A method for synthesizing 4-arylbutyronitrile compounds

Abstract

The present invention discloses a new method for synthesizing 4-arylbutyronitrile compounds, that is, under visible light irradiation, a catalytic system composed of an iron(III) complex [HIBnBn CN [FeCl4] (where [HIBnBn CN =1-(4-cyanobenzyl)-3-benzylimidazolium cation) and lithium chloride is used to synthesize 4-arylbutyronitrile compounds through the hydroalkylation reaction of acrylonitrile and toluene compounds. This is the first example of the hydroalkylation reaction of acrylonitrile and toluene compounds realized by visible light-induced iron catalysis, providing a new synthesis method for a series of 4-arylbutyronitrile compounds. This method not only has 100% atom economy, but also has mild reaction conditions and can proceed smoothly at room temperature only with visible light, a simple and easily available iron(III) complex and lithium chloride, which is beneficial to large-scale synthesis applications. Therefore, the synthesis method provided by the present invention conforms to the concept of sustainable green synthesis chemistry.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic synthesis preparation, and particularly relates to a new method for synthesizing 4-arylbutyronitrile compounds. Background Art

[0002] 4-arylbutyronitrile compounds are an important structural unit in the field of organic synthesis and can be widely used in the synthesis of pharmaceuticals, agrochemicals, and polymeric materials. For example, they are intermediates for synthesizing herbicides, cough medications, and enzyme inhibitors. In addition, 4-arylbutyronitrile compounds can be further transformed into amide and carboxylic acid compounds, showing a broader application scope. Therefore, the synthesis methods of such compounds have received extensive attention. Traditional synthesis methods include dehydration of amide compounds or azidation and elimination of carboxyl-containing compounds. These methods often require high temperatures or the use of noble metal catalysts to achieve, have poor substrate functional group tolerance, and also emit toxic waste. In recent years, some research groups have broken the traditional thinking and developed some new synthesis methods for 4-arylbutyronitrile compounds. For example, the Ukaji research group achieved the reaction of acrylonitrile compounds with benzyl alcohol compounds at 70 °C using a catalytic system composed of TiCl4(collidine) (collidine = 2,4,6-trimethylpyridine) and metallic manganese; the Li Chaojun research group achieved the reaction of acrylonitrile with hydrazone compounds at room temperature using a catalytic system composed of Fe(dmpe)2Cl2 (dmpe = 1,2-bis(dimethylphosphino)ethane) and potassium phosphate. With the development of photochemistry, the Akita research group used [Ir(dF(CF3)ppy)2(bpy)](PF6) (ppy = 2-phenylpyridine, bpy = bipyridine) as a photocatalyst to achieve the reaction of acrylonitrile compounds with fluoroborate compounds under light irradiation, and for the first time synthesized 4-arylbutyronitrile compounds by a photoreaction method. However, the reaction scope is very small and the atom economy is poor. So far, there has been no visible light-induced, iron-catalyzed hydroalkylation reaction of acrylonitrile and toluene compounds. If this reaction can be achieved, it can provide a new synthesis method with 100% atom economy for 4-arylbutyronitrile compounds. Summary of the Invention

[0003] The object of the present invention is to provide a new method for synthesizing 4-arylbutyronitrile compounds, that is, under visible light irradiation, using an iron(III) complex [HIBnBn CN [FeCl4] ([HIBnBn CNA catalytic system composed of [HIBnBn

[0004] The present invention adopts the following technical solutions:

[0005] [FeCl4] catalyst, lithium chloride and a solvent, and undergoes a photoreaction to obtain 4-arylbutyronitrile compounds. CN [FeCl4] and lithium chloride was used to synthesize 4-arylbutyronitrile compounds through the hydroalkylation reaction of acrylonitrile with toluene compounds. The synthesis method provided by the present invention does not require the addition of a photosensitizer. The catalytic system is only composed of an iron(III) complex and lithium chloride which are cheap and easily available, the reaction conditions are mild, and the reaction has 100% atom economy.

[0006] The present invention discloses the application of the iron(III) complex [HIBnBn CN [FeCl4] as a catalyst in the synthesis of 4-arylbutyronitrile compounds.

[0007] In the present invention, the iron(III) complex [HIBnBn CN [FeCl4] is an iron(III) complex containing 1-(4-cyanobenzyl)-3-benzylimidazolium cation, and its chemical structural formula is as follows:

[0008]

[0009] In the present invention, the toluene compounds are represented by the following chemical formula:

[0010]

[0011] R 1 is one or more of hydrogen, halogen, alkyl, alkoxy, cyano, carbonyl, ester group, such as hydrogen, ortho-substituted fluorine, meta-substituted fluorine, para-substituted fluorine, chlorine, bromine, methyl, methoxy, tert-butyl, cyano, ketone carbonyl, ester group or disubstituted 3,5-dimethyl.

[0012] In the present invention, the 4-arylbutyronitrile compounds are represented by the following chemical structural formula:

[0013] In the formula, R 1 is derived from the toluene compounds.

[0014] In the above technical solution, the reaction temperature is room temperature and the time is 6 to 48 hours. The preferred time is 12 to 36 hours.

[0015] In the above technical solution, the light is visible light, specifically LED light illumination. Preferably, the power of the LED light is 14 W to 50 W. Preferably, the LED light is a purple LED light with a power of 28 W to 38 W.

[0016] In the above technical solution, the inert gas is argon; the solvent is acetonitrile.

[0017] In the above technical solution, the molar ratio of the catalyst, lithium chloride, and acrylonitrile is 0.05 to 0.15∶0.1 to 0.3∶1. Preferably, it is 0.08 to 0.12∶0.1 to 0.2∶1. The molar ratio of acrylonitrile to toluene compounds is 0.3∶2 to 6 mmol, preferably 0.3∶3 to 5.

[0018] In the above technical solution, after the reaction is completed, it is extracted with ethyl acetate, and the product is purified by column chromatography to obtain 4-arylbutyronitrile compounds.

[0019] The reaction process of the present invention can be represented as follows:

[0020]

[0021] Due to the application of the above technical solution, the present invention has the following advantages:

[0022] 1. The present invention uses a catalytic system composed of an iron(III) complex and lithium chloride. For the first time, at room temperature, with visible light as the energy source and without adding a photocatalyst, the hydroalkylation reaction of acrylonitrile with toluene compounds is realized, providing a new synthesis method for 4-arylbutyronitrile compounds. Compared with the existing synthesis methods, the reaction conditions of the present invention are mild, without the need for precious metal photocatalysts, and the reaction has 100% atom economy (this reaction has no other by-products and is 100% converted into the target product);

[0023] 2. The catalytic system composed of the iron(III) complex and lithium chloride used in the present invention is cheap and easily available, and the raw materials such as the reactants used are also cheap and easily available, which is conducive to large-scale synthesis applications and also conforms to the development concept of sustainable green synthesis chemistry. Specific Embodiments

[0024] The substrates, ethyl acetate, and petroleum ether used in the present invention are all commercially available products. The acetonitrile used is a commercially available ultra-dry solvent, and tetrahydrofuran and n-hexane are both ultra-dry solvents treated in the laboratory. The specific preparation methods and testing methods are conventional techniques in the art, and the yield is the isolated yield (except as specifically indicated). The reactions of the present invention are all carried out at room temperature.

[0025] Example 1 Synthesis of Iron(III) Complex [HIBnBn CN [FeCl4]

[0026] 1-(4-Cyanobenzyl)-3-benzylimidazolium chloride (0.31 g, 1.0 mmol) and iron(III) chloride (0.15 g, 0.9 mmol) were added to 20 mL of a tetrahydrofuran solution, and the reaction was carried out at 60 o °C for 24 h. After centrifugation, n-hexane was added to the obtained supernatant, and recrystallization was carried out. A red-brown solid powder was precipitated at room temperature, filtered, and the yield was 80%.

[0027] The chemical structural formula is as follows:

[0028]

[0029] Elemental analysis of the product was carried out, and the results are as follows:

[0030]

[0031] The iron(III) complex [HIBnBn CN [FeCl4] exists in the form of an ion pair, and the anion [FeCl4] - was characterized by Raman spectroscopy and found to have a characteristic peak at 330 cm -1 , which is consistent with the literature reports (reference Inorg. Chem. , 2001, 40 , 2298.). The cation [HIBnBn CN + of the iron(III) complex was characterized by high-resolution mass spectrometry and found to have a molecular ion peak at 274.3470. Theoretically, the molecular ion peak of [HIBnBn CN + is at 274.3470, and the measured value is consistent with the theoretical value. It is proved that the obtained compound is the target iron(III) complex.

[0032] Example 2 Using [HIBnBn CN [FeCl4] as a catalyst, the photo-catalytic hydroalkylation reaction of acrylonitrile and toluene

[0033] Under nitrogen protection, the catalyst (14.2 mg, 0.03 mmol), acrylonitrile (20 μL, 0.3 mmol), lithium chloride (1.3 mg, 0.03 mmol), toluene (0.48 mL, 4.5 mmol) were successively added to the reaction flask, and acetonitrile (1.0 mL) was used as the solvent. At room temperature, the reaction was irradiated with a 30 W 390 nm LED lamp for 24 h, quenched with water, and the reaction product was extracted with ethyl acetate and purified by column chromatography (using a mixed solvent of ethyl acetate / petroleum ether with a volume ratio of 1:20 as the eluent), and the yield was 92%.

[0034] ​​The product was dissolved in CDCl3 (0.4 mL), sealed in a tube, and characterized by measurement on a Unity Inova-400 NMR spectrometer at room temperature: 1 1H NMR (400 MHz, CDCl3) δ 7.34 – 7.27 (m, 2H), 7.26 – 7.22 (m, 1H), 7.21– 7.15 (m, 2H), 2.78 (t, J J = 7.4 Hz, 2H), 2.31 (t, J J = 7.1 Hz, 2H), 1.98 (p, J J=7.2 Hz, 2H).

[0035] Based on the above reaction of acrylonitrile and toluene, single-factor changes were made, and the results are as follows:

[0036]

[0037]

[0038] a Reaction conditions: 1 (0.3 mmol), 2 (4.5 mmol), catalyst (10 mol%), LiCl (10 mol%), acetonitrile 1.0 mL, reaction at room temperature for 24 h. The gas-phase yield of the product was monitored by gas chromatography using n-dodecane as an internal standard. b Without lithium chloride.

[0039]

[0040]

[0041]

[0042]

[0043]

[0044] Using [HIBnBn CN [FeCl4] as the catalyst, the product yields obtained with different light sources are as follows:

[0045]

[0046]

[0047] Using [HIBnBn CN [FeCl4] as the catalyst, the product yields obtained with different amounts of toluene are as follows:

[0048]

[0049] Example 3 Using [HIBnBn CN [FeCl4] as the catalyst, the hydroalkylation reaction of 2-fluorotoluene and acrylonitrile was catalyzed by visible light

[0050] Under nitrogen protection, iron catalyst (14.2 mg, 0.03 mmol), acrylonitrile (20 μL, 0.3 mmol), lithium chloride (1.3 mg, 0.03 mmol) and 2-fluorotoluene (0.5 mL, 4.5 mmol) were successively added into the reaction flask. Using acetonitrile (1.0 mL) as the solvent, at room temperature, the reaction was irradiated with a 30 W 390 nm LED lamp for 24 hours, the reaction was quenched with water, the reaction product was extracted with ethyl acetate, and purified by column chromatography (using a mixed solvent with a volume ratio of ethyl acetate / petroleum ether of 1:20 as the eluent), and the yield was 58%.

[0051] The product was dissolved in CDCl3 (0.4 mL), sealed in a tube, and characterized on a Unity Inova-400 NMR spectrometer at room temperature: 1 H NMR (400 MHz, CDCl3) δ 7.25 – 7.17 (m, 2H), 7.11 – 7.00 (m, 2H), 2.84– 2.78 (m, 2H), 2.35 (t, J = 7.2 Hz, 2H), 1.99 (p, J = 7.2 Hz, 2H).

[0052] Example 4 Using [HIBnBn CN [FeCl4] as the catalyst, the hydroalkylation reaction of 3-fluorotoluene and acrylonitrile was catalyzed by visible light

[0053] Under nitrogen protection, iron catalyst (14.2 mg, 0.03 mmol), acrylonitrile (20 μL, 0.3 mmol), lithium chloride (1.3 mg, 0.03 mmol) and 3-fluorotoluene (0.5 mL, 4.5 mmol) were successively added into the reaction flask. Using acetonitrile (1.0 mL) as the solvent, at room temperature, the reaction was irradiated with a 30 W 390 nm LED lamp for 24 hours, the reaction was quenched with water, the reaction product was extracted with ethyl acetate, and purified by column chromatography (using a mixed solvent with a volume ratio of ethyl acetate / petroleum ether of 1:20 as the eluent), and the yield was 60%.

[0054] The product was dissolved in CDCl3 (0.4 mL), sealed in a tube, and characterized on a Unity Inova-400 NMR spectrometer at room temperature:1 1H NMR (400 MHz, CDCl3) δ 7.24 – 7.16 (m, 1H), 6.93 – 6.79 (m, 3H), 2.71 (t, J J = 7.5 Hz, 2H), 2.26 (t, J J = 7.1 Hz, 2H), 1.91 (p, J J = 7.1 Hz, 2H).

[0055] Example 5 Using [HIBnBn CN [FeCl4] as the catalyst, the hydroalkylation reaction of 4-fluorotoluene with acrylonitrile was catalyzed by visible light

[0056] Under nitrogen protection, iron catalyst (14.2 mg, 0.03 mmol), acrylonitrile (20 μL, 0.3 mmol), lithium chloride (1.3 mg, 0.03 mmol) and 4-fluorotoluene (0.5 mL, 4.5 mmol) were successively added to the reaction flask. Using acetonitrile (1.0 mL) as the solvent, at room temperature, the reaction was irradiated with a 30 W 390 nm LED lamp for 24 hours. The reaction was quenched with water, and the reaction product was extracted with ethyl acetate and purified by column chromatography (using a mixed solvent with a volume ratio of ethyl acetate / petroleum ether of 1:20 as the eluent), and the yield was 92%.

[0057] The product was dissolved in CDCl3 (0.4 mL), sealed in a tube, and characterized by measurement on a Unity Inova-400 NMR instrument at room temperature: 1 1H NMR (400 MHz, CDCl3) δ 7.17 – 7.12 (m, 2H), 7.03 – 6.96 (m, 2H), 2.76 (t, J J = 7.5 Hz, 2H), 2.32 (t, J J = 7.0 Hz, 2H), 1.96 (p, J J = 7.1 Hz, 2H).

[0058] Example 6 Using [HIBnBn CN [FeCl4] as the catalyst, the hydroalkylation reaction of 4-chlorotoluene with acrylonitrile was catalyzed by visible light

[0059] Under nitrogen protection, iron catalyst (14.2 mg, 0.03 mmol), acrylonitrile (20 μL, 0.3 mmol), lithium chloride (1.3 mg, 0.03 mmol) and 4-chlorotoluene (0.53 mL, 4.5 mmol) were successively added into a reaction flask. Using acetonitrile (1.0 mL) as the solvent, the reaction was irradiated with a 30 W 390 nm LED lamp at room temperature for 24 hours. The reaction was quenched with water, and the reaction product was extracted with ethyl acetate and purified by column chromatography (using a mixed solvent with a volume ratio of ethyl acetate / petroleum ether of 1:20 as the eluent), and the yield was 73%.

[0060] The product was dissolved in CDCl3 (0.4 mL), sealed in a tube, and characterized by measurement on a Unity Inova-400 NMR instrument at room temperature: 1 1H NMR (400 MHz, CDCl3) δ 7.31 – 7.25 (m, 2H), 7.15 – 7.09 (m, 2H), 2.76 (t, J J = 7.5 Hz, 2H), 2.32 (t, J J = 7.0 Hz, 2H), 1.96 (p, J J = 7.1 Hz, 2H).

[0061] Example 7 Visible-light-catalyzed hydroalkylation reaction of 4-bromotoluene with acrylonitrile using [HIBnBn CN [FeCl4] as the catalyst

[0062] Under nitrogen protection, the catalyst (14.2 mg, 0.03 mmol), acrylonitrile (20 μL, 0.3 mmol), lithium chloride (1.3 mg, 0.03 mmol) and 4-bromotoluene (0.55 mL, 4.5 mmol) were successively added into a reaction flask. Using acetonitrile (1.0 mL) as the solvent, the reaction was irradiated with a 30 W 390 nm LED lamp at room temperature for 24 hours. The reaction was quenched with water, and the reaction product was extracted with ethyl acetate and purified by column chromatography (using a mixed solvent with a volume ratio of ethyl acetate / petroleum ether of 1:10 as the eluent), and the yield was 73%.

[0063] The product was dissolved in CDCl3 (0.4 mL), sealed in a tube, and characterized by measurement on a Unity Inova-400 NMR instrument at room temperature: 1 1H NMR (400 MHz, CDCl3) δ 7.47 – 7.40 (m, 2H), 7.10 – 7.03 (m, 2H), 2.74 (t, J J = 7.4 Hz, 2H), 2.32 (t,J = 7.0 Hz, 2H), 2.02 – 1.91 (m, 2H).

[0064] Example VIII Using [HIBnBn CN [FeCl4] as the catalyst, the hydroalkylation reaction of p-xylene and acrylonitrile was catalyzed by visible light

[0065] Under nitrogen protection, iron catalyst (14.2 mg, 0.03 mmol), acrylonitrile (20 μL, 0.3 mmol), lithium chloride (1.3 mg, 0.03 mmol) and p-xylene (0.56 mL, 4.5 mmol) were successively added to the reaction flask. Using acetonitrile (1.0 mL) as the solvent, at room temperature, the reaction was irradiated with a 30 W 390 nm LED lamp for 24 hours, the reaction was quenched with water, the reaction product was extracted with ethyl acetate, and purified by column chromatography (using a mixed solvent with a volume ratio of ethyl acetate / petroleum ether of 1:30 as the eluent), and the yield was 73%.

[0066] The product was dissolved in CDCl3 (0.4 mL), sealed in a tube, and characterized by measurement on a Unity Inova-400 NMR spectrometer at room temperature: 1 1H NMR (400 MHz, CDCl3) δ 7.14 – 7.05 (m, 4H), 2.73 (t, J = 7.4 Hz, 2H), 2.32 (s, J = 1.7 Hz, 3H), 2.29 (t, J = 7.1 Hz, 2H), 1.96 (p, J = 7.2 Hz, 2H).

[0067] Example IX Using [HIBnBn CN [FeCl4] as the catalyst, the hydroalkylation reaction of p-methoxytoluene and acrylonitrile was catalyzed by visible light

[0068] Under nitrogen protection, iron catalyst (14.2 mg, 0.03 mmol), acrylonitrile (20 μL, 0.3 mmol), lithium chloride (1.3 mg, 0.03 mmol) and p-methoxytoluene (0.57 mL, 4.5 mmol) were successively added to the reaction flask. Using acetonitrile (1.0 mL) as the solvent, at room temperature, the reaction was irradiated with a 30 W 390 nm LED lamp for 24 hours, the reaction was quenched with water, the reaction product was extracted with ethyl acetate, and purified by column chromatography (using a mixed solvent with a volume ratio of ethyl acetate / petroleum ether of 1:10 as the eluent), and the yield was 28%.

[0069] The product was dissolved in CDCl3 (0.4 mL), sealed in a tube, and characterized by measurement on a Unity Inova-400 NMR spectrometer at room temperature: 1 H NMR (400 MHz, CDCl3) δ 7.13 – 7.08 (m, 2H), 6.88 – 6.82 (m, 2H), 3.79(s, 3H), 2.72 (t, J = 7.4 Hz, 2H), 2.32 – 2.28 (m, 2H), 1.95 (p, J = 7.2 Hz, 2H).

[0070] Example 10 Using [HIBnBn CN [FeCl4] as a catalyst, the hydroalkylation reaction of p-tert-butyltoluene with acrylonitrile was catalyzed by visible light

[0071] Under nitrogen protection, iron catalyst (14.2 mg, 0.03 mmol), acrylonitrile (20 μL, 0.3 mmol), lithium chloride (1.3 mg, 0.03 mmol) and p-tert-butyltoluene (0.78 mL, 4.5 mmol) were successively added to a reaction flask. Using acetonitrile (1.0 mL) as a solvent, at room temperature, the reaction was irradiated with a 30 W 390 nm LED lamp for 24 hours, quenched with water, and the reaction product was extracted with ethyl acetate and purified by column chromatography (using a mixed solvent with a volume ratio of ethyl acetate / petroleum ether of 1:10 as the eluent), and the yield was 37%.

[0072] The product was dissolved in CDCl3 (0.4 mL), sealed in a tube, and characterized by measurement on a Unity Inova-400 NMR spectrometer at room temperature: 1 H NMR (400 MHz, CDCl3) δ 7.35 – 7.31 (m, 2H), 7.14 – 7.10 (m, 2H), 2.75(t, J = 7.4 Hz, 2H), 2.34 – 2.30 (m, 2H), 1.97 (p, J = 7.2 Hz, 2H), 1.31 (s, 9H).

[0073] Example 11 Using [HIBnBn CN [FeCl4] as a catalyst, the hydroalkylation reaction of p-cyanotoluene with acrylonitrile was catalyzed by visible light

[0074] Under nitrogen protection, iron catalyst (14.2 mg, 0.03 mmol), acrylonitrile (20 μL, 0.3 mmol), lithium chloride (1.3 mg, 0.03 mmol) and p-cyanotoluene (0.78 mL, 4.5 mmol) were successively added into a reaction flask. Using acetonitrile (1.0 mL) as the solvent, at room temperature, the reaction was irradiated with a 30 W 390 nm LED lamp for 24 hours, quenched with water, and the reaction product was extracted with ethyl acetate and purified by column chromatography (using a mixed solvent with a volume ratio of ethyl acetate / petroleum ether of 1:5 as the eluent), and the yield was 52%.

[0075] The product was dissolved in CDCl3 (0.4 mL), sealed in a tube, and characterized by measurement on a Unity Inova-400 NMR spectrometer at room temperature: 1 H NMR (400 MHz, CDCl3) δ 7.65 – 7.59 (m, 2H), 7.35 – 7.29 (m, 2H), 2.90– 2.83 (t, 2H), 2.36 (t, J J = 7.0 Hz, 2H), 2.01 (m, J J = 8.8, 7.0 Hz, 2H).

[0076] Example 12 Hydrogen alkylation reaction of acetophenone with acrylonitrile using [HIBnBn CN [FeCl4] as the catalyst under visible light

[0077]

[0078] Under nitrogen protection, iron catalyst (14.2 mg, 0.03 mmol), acrylonitrile (20 μL, 0.3 mmol), lithium chloride (1.3 mg, 0.03 mmol) and acetophenone (0.6 mL, 4.5 mmol) were successively added into a reaction flask. Using acetonitrile (1.0 mL) as the solvent, at room temperature, the reaction was irradiated with a 30 W 390 nm LED lamp for 24 hours, quenched with water, and the reaction product was extracted with ethyl acetate and purified by column chromatography (using a mixed solvent with a volume ratio of ethyl acetate / petroleum ether of 1:5 as the eluent), and the yield was 62%.

[0079] The product was dissolved in CDCl3 (0.4 mL), sealed in a tube, and characterized by measurement on a Unity Inova-400 NMR spectrometer at room temperature: 1 H NMR (400 MHz, CDCl3) δ 7.94 – 7.89 (m, 2H), 7.32 – 7.28 (m, 2H), 2.85(t,J = 7.5 Hz, 2H), 2.59 (s, 3H), 2.35 (t, J = 7.0 Hz, 2H), 2.01 (m, J = 8.6, 7.1Hz, 2H).

[0080] Example XIII Using [HIBnBn CN [FeCl4] as a catalyst, the hydroalkylation reaction of methyl p - toluate with acrylonitrile was catalyzed by visible light

[0081]

[0082] Under nitrogen protection, iron catalyst (14.2 mg, 0.03 mmol), acrylonitrile (20 μL, 0.3 mmol), lithium chloride (1.3 mg, 0.03 mmol) and methyl p - toluate (0.63 mL, 4.5 mmol) were successively added into a reaction flask. Using acetonitrile (1.0 mL) as the solvent, at room temperature, the reaction was irradiated with a 30 W 390 nm LED lamp for 24 hours. The reaction was quenched with water, and the reaction product was extracted with ethyl acetate and purified by column chromatography (using a mixed solvent with a volume ratio of ethyl acetate / petroleum ether of 1:5 as the eluent), and the yield was 75%.

[0083] The product was dissolved in CDCl3 (0.4 mL), sealed in a tube, and characterized on a Unity Inova - 400 NMR spectrometer at room temperature: 1 H NMR (400 MHz, CDCl3) δ 8.01 – 7.97 (m, 2H), 7.29 – 7.25 (m, 2H), 3.91(s, 3H), 2.84 (t, J = 7.5 Hz, 2H), 2.34 (t, J = 7.0 Hz, 2H), 2.01 (m, J = 8.5, 7.0Hz, 2H).

[0084] Example XIV Using [HIBnBn CN [FeCl4] as a catalyst, the hydroalkylation reaction of mesitylene with acrylonitrile was catalyzed by visible light

[0085]

[0086] Under nitrogen protection, iron catalyst (14.2 mg, 0.03 mmol), acrylonitrile (20 μL, 0.3 mmol), lithium chloride (1.3 mg, 0.03 mmol) and mesitylene (0.63 mL, 4.5 mmol) were successively added into a reaction flask. Using acetonitrile (1.0 mL) as the solvent, at room temperature, the reaction was irradiated with a 30 W 390 nm LED lamp for 24 hours, quenched with water, and the reaction product was extracted with ethyl acetate and purified by column chromatography (using a mixed solvent with a volume ratio of ethyl acetate / petroleum ether of 1:5 as the eluent), and the yield was 24%.

[0087] The product was dissolved in CDCl3 (0.4 mL), sealed in a tube, and characterized by measurement on a Unity Inova-400 NMR spectrometer at room temperature: 1 1H NMR (400 MHz, CDCl3) δ 6.87 (s, 1H), 6.80 (d, J J = 1.6 Hz, 2H), 2.70 (t, J J = 7.4 Hz, 2H), 2.32 (t, J J = 7.1 Hz, 2H), 2.29 (s, 6H), 1.96 (p, J J = 7.2 Hz, 2H).

[0088] Example 15 Using [HIBnBn CN [FeCl4] as the catalyst, the hydroalkylation reaction of ethylbenzene and acrylonitrile was catalyzed by visible light.

[0089]

[0090] Under nitrogen protection, iron catalyst (14.2 mg, 0.03 mmol), acrylonitrile (20 μL, 0.3 mmol), lithium chloride (1.3 mg, 0.03 mmol) and ethylbenzene (0.55 mL, 4.5 mmol) were successively added into a reaction flask. Using acetonitrile (1.0 mL) as the solvent, at room temperature, the reaction was irradiated with a 30 W 390 nm LED lamp for 24 hours, quenched with water, and the reaction product was extracted with ethyl acetate and purified by column chromatography (using a mixed solvent with a volume ratio of ethyl acetate / petroleum ether of 1:20 as the eluent), and the yield was 30%.

[0091] The product was dissolved in CDCl3 (0.4 mL), sealed in a tube, and characterized by measurement on a Unity Inova-400 NMR spectrometer at room temperature: 11H NMR (400 MHz, CDCl3) δ 7.36 – 7.29 (m, 2H), 7.25 – 7.16 (m, 3H), 2.91– 2.81 (m, 1H), 2.27 – 2.06 (m, 2H), 2.02 – 1.83 (m, 2H), 1.31 (d, J J = 7.0 Hz, 3H).

[0092] Example 16 Using [HIBnBn CN [FeCl4] as a catalyst, the hydroalkylation reaction of cumene and acrylonitrile was catalyzed by visible light

[0093]

[0094] Under nitrogen protection, iron catalyst (14.2 mg, 0.03 mmol), acrylonitrile (20 μL, 0.3 mmol), lithium chloride (1.3 mg, 0.03 mmol) and cumene (0.55 mL, 4.5 mmol) were successively added into the reaction flask. Using acetonitrile (1.0 mL) as the solvent, at room temperature, the reaction was irradiated with a 30 W 390 nm LED lamp for 24 hours, quenched with water, and the reaction product was extracted with ethyl acetate and purified by column chromatography (using a mixed solvent with a volume ratio of ethyl acetate / petroleum ether of 1:20 as the eluent), and the yield was 30%.

[0095] The product was dissolved in CDCl3 (0.4 mL), sealed in a tube, and characterized by measurement on a Unity Inova-400 NMR spectrometer at room temperature: 1 1H NMR (400 MHz, CDCl3) δ 7.35 – 7.32 (m, 2H), 7.30 (d, J J = 1.7 Hz, 2H), 7.25 – 7.21 (m, 1H), 2.03 – 2.01 (m, 4H), 1.36 (s, 6H).

Claims

1. A method for synthesizing 4-arylbutyronitrile compounds, characterized in that, It includes the following steps: in an inert gas, using acrylonitrile and a toluene compound as raw materials, under the presence of a catalyst of iron(III) complex [HIBnBnCN][FeCl4], lithium chloride and a solvent, a photoreaction is carried out to obtain 4-arylbutyronitrile compounds; the toluene compound is represented by the following chemical formula: ； R 1 is one or more of hydrogen, halogen, alkyl, alkoxy, and cyano; The chemical structural formula of the iron(III) complex [HIBnBnCN][FeCl4] is as follows: 。 2. The method for synthesizing 4-arylbutyronitrile compounds according to claim 1, characterized in that, R 1 is hydrogen, fluorine, chlorine, bromine, methyl, methoxy, tert-butyl, cyano.

3. The method for synthesizing 4-arylbutyronitrile compounds according to claim 1, characterized in that, The 4-arylbutyronitrile compounds are represented by the following chemical structural formula: ； wherein R 1 is derived from a toluene compound.

4. The method for synthesizing 4-arylbutyronitrile compounds according to claim 1, wherein The reaction temperature is room temperature and the time is 6 to 48 hours.

5. The method for synthesizing 4-arylbutyronitrile compounds according to claim 1, wherein, The light irradiation is visible light irradiation.

6. The method for synthesizing 4-arylbutyronitrile compounds according to claim 1, wherein, The molar ratio of the catalyst, lithium chloride and acrylonitrile is 0.05 to 0.15∶0.1 to 0.3∶1.

7. Use of the iron(III) complex [HIBnBnCN][FeCl4] as a catalyst in the synthesis of the 4-arylbutyronitrile compounds described in claim 1, characterized in that, The chemical structural formula of the iron(III) complex [HIBnBnCN][FeCl4] is as follows: 。

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