follows 1 H NMR(400MHz,DMSO-d6)δ6.08(brs,2H),6.56(d,J=8Hz,2H),7.34(d,J=8Hz,2H).

[0076] The 13C NMR characterization of 4-aminobenzonitrile is as follows: 13 C NMR(100MHz,DMSO-d6):δ96.0,114.0,121.2,134.0,153.5.

[0077] Example 7: Preparation of 4-nitrobenzonitrile

[0078] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40 (5 mol%), aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were separately added to a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and 4-nitrofluorobenzene (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was detected by thin-layer chromatography (TCL). Then, the organic solvent was removed under reduced pressure, and the product was separated and purified by column chromatography and dried to obtain the final product 4-nitrobenzonitrile with a yield of 78%.

[0079] The reaction equation is as follows:

[0080]

[0081] The 1H NMR characterization of 4-nitrobenzonitrile is as follows: 1 H NMR(400MHz,CDCl3)δ8.38(d,J=8.8Hz,2H),7.92(d,J=8.8Hz,2H).

[0082] The 13C NMR characterization of 4-nitrobenzonitrile is as follows: 13 C NMR(100MHz,CDCl3)δ150.0,133.4,124.2,118.2,116.7.

[0083] Example 8: Preparation of 4-acetylbenzonitrile

[0084] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H5[PMo 10 V2O40 ZnS (1.5 equiv.), Cs2CO3 (2 equiv.), and 32.5H2O (5 mol%) were added to a 10 mL Schlenk tube. Subsequently, 2 mL of acetonitrile (MeCN) and 1-(4-chlorophenyl)ethanone (0.3 mmol) were added successively while purging with nitrogen. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was detected by thin-layer chromatography (TCL). Then, the organic solvent was removed under reduced pressure, and the product was separated and purified by column chromatography and dried to obtain the final product 4-acetylbenzonitrile with a yield of 81%.

[0085] The reaction equation is as follows:

[0086]

[0087] The 1H NMR characterization of 4-acetylbenzonitrile is as follows: 1 H NMR (400 MHz, CDCl3): δ 8.04 (d, J = 8.4 Hz, 2H), 7.77 (d, J = 8.4 Hz, 2H), 2.64 (s, 3H).

[0088] The 13C NMR characterization of 4-acetylbenzonitrile is as follows: 13 C NMR (100 MHz, CDCl3) δ 196.8, 140.1, 132.8, 128.9, 118.2, 116.7, 27.0.

[0089] Example 9: Preparation of 4-cyanobenzaldehyde

[0090] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40 (5 mol%), aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were added to a 10 mL Schlenk tube. Subsequently, 2 mL of acetonitrile (MeCN) and 4-chlorobenzaldehyde (0.3 mmol) were added successively while purging with nitrogen. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was detected by thin-layer chromatography (TCL). Then, the organic solvent was removed under reduced pressure, and the product was separated and purified by column chromatography and dried to obtain the final product 4-cyanobenzaldehyde with a yield of 79%.

[0091] The reaction equation is as follows:

[0092]

[0093] The 1H NMR characterization of 4-cyanobenzaldehyde is as follows: 1 H NMR(400MHz,CDCl3)δ10.14(s,1H),8.04(d,J=8.0Hz,2H),7.89(d,J=7.2Hz,2H).

[0094] The 13C NMR characterization of 4-cyanobenzaldehyde is as follows: 13 C NMR(100MHz,CDCl3)δ190.6,138.5,132.6,129.6,117.5,117.2,125.1.

[0095] Example 10: Preparation of 4-cyanobiphenyl

[0096] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40 (5 mol%), aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were respectively added into a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and 4-chlorobiphenyl (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, the final product was detected by thin layer chromatography (TCL), and then the organic solvent was removed under reduced pressure. It was separated, purified, and dried by column chromatography to obtain the final product 4-cyanobiphenyl with a yield of 83%.

[0097] The reaction equation is as follows:

[0098]

[0099] The 1H NMR characterization of 4-cyanobiphenyl is as follows: 1 H NMR(400MHz,CDCl3):δ7.73-7.67(m,4H),7.58(d,J=7.6Hz,2H),7.50-7.42(m,3H).

[0100] The 13C NMR characterization of 4-cyanobiphenyl is as follows: 13 C NMR(100MHz,CDCl3):δ145.6,139.1,132.5,129.0,128.6,127.7,127.2,118.9,110.8.

[0101] Example 11: Preparation of phenanthrene-9-carbonitrile

[0102] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40 (5 mol %), aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were respectively added into a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and 9-chlorophenanthrene (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was detected by thin-layer chromatography (TCL). Then, the organic solvent was removed under reduced pressure, and the product was separated, purified by column chromatography, and dried to obtain the final product 9-iodophenanthrene with a yield of 81%.

[0103] The reaction equation is as follows:

[0104]

[0105] The 1H NMR characterization of 9-iodophenanthrene is as follows: 1 1H NMR (400 MHz, CDCl3) δ 8.56 - 8.52 (m, 2H), 8.20 - 8.18 (m, 1H), 8.07 (s, 1H), 7.79 (d, J = 7.6 Hz, 1H), 7.73 - 7.58 (m, 4H).

[0106] The 13C NMR characterization of 9-iodophenanthrene is as follows: 13 13C NMR (100 MHz, CDCl3) δ 135.3, 131.4, 129.6, 129.6, 129.4, 129.2, 128.5, 127.9, 127.8, 127.4, 125.7, 122.8, 122.5, 117.7, 109.0.

[0107] Example 12: Preparation of terephthalonitrile

[0108] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40(5 mol%), zinc sulfide (1.5 equiv.), and cesium carbonate (2 equiv.) were added to a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and 4-fluorobenzonitrile (0.3 mmol) were added successively. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was detected by thin-layer chromatography (TCL). Then, the organic solvent was removed under reduced pressure, and the product was separated, purified by column chromatography, and dried to obtain the final product terephthalonitrile with a yield of 72%.

[0109] The reaction equation is as follows:

[0110]

[0111] The 1H NMR characterization of terephthalonitrile is as follows: 1 1H NMR (400 MHz, CDCl3) δ 7.77 (s, 4H).

[0112] The 13C NMR characterization of terephthalonitrile is as follows: 13 13C NMR (100 MHz, CDCl3) δ 132.7, 116.9, 116.6.

[0113] Example 13: Preparation of 2-cyanopyridine

[0114] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40 (5 mol%), aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were added to a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and 2-fluoropyridine (0.3 mmol) were added successively. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was detected by thin-layer chromatography (TCL). Then, the organic solvent was removed under reduced pressure, and the product was separated, purified by column chromatography, and dried to obtain the final product 2-cyanopyridine with a yield of 74%.

[0115] The reaction equation is as follows:

[0116]

[0117] The 1H NMR characterization of 2-cyanopyridine is as follows: 11H NMR (400 MHz, CDCl3) δ 7.59 - 7.62 (m, 1H), 7.76 (d, J = 8.0 Hz, 1H), 7.92 (t, J = 8.0 Hz, 1H), 8.75 (d, J = 4.0 Hz, 1H).

[0118] The 13C NMR characterization of 2 - cyanopyridine is as follows: 13 13C NMR (100 MHz, CDCl3) δ 117.0, 126.8, 128.3, 133.5, 136.9, 150.8.

[0119] Example 14: Preparation of 2 - acetylbenzonitrile

[0120] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α - PW 12 O 40 (5 mol%), zinc sulfide (1.5 equiv.), and cesium carbonate (2 equiv.) were separately added to a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and 2 - fluoroacetophenone (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight - position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction ended, it was taken out, and the final product was detected by thin - layer chromatography (TCL). Then, the organic solvent was removed under reduced pressure, and it was separated, purified, and dried by column chromatography to obtain the final product 2 - acetylbenzonitrile with a yield of 75%.

[0121] The reaction equation is as follows:

[0122]

[0123] The 1H NMR characterization of 2 - acetylbenzonitrile is as follows: 1 1H NMR (400 MHz, CDCl3): δ 2.62 (s, 3H), 7.62 (dt, J = 1.2, 7.6 Hz, 1H), 7.69 (dt, J = 1.2, 7.6 Hz, 1H), 7.74 (dd, J = 1.2, 7.4 Hz, 1H), 7.94 (d, J = 8.0 Hz, 1H).

[0124] The 13C NMR characterization of 2 - acetylbenzonitrile is as follows: 13 13C NMR (100 MHz, CDCl3): δ 27.4, 110.3, 117.9, 129.8, 132.4, 132.5, 135.0, 139.1, 196.0.

[0125] Example 15: Preparation of 3,5 - dimethylbenzonitrile

[0126] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40 (5 mol%), zinc sulfide (1.5 equiv.), and cesium carbonate (2 equiv.) were respectively added into a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and 3,5-dimethylchlorobenzene (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, the final product was detected by thin-layer chromatography (TCL), then the organic solvent was removed under reduced pressure, and it was separated, purified, and dried by column chromatography to obtain the final product 3,5-dimethylbenzonitrile with a yield of 89%.

[0127] The reaction equation is as follows:

[0128]

[0129] Figure 3 This is the 1H NMR spectrum of 3-ethylbenzonitrile in Example 15.

[0130] The 1H NMR characterization of 3,5-dimethylbenzonitrile is as follows: 1 H NMR (400 MHz, CDCl3) δ 7.27 (s, 2H), 7.22 (s, 1H), 2.35 (s, 6H).

[0131] Figure 4 This is the 13C NMR spectrum of 3-ethylbenzonitrile in Example 15.

[0132] The 13C NMR characterization of 3,5-dimethylbenzonitrile is as follows: 13 C NMR (100 MHz, CDCl3) δ 139.1, 134.6, 129.6, 119.2, 112.0, 21.0.

[0133] Example 16: Preparation of naphthalene-2-carbonitrile

[0134] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H6[P2W 18 O 62(5 mol %), aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were added to a 10 mL Schlenk tube. Subsequently, 2 mL of acetonitrile (MeCN) and 2-chloronaphthalene (0.3 mmol) were added successively while purging with nitrogen. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was detected by thin-layer chromatography (TCL). Then, the organic solvent was removed under reduced pressure, and the product was separated and purified by column chromatography and dried to obtain the final product, naphthalene-2-carbonitrile, with a yield of 85%.

[0135] The reaction equation is as follows:

[0136]

[0137] Figure 5 This is the 1H NMR spectrum of 3-ethylbenzonitrile in Example 16.

[0138] The 1H NMR characterization of naphthalene-2-carbonitrile is as follows: 1 H NMR (400 MHz, CDCl3) δ 8.21 (dd, J = 7.9, 2.6 Hz, 1H), 7.92 - 7.86 (m, 3H), 7.67 - 7.57 (m, 3H).

[0139] Figure 6 This is the 13C NMR spectrum of 3-ethylbenzonitrile in Example 16.

[0140] The 13C NMR characterization of naphthalene-2-carbonitrile is as follows: 13 C NMR (100 MHz, CDCl3) δ 134.6, 134.1, 132.2, 129.2, 129.1, 128.4, 128.1, 127.7, 126.3, 119.3, 109.4.

[0141] Example 17: Preparation of 3-ethylbenzonitrile

[0142] Potassium ferrocyanide (0.6 mmol) and the polyoxometalate catalyst H3[α-PW 12 O 40(5 mol%), zinc sulfide (1.5 equiv.), and cesium carbonate (2 equiv.) were added to a 10 mL Schlenk tube. Subsequently, 2 mL of acetonitrile (MeCN) and 3-ethylfluorobenzene (0.3 mmol) were added successively while purging with nitrogen. The reaction tube cap was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, the final product was detected by thin-layer chromatography (TCL), and then the organic solvent was removed under reduced pressure. It was separated, purified, and dried by column chromatography to obtain the final product 3-ethylbenzonitrile with a yield of 75%.

[0143] The reaction equation is as follows:

[0144]

[0145] Figure 7 This is the 1H NMR spectrum of 3-ethylbenzonitrile in Example 17.

[0146] The 1H NMR characterization of 3-ethylbenzonitrile is as follows: 1 H NMR (400 MHz, CDCl3) δ 7.51 - 7.41 (m, 3H), 7.38 (t, J = 7.3 Hz, 1H), 2.69 (q, J = 7.6 Hz, 2H), 1.25 (td, J = 7.7, 1.6 Hz, 3H).

[0147] Figure 8 This is the 13C NMR spectrum of 3-ethylbenzonitrile in Example 17.

[0148] The 13C NMR characterization of 3-ethylbenzonitrile is as follows: 13 C NMR (100 MHz, CDCl3) δ 145.5, 132.6, 131.4, 129.5, 129.1, 119.1, 112.2, 28.5, 15.2.

[0149] Example 18: Preparation of 5-cyanoindole

[0150] First, potassium ferrocyanide (0.6 mmol) and polyoxometalate catalyst H3[α-PW 12 O 40(5 mol%), aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were added to a 10 mL Schlenk tube. Subsequently, 2 mL of acetonitrile (MeCN) and 5-chloroindole (0.3 mmol) were sequentially added while purging with nitrogen. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was detected by thin-layer chromatography (TCL). Then, the organic solvent was removed under reduced pressure, and the product was separated, purified by column chromatography, and dried to obtain the final product 5-cyanoindole with a yield of 83%.

[0151] The reaction equation is as follows:

[0152]

[0153] The 1H NMR characterization of 5-cyanoindole is as follows: 1 H NMR (400 MHz, CDCl3) δ 8.85 (s, 1H), 8.00 (s, 1H), 7.49 - 7.35 (m, 3H), 6.63 (s, 1H).

[0154] The 13C NMR characterization of 5-cyanoindole is as follows: 13 C NMR (100 MHz, CDCl3) δ 137.5, 127.6, 126.6, 126.4, 124.7, 121.0, 112.1, 103.3, 102.4.

[0155] Example 19: Preparation of 2,3-dihydrobenzo[b][1,4]dioxine-6-carbonitrile

[0156] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H5[PMo 10 V2O 40 ·32.5H2O (5 mol%), zinc sulfide (1.5 equiv.), and cesium carbonate (2 equiv.) were added to a 10 mL Schlenk tube. Subsequently, 2 mL of acetonitrile (MeCN) and 6-chloro-2,3-dihydrobenzo[b][1,4]dioxine (0.3 mmol) were sequentially added while purging with nitrogen. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was detected by thin-layer chromatography (TCL). Then, the organic solvent was removed under reduced pressure, and the product was separated, purified by column chromatography, and dried to obtain the final product 2,3-dihydrobenzo[b][1,4]dioxine-6-carbonitrile with a yield of 78%.

[0157] The reaction equation is as follows:

[0158]

[0159] The 1H NMR characterization of 2,3-dihydrobenzo[b][1,4]dioxane-6-carbonitrile is as follows: 1 H NMR(400MHz,CDCl3)δ7.15 - 7.13(m,2H),6.92 - 6.90(m,1H),4.33 - 4.27(m,4H).

[0160] The 13C NMR characterization of 2,3-dihydrobenzo[b][1,4]dioxane-6-carbonitrile is as follows: 13 C NMR(100MHz,CDCl3)δ147.7,143.8,126.0,121.3,118.9,118.3,104.5,64.6,64.1.

[0161] Example 20: Preparation of 2-cyanothiophene

[0162] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H6[P2W 18 O 62 (5 mol%), zinc chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were separately added into a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and 2-fluorothiophene (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, the final product was detected by thin-layer chromatography (TCL), then the organic solvent was removed under reduced pressure, and it was separated, purified, and dried by column chromatography to obtain the final product 2-cyanothiophene with a yield of 79%.

[0163] The reaction equation is as follows:

[0164]

[0165] The 1H NMR characterization of 2-cyanothiophene is as follows: 1 H NMR(400MHz,CDCl3)δ7.65 - 7.62(m,2H),7.16 - 7.14(m,1H).

[0166] The 13C NMR characterization of 2-cyanothiophene is as follows: 13 C NMR(100MHz,CDCl3)δ137.3,132.5,127.6,114.1,109.6.

[0167] Example 21: Reaction Substrate Expansion and Condition Optimization

[0168] 1. Expansion of reaction substrates

[0169] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40 (5 mol%), aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were respectively added into a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and halobenzene (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was detected by thin-layer chromatography (TCL). Then, the organic solvent was removed under reduced pressure, and it was separated, purified, and dried by column chromatography to obtain the final product benzonitrile. The yields of benzonitrile with different halobenzenes as substrates are shown in Table 1.

[0170] Table 1 Yields of benzonitrile under different atmosphere conditions

[0171] Serial number Halobenzene Yield (%) 1 Iodobenzene 92 2 Bromobenzene 90 3 (i.e., Example 1) Chlorobenzene 86 4 Fluorobenzene 82

[0172] As can be seen from the above table, the method of the present invention is not only still applicable to substrates such as bromobenzene and iodobenzene, but also applicable to substrates such as fluorobenzene or chlorobenzene, and the yields are all relatively high, providing a feasible synthetic route for substrates that were difficult to utilize in the past.

[0173] 2. Optimization of solvents

[0174] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40 (5 mol%), aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were respectively added into a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, the solvent and chlorobenzene (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was monitored by TLC. Then, the organic solvent was removed under reduced pressure, and it was separated, purified, and dried by column chromatography to obtain the final product benzonitrile. The yields of the final product benzonitrile under different solvent conditions are shown in Table 2.

[0175] Table 2 Yields of benzonitrile under different solvent conditions

[0176] Serial number Solvent Yield (%) 1 DMSO 68 2 THF 80 3 (i.e., Example 1) MeCN 86 4 DCM 57 5 Toluene 49 6 DMF 58

[0177] The above results indicate that the product can be obtained under different solvent conditions. However, the hourly yields using DMSO, THF, DCM, Toluene, and DMF as solvents are 68%, 80%, 57%, 49%, and 58% respectively, all of which are lower than the yield of benzonitrile using MeCN as the solvent. Therefore, for the substrates chlorobenzene and potassium ferrocyanide, MeCN is the optimal solvent.

[0178] 3. Optimization of Polyoxometalate Catalysts

[0179] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst, aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were respectively added into a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and chlorobenzene (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight - position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction ended, it was taken out, the final product was monitored by TLC, then the organic solvent was removed under reduced pressure, and it was separated, purified, and dried by column chromatography to obtain the final product benzonitrile. The yields of the final product benzonitrile under different polyoxometalate catalyst conditions are shown in Table 3.

[0180] Table 3 Yields of Benzonitrile under Different Polyoxometalate Catalysts

[0181] Serial number Polyoxometalate catalyst Yield (%) 1 <![CDATA[H3[PMo 12 O 40 > 75 2 <![CDATA[Sodium 10 [α-Silicotungstic acid 34 ·18H₂O]]> 53 3 <![CDATA[H6[P2W 18 O 62 > 62 4 <![CDATA[Na2H[α-PMo 12 O 40 ·14H2O]]> 83 5 <![CDATA[H5[PMo 10 V2O 40 ·32.5H2O]]> 79 6 (i.e., Example 1) <![CDATA[H3[α-PW 12 O 40 > 86

[0182] The above results show that the product can be obtained under different catalyst conditions. For the substrates chlorobenzene and potassium ferrocyanide, H3[α - PW 12 O 40 is the optimal catalyst.

[0183] 4. Optimization of Light Source

[0184] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α - PW 12 O 40 (5 mol%), aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were respectively added into a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and chlorobenzene (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight - position parallel reactor. Under a nitrogen atmosphere, it was irradiated with light and stirred at room temperature for 48 h. After the reaction ended, it was taken out, the final product was monitored by TLC, then the organic solvent was removed under reduced pressure, and it was separated, purified, and dried by column chromatography to obtain the final product benzonitrile. The yields of the final product benzonitrile under different light source conditions are shown in Table 4.

[0185] Table 4 Yields of Benzonitrile under Different Light Sources

[0186]

[0187]

[0188] The above results indicate that for the substrates chlorobenzene and potassium ferrocyanide, blue light (Blue LED) is the optimal light source.

[0189] 5. Optimization of additives

[0190] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40 (5 mol%), additive, and cesium carbonate (2 equiv.) were respectively added into a 10 mL Schlenk tube. Subsequently, while purging with nitrogen, 2 mL of acetonitrile (MeCN) and haloarene (0.3 mmol) were successively added. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, the final product was monitored by TLC, and then the organic solvent was removed under reduced pressure. It was separated, purified, and dried by column chromatography to obtain the final product benzonitrile. The yields of the final product benzonitrile under different additive conditions are shown in Table 5.

[0191] Table 5 Yields of benzonitrile under different additive conditions

[0192]

[0193]

[0194] The above results indicate that the reaction yields of the substrates chlorobenzene or fluorobenzene can be significantly improved under the condition of having an additive, while the yields of the substrates iodobenzene or bromobenzene can also reach above medium without an additive; for the substrates chlorobenzene and potassium ferrocyanide, aluminum chloride is the optimal additive.

[0195] 6. Optimization of raw material ratio

[0196] Potassium ferrocyanide, polyoxometalate catalyst H3[α-PW 12 O 40(5 mol%), aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were added to a 10 mL Schlenk tube. Subsequently, 2 mL of acetonitrile (MeCN) and chlorobenzene were added successively while purging with nitrogen. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was monitored by TLC. Then, the organic solvent was removed under reduced pressure, and the product was separated, purified by column chromatography, and dried to obtain the final product benzonitrile. Under different raw material ratio conditions, the yields of the final product benzonitrile are shown in Table 6.

[0197] Table 6 Yields of Benzonitrile under Different Raw Material Ratio Conditions

[0198] Serial number Raw material ratio (chlorobenzene: potassium ferrocyanide) Yield (%) 1 1:1 57 2 1:1.5 62 3 (i.e., Example 1) 1:2 86 4 1:2.5 84 5 1:3 82

[0199] The above results show that under different raw material ratio conditions, the product can be obtained. For the substrates chlorobenzene and potassium ferrocyanide, a 1:2 ratio is the optimal ratio of the reactants.

[0200] 7. Optimization of the Base

[0201] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40 (5 mol%), aluminum chloride (1.5 equiv.), and the base were added to a 10 mL Schlenk tube. Subsequently, 2 mL of acetonitrile (MeCN) and chlorobenzene (0.3 mmol) were added successively while purging with nitrogen. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under a nitrogen atmosphere, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, and the final product was monitored by TLC. Then, the organic solvent was removed under reduced pressure, and the product was separated, purified by column chromatography, and dried to obtain the final product benzonitrile. Under different base conditions, the yields of the final product benzonitrile are shown in Table 7.

[0202] Table 7 Yields of Benzonitrile under Different Base Conditions

[0203] Serial number Base Yield (%) 1 <![CDATA t BuOLi]]> 64 2 (i.e., Example 1) <![CDATA[Cs2CO3]]> 86 3 <![CDATA[K3PO4]]> 43 4 NaOH 57 5 <![CDATA[Na2CO3]]> 69 6 None No target product

[0204] The above results show that under different base conditions, the product can be obtained. For the substrates chlorobenzene and potassium ferrocyanide, cesium carbonate is the optimal base; without a base, the target product cannot be obtained.

[0205] 8. Optimization of the Atmosphere

[0206] Potassium ferrocyanide (0.6 mmol), polyoxometalate catalyst H3[α-PW 12 O 40(5 mol%), aluminum chloride (1.5 equiv.), and cesium carbonate (2 equiv.) were added to a 10 mL Schlenk tube. Subsequently, while purging with gas, 2 mL of acetonitrile (MeCN) and chlorobenzene (0.3 mmol) were added sequentially. The reaction tube lid was tightened, and the reaction tube was placed in an eight-position parallel reactor. Under different atmosphere conditions, it was irradiated with blue light (455 nm) and stirred at room temperature for 48 h. After the reaction was completed, it was taken out, the final product was monitored by TLC, and then the organic solvent was removed under reduced pressure. It was separated, purified, and dried by column chromatography to obtain the final product benzonitrile. Under different atmosphere conditions, the yields of the final product benzonitrile are shown in Table 8.

[0207] Table 8 Yields of Benzonitrile under Different Atmosphere Conditions

[0208] Serial number Atmosphere Yield (%) 1 Air 35 2 <![CDATA[O2]]> 43 3 (i.e., Example 1) <![CDATA[N2]]> 86

[0209] The above results indicate that for the substrates chlorobenzene and potassium ferrocyanide, nitrogen is the optimal atmosphere.

[0210] The above-described embodiments are only preferred embodiments of the present invention, and are only used to explain the present invention, not to limit the scope of implementation of the present invention. For those skilled in the art of this technology, of course, according to the technical content disclosed in this specification, other implementation methods can be easily made by means of substitution or change. Therefore, all changes and improvements made on the principle of the present invention should be included within the scope of the patent application of the present invention.

Claims

1. A method for preparing aryl or heteroaryl nitrile compounds by photoinduced polyoxometalate catalysis, characterized in that, It includes the following steps: Using a haloarene or haloheteroarene and potassium ferrocyanide as raw materials, under the conditions of the presence of a polyacid catalyst and a base, a photocatalytic reaction is carried out at room temperature to synthesize an aryl or heteroaryl nitrile compound; The reaction equation is: Wherein, Ar is an aryl or heteroaryl; R is a substituent, and the substituent is hydrogen, an electron-donating group or an electron-withdrawing group; X is a halogen.

2. The method according to claim 1, wherein The aryl is selected from phenyl, naphthyl, biphenyl, phenanthryl; the heteroaryl is selected from pyridyl, indolyl, thienyl, 2,3-dihydrobenzo[b][1,4]dioxanyl.

3. The method according to claim 1, characterized in that, The electron-donating group is at least one of C1-C4 alkyl, C1-C4 alkoxy, hydroxyl, methylthio or amino.

4. The method according to claim 1, wherein The electron-withdrawing group is at least one of nitro, cyano, aldehyde or halogen.

5. The method according to claim 1, wherein The molar ratio of the haloarene or haloheteroarene to potassium ferrocyanide is 1:1-3.

6. The method according to claim 1, wherein The polyoxometalate catalyst is selected from H3[PMo 12 O 40 , Na 10 [α-SiW9O 34 ·18H2O, H6[P2W 18 O 62 , Na2H[α-PMo 12 O 40 ·14H2O, H5[PMo 10 V2O 40 ·32.5H2O or H3[α-PW 12 O 40 , and is one of them.

7. The method according to claim 1, characterized in that, The addition amount of the polyacid catalyst is 1-5 mol% of the haloarene or haloheteroarene.

8. The method according to claim 1, characterized in that, The base is selected from one of lithium tert-butoxide, cesium carbonate, potassium phosphate, sodium hydroxide or sodium carbonate.

9. The method according to claim 1, characterized in that, There is also an additive in the reaction system, and the additive is selected from one of aluminum fluoride, zinc sulfide, zinc chloride, tin chloride, aluminum chloride or aluminum oxide.

10. The method according to claim 1, characterized in that, There is also a solvent in the reaction system, and the solvent is selected from one of dimethyl sulfoxide, acetonitrile, dichloromethane, toluene, tetrahydrofuran or N,N-dimethylformamide.

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