Synthesis method of 1,1-diselenoolefin compound

Abstract

The present invention discloses a method for synthesizing 1,1-diselenoolefin compounds. An alkenylthianthrenium salt compound (1a), a diselenide compound (1b) and a base are mixed, and under nitrogen protection, a solvent is added. After reacting at room temperature for 5 to 6 hours, the product 1,1-diselenoolefin compound (1c) is obtained through post-treatment; this method has simple operation, mild conditions, no metal catalysis, and the final products can all have a medium or higher yield;

Description

Technical Field

[0001] The present invention relates to a method for synthesizing 1,1-diselenoolefin compounds, that is, a method for efficiently synthesizing 1,1-diselenoolefin compounds by reacting various alkenyl thianthrenium salts with diselenide derivatives. Background Art

[0002] As a current new C-H direct functional group tool, thianthrenium salts have been widely used in reactions such as transition metal catalysis and photochemistry. Thianthrenium salts can be divided into aryl thianthrenium salts, alkenyl thianthrenium salts, and alkyl thianthrenium salts. As an electrophilic alkenylation reagent, alkenyl thianthrenium salts can react with other reagents such as alkynes, alkenes, or some nucleophiles to obtain corresponding alkenylated or allylated products. (Angew. Chem. Int. Ed. 2020, 59, 5616 - 5620), (J. Am. Chem. Soc. 2021, 143, 21503 - 21510).

[0003] Selenoolefins are very important synthetic building blocks in organic synthesis reactions. They can be used as intermediates for generating conjugated olefin products. Selenoolefins can also undergo many cross-coupling reactions under the catalysis of transition metals to synthesize many corresponding alkenyl compounds (j. tetlet. 2016, 57, 4128 - 4132), such as Pd (Chem. Commun., 2015, 51, 15522 - 15525), Fe (Org. Biomol. Chem., 2012, 10, 798 - 807) and other transition metal catalyses. They can also generate selenium-containing heterocycles under the action of n-BuLi (J. Org. Chem. 2007, 72, 18, 6726 - 6734). And 1,1-diselenoolefins can also generate alkenyllithium intermediates under the action of n-BuLi. This intermediate is very active and can undergo a series of nucleophilic reactions (j. tetlet. 1982, 33, 3411 - 3414).

[0004] Currently, there is little research on the synthesis of 1,1-diselenoolefin compounds. Currently, there are mainly the following two synthetic routes: (1) Benzaldehyde and its derivatives react with carbon tetrabromide to obtain 1,1-dibromoolefins, and then the obtained 1,1-dibromoolefins react with diselenide and its derivatives to obtain the final product (j. tetlet. 2016, 57, 4128 - 4132), (J. Org. Chem. 2002, 51, 875 - 8.); (2) Phenylacetylenecarboxylic acid and its derivatives react with diaryl diselenide and its derivatives to obtain the final product (Org. Lett. 2018, 20, 3678 - 3681). Summary of the Invention

[0005] The object of the present invention is to provide a method for synthesizing 1,1-diselenoolefin compounds, which generates the target product by reacting alkenyl thianthrenium salts with diselenide compounds. This reaction is simple to operate and easy to control, and the post-treatment is convenient, supplementing the synthesis method of 1,1-diseleno substrates of alkyl olefins.

[0006] The technical solution of the present invention is as follows:

[0007] A method for synthesizing 1,1-diselenoolefin compounds, the method comprising:

[0008] Mix an alkenyl thianthrenium salt compound (1a), a diselenide compound (1b) with a base, under nitrogen protection, add a solvent, and react at room temperature for 5 - 6 h, and then obtain the product 1,1-diselenoolefin compound (1c) through post-treatment;

[0009] Among them, the molar ratio of the alkenyl thianthrenium salt compound (1a), the diselenide compound (1b), and the base is 1.0 - 1.1:1:2.0 - 3.0;

[0010] The base is selected from sodium hydroxide, potassium hydroxide, potassium tert-butoxide, potassium carbonate, etc., and potassium hydroxide is preferred;

[0011] The solvent is selected from tetrahydrofuran, acetonitrile, dichloromethane, N,N-dimethylformamide, etc., and dichloromethane is preferred; the volume molar ratio of the solvent to the diselenide compound (1b) is 5 - 10:1, mL / mmol;

[0012] The specific post-treatment method is: after the reaction is completed, the reaction solution is directly concentrated, subjected to column chromatography, using pure petroleum ether as the eluent, collecting the eluent containing the target compound, evaporating the solvent and drying to obtain the 1,1-diselenoolefin compound (1c);

[0013] The reaction general formula is as follows:

[0014]

[0015] In formula (1a), (1b) or (1c),

[0016] R is C 1-8 alkyl or C 3-8 cycloalkyl; the C 1-8 alkyl or C 3-8 cycloalkyl is unsubstituted, or is substituted by one or more groups independently selected from aryl, alkenyl, hydroxyl, halogen, trifluoromethyl, acyloxy, dialkylamino, sulfonyl, alkyl or cycloalkyl; preferably R is cyclohexyl, octyl, bromopropyl, hydroxypropyl or phenethyl;

[0017] R 1 is C 1-8 alkyl, C 3-8Cycloalkyl, C 2-7 Heterocycloalkyl, aryl, heteroaryl, alkenyl, alkynyl or acyl; wherein the C 1-8 Alkyl, C 3-8 Cycloalkyl, C 2-7 Heterocycloalkyl, aryl, heteroaryl is unsubstituted or substituted by one or more groups independently selected from halogen, hydroxy, oxo, trifluoromethyl, aryl, alkyl, cycloalkyl, alkoxy, alkylamino, amido, amine acyl, ester, acyloxy or sulfonyl; preferably R 1 Is methyl, phenyl, p-methoxyphenyl, p-trifluoromethylphenyl, p-fluorophenyl, p-bromophenyl, p-methylphenyl or thienyl.

[0018] The 1,1-diselenoolefin compound synthesized in the present invention can react with butyllithium reagent to obtain two useful organic synthesis building blocks in one step, namely monoselenoolefin and diselenide products. The synthesized monoselenoolefin product can be further converted into olefin compounds. (Tetrahedron Lett. 1982, 23, 3411 - 3414)

[0019] The present invention has the following advantages:

[0020] The reaction system is simple and easy to operate, the raw material preparation is simple, and the post-treatment is convenient. The innovation of the present invention lies in supplementing the synthesis method of 1,1-diselenoolefin of alkyl olefin. This method uses metal-free catalysis and the raw material preparation is simple. The 1,1-diselenoolefins prepared by this method can all achieve medium or higher yields. Specific Embodiments

[0021] The present invention will be further described below through specific examples, but the protection scope of the present invention is not limited thereto.

[0022] In the following examples, diphenyldiselenide and dimethyldiselenide were purchased from Energy Chemical, the purity of diphenyldiselenide: 96%, the purity of dimethyldiselenide: 97%; the rest of the diselenides were all prepared according to the reference: Org. Lett. 2010, 12, 15, 3288–3291; all vinyl thianthrenium salts were prepared according to the reference: Angew. Chem. Int. Ed. 2020, 59, 5616 - 5620.

[0023] Example 1

[0024] Synthesis of 2-cyclohexyl-1,1-diphenylselenoethylene

[0025] Cyclohexenylthianthrenium salt (84.7 mg, 0.22 mmol), diphenyldiselenide (62.4 mg, 0.2 mmol), and potassium hydroxide (28.1 mg, 0.5 mmol) were added to a 5 mL microwave tube equipped with a magnetic stir bar. The tube was purged with N2 three times, and 1 mL of DCM was added. The reaction was carried out for 6 h. The reaction mixture was concentrated, and the residue was purified by silica gel column chromatography eluting with pure petroleum ether. After concentration, 69.7 mg of the product was obtained with a yield of 83%. The product was a colorless liquid. 1 H NMR (400 MHz, CDCl3) δ 7.43 (m, 4H), 7.28 (m, 2.1 Hz, 6H), 6.32 (d, J = 9.2 Hz, 1H), 2.66 (m, 1H), 1.78–1.61 (m, 5H), 1.38–1.24 (m, 2H), 1.17 (m, 3H) ppm; 13C NMR (101 MHz, CDCl3) δ 151.64, 133.27 (2C), 132.67 (2C), 131.40, 131.19, 129.05 (2C), 128.90 (2C), 127.50, 127.17, 116.86, 42.74, 32.41 (2C), 25.84, 25.56 (2C) ppm; HRMS m / z (ESI) calcd for C 20 H 22 KSe2[M+K] + 460.9684, found: 460.9679.

[0026] The structural formula of the product is:

[0027]

[0028] Example 2

[0029] Synthesis of 1,1-Diphenylseleno-1-decene

[0030] Octenylthianthrenium salt (97.2 mg, 0.22 mmol), diphenyldiselenide (62.4 mg, 0.2 mmol), and potassium hydroxide (28.1 mg, 0.5 mmol) were added to a 5 mL microwave tube equipped with a magnetic stir bar. The tube was purged with N2 three times, and 1 mL of DCM was added. The reaction was carried out for 6 h. The reaction mixture was concentrated, and the residue was purified by silica gel column chromatography eluting with pure petroleum ether. After concentration, 67.5 mg of the product was obtained with a yield of 75%. The product was a colorless liquid. 11H NMR (400 MHz, CDCl3) δ 7.49–7.44 (m, 2H), 7.44–7.38 (m, 2H), 7.33–7.22 (m, 6H), 6.44 (t, J = 7.2 Hz, 1H), 2.36 (q, J = 7.3 Hz, 2H), 1.47–1.36 (m, 2H), 1.29 (m, 10H), 0.91 (t, J = 6.9 Hz, 3H) ppm; 13 13C NMR (101 MHz, CDCl3) δ 145.86, 133.64 (2C), 132.51 (2C), 131.24, 131.14, 129.07 (2C), 128.90 (2C), 127.63, 127.12, 118.66, 33.65, 31.85, 29.70, 29.37, 29.24, 29.18, 28.91, 22.67, 14.10 ppm; HRMS m / z (ESI) calcd for C 22 H 29 Se2[M+H] + 453.0594, found: 453.0586.

[0031] The structural formula of the product is:

[0032]

[0033] Example 3

[0034] Synthesis of 5-bromo-1,1-diphenylseleno-1-butene

[0035] According to the method described in Example 1, except that the alkenyl thianthrenium salt substrate used was bromopropyl alkenyl thianthrenium salt (99.2 mg, 0.22 mmol), 43.2 mg of the product was obtained, with a yield of 47%, and the product was a colorless liquid. 1 1H NMR (400 MHz, CDCl3) δ 7.51–7.46 (m, 2H), 7.46–7.41 (m, 2H), 7.36–7.24 (m, 6H), 6.39–6.24 (t, J = 7.2 Hz, 1H), 3.38 (t, J = 6.8 Hz, 2H), 2.52 (q, J = 7.3 Hz, 2H), 2.05–1.87 (m, 2H) ppm; 13C NMR (101 MHz, CDCl3) δ 141.55, 134.15 (2C), 132.65 (2C), 130.76, 130.72, 129.25 (2C), 129.05 (2C), 128.03, 127.40, 121.22, 32.78, 32.21, 31.94 ppm; HRMS m / z (ESI) calcd for C17 H 18 BrSe2[M+H] + 460.8917, found: 460.8912.

[0036] The product structural formula is:

[0037]

[0038] Example 4

[0039] Synthesis of 5,5-diphenylseleno-4-en-1-pentanol

[0040] According to the method described in Example 1, except that the alkenylthianthrene salt used is hydroxypropyl alkenylthianthrene salt (85.4 mg, 0.22 mmol), 53.9 mg of the product is obtained, and the yield is 68%. The product is a colorless liquid. 1 H NMR (400 MHz, DMSO-d6) δ 7.45–7.40 (m, 2H), 7.39–7.27 (m, 8H), 6.49 (t, J = 7.3 Hz, 1H), 4.46 (t, J = 5.1 Hz, 1H), 3.37 (q, J = 6.5, 5.1 Hz, 2H), 2.35 (q, J = 7.4 Hz, 2H), 1.59–1.45 (m, 2H) ppm; 13C NMR (101 MHz, DMSO-d6) δ 147.27, 133.27 (2C), 131.89 (2C), 131.10, 131.08, 129.95 (2C), 129.77 (2C), 128.30, 127.66, 117.66, 60.60, 32.17, 30.63 ppm; HRMS m / z (ESI) calcd for C 17 H 19 OSe2[M+H] + 398.9761, found: 398.9757.

[0041] The product structural formula is:

[0042]

[0043] Example 5

[0044] Synthesis of 4-phenyl-1,1-diphenylseleno-1-butene

[0045] Ethylphenylvinylthianthium salt (95.5 mg, 0.22 mmol), diphenyldiselenide (-62.4 mg, 0.2 mmol), and potassium hydroxide (28.1 mg, 0.5 mmol) were added to a 5 mL microwave tube equipped with a magnetic stir bar. The tube was purged with N2 three times, and 1 mL of DCM was added. The reaction was carried out for 6 h. The reaction mixture was concentrated, and the residue was purified by silica gel column chromatography eluted with pure petroleum ether. After concentration, 62.8 mg of the product was obtained with a yield of 71%. The product was a colorless liquid.

[0046] 1 H NMR (400 MHz, DMSO-d6) δ 7.33 (m, 5H), 7.25 (M, 8H), 7.15–7.09 (m, 2H), 6.41 (t, J = 6.8 Hz, 1H), 2.77–2.56 (m, 4H). 13 C NMR (101 MHz, DMSO-d6) δ 145.9, 141.2, 133.5 (2C), 131.8 (2C), 131.1, 130.8, 129.9 (2C), 129.7 (2C), 129.0 (2C), 128.8 (2C), 128.4, 127.6, 126.4, 118.6, 35.5, 34.6. HRMS m / z (ESI) calcd for C 20 H 20 KSe2 [M+K] + 482.9527, found: 482.9531

[0047] The structural formula of the product is:

[0048]

[0049] Example 6

[0050] Synthesis of 4-phenyl-1,1-bis(p-fluorophenyl)-1-butene

[0051] According to the method described in Example 5, except that the diselenide substrate used was p-fluorodiphenyldiselenide (69.6 mg, 0.2 mmol), 71.7 mg of the product was obtained with a yield of 75%. The product was a colorless liquid. 1 H NMR (400 MHz, DMSO-d6) δ 7.35–7.25 (m, 4H), 7.25–7.19 (m, 3H), 7.18–7.05 (m, 6H), 6.34 (t, J = 6.9 Hz, 1H), 2.69 (m, 2H), 2.66–2.59 (m, 2H) ppm; 1313C NMR (101 MHz, DMSO-d6) δ 163.59 (d, J = 28.3 Hz), 161.15 (d, J = 27.6 Hz), 144.95, 141.14, 136.10 (d, J = 8.1 Hz) (2C), 134.91 (d, J = 8.0 Hz) (2C), 129.00 (2C), 128.77 (2C), 126.46, 125.67 (d, J C-F = 3.6 Hz), 125.61 (d, J C-F = 3.3 Hz), 119.61, 116.96 (d, J C-F = 21.6 Hz, 2C), 116.71 (d, J C-F = 21.6 Hz, 2C), 35.38, 34.61 ppm; HRMS m / z (ESI) calcd for C 22 H 19 F2Se2 [M + H] + 480.9780, found: 480.9795.

[0052] The structure formula of the product is:

[0053]

[0054] Example 7

[0055] Synthesis of 4-phenyl-1,1-bis(4-bromophenyl)-1-butene

[0056] According to the method described in Example 5, except that the diselenide substrate used was p-bromodiphenyldiselenide (93.9 mg, 0.2 mmol), 80.0 mg of the product was obtained with a yield of 60%, and the product was a colorless liquid. 1 1H NMR (400 MHz, DMSO-d6) δ 7.39–7.11 (m, 14H), 6.50 (t, J = 7.0 Hz, 1H), 2.72 (m, 2H), 2.69–2.60 (m, 2H) ppm; 13 13C NMR (101 MHz, DMSO-d6) δ 147.59, 141.09, 134.88 (2C), 133.89 (2C), 133.25, 132.74, 129.88, 129.79 (2C), 129.62, 129.58 (2C), 129.02 (2C), 128.80 (2C), 126.48, 118.25, 35.59, 34.51 ppm; HRMS m / z (EI) calcd for C 22 H 18 Br2Se2 [M] +599.8106, found: 599.8101.

[0057] The product structural formula is:

[0058]

[0059] Example 8

[0060] Synthesis of 4-Phenyl-2,2-bis(p-methoxyphenylseleno)-1-butene

[0061] According to the method described in Example 5, except that the diselenide substrate used was p-methoxydiphenyl diselenide (74.4 mg, 0.2 mmol), 53.2 mg of the product was obtained with a yield of 53%, and the product was a light yellow liquid. 1 H NMR (400 MHz, DMSO-d6) δ 7.31–7.19 (m, 7H), 7.10 (dd, J = 6.9, 1.7 Hz, 2H), 6.94–6.84 (m, 4H), 6.04 (t, J = 6.7 Hz, 1H), 3.78 (s, 3H), 3.75 (s, 3H), 2.66–2.54 (m, 4H) ppm; 13 C NMR (101 MHz, DMSO-d6) δ 160.00, 159.59, 141.27, 140.23, 136.62 (2C), 134.96 (2C), 128.96 (2C), 128.72 (2C), 126.37, 121.34, 120.37, 120.30, 115.64 (2C), 115.38 (2C), 55.68, 55.65, 35.07, 34.83 ppm; HRMS m / z (ESI) calcd for C 24 H 24 O2Se2 [M] + 504.0107, found: 504.0092.

[0062] The product structural formula is:

[0063]

[0064] Example 9

[0065] Synthesis of 4-Phenyl-2,2-bis(p-trifluoromethylphenylseleno)-1-butene

[0066] According to the method described in Example 5, except that the diselenide substrate used was p-trifluoromethyldiphenyl diselenide (89.6 mg, 0.2 mmol), 60.1 mg of the product was obtained with a yield of 52%, and the product was a light yellow liquid. 11H NMR (400 MHz, DMSO-d6) δ 7.56 (dd, J = 14.9, 8.1 Hz, 4H), 7.40 (dd, J = 18.1, 8.1 Hz, 4H), 7.34–7.27 (m, 2H), 7.27–7.16 (m, 3H), 6.81 (t, J = 7.0 Hz, 1H), 2.80 (m, 2H), 2.76–2.66 (m, 2H) ppm; 13 13C NMR (101 MHz, DMSO-d6) δ 152.47, 141.06, 137.15 (2C), 136.94 (2C), 132.36 (2C), 131.90 (2C), 129.05 (2C), 128.94 (2C), 128.14 (d, J C-F = 31.7 Hz, 1C), 127.89 (d, J C-F = 31.9 Hz, 1C), 126.53, 126.25 (d, J C-F = 3.9 Hz, 2C), 124.80 (d, J C-F = 272.3 Hz, 2C), 115.79, 36.91, 34.30 ppm; HRMS m / z (EI) calcd for C 24 H 18 F6Se2 [M] + 579.9643, found: 579.9617.

[0067] The structure formula of the product is:

[0068]

[0069] Example 10

[0070] Synthesis of 4-Phenyl-2,2-bis(2-thienyl)seleno-1-butene

[0071] According to the method described in Example 5, except that the diselenide substrate used was bis(2-thienyl) diselenide (64.8 mg, 0.20 mmol), 75.4 mg of the product was obtained with a yield of 83%, and the product was a colorless liquid. 1 1H NMR (400 MHz, DMSO-d6) δ 7.78 (dd, J = 5.3, 1.2 Hz, 1H), 7.73 (dd, J = 5.3, 1.2 Hz, 1H), 7.28–7.15 (m, 5H), 7.14–7.09 (m, 3H), 7.06 (dd, J = 5.3, 3.5 Hz, 1H), 6.03–5.96 (m, 1H), 2.65–2.55 (m, 4H) ppm; 1313C NMR(101MHz,DMSO-d6)δ141.12,139.24,137.67,136.93,133.88,133.09,129.18,128.92(2C),128.77(3C),126.40,123.72,123.06,122.52,34.91,34.71ppm;HRMS m / z(EI)calcd for C 18 H 16 S2Se2[M] + 455.9024,found:455.9004.

[0072] The structure formula of the product is:

[0073]

[0074] Example 11

[0075] Synthesis of 4-phenyl-1,1-dimethylseleno-1-butene

[0076] According to the method described in Example 5, except that the diselenide substrate used was dimethyldiselenide (37.6 mg, 0.20 mmol), 40.7 mg of the product was obtained in a yield of 64%, and the product was a colorless liquid. 1 1H NMR(400MHz,DMSO-d6)δ7.31–7.25(m,2H),7.22–7.16(m,3H),6.11(t,J = 7.0Hz,1H),2.68(m,2H),2.56(m,2H),2.12(s,3H),2.08(s,3H)ppm; 13 13C NMR(101MHz,DMSO-d6)δ141.60,137.33,128.86(2C),128.72(2C),126.35,120.05,35.02,34.95,9.18,9.02ppm;HRMS m / z(EI)calcd forC 12 H 16 Se2[M] + 319.9582,found:319.9571.

[0077] The structure formula of the product is:

[0078]

[0079] Application Example 1 (taking the product obtained in Example 5 as an example)

[0080] Synthesis of 4-phenyl-1-phenylselenobutene and diphenyldiselenide (2.5a)

[0081]

[0082] 4-Phenyl-1,1-diphenylseleno-1-butene (88.4 mg, 0.2 mmol) was added to a 25 mL microwave tube equipped with a magnetic stir bar. The tube was purged with N2 three times, and 1 mL of THF solvent was added. n-Butyllithium (0.2 ml, 1 mol / L) was added at -78 °C, and the reaction was carried out at room temperature for 30 min. The reaction was quenched with water at -78 °C and then continued at room temperature for 30 min. The THF was removed by rotary evaporation, and the product was extracted with ethyl acetate. The organic phase was collected and purified by silica gel column chromatography using pure petroleum ether as the eluent, and then concentrated to obtain the product. 4-Phenyl-1-phenylselenobutene (2.4a): 50.1 mg, yield 87%, colorless liquid; diphenyldiselenide (2.5a): 26.5 mg, yield 85%, yellow solid. (Reference: Tetrahedron Lett. 1982, 23, 3411 - 3414)

[0083] 2.4a: 1 H NMR (400 MHz, DMSO-d6) δ 7.33–7.18 (m, 10H), 6.46 (m, 1H), 6.09 (m, 1H), 2.73 (t, J = 7.5 Hz, 2H), 2.50–2.42 (m, 2H). 13 C NMR (101 MHz, DMSO-d6) δ 141.6, 140.0, 131.1, 131.0 (2C), 129.9 (2C), 128.9 (2C), 128.7 (2C), 127.1, 126.3, 116.8, 35.7, 34.8. HRMS m / z (ESI) calcd for C 16 H 16 NaSe2 [M+Na] + 311.0309, found: 311.0300.

[0084] Application Example 2

[0085] Synthesis of 4-phenyl-1-butene (2.4c)

[0086]

[0087] 4-Phenyl-1,1-diphenylseleno-1-butene (88.4 mg, 0.2 mmol) was added to a 25 mL microwave tube equipped with a magnetic stir bar. The tube was purged with N2 three times, and 1 mL of THF solvent was added. n-Butyllithium (0.2 ml, 1 mol / L) was added at -78 °C, and the reaction was carried out at room temperature for 30 min. Methyl iodide (28.4 mg, 0.2 mmol) was added at -78 °C, and the reaction was carried out at room temperature for 30 min. The THF was evaporated to dryness, and the residue was extracted with ethyl acetate. The organic phase was collected, purified by silica gel column chromatography using pure petroleum ether as the eluent, and concentrated to give product 2.4b (48.2 mg, 80%). (Reference: Tetrahedron Lett. 1982, 23, 3411 - 3414)

[0088] 2.4b: 1 H NMR (400 MHz, DMSO-d6) δ 7.33–7.26 (m, 7H), 7.22 (m, 3H), 5.91 (m, 1H), 2.69 (t, J = 7.4 Hz, 2H), 2.46–2.38 (m, 2H), 1.84 (s, 3H). 13 C NMR (101 MHz, DMSO-d6) δ 141.7, 137.0, 132.4 (2C), 130.2, 129.8 (2C), 129.0 (2C), 128.7 (2C), 127.5, 126.3, 126.0, 35.0 31.3, 20.3. HRMS m / z (ESI) calcd for C 17 H 19 Se2[M+H] + 303.0646, found: 303.0642.

[0089] 2.4b (60 mg, 0.2 mmol), tributyltin hydride (174.6 mg, 0.6 mmol), and 2,2'-azobis(isobutyronitrile) (3.3 mg, 0.02 mmol) were added to a 5 mL microwave tube equipped with a magnetic stir bar. 0.5 mL of benzene was added as the solvent, and the reaction was carried out at 90 °C for 3 h. The product was purified by silica gel column chromatography using pure petroleum ether as the eluent and concentrated to give 2.4c (13.2 mg, 45%). The product was a colorless transparent liquid. (Reference: Tetrahedron Lett. 1982, 23, 3411 - 3414).

Claims

1. A method for synthesizing a 1,1-diselenoolefin compound, characterized in that, The method is as follows: Mix the alkenylthianthrenium salt compound (1a), diselenide compound (1b) with a base, add a solvent under nitrogen protection, react at room temperature for 5 - 6 h, and then obtain the product 1,1-diselenoalkene compound (1c) through post-treatment; The reaction general formula is as follows: In formula (1a), (1b) or (1c), R is phenethyl; R 1 is C 1-8 alkyl, C 3-8 cycloalkyl, C 2-7 heterocycloalkyl, aryl, heteroaryl, alkenyl, alkynyl or acyl; wherein the C 1-8 alkyl, C 3-8 cycloalkyl, C 2-7 heterocycloalkyl, aryl, heteroaryl is unsubstituted or substituted by one or more groups independently selected from halogen, hydroxy, oxo, trifluoromethyl, aryl, alkyl, cycloalkyl, alkoxy, alkylamino, amido, amine acyl, ester, acyloxy or sulfonyl.

2. The synthesis method of the 1,1-diselenoolefin compound according to claim 1, characterized in that, The molar ratio of the alkenylthianthrenium salt compound (1a), diselenide compound (1b), and base is 1.0 - 1.1:1:2.0 - 3.

0.

3. The synthesis method of the 1,1-diselenoolefin compound according to claim 1, characterized in that, The base is selected from sodium hydroxide, potassium hydroxide, potassium tert-butoxide or potassium carbonate.

4. The method for synthesizing the 1,1-diselenoolefin compound according to claim 1, characterized in that, The solvent is selected from tetrahydrofuran, acetonitrile, dichloromethane or N,N-dimethylformamide.

5. The synthesis method of the 1,1-diselenoolefin compound according to claim 1, characterized in that, The volume molar ratio of the solvent to the diselenide compound (1b) is 5 - 10:1, mL / mmol.

6. The synthesis method of the 1,1-diselenoolefin compound according to claim 1, wherein, The method of post-treatment is: after the reaction is completed, directly concentrate the reaction solution, perform column chromatography, use pure petroleum ether as the eluent, collect the eluent containing the target compound, evaporate the solvent and dry it to obtain the 1,1-diselenoalkene compound (1c).

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