A method for photocatalytic styrene thiolation and pyridination

Abstract

The invention discloses a method for photocatalytic styrene thiolation pyridylation, wherein the method uses an electron donor-acceptor complex as a bifunctional reagent to photocatalyze styrene thiolation pyridylation, and the method uses thiophenol compounds, styrene compounds and 4-cyanopyridine compounds as raw materials, and the styrene thiolation pyridylation compound can be obtained by light reaction under solvent and alkaline conditions and nitrogen conditions. The method of the present invention has the advantages of simple operation, mild reaction conditions, few by-products, high atom economy, etc., and is suitable for industrial production.

Description

Technical Field

[0001] The invention belongs to the field of organic chemical synthesis, and in particular relates to a method for photocatalytic styrene thiolation and pyridylation. Background Art

[0002] Visible light photocatalysis is a powerful tool for synthetic transformations due to its mild and environmentally friendly reaction conditions. Typically, exogenous photocatalysts (such as iridium and ruthenium complexes or organic dyes) are indispensable for visible light photocatalytic reactions because most organic compounds cannot absorb visible light. Recently, visible light-induced electron donor-acceptor (EDA) complexes can effectively achieve organic transformations without external photocatalysts under mild conditions. However, most EDA complex reactions are limited to two-component reaction modes. To date, there are only a few examples of intermolecular three-component difunctionalization of olefins using EDA complex approaches. Typically, these methods require redox co-agents to regulate substrates and sacrificial donors, which reduces the atom economy of these reactions.

[0003] Pyridine compounds are common in pharmaceuticals and agrochemicals, so there is a great demand for the development of new and efficient methods for the introduction of pyridine. Currently, 4-cyanopyridine has been widely used for photocatalytic reduction pyridylation. At the same time, it can also be used for pyridylation reactions of olefins with β-functionalization, including CF3, N3, sulfonylation, perfluoroalkylation, phosphonylation, acetalization and malonic acid. On the other hand, organosulfur compounds are widely present in medicinal chemistry, biology and functional materials. Sulfur anions can also form EDA complexes with electron-deficient substrates (such as aryl, olefin and carbonyl substrates) and have been successfully used to construct CS bonds. Summary of the invention

[0004] The object of the present invention is to provide a method for photocatalytic styrene thiolation and pyridinization, wherein the method uses an electron donor-acceptor complex as a bifunctional reagent to photocatalyze the styrene thiolation and pyridinization, and the method has the advantages of simple operation, mild reaction conditions, few by-products, high atom economy, and the like.

[0005] The technical solution of the present invention is:

[0006] A method for photocatalytic styrene thiolation and pyridinization, wherein the method uses an electron donor-acceptor complex as a bifunctional reagent to photocatalyze the styrene thiolation and pyridinization, and uses a thiophenol compound, a styrene compound and a 4-cyanopyridine compound as raw materials, and performs a light irradiation reaction under a solvent and alkaline conditions and nitrogen conditions to obtain a styrene thiolation and pyridinization product, and the general reaction formula is:

[0007]

[0008] Wherein, R1 is any one or more of unsubstituted or mono-substituted or poly-substituted alkyl, alkoxy, halogen, ester group, amino, and amide group; R2 is any one or more of unsubstituted or mono-substituted or poly-substituted alkyl, alkoxy, halogen, ester group, amino, and amide group; R3 is any one or more of unsubstituted or mono-substituted or poly-substituted alkyl, alkoxy, halogen, ester group, amino, and amide group; and the base is any one or more of lithium formate, sodium formate, cesium formate, potassium formate, and potassium carbonate.

[0009] As a preferred embodiment, R1 is any one of 4-methyl, 2-methoxy, 4-tert-butyl, 4-fluoro, and -3,5-dimethyl; R2 is any one of ortho-methyl, 4-methyl, 4-methoxy, 2-methoxy, and -H; and R3 is any one of -H, 2-methyl, and 2,6-dimethyl.

[0010] As a preferred embodiment, the solvent is dimethyl sulfoxide.

[0011] As a preferred embodiment, the base is lithium formate hydrate.

[0012] As a preferred embodiment, the material feed ratio of the method is: 1.0 molar equivalent of thiophenol compound, 4.0 molar equivalent of styrene compound, 1.5 molar equivalent of 4-cyanopyridine compound, and 3.0 molar equivalent of base.

[0013] As a preferred embodiment, the reaction temperature of the method is room temperature.

[0014] As a preferred solution, the light source of the illumination condition of the method is a blue light LED with a wavelength of 455nm and a power of 10W.

[0015] The beneficial effects achieved by the present invention are:

[0016] (1) The present invention provides a method for photocatalytic styrene thiolation and pyridinization, wherein the method uses an electron donor-acceptor complex as a bifunctional reagent to photocatalyze the styrene thiolation and pyridinization. The method uses thiophenol compounds, styrene compounds and 4-cyanopyridine compounds as raw materials, and can obtain styrene thiolation and pyridinization products by light irradiation reaction under solvent and alkaline conditions and nitrogen conditions. The method has the advantages of mild reaction conditions, simple operation, high yield, low cost, etc., and is suitable for industrial scale-up production.

[0017] (2) The method of the present invention has few by-products and is easy to post-process.

[0018] (3) The method of the present invention has high atom economy and conforms to the concept of "green chemistry". DETAILED DESCRIPTION

[0019] The present invention is described clearly and completely below through specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention belong to the protection scope of the present invention.

[0020] Example 1: Synthesis of 4-(1-phenyl-2-(p-tolylthio)ethyl)pyridine

[0021]

[0022] Add a stirring magnet to a 25mL reaction tube, add 0.2mmol (1.0eq) of p-methylthiophenol, 0.3mmol (1.5eq) of 4-cyanopyridine, and 0.6mmol (3.0eq) of lithium formate hydrate. Replace nitrogen three times, add 0.8mmol (4eq) of styrene and 4mL of anhydrous dimethyl sulfoxide under nitrogen flow conditions. Under 10W wavelength 455nm blue LED light, react at room temperature for 24h. After the reaction is completed, add 10mL of water, extract with ethyl acetate three times, 10mL each time, combine the organic phases, wash once with sodium chloride aqueous solution, dry with anhydrous sodium sulfate, concentrate, and purify by column chromatography to obtain 48mg of colorless oily liquid, with a yield of 79%. 1 H NMR(400MHz, CDCl3)δ8.50(d,J=6.0Hz,2H),7.30(t,J=7.3Hz,2H),7.27–7.15(m,5H),7.13(d,J=6 .0Hz,2H),7.09(d,J=8.0Hz,2H),4.11(t,J=7.8Hz,1H),3.51(dd,J=7.8,1.5Hz,2H),2.32(s,3H). 13 C NMR (101MHz, CDCl3) δ151.85,150.00,141.64,136.92,131.95,130.89,129.95,1 28.90,128.00,127.32,123.46,50.14,39.81,21.14.HRMS(ESI):(m / z)Calcd.for C 20 H 30 NS[M+H] + ,306.1311,found 306.1312.

[0023] Example 2: Synthesis of 4-(2-((4-(tert-butyl)phenyl)thio)-1-phenylethyl)pyridine

[0024]

[0025] Add a stirring magnet to a 25mL reaction tube, add 4-cyanopyridine 0.3mmol (1.5eq), lithium formate hydrate 0.6mmol (3.0eq). Replace nitrogen 3 times, add tert-butylthiophenol 0.2mmol (1.0eq), styrene 0.8mmol (4eq) and anhydrous dimethyl sulfoxide 4mL under nitrogen flow conditions. Under 10W wavelength 455nm blue LED light, react at room temperature for 24h. After the reaction is completed, add 10mL of water, extract with ethyl acetate 3 times, 10mL each time, combine the organic phases, wash once with sodium chloride aqueous solution, dry with anhydrous sodium sulfate, concentrate, and purify by column chromatography to obtain 51mg of yellow oily liquid with a yield of 73%. 1 H NMR (400MHz, CDCl3) δ8.49 (d, J = 4.9 Hz, 2H), 7.33–7.27 (m, 4H), 7.27–7.22 (m, 3H), 7.18 (d, J = 7. 1Hz, 2H), 7.14 (d, J = 5.8Hz, 2H), 4.15 (t, J = 7.8Hz, 1H), 3.53 (dd, J = 7.8, 1.6Hz, 2H), 1.30 (s, 9H). 13 C NMR (101MHz, CDCl3) δ151.93,150.01,141.66,132.18,130.32,128.90,128.00,1 27.33,126.21,123.47,50.29,39.60,34.60,31.36.HRMS(ESI):(m / z)Calcd.forC 23 H 26 NS[M+H] + ,348.1780,found 348.1789.

[0026] Example 3: Synthesis of 4-(2-(2-methoxyphenyl)thio)-1-phenylethyl)pyridine

[0027]

[0028] Add a stirring magnet to a 25mL reaction tube, add 4-cyanopyridine 0.3mmol (1.5eq), lithium formate hydrate 0.6mmol (3.0eq). Replace nitrogen 3 times, add 2-methoxythiophenol 0.2mmol (1.0eq), styrene 0.8mmol (4eq) and anhydrous dimethyl sulfoxide 4mL under nitrogen flow conditions. Under 10W wavelength 455nm blue LED light, react at room temperature for 24h. After the reaction is completed, add 10mL of water, extract with ethyl acetate 3 times, 10mL each time, combine the organic phases, wash once with sodium chloride aqueous solution, dry with anhydrous sodium sulfate, concentrate, and purify by column chromatography to obtain 47mg of yellow oily liquid, with a yield of 73%. 1 H NMR (400MHz, CDCl3) δ8.49(d,J=5.7Hz,2H),7.30(t,J=7.3Hz,2H),7.27–7.21(m,3H),7.20(d,J=1.5Hz,1H),7.18(s,1H),7. 15(d,J=6.0Hz,2H),6.89(t,J=7.5Hz,1H),6.85(d,J=8.2Hz,1H),4.15(t,J=7.7Hz,1H),3.85(s,3H),3.53(d,J=7.7Hz,2H). 13 C NMR (101MHz, CDCl3) δ158.09,151.96,149.93,141.81,131.38,128.85,128.28,127.95,1 27.25,123.43,121.10,110.82,76.84,55.84,50.30,37.44.HRMS(ESI):(m / z)Calcd.for C 20 H 20 NOS[M+H] + ,322.1260,found 322.1259.

[0029] Example 4: Synthesis of 4-(2-(4-fluorophenylthio)-1-phenylethyl)pyridine

[0030]

[0031] Add a stirring magnet to a 25mL reaction tube, add 4-cyanopyridine 0.3mmol (1.5eq), lithium formate hydrate 0.6mmol (3.0eq). Replace nitrogen 3 times, add 4-fluorothiophenol 0.2mmol (1.0eq), styrene 0.8mmol (4eq) and anhydrous dimethyl sulfoxide 4mL under nitrogen flow conditions. Under 10W wavelength 455nm blue LED light, react at room temperature for 24h. After the reaction is completed, add 10mL of water, extract with ethyl acetate 3 times, 10mL each time, combine the organic phases, wash once with sodium chloride aqueous solution, dry with anhydrous sodium sulfate, concentrate, and purify by column chromatography to obtain 42mg of yellow oily liquid, with a yield of 68%. 1 H NMR(400MHz, CDCl3) δ8.51(d,J=5.0Hz,2H),7.34–7.26(m,4H),7.25(dd,J=5.3,1.9Hz,1H),7.18(d,J=1.5Hz ,1H),7.16(s,1H),7.13(d,J=6.0Hz,2H),6.98(t,J=8.7Hz,2H),4.09(t,J=7.8Hz,1H),3.50(d,J=7.5Hz,2H). 13 CNMR(101MHz, CDCl3)δ162.11(d,J=247.1Hz),151.60,150.05,141.37,133.16(d,J=8.3Hz) ,130.61(d,J=3.1Hz),128.92,127.95,127.39,123.34,116.27(d,J=21.8Hz),50.24,40.37. 19 F NMR(376MHz,CDCl3)δ-114.54.HRMS(ESI):(m / z)Calcd.for C 19 H 17 FNS[M+H] + ,310.1060,found 310.1064.

[0032] Example 5: Synthesis of 4-(2-((3,5-dimethylphenyl)thio)-1-phenylethyl)pyridine

[0033]

[0034] Add a stirring magnet to a 25mL reaction tube, add 4-cyanopyridine 0.3mmol (1.5eq), lithium formate hydrate 0.6mmol (3.0eq). Replace nitrogen 3 times, add 3,5-dimethylthiophenol 0.2mmol (1.0eq), styrene 0.8mmol (4eq) and anhydrous dimethyl sulfoxide 4mL under nitrogen flow conditions. Under 10W wavelength 455nm blue LED light, react at room temperature for 24h. After the reaction is completed, add 10mL of water, extract with ethyl acetate 3 times, 10mL each time, combine the organic phases, wash once with sodium chloride aqueous solution, dry with anhydrous sodium sulfate, concentrate, and purify by column chromatography to obtain 55mg of yellow oily liquid with a yield of 86%. 1 H NMR (400MHz, CDCl3) δ8.51(d,J=4.6Hz,2H),7.31(t,J=7.3Hz,2H),7.25(dt,J=4.6,1.9Hz,1H),7.21(d,J=1.5Hz,1H),7.1 9(s,1H),7.16(d,J=5.9Hz,2H),6.91(s,2H),6.83(s,1H),4.16(t,J=7.8Hz,1H),3.54(dd,J=7.8,1.5Hz,2H),2.27(s,6H). 13 C NMR (101MHz, CDCl3) δ151.87,149.96,141.70,138.73,135.31,128.88,128.47,1 27.99,127.58,127.32,123.44,50.23,39.00,21.29.HRMS(ESI):(m / z)Calcd.for C 21 H 22 NS[M+H] + ,320.1467,found 320.1474.

[0035] Example 6: Synthesis of 4-(2-((3,5-dimethylphenyl)thio)-1-o-tolylethyl)pyridine

[0036]

[0037] Add a stirring magnet to a 25mL reaction tube, add 4-cyanopyridine 0.3mmol (1.5eq), lithium formate hydrate 0.6mmol (3.0eq). Replace nitrogen 3 times, add 3,5-dimethylthiophenol 0.2mmol (1.0eq), o-vinyltoluene 0.8mmol (4eq) and anhydrous dimethyl sulfoxide 4mL under nitrogen flow conditions. Under 10W wavelength 455nm blue LED light, react at room temperature for 24h. After the reaction is completed, add 10mL of water, extract with ethyl acetate 3 times, 10mL each time, combine the organic phases, wash once with sodium chloride aqueous solution, dry with anhydrous sodium sulfate, concentrate, and purify by column chromatography to obtain 55mg of yellow oily liquid, with a yield of 82%. 1 H NMR (400MHz, CDCl3) δ8.48(d,J=6.0Hz,2H),7.24(t,J=8.3Hz,2H),7.16(dd,J=6.4,1.7Hz,2H),7.11(d,J=6.1H z,2H),6.91(s,2H),6.83(s,1H),4.36(t,J=7.7Hz,1H),3.50(qd,J=13.0,7.7Hz,2H),2.26(s,6H),2.17(s,3H). 13 C NMR (101MHz, CDCl3) δ151.72,149.89,139.57,138.73,136.36,135.31,130.95,128.53,127. 76,127.22,126.96,126.45,123.71,45.86,39.25,21.27,19.72.HRMS(ESI):(m / z)Calcd.for C 22 H 24 NS[M+H] + ,334.1624,found 334.1619.

[0038] Example 7: Synthesis of 4-(2-((3,5-dimethylphenyl)thio)-1-m-tolylethyl)pyridine

[0039]

[0040] Add a stirring magnet to a 25mL reaction tube, add 4-cyanopyridine 0.3mmol (1.5eq), lithium formate hydrate 0.6mmol (3.0eq). Replace nitrogen 3 times, add 3,5-dimethylthiophenol 0.2mmol (1.0eq), m-vinyltoluene 0.8mmol (4eq) and anhydrous dimethyl sulfoxide 4mL under nitrogen flow conditions. Under 10W wavelength 455nm blue LED light, react at room temperature for 24h. After the reaction is completed, add 10mL of water, extract with ethyl acetate 3 times, 10mL each time, combine the organic phases, wash once with sodium chloride aqueous solution, dry with anhydrous sodium sulfate, concentrate, and purify by column chromatography to obtain 47mg of yellow oily liquid, with a yield of 70%. 1 H NMR(400MHz, CDCl3)δ8.52(s,2H),7.24–7.15(m,3H),7.10–6.98(m,3H),6.92(s,2H),6. 84(s,1H),4.13(t,J=7.8Hz,1H),3.55(dd,J=7.8,3.2Hz,2H),2.32(s,3H),2.28(s,6H). 13 C NMR (101MHz, CDCl3) δ152.01,149.97,141.68,138.73,138.57,135.42,128.77,128.45,1 28.12,127.58,124.96,123.47,50.26,38.99,21.58,21.31.HRMS(ESI):(m / z)Calcd.for C 22 H 24 NS[M+H] + ,334.1624,found 334.1629.

[0041] Example 8: Synthesis of 4-(2-((3,5-dimethylphenyl)thio)-1-p-tolylethyl)pyridine

[0042]

[0043] Add a stirring magnet to a 25mL reaction tube, add 4-cyanopyridine 0.3mmol (1.5eq), lithium formate hydrate 0.6mmol (3.0eq). Replace nitrogen 3 times, add 3,5-dimethylthiophenol 0.2mmol (1.0eq), p-vinyltoluene 0.8mmol (4eq) and anhydrous dimethyl sulfoxide 4mL under nitrogen flow conditions. Under 10W wavelength 455nm blue LED light, react at room temperature for 24h. After the reaction is completed, add 10mL of water, extract with ethyl acetate 3 times, 10mL each time, combine the organic phases, wash once with sodium chloride aqueous solution, dry with anhydrous sodium sulfate, concentrate, and purify by column chromatography to obtain 54mg of colorless oily liquid, with a yield of 81%. 1 H NMR (400MHz, CDCl3) δ8.51(d,J=3.9Hz,2H),7.16(d,J=5.3Hz,2H),7.14(d,J=8.2Hz,2H),7.10(d,J=8.2Hz, 2H), 6.92 (s, 2H), 6.84 (s, 1H), 4.14 (t, J = 7.8Hz, 1H), 3.53 (dd, J = 7.8, 1.9Hz, 2H), 2.33 (s, 3H), 2.28 (s, 6H). 13 CNMR(101MHz, CDCl3)δ152.23,149.97,138.76,138.75,137.08,135.44,129.63,128.45,127.88 ,127.55,123.44,77.48,77.16,76.84,49.89,39.09,21.33,21.16.HRMS(ESI):(m / z)Calcd.for C 22 H 24 NS[M+H] + ,334.1624,found 334.1643.

[0044] Example 9: Synthesis of 4-(2-((3,5-dimethylphenyl)thio)-1-(4-methoxyphenyl)ethyl)pyridine

[0045]

[0046] Add a stirring magnet to a 25mL reaction tube, add 4-cyanopyridine 0.3mmol (1.5eq), lithium formate hydrate 0.6mmol (3.0eq). Replace nitrogen 3 times, add 3,5-dimethylthiophenol 0.2mmol (1.0eq), 4-methoxystyrene 0.8mmol (4eq) and anhydrous dimethyl sulfoxide 4mL under nitrogen flow conditions. Under 10W wavelength 455nm blue LED light, react at room temperature for 24h. After the reaction is completed, add 10mL of water, extract with ethyl acetate 3 times, 10mL each time, combine the organic phases, wash once with sodium chloride aqueous solution, dry with anhydrous sodium sulfate, concentrate, and purify by column chromatography to obtain 50mg of yellow oily liquid with a yield of 72%. 1 H NMR (400MHz, CDCl3) δ8.51(d,J=4.2Hz,2H),7.15(d,J=5.9Hz,2H),7.12(d,J=8.7Hz,2H),6.92(s,2H),6. 86(d,J=8.7Hz,2H),6.84(s,1H),4.13(t,J=7.8Hz,1H),3.78(s,3H),3.52(d,J=7.8Hz,2H),2.28(s,6H). 13 C NMR (101MHz, CDCl3) δ158.76,152.31,149.93,138.72,135.42,133.73,129.00,128. 41,127.51,123.35,114.24,55.31,49.43,39.19,21.29.HRMS(ESI):(m / z)Calcd.for C 22 H 24 NOS[M+H] + ,350.1573,found350.1574.

[0047] Example 10: Synthesis of 4-(2-((3,5-dimethylphenyl)thio)-1-(2-methoxyphenyl)ethyl)pyridine

[0048]

[0049] Add a stirring magnet to a 25mL reaction tube, add 4-cyanopyridine 0.3mmol (1.5eq), lithium formate hydrate 0.6mmol (3.0eq). Replace nitrogen 3 times, add 3,5-dimethylthiophenol 0.2mmol (1.0eq), 2-methoxystyrene 0.8mmol (4eq) and anhydrous dimethyl sulfoxide 4mL under nitrogen flow conditions. Under 10W wavelength 455nm blue LED light, react at room temperature for 24h. After the reaction is completed, add 10mL of water, extract with ethyl acetate 3 times, 10mL each time, combine the organic phases, wash once with sodium chloride aqueous solution, dry with anhydrous sodium sulfate, concentrate, and purify by column chromatography to obtain 55mg of colorless oily liquid, with a yield of 79%. 1 H NMR (400MHz, CDCl3) δ8.48(d,J=5.8Hz,2H),7.23(dt,J=8.2,1.7Hz,1H),7.17(d,J=6.0Hz,2H),7.12(dd,J=7.6,1.6Hz,1H),6.92(t,3H,J =7.6Hz), 6.84(d,J=8.2Hz,1H),6.81(s,1H),4.61(dd,J=8.5,7.0Hz,1H),3.74(s,3H),3.53(ddd,J=21.7,12.9,7.8Hz,2H),2.26(s,6H). 13 C NMR (101MHz, CDCl3) δ157.01,151.92,149.70,138.55,135.80,130.11,128.44,128.28,128. 18,127.34,123.81,120.75,110.97,55.41,43.65,37.55,21.32.HRMS(ESI):(m / z)Calcd.for C 22 H 24 NOS[M+H] + ,350.1573,found 350.1562.

[0050] Example 11: Synthesis of 4-(2-((3,5-dimethylphenyl)thio)-1-phenylethyl)-2-methylpyridine

[0051]

[0052] Add a stirring magnet to a 25mL reaction tube, add 2-methyl 4-cyanopyridine 0.3mmol (1.5eq), lithium formate hydrate 0.6mmol (3.0eq). Replace nitrogen 3 times, add 3,5-dimethylthiophenol 0.2mmol (1.0eq), styrene 0.8mmol (4eq) and anhydrous dimethyl sulfoxide 4mL under nitrogen flow conditions. Under 10W wavelength 455nm blue LED light, react at room temperature for 24h. After the reaction is completed, add 10mL of water, extract with ethyl acetate 3 times, 10mL each time, combine the organic phases, wash once with sodium chloride aqueous solution, dry with anhydrous sodium sulfate, concentrate, and purify by column chromatography to obtain 55mg of colorless oily liquid, with a yield of 82%. 1 H NMR (400MHz, CDCl3) δ8.39(d,J=5.1Hz,1H),7.32(t,J=7.3Hz,2H),7.25(d,J=5.0Hz,1H),7.20(d,J=7.0Hz,2H),7.01(s,1H ),6.98(d,J=5.2Hz,1H),6.91(s,2H),6.83(s,1H),4.12(t,J=7.8Hz,1H),3.53(d,J=7.8Hz,2H),2.51(s,3H),2.27(s,6H). 13 C NMR (101MHz, CDCl3) δ158.65,152.18,149.31,141.91,138.74,135.47,128.89,128.46,128. 00,127.60,127.30,123.01,120.52,50.37,39.05,24.56,21.32.HRMS(ESI):(m / z)Calcd.for C 22 H 24 NS[M+H] + ,334.1624,found 334.1625.

[0053] Example 12: Synthesis of 4-(2-((3,5-dimethylphenyl)thio)-1-phenylethyl)-2,6-dimethylpyridine

[0054]

[0055] Add a stirring magnet to a 25mL reaction tube, add 0.3mmol (1.5eq) of 2,6-dimethyl 4-cyanopyridine, and 0.6mmol (3.0eq) of lithium formate hydrate. Replace nitrogen three times, and under nitrogen flow conditions, add 0.2mmol (1.0eq) of 3,5-dimethylthiophenol, 0.8mmol (4eq) of styrene, and 4mL of anhydrous dimethyl sulfoxide. Under 10W wavelength 455nm blue LED light, react at room temperature for 24h. After the reaction is completed, add 10mL of water, extract with ethyl acetate three times, 10mL each time, combine the organic phases, wash once with sodium chloride aqueous solution, dry with anhydrous sodium sulfate, concentrate, and purify by column chromatography to obtain 68mg of colorless oily liquid, with a yield of 95%. 1 H NMR (400MHz, CDCl3) δ7.31(t,J=7.3Hz,2H),7.24(d,J=6.0Hz,1H),7.20(d,J=7.1Hz,2H),6.9 1(s,2H),6.82(s,3H),4.09(t,J=7.8Hz,1H),3.52(d,J=7.8Hz,2H),2.47(s,6H),2.27(s,6H). 13 C NMR (101MHz, CDCl3) δ157.94,152.39,142.06,138.68,135.60,128.83,128.38,127. 97,127.54,127.2,119.97,50.41,39.03,24.58,21.31.HRMS(ESI):(m / z)Calcd.for C 23 H 26 NS[M+H] + ,348.1780,found 348.1773.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. All modifications, equivalent substitutions, improvements, etc. within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for photocatalytic styrene thiolation and pyridination, characterized in that: The method uses an electron donor-acceptor complex as a bifunctional reagent to photocatalyze the thiolation and pyridinization of styrene. The method uses a thiophenol compound, a styrene compound and a 4-cyanopyridine compound as raw materials, and performs a light irradiation reaction under a solvent and alkaline conditions and nitrogen conditions to obtain a styrene thiolation and pyridinization product. The general reaction formula is: Wherein, R1 is any one or more of unsubstituted or monosubstituted or polysubstituted alkyl, alkoxy, and halogen, R2 is any one or more of unsubstituted or monosubstituted or polysubstituted alkyl, alkoxy, and halogen, R3 is any one or more of unsubstituted or monosubstituted or polysubstituted alkyl, alkoxy, and halogen, and the base is any one or more of lithium formate, sodium formate, cesium formate, potassium formate, and potassium carbonate; the illumination conditions of the illumination reaction are: the light source is a blue light LED with a wavelength of 455nm and a power of 10W.

2. The method for photocatalytic styrene thiolation and pyridylation according to claim 1, characterized in that: R1 is any one of 4-methyl, 2-methoxy, 4-tert-butyl, 4-fluoro, and -3,5-dimethyl; R2 is any one of ortho-methyl, 4-methyl, 4-methoxy, -2-methoxy, and -H; and R3 is any one of -H, 2-methyl, and 2,6-dimethyl.

3. The method for photocatalytic styrene thiolation and pyridylation according to claim 1, characterized in that: The solvent is dimethyl sulfoxide.

4. The method for photocatalytic styrene thiolation and pyridylation according to claim 1, characterized in that: The base is lithium formate.

5. The method for photocatalytic styrene thiolation and pyridylation according to claim 1, characterized in that: The material feeding ratio of the method is: 1.0 molar equivalent of thiophenol compound, 4.0 molar equivalent of styrene compound, 1.5 molar equivalent of 4-cyanopyridine compound and 3.0 molar equivalent of base.

6. The method for photocatalytic styrene thiolation and pyridylation according to claim 1, characterized in that: The reaction temperature of the method is room temperature.

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