Method for preparing tertiary benzylamine through photocatalysis

Abstract

The invention discloses a method for preparing tertiary benzylamine through photocatalysis, and belongs to the field of organic synthesis. According to the process disclosed by the invention, amine is taken as a raw material, diarylamine pyran salt is taken as a catalyst, and an amine derivative arylation product can be obtained at a relatively high yield under the irradiation of 456 nm visible light. According to the method, acid and high-temperature conditions are not needed, meanwhile, residues of transition metal are avoided, and various tertiary benzylamine is catalytically synthesized under mild reaction conditions by adopting a novel and low-cost organic photocatalyst.

Description

Technical Field

[0001] The invention belongs to the field of organic synthesis, and in particular relates to a method for preparing tertiary benzylamine by photocatalysis. Background Art

[0002] Tertiary benzylamine structures are often found in drug molecules, such as Imatinib and Alogliptin, which are among the top 200 small molecule drugs sold (see: Vitaku, E.; Smith, DT; Njardarson, JTJ Med.Chem. 2014, 57, 10257.). Currently, the most direct and economical synthesis method is to use the free radical arylation of cheap and readily available tertiary amines. In 2011, MacMillan's group used Ir(ppy) 3 As a photocatalyst, it undergoes oxidative quenching to achieve arylation of tertiary amines (see: McNally, Andrew; Prier, Christopher K.; MacMillan, David WC Science 2011, 334 , 1114-1117.). In subsequent studies, Ir(ppy) was also used. 3 As a photocatalyst to synthesize tertiary benzylamine. Despite the above research progress, the above method has certain limitations. The reaction requires the addition of precious metal photocatalysts, which easily results in metal residues, which is not conducive to large-scale production. Therefore, it is of great research value to develop a method to achieve amine α-position functionalization under low-cost organic photocatalysts without transition metals and high temperatures from a wide range of substrate raw materials. Summary of the invention

[0003] The object of the present invention is to provide a method for preparing tertiary benzylamine by photocatalysis, which is specifically achieved by the following technical scheme: A method for preparing tertiary benzylamine by photocatalysis As raw materials, triaryl pyryl salt It is a photocatalyst that can realize α-position arylation and heteroarylation of amines under visible light irradiation.

[0004] Furthermore, the raw materials The R1, R2, and R3 groups are various substituted aryl, heteroaryl, or alkyl groups.

[0005] Furthermore, the triaryl pyrylium salt is a diarylamine pyrylium salt (DPA-TPT) .

[0006] Furthermore, the amount of photocatalyst added is 2%-5% by mole of the raw material.

[0007] Furthermore, the reaction is carried out in an inert gas atmosphere using N,N-dimethylformamide as solvent.

[0008] Furthermore, the visible light is blue light.

[0009] The synthetic route of the present invention is as follows:

[0010] Typical reactions are as follows:

[0011] The beneficial effects of the present invention are: The method has mild conditions and avoids the residue of transition metal. A pyrylium salt substituted with a diarylamine as a low-cost organic photocatalyst is adopted, and the α-position CH bond aromaticity and heteroarylization of the tertiary amine are achieved through reduction quenching, thereby preparing various tertiary benzylamines. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the embodiments. If the specific conditions are not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0013] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0014] The photocatalyst diarylamine pyrylium salt used in the present invention is synthesized by the following method:

[0015] According to the literature a) Qianqian Qiu, Pengfei Xu, Yanjun Zhu, Junru Yu, MengruWei, Wenbin Xi, Dr. Hui Feng, Prof. Jianrong Chen, Prof. Zhaosheng Qian.Chem.Eur. J. 2019, 25, 15983-15987. b) A. Franconetti, L. Contreras-Bernal, S.Jatunov, M. Gómez-Guillén, M. Angulo, R. Prado-Gotor, F. Phys. Chem. Chem.Phys. 2014, 16, 18442-18453. and repeated trials, the specific steps are as follows: Step 1: In a dry 100 mL round-bottom flask, triphenylamine (1.0 equivalent, 10 mmol) and zinc chloride (2.0 equivalent, 20 mmol) were dissolved in dichloromethane (20 mL), and then acetyl chloride (1.0 equivalent, 10 mmol) in dichloromethane solution (2 mL) was slowly added dropwise, stirred vigorously at room temperature for more than 5 minutes, and then refluxed for 20 hours. After the reaction solution was cooled to room temperature, it was added to HCl aqueous solution (2 M, 100 mL), and the organic phase was extracted with dichloroethane, and the collected organic phase was dried over anhydrous sodium sulfate. The desiccant was filtered to obtain an organic clear liquid, which was then concentrated using a rotary evaporator to remove the organic solvent. Finally, it was purified by column chromatography, eluted with petroleum ether (60-90 ℃)-ethyl acetate solution (V petroleum ether: V ethyl acetate = 20:1), and the pure solution was collected and concentrated using a rotary evaporator to remove the organic solvent to obtain the crude product 1-(4-(N,N-diphenylamino)phenyl)ethanone.

[0016] Step 2: Add 1-(4-(N,N-diphenylamino)phenyl)ethanone (1.0 equivalent, 5 mmol) and trans-chalcone (2.0 equivalent, 10 mmol) synthesized in the previous step to a 100 mL dry round-bottom flask, then add 20 mL of DCE (1,2-dichloroethane), react at 80 °C, slowly drop tetrafluoroboric acid-diethyl ether complex (2.0 equivalent, 10 mmol), it can be observed that the reaction solution changes from yellow to blue-purple, then heat and reflux for 1.5 hours. After the reaction is completed, cool to room temperature, wash with ice ether, filter and dry to obtain a crude product of black purple solid. The crude product is purified by column chromatography using dichloromethane to dichloromethane-acetone solution (V petroleum ether: V acetone = 20:1) for gradient elution to obtain the desired product purple solid.

[0017] 2-(4-(diphenylamino)phenyl)-4,6-diphenylpyrylium tetrafluoroborate(DPA-TPT) 1 H NMR (400 MHz, DMSO- d 6 ) δ 8.85 (s, 2H), 8.48 (t, J = 7.4 Hz, 4H),8.44 (d, J = 9.1 Hz, 2H), 7.81 (d, J = 7.9 Hz, 2H), 7.77 – 7.69 (m, 5H), 7.52 (t, J = 7.8 Hz, 4H), 7.37 – 7.31 (m, 6H), 6.95 (d, J = 9.1 Hz, 2H). 13 C NMR (101 MHz, DMSO- d 6 ) δ 170.2, 167.7, 162.8, 154.2, 145.0, 135.5, 133.3, 131.7, 130.8,130.5, 130.4, 130.2, 129.9, 129.8, 129.6, 129.3, 128.6, 127.5, 127.2, 118.1.HRMS (ESI), m / z: [M + ] calculated for C 35 H 26 NO + 476.2009; found 476.2019. The raw material tertiary amine used in the present invention is synthesized by the following method:

[0018] According to the literature a) R. Wang, J. Wang, Y. Zhang, B. Wang, Y. Xia, F. Xue, W.Jin and C. Liu, Adv. Synth. Catal., 2023, 365, 900. b) SaekoNishimoto,HiromichiNakahashi,MasahiroToyota, Tetrahedron Letters 61 (2020) 152599. c) Z. Li and C.-J. Li, J. Am. Chem. Soc., 2005,127, 6968. The specific steps are as follows: (1) Synthesis steps of secondary amines: First, prepare a dry round-bottom flask equipped with a magnetic stirrer, add the reaction raw materials aniline derivative (1.0 equivalent), haloformamide (1.2 equivalent) and sodium bicarbonate (1.5 equivalent) into the round-bottom flask, and finally add DMSO solvent (1 mL / mmol) to react at room temperature for about 12 hours. Monitor the reaction by TLC. After the reaction is completed, add water and ethyl acetate to extract the organic matter, and finally use anhydrous MgSO 4 The organic phase was dried, filtered, and the solution was concentrated under reduced pressure, and the obtained residue was subjected to column chromatography to finally collect our product.

[0019] (2) Synthesis steps of tertiary amine: First, prepare a dry round-bottom flask equipped with a magnetic stirrer, add the reaction raw materials aniline derivative (1.25 equivalents), dibromobutane (1.0 equivalents), and potassium carbonate (2.0 equivalents) into the round-bottom flask, and finally add acetonitrile (1 mL / mmol), reflux at 90 °C, and react for 12 hours. Monitor the reaction by TLC, and extract the liquid after the reaction with water and ethyl acetate to extract the organic matter, and finally use anhydrous MgSO 4 The organic phase was dried, filtered, and the solution was concentrated under reduced pressure, and the obtained residue was finally purified by silica gel column chromatography to obtain the desired product.

[0020] Example 1 Weigh 1,4-dicyanobenzene (25.6 mg, 0.2 mmol), sodium carbonate (4.2 mg, 0.04 mmol), (48.6 mg, 0.3 mmol), photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol), then carefully added to the reaction tube, vented three times through the double-row tube, and added 2 mL of N,N-dimethylformamide in a nitrogen atmosphere. Then placed under two 456 nm, 45 W blue light lamps, reacted at room temperature for 12 h. Dry loading, column chromatography (300-400 mesh chromatography silica gel) to obtain the product 37.1 mg, (petroleum ether: ethyl acetate = 20:1), yield 71%. 1 H NMR (400 MHz, Chloroform-d)δ7.58 (d, J = 7.1 Hz, 2H), 7.34 (d, J = 7.9 Hz, 2H), 6.96 (d, J= 7.9 Hz, 2H), 6.35 (d, J = 8.1 Hz, 2H), 4.69 (d, J = 8.7 Hz, 1H), 3.72 (t, J= 5.4 Hz, 1H), 3.39 (q, J = 8.2 Hz, 1H), 2.42 (q, J = 8.9 Hz, 1H), 2.21 (s,3H), 1.99 (dq, J = 9.8, 6.4, 5.3 Hz, 2H), 1.93 – 1.85 (m, 1H). Weigh 1,4-dicyanobenzene (25.6 mg, 0.2 mmol), sodium carbonate (4.2 mg, 0.04 mmol), (73.5 mg, 0.3 mmol), photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol), then carefully added to the reaction tube, vented three times through the double-row tube, and added 2 mL of N,N-dimethylformamide in a nitrogen atmosphere. Then placed under two 456 nm, 45 W blue light lamps, reacted at room temperature for 12 h. Dry loading, column chromatography (300-400 mesh chromatography silica gel) to obtain the product 42.1 mg, (petroleum ether: ethyl acetate = 20:1), yield 61%. 1H NMR (400MHz, Chloroform-d) δ 7.60 (d, J = 8.0 Hz, 2H), 7.33 (d, J = 8.0 Hz, 2H), 6.83 (d, J = 8.9 Hz, 1H), 6.69 (d, J = 2.7 Hz, 1H), 6.45 (dd, J = 9.0, 3.0 Hz, 1H), 4.67 (dd, J = 8.4, 2.2 Hz, 1H), 3.78 (s, 3H), 3.76 – 3.70 (m, 1H), 3.39 (q, J = 8.2 Hz, 1H), 2.52 – 2.40 (m, 1H), 2.03 (dt, J = 11.1, 6.8 Hz, 2H),1.94 – 1.87 (m, 1H). 13 C NMR (101 MHz, Chloroform-d) δ 150.1, 148.7, 140.8,132.5, 126.7, 127.8 – 119.6 (m), 118.8, 116.2, 114.3, 110.8, 110.6 (q, J =5.5 Hz), 63.2, 56.8, 49.8, 36.0, 23.3. HRMS (ESI) cacld for C 19 H 17 F 3 N 2 NaO (M+):369.1185, found 369.1185. Example 2 Weigh 1,4-dicyanobenzene (25.6 mg, 0.2 mmol), sodium carbonate (4.2 mg, 0.04 mmol), (56.7 mg, 0.3mmol), photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol), added to the reaction tube, vented three times through the double-row tube, added 2 mL N,N-dimethylformamide in a nitrogen atmosphere, and then placed under two 456 nm, 45W blue light lamps, reacted at room temperature for 12 h. Dry loading, column chromatography (300-400 mesh chromatography silica gel) to obtain the product 45.3 mg, (petroleum ether: ethyl acetate = 20:1), yield 75%. 1H NMR (400 MHz, Chloroform-d) δ 7.59 (d, J = 8.0 Hz, 2H), 7.31 (d, J = 8.0 Hz, 2H), 6.97 (d,J = 8.3 Hz, 2H), 6.48 (d, J = 8.4 Hz, 2H), 4.61 (dd, J = 11.8, 5.9 Hz, 1H),3.84 (d, J = 13.1 Hz, 1H), 3.47 (dd, J = 14.5, 11.2 Hz, 1H), 2.21 (s, 3H),2.01 – 1.88 (m, 2H), 1.79 – 1.66 (m, 2H), 1.58 – 1.40 (m, 2H), 1.39 – 1.22(m, 2H). 13 C NMR (101 MHz, Chloroform-d) δ 150.4, 146.3, 132.6, 129.8, 126.7,125.1, 119.0, 63.0, 45.4, 38.2, 29.6, 28.4, 26.6. HRMS (ESI) cacld for C 20 H 23 N 2 (M+): 291.1856, found 291.1856. Weigh 1,4-dicyanobenzene (25.6 mg, 0.2 mmol), sodium carbonate (4.2 mg, 0.04 mmol), (48.9 mg, 0.3 mmol), photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol), added to the reaction tube, vented three times through the double-row tube, added 2 mL N,N-dimethylformamide in a nitrogen atmosphere, and then placed under two 456 nm, 45W purple lamps for reaction at room temperature for 12 h. Dry loading, column chromatography (300-400 mesh chromatography silica gel) to obtain the product 37.4 mg, (petroleum ether: ethyl acetate = 20:1), yield 71%. 1H NMR (400 MHz, Chloroform-d) δ 7.49 (d, J = 6.2 Hz, 2H), 7.42 (d, J = 7.7 Hz, 2H), 7.15 (d,J = 7.3 Hz, 2H), 6.91 – 6.88 (m, 2H), 6.87 (s, 1H), 4.45 – 4.38 (m, 1H), 3.99 – 3.92 (m, 3H), 3.62 (t, J = 9.9 Hz, 1H), 3.41 (d, J = 13.2 Hz, 1H), 3.16 –3.07 (m, 1H). Example 3 Weigh 1,4-dicyanobenzene (25.6 mg, 0.2 mmol), sodium carbonate (4.2 mg, 0.04 mmol), (43.8 mg, 0.3 mmol), photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol), added to the reaction tube, vented three times through the double-row tube, added 2 mL N,N-dimethylformamide in a nitrogen atmosphere, and then placed under two 456 nm, 45W purple lamps for reaction at room temperature for 36 h. Dry loading, column chromatography (300-400 mesh chromatography silica gel) to obtain the product 23.1 mg (petroleum ether: ethyl acetate = 20:1), yield 47%. 1 H NMR (400 MHz, Chloroform-d) δ 7.6 (d, J = 8.2 Hz, 2H), 7.5 (d, J = 8.8 Hz, 2H), 7.3 (d, J =8.2 Hz, 2H), 6.7 (d, J = 9.0 Hz, 2H), 4.7 (s, 2H), 3.2 (s, 3H). 13 C NMR (101MHz, Chloroform-d) δ 151.7, 143.2, 133.8, 132.9, 127.1, 120.4, 118.8, 111.9,111.5, 98.8, 56.0, 39.2. HRMS (ESI) cacld for C 16 H 14 N 3 + (M+H) + : 248.1182, found248.1173. Example 4 Weigh 1,4-dicyanobenzene (25.6 mg, 0.2 mmol), sodium carbonate (4.2 mg, 0.04 mmol), and photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol), add them to the reaction tube, vent three times through the double-row tube, add 2 mL of N,N-dimethylformamide in a nitrogen atmosphere, and finally add (44.1 mg, 0.3 mmol), then placed under two 456 nm, 45 W blue light lamps, reacted at room temperature for 12 h. Dry loading, column chromatography (300-400 mesh silica gel) to obtain the product 35.2 mg, (petroleum ether: ethyl acetate = 20:1), yield 71%. 1 H NMR (400 MHz, Chloroform-d) δ 7.6 (d, J = 8.1 Hz, 2H), 7.3 (d, J = 8.0 Hz, 2H), 7.2 (t, J =7.7 Hz, 1H), 7.0 (d, J = 7.2 Hz, 1H), 6.7 – 6.6 (m, 2H), 4.5 (t, J = 4.6 Hz,1H), 2.9 (s, 3H), 2.6 (dt, J = 15.7, 4.4 Hz, 1H), 2.5 – 2.4 (m, 1H), 2.2 (dq,J = 11.9, 5.9, 5.4 Hz, 1H), 2.0 (dt, J = 13.1, 4.5 Hz, 1H). 13 C NMR (101 MHz, Chloroform-d) δ 149.9, 145.4, 132.3, 128.5, 127.5, 127.2, 122.2, 118.8,116.1, 110.7, 110.1, 63.0, 37.8, 29.6, 23.8. Weigh 1,4-dicyanobenzene (25.6 mg, 0.2 mmol), sodium carbonate (4.2 mg, 0.04 mmol), and photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol), add them to the reaction tube, vent three times through the double-row tube, add 2 mL of N,N-dimethylformamide in a nitrogen atmosphere, and then add (47.3 mg, 0.3 mmol), then placed under two 456 nm, 45 W ultraviolet lamps, reacted at room temperature for 12 h. Dry loading, column chromatography (300-400 mesh silica gel) to obtain the product 51.4 mg, (petroleum ether:ethyl acetate = 20:1), yield 83%.1 H NMR (400MHz, Chloroform-d) δ 7.5 (d, J = 8.4 Hz, 2H), 7.4 (d, J = 8.2 Hz, 2H), 7.2(s, 2H), 7.2 (d, J = 1.7 Hz, 2H), 7.2 (d, J = 2.7 Hz, 1H), 7.2 (q, J = 4.5, 4.0 Hz, 1H), 6.8 – 6.8 (m, 1H), 6.8 (d, J = 7.4 Hz, 2H), 5.8 (s, 1H), 3.7 (dt, J = 10.8, 5.2 Hz, 1H), 3.5 – 3.4 (m, 1H), 3.0 (dt, J = 15.6, 4.9 Hz,1H), 2.9 – 2.8 (m, 1H). Example 5 Weigh 1,4-dicyanobenzene (25.6 mg, 0.2 mmol), sodium carbonate (4.2 mg, 0.04 mmol), and photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol), add them to the reaction tube, vent three times through the double-row tube, add 2 mL of N,N-dimethylformamide in a nitrogen atmosphere, and finally add (38.1 mg, 0.3 mmol), then placed under two 456 nm, 45 W blue light lamps, reacted at room temperature for 12 h. Dry loading, column chromatography (300-400 mesh chromatography silica gel) to obtain the product 23 mg (petroleum ether: ethyl acetate = 10:1), yield 50%. 1 H NMR (400 MHz, Chloroform-d) δ 7.6 (d, J = 8.1 Hz, 2H), 7.4 (d, J = 8.0 Hz, 2H), 3.6 (s,2H), 2.4 (td, J = 9.3, 8.3, 3.0 Hz, 1H), 2.2 (s, 3H), 1.9 – 1.8 (m, 4H), 1.6 (d, J = 12.5 Hz, 1H), 1.3 (h, J = 12.4 Hz, 5H). 13 C NMR (101 MHz, Chloroform-d)δ 146.6, 132.0, 129.1, 119.1, 110.3, 62.8, 57.5, 37.8, 28.7, 26.3, 25.9. Example 6 Weigh 1,4-dicyanobenzene (25.6 mg, 0.2 mmol), sodium carbonate (4.2 mg, 0.04 mmol), and photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol), add them to the reaction tube, vent three times through the double-row tube, add 2 mL of N,N-dimethylformamide in a nitrogen atmosphere, and finally add (63.3 mg, 0.3 mmol), then placed under two 456 nm, 45 W blue light lamps, reacted at room temperature for 24 h. Dry loading, column chromatography (300-400 mesh chromatography silica gel) to obtain the product 39.1 mg (petroleum ether:ethyl acetate = 20:1), yield 61%. 1 H NMR (400MHz, Chloroform-d) δ 7.6 (d, J = 8.4 Hz, 2H), 7.4 (d, J = 8.1 Hz, 2H), 7.3 –7.3 (m, 2H), 7.2 – 7.2 (m, 3H), 7.2 (dd, J = 8.8, 7.3 Hz, 2H), 6.8 – 6.7 (m,3H), 5.2 (q, J = 7.0 Hz, 1H), 4.6 – 4.4 (m, 2H), 1.6 (d, J = 7.0 Hz, 3H). 13 CNMR (101 MHz, Chloroform-d) δ 148.8, 148.6, 139.4, 132.4, 129.1, 128.4,127.6, 126.7, 126.3, 118.8, 117.9, 114.5, 110.7, 57.2, 50.6, 18.7. HRMS (ESI)cacld for C 22 H 21 N 2 + (M+H) + : 313.1699, found 313.1697. Example 7 Weigh 1,4-dicyanobenzene (25.6 mg, 0.2 mmol), sodium carbonate (4.2 mg, 0.04 mmol), (54.9 mg, 0.3 mmol), photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol), added to the reaction tube, vented three times through the double-row tube, added 2 mL N,N-dimethylformamide in a nitrogen atmosphere, and then placed under two 456 nm, 45 W blue light lamps, reacted at room temperature for 36 h. Dry loading, column chromatography (300-400 mesh chromatography silica gel) to obtain the product 34.1 mg (petroleum ether:ethyl acetate = 5:1), yield 60%. 1 H NMR (400 MHz, Chloroform-d) δ 7.6 (d, J = 8.3 Hz, 2H), 7.5 (d, J = 8.2 Hz, 2H), 7.3 (ddd, J= 9.2, 4.5, 2.8 Hz, 2H), 7.3 (dd, J = 8.0, 1.6 Hz, 2H), 7.3 (d, J = 1.6 Hz,1H), 7.2 – 7.1 (m, 2H), 6.8 – 6.7 (m, 1H), 6.5 (d, J = 7.7 Hz, 2H), 5.5 (s,1H), 4.2 (s, 1H). Example 8 Weigh 4-cyanopyridine (20.8 mg, 0.2 mmol), sodium carbonate (4.2 mg, 0.04 mmol), (32.4 mg, 0.3mmol), photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol), added to the reaction tube, vented three times through the double-row tube, added 2 mL N,N-dimethylformamide in a nitrogen atmosphere, and then placed under two 456 nm, 90W blue light lamps, reacted at room temperature for 24 h. Dry loading, column chromatography (300-400 mesh chromatography silica gel) to obtain the product 33.2 mg (petroleum ether: ethyl acetate = 5:1), yield 61%. 1 H NMR (400MHz, Chloroform-d) δ 8.6 (d, J = 4.5 Hz, 2H), 7.4 (d, J = 4.8 Hz, 2H), 6.9(d, J = 7.9 Hz, 2H), 6.5 (d, J = 8.0 Hz, 2H), 5.3 (s, 1H), 3.1 (s, 3H), 3.0 (s, 3H), 2.2 (s, 3H). 13C NMR (101 MHz, Chloroform-d) δ 169.7, 150.2, 147.4,143.4, 129.8, 127.5, 122.7, 113.7, 57.4, 37.1, 36.3, 20.3. HRMS (ESI) cacldfor C 16 H 20 N 3 O + (M+H) + : 270.1601, found 270.1591. Example 9 Weigh (26.8 mg, 0.2 mmol), sodium carbonate (4.2 mg, 0.04 mmol), and photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol) were added to the reaction tube, and the air was purged three times through the double-row tube. 2 mL of N,N-dimethylformamide was added in a nitrogen atmosphere, and finally, (48.6 mg, 0.3 mmol), then placed under two 456 nm, 45 W blue light lamps, reacted at room temperature for 12 h. Dry loading, column chromatography (300-400 mesh chromatography silica gel) to obtain the product 30.1 mg (petroleum ether:ethyl acetate = 5:1), yield 56%. 1 H NMR (400 MHz, Chloroform-d) δ 8.2 (s, 1H), 8.0 (d, J = 4.1 Hz, 1H), 7.1 (d, J = 4.8 Hz, 1H), 7.1 (td,J = 7.3, 2.0 Hz, 2H), 6.9 – 6.8 (m, 2H), 6.8 (t, J = 7.3 Hz, 1H), 4.7 (dd, J= 8.3, 4.0 Hz, 1H), 4.0 (s, 3H), 3.5 (dt, J = 11.9, 4.6 Hz, 1H), 3.1 – 3.0(m, 1H), 2.0 – 1.9 (m, 1H), 1.9 (dt, J = 14.1, 4.1 Hz, 1H), 1.8 (td, J = 8.8,8.3, 4.6 Hz, 1H), 1.8 – 1.7 (m, 1H), 1.7 – 1.6 (m, 1H), 1.6 – 1.5 (m, 1H). 13CNMR (101 MHz, Chloroform-d) δ 152.6, 151.8, 142.7, 141.5, 132.7, 128.8,122.4, 121.0, 120.1, 56.0, 54.4, 54.1, 32.8, 26.0, 22.7. HRMS (ESI) cacld forC 17 H 21 N 2 O + (M+H) + : 269.1649, found 269.1641. Example 10 Pick (42.4 mg, 0.2 mmol), sodium carbonate (4.2 mg, 0.04 mmol), and photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol) were added to the reaction tube, and the air was purged three times through the double-row tube. 2 mL of N,N-dimethylformamide was added in a nitrogen atmosphere, and finally (48.6 mg, 0.3 mmol), then placed under two 456 nm, 45 W blue light lamps, reacted at room temperature for 24 h. Dry loading, column chromatography (300-400 mesh silica gel) to obtain the product 34.3 mg (petroleum ether:ethyl acetate = 10:1), yield 50%. 1 H NMR (400MHz, Chloroform-d) δ 8.5 (d, J = 5.1 Hz, 1H), 7.6 – 7.6 (m, 2H), 7.6 (dd, J =3.3, 1.7 Hz, 1H), 7.2 (d, J = 9.0 Hz, 1H), 7.2 – 7.1 (m, 3H), 6.9 (d, J = 8.5Hz, 2H), 6.8 (t, J = 7.3 Hz, 1H), 4.5 (dd, J = 7.3, 4.2 Hz, 1H), 3.5 – 3.4(m, 1H), 3.2 – 3.2 (m, 1H), 2.3 (d, J = 1.5 Hz, 3H), 2.0 (dq, J = 11.3, 3.7Hz, 1H), 1.9 (ddd, J = 9.9, 7.4, 3.0 Hz, 1H), 1.8 (dt, J = 10.7, 4.4 Hz, 2H), 1.7 – 1.6 (m, 1H), 1.6 (dq, J = 8.9, 4.3 Hz, 1H).13 C NMR (101 MHz, Chloroform-d) δ 162.9, 160.5, 156.3, 154.1, 151.5, 149.7, 139.2 (d, J = 7.7 Hz), 131.6(d, J = 5.3 Hz), 129.1, 125.5 (d, J = HRMS (ESI) cacld for C 23 H 24 FN 2 + (M+H) + : 347.1918, found 347.1927. Embodiment 11 Take sodium carbonate (4.2 mg, 0.04 mmol), (48.6 mg, 0.3 mmol), photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol), added to the reaction tube, vented three times through the double-row tube, added 2 mL of N,N-dimethylformamide in a nitrogen atmosphere, and finally added (42.4 mg, 0.2 mmol), then placed under two 456 nm, 45 W blue light lamps, reacted at room temperature for 36 h. Dry loading, column chromatography (300-400 mesh chromatography silica gel) to obtain the product 31.1 mg (petroleum ether:ethyl acetate = 20:1), yield 56%. 1H NMR (400 MHz, Chloroform-d) δ 7.7 (d, J = 4.7 Hz, 1H), 7.5 (d, J = 3.8 Hz, 1H), 7.3 – 7.3(m, 2H), 7.0 (d, J = 8.2 Hz, 2H), 6.6 (d, J = 8.2 Hz, 2H), 5.0 (d, J = 7.3Hz, 1H), 3.8 (t, J = 7.8 Hz, 1H), 3.4 (q, J = 7.9 Hz, 1H), 2.4 (dq, J = 18.3,8.8 Hz, 2H), 2.4 – 2.3 (m, 1H), 2.2 (s, 3H), 2.2 – 2.1 (m, 1H). 13 C NMR (101MHz, Chloroform-d) δ 168.2, 150.8, 144.7, 141.0, 129.7, 126.0, 124.7, 124.2,120.0, 112.3, 110.7, 57.2, 48.8, 32.3, 24.1, 20.2. HRMS (ESI) cacld forC 18 H 19 N 2 O + (M+H) + :279.1492, found 279.1499. Example 12 Pick (50.4 mg, 0.2 mmol)、Sodium carbonate(4.2 mg, 0.04 mmol)、 (48.6 mg, 0.3 mmol), photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol), added to the reaction tube, vented three times through the double-row tube, added 2 mL N,N-dimethylformamide in a nitrogen atmosphere, and then placed under two 456 nm, 45W blue light lamps, reacted at room temperature for 36 h. Dry loading, column chromatography (300-400 mesh chromatography silica gel) to obtain the product 35.6 mg (petroleum ether: ethyl acetate = 20:1), yield 47%. 1H NMR (400 MHz, Chloroform-d) δ 8.0 (d, J = 7.9 Hz, 1H), 7.7 (d, J = 7.4 Hz, 1H), 7.3 (d, J =8.2 Hz, 1H), 7.3 (d, J = 6.7 Hz, 1H), 6.9 (d, J = 8.0 Hz, 2H), 6.4 (d, J =8.1 Hz, 2H), 5.5 (d, J = 8.5 Hz, 1H), 3.8 (t, J = 8.1 Hz, 1H), 3.4 (q, J =8.5 Hz, 1H), 2.5 – 2.4 (m, 1H), 2.2 (s, 3H), 2.1 – 2.1 (m, 1H), 2.0 (dd, J =7.9, 4.0 Hz, 1H), 1.7 (s, 9H). 13 C NMR (101 MHz, Chloroform-d) δ 157.6, 149.0,144.9, 142.3, 133.5, 129.5, 125.1, 124.3, 124.0, 120.4, 114.8, 112.2, 85.7,58.8, 48.8, 33.2, 28.2, 23.2, 20.2. HRMS (ESI) cacld for C 23 H 28 N 3 O 2 + (M+H) + :378.2176, found 378.2171. Example 13 Weigh 1,4-dicyanobenzene (25.6 mg, 0.2 mmol), sodium carbonate (4.2 mg, 0.04 mmol), (79.2 mg, 0.3 mmol), photocatalyst diarylamine pyrylium salt (5.6 mg, 0.01 mmol), added to the reaction tube, vented three times through the double-row tube, added 2 mL N,N-dimethylformamide in a nitrogen atmosphere, and then placed under two 456 nm, 45 W blue light lamps, reacted at room temperature for 24 h. Dry loading, column chromatography (300-400 mesh chromatography silica gel) to obtain the product 38.2 mg (petroleum ether:ethyl acetate = 5:1), yield 52%. 1H NMR (400 MHz, Chloroform-d) δ 7.8 (d, J = 8.8 Hz,2H), 7.6 (d, J = 8.2 Hz, 2H), 7.4 (d, J = 8.2 Hz, 2H), 6.6 (d, J = 8.8 Hz,2H), 4.4 (t, J = 5.6 Hz, 2H), 4.2 (s, 1H), 3.6 (s, 2H), 3.2 (q, J = 6.9 Hz,2H), 2.8 (t, J = 5.6 Hz, 2H), 2.3 (s, 3H), 1.6 (p, J = 7.2 Hz, 2H), 1.5 (dt,J = 14.9, 7.3 Hz, 2H), 1.0 (t, J = 7.3 Hz, 3H). 13 C NMR (101 MHz, Chloroform-d)δ 166.8, 152.3, 145.1, 132.1, 131.6, 129.3, 119.1, 117.8, 111.3, 110.7, 61.9,61.8, 55.7, 43.0, 42.7, 31.3, 20.2, 13.8. HRMS (ESI) cacld for C 22 H 28 N 3 O 2 + (M+H) + :366.2176, found 366.2168. The embodiments described above only express several preferred embodiments of the present invention, and the descriptions thereof are relatively specific and detailed, but are not intended to limit the present invention. It should be noted that for those skilled in the art, the present invention may also have various changes and modifications, and any modifications, equivalent substitutions, improvements, etc. made within the concept and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing tertiary benzylamine by photocatalysis, characterized in that: Amine As raw materials, triaryl pyryl salt As a photocatalyst, it can realize arylation and heteroarylation of amine α-position under visible light irradiation to prepare various substituted tertiary benzylamines.

2. The method for preparing tertiary benzylamine by photocatalysis according to claim 1, characterized in that: raw material The R1, R2, and R3 groups are various substituted aryl, heteroaryl, or alkyl groups.

3. The method for preparing tertiary benzylamine by photocatalysis according to claim 1, characterized in that: The triaryl pyryl salt is a diarylamine pyryl salt .

4. The method for preparing tertiary benzylamine by photocatalysis according to claim 1, characterized in that: The amount of photocatalyst added is 2%-5% by mole of the raw material.

5. The method for preparing tertiary benzylamine by photocatalysis according to claim 1, characterized in that: The reaction was carried out in an inert gas atmosphere using N,N-dimethylformamide as solvent.

6. The method for preparing tertiary benzylamine by photocatalysis according to claim 1, characterized in that: The visible light is blue light.

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