A method for the synthesis of chiral alpha-aryl thioesters

Abstract

The application belongs to the field of organic synthesis, and particularly relates to a synthesis method of chiral alpha-aryl thioester. The synthesis method comprises the following steps: in the presence of a transition metal catalyst (bis-(1,5-cyclooctadiene) nickel), a nitrogen ligand ((4R, 4'R)-4-((R)-sec-butyl)-4'-((S)-sec-butyl ester)-1,1'-bis(3-(tert-butyl)phenyl)-4,4',5,5'-tetrahydro-1H,1'H-2,2'-biimidazole) and a photocatalyst (2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile), a base (triethylamine) and a reducing agent, a chiral alpha-aryl thioester is synthesized by a reductive cross-coupling reaction in combination with an organic solvent (tetrahydrofuran). The application uses cheap nickel metal as a catalyst, constructs a cross-coupling reaction of a C-C bond, and has the advantages of mild reaction conditions, high selectivity and the like.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis, and specifically relates to a method for synthesizing chiral α-aryl thioesters. Background Technology

[0002] Thioester bonds are fundamental structural units in organic synthesis, thus attracting considerable attention from researchers. They are also important structural units found in many enzymes, such as acyl carrier proteins (A, B) and acyl-CoA compounds (C). This structure is also abundant in natural and pharmaceutical molecules (DF). Furthermore, thioester compounds are important intermediates in polymer materials. These thioesters can also be used as precursors in transition metal-catalyzed cross-coupling reactions. Therefore, the synthesis and modification of transition metal-catalyzed thioester compounds have significant scientific and commercial application value.

[0003]

[0004] Natural products and drug molecules containing thioester bonds Summary of the Invention

[0005] This invention provides a transition metal-catalyzed cross-coupling reaction between racemic α-chlorothioester compounds and aryl iodides, yielding a variety of chiral α-aryl thioester compounds with biological activity and medicinal value. This direct and easily operable method allows for the chemical selective construction of carbon-carbon bonds, and the synthetic method is simple and efficient. The specific scheme is as follows:

[0006]

[0007] A method for synthesizing a chiral α-aryl thioester compound, comprising a racemic α-chlorothioester compound of Formula 1 and an aryl iodide compound of Formula 2, wherein the chiral α-aryl thioester of Formula 3 is synthesized by a reduction cross-coupling reaction in the presence of a nickel catalyst, a nitrogen ligand, a photocatalyst, a base, a reducing agent, and an organic solvent.

[0008] Where R 1 R1 is selected from any one of methyl, ethyl, n-propyl, methylthioethyl, and 4-fluorobenzyl, and R2 is selected from any one of methyl, tert-butyl, methoxy, and acetyl. The method of this invention can achieve one-pot synthesis of chiral α-aryl thioester compounds, reducing reaction steps and thus improving product yield; the raw materials used in the synthesis method are simple and economical; R2 in this invention... 1 R 2 It offers a variety of options and has wider applicability.

[0009] Preferably, the reaction is carried out under the protection of an inert gas, and preferably, the inert gas is nitrogen.

[0010] Preferably, the synthesis occurs in the presence of a nickel catalyst, a nitrogen ligand, a photocatalyst, a base, a reducing agent, and an organic solvent.

[0011] Preferably, the nickel catalyst is bis-(1,5-cyclooctadiene)nickel; the nitrogen ligand is (4R,4′R)-4-((R)-sec-butyl)-4′-((S)-sec-butyl ester)-1,1′-bis(3-(tert-butyl)phenyl)-4,4′,5,5′-tetrahydro-1H,1′H-2,2′-bisimidazole; the base is triethylamine; and the reducing agent is dihydropyridine.

[0012] Preferably, the organic solvent is tetrahydrofuran.

[0013] Preferably, the molar ratio of the racemic α-chlorothioester shown in Formula 1, the aryl iodide shown in Formula 2, and the catalyst in the reaction is 1-2:1-2:0.05-0.2; and the reaction temperature is 25°C.

[0014] Preferably, the method of the present invention can synthesize chiral α-aryl thioesters with the following structures:

[0015]

[0016]

[0017] Chiral α-aryl thioesters were synthesized by reductive cross-coupling of racemic α-chlorothioester compounds and aryl iodides in the presence of a nickel catalyst (bis-(1,5-cyclooctadiene)nickel), a nitrogen ligand (4R,4′R)-4-((R)-sec-butyl)-4′-((S)-sec-butyl ester)-1,1′-bis(3-(tert-butyl)phenyl)-4,4′,5,5′-tetrahydro-1H,1′H-2,2′-bisimidazole, a photocatalyst 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile, a base triethylamine, a reducing agent diethyl 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate, and an organic solvent tetrahydrofuran.

[0018] The technical solution of the present invention can achieve at least one of the following beneficial effects:

[0019] The raw materials used in the synthesis method of this invention are all inexpensive and readily available;

[0020] This invention employs a one-pot synthesis method, which reduces the loss of raw materials and increases the yield of the product due to fewer reaction steps.

[0021] The operation steps required by this invention are relatively simple, requiring no extreme heating or cooling, and the reaction can be carried out under normal pressure, making it safe and convenient.

[0022] R in this invention1 R 2 Since there are multiple options, the method of the present invention has a wider range of applications and can synthesize a variety of chiral α-aryl thioesters.

[0023] Instruction manual illustrations

[0024] The attached figures show the proton and carbon NMR spectra of the products from each embodiment. The figure numbers correspond to the embodiment numbers. Figure A is the proton NMR spectrum, and Figure B is the carbon NMR spectrum. Figure 1A The above is the proton NMR spectrum of the product obtained in Example 1. Figure 1B The carbon NMR spectrum of the product obtained in Example 1; Figure 2A The above is the proton NMR spectrum of the product obtained in Example 2. Figure 2B The carbon NMR spectrum of the product obtained in Example 2; Figure 3A The image shows the proton NMR spectrum of the product obtained in Example 3. Figure 3B The carbon NMR spectrum of the product obtained in Example 3; Figure 4A The above is the proton NMR spectrum of the product obtained in Example 4. Figure 4B The carbon NMR spectrum of the product obtained in Example 4; Figure 5A The above is the proton NMR spectrum of the product obtained in Example 5. Figure 5B The carbon NMR spectrum of the product obtained in Example 5; Figure 6A The above is the proton NMR spectrum of the product obtained in Example 6. Figure 6B The carbon NMR spectrum of the product obtained in Example 6; Figure 7A The above is the proton NMR spectrum of the product obtained in Example 7. Figure 7B The carbon NMR spectrum of the product obtained in Example 7; Figure 8A The above is the proton NMR spectrum of the product obtained in Example 8. Figure 8B The carbon NMR spectrum of the product obtained in Example 8; Figure 9A The image shows the proton NMR spectrum of the product obtained in Example 9. Figure 9B The carbon NMR spectrum of the product obtained in Example 9; Figure 10A The above is the proton NMR spectrum of the product obtained in Example 10. Figure 10B The image shows the carbon NMR spectrum of the product obtained in Example 10. Specific Implementation

[0025] To facilitate understanding by those skilled in the art, the concept of the present invention will be further explained below with reference to embodiments. The specific descriptions of the following embodiments are not intended to limit the present invention, but are merely for the convenience of those skilled in the art to understand the technical solution. All raw materials mentioned in the specification were purchased from the market or synthesized through simple methods. Other pharmaceuticals were purchased from Amex, Bide, Sigma-Aldrich, Acros, Alfa Aesar, Adamas-beta, or J&K. The nuclear magnetic resonance spectrometer was a Bruker 400M.

[0026] Example 1

[0027] The reaction was carried out according to a general procedure with Ni(COD)2 (2.8 mg, 0.01 mmol), (4R, 4'R)-4-((R)-sec-butyl)-4'-((S)-sec-butyl ester)-1,1'-bis(3-(tert-butyl)phenyl)-4,4',5,5'-tetrahydro-1H,1'H-2,2'-bisimidazole (5.4 mg, 0.011 mmol), THF (2 mL), S-(tert-butyl)-2-chlorothiopropane ester (1a) (18 mg, 17 μL, 0.1 mmol), iodobenzene (2a) (47.4 mg, 0.3 mmol), Et3N (42 μL, 0.3 mmol), dihydropyridine (76 mg, 0.3 mmol) and 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile (8 mg, 0.01 mmol). The crude product was purified by rapid silica gel chromatography (eluting with petroleum ether: ethyl acetate = 100:1) to obtain a pale yellow oily product (18.7 mg, 84% yield, 90% ee). 1 H NMR (400MHz, CHCl3) δ: 7.36-7.26 (m, 5H), 3.80 (q, J=7.6, 7.1Hz, 1H), 1.48 (d, J=8.1Hz, 3H), 1.42 (s, 9H)ppm. 13 C{ 1 H} NMR (101MHz, CDCl3) δ: 208.1, 141.2, 129.0, 127.7, 127.2, 54.5, 48.0, 27.5, 18.0ppm.

[0028] By changing the raw materials in Example 1, the following 10 sets of experimental examples were designed, where the first set of experiments is Example 1, and the corresponding NMR spectrum of the product is shown in Figure 1. The NMR spectra of the products in the remaining sets 2-10 correspond to the sequence numbers of the respective examples.

[0029] The table lists the structural formulas of the products in each of the 1-10 examples. In the 10 examples, only the types of racemic α-chlorothioester and aryl iodide substrates used are different. Other raw materials, amounts, conditions, etc. are kept the same. The last two columns list the yield and ee value of the products in each example.

[0030]

[0031] Example 2

[0032] The reaction was carried out according to the usual procedure, using Ni(COD)2 (2.8 mg, 0.01 mmol), (4R, 4'R)-4-((R)-sec-butyl)-4'-((S)-sec-butyl ester)-1,1'-bis(3-(tert-butyl)phenyl)-4,4',5,5'-tetrahydro-1H,1'H-2,2'-bisimidazole (5.4 mg, 0.011 mmol), and THF (2 mL), respectively. The crude product was purified by rapid chromatography on silica gel (eluting with petroleum ether:ethyl acetate = 100:1) to give a pale yellow oil (21.5 mg, 86% yield, 91% ee). The crude product contained S-(tert-butyl)-2-chloropropanethioester (1a) (18 mg, 17 μL, 0.1 mmol), 1-bromo-4-methylbenzene (2b) (51.3 mg, 0.3 mmol), Et3N (42 μL, 0.3 mmol), dihydropyridine (76 mg, 0.3 mmol), and 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile (8 mg, 0.01 mmol). 1 H NMR (400MHz, CHCl3) δ: 7.18 (d, J=8.2Hz, 2H), 7.13 (d, J=8.3Hz, 2H), 3.76 (q, J=7.1Hz, 1H), 2.33 (s, 3H), 1.46 (d, J=7.1Hz, 3H), 1.41 (s, 9H)ppm. 13 C{ 1 H} NMR (101MHz, CDCl3) δ: 201.9, 137.3, 136.8, 129.3, 127.6, 54.2, 47.9, 29.7, 21.1, 18.6ppm.

[0033] Example 3

[0034] The reaction was carried out according to the usual procedure, using Ni(COD)2 (2.8 mg, 0.01 mmol), (4R, 4'R)-4-((R)-sec-butyl)-4'-((S)-sec-butyl ester)-1,1'-bis(3-(tert-butyl)phenyl)-4,4',5,5'-tetrahydro-1H,1'H-2,2'-bisimidazole (5.4 mg, 0.011 mmol), and THF (2 mL) respectively. The crude product contained, in addition to, S-(tert-butyl)-2-chloropropane thioester (1a) (17 μL, 0.1 mmol), 1-(tert-butyl)-4-methylbenzene (2c) (44.5 mg, 0.3 mmol), Et3N (42 μL, 0.3 mmol), dihydropyridine (76 mg, 0.3 mmol), and 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile (8 mg, 0.01 mmol). The crude product was rapidly purified by silica gel chromatography (eluting with petroleum ether:ethyl acetate = 100:1) to give a product (23.9 mg, 86% yield, 90% ee) as a pale yellow oil. 1 H NMR (400MHz, CHCl3) δ: 7.35 (s, 2H), 7.22 (d, J=8.4Hz, 2H), 3.78 (q, J=7.1Hz, 1H), 1.47 (d, J=7.8Hz, 3H), 1.43 (s, 9H), 1.31 (s, 9H)ppm. 13 C{ 1 H} NMR (101MHz, CDCl3) δ: 202.0, 149.9, 137.1, 127.3, 125.5, 54.0, 47.9, 34.5, 31.4, 29.8, 18.7ppm.

[0035] Example 4

[0036] The reaction was carried out according to the general procedure, using Ni(COD)2 (2.8 mg, 0.01 mmol), (4R, 4'R)-4-((R)-sec-butyl)-4'((S)-sec-butyl ester)-1,1'-bis(3-(tert-butyl)phenyl)-4,4',5,5'-tetrahydro-1H,1'H-2,2'-bisimidazole (5.4 mg, 0.011 mmol), THF (2 mL), S-(tert-butyl)-2-chloropropanethioester (1a) (17 μL, 0.1 mmol), 1-bromo-4-methoxybenzene (2d) (56.1 mg, 0.3 mmol), Et3N (42 μL, 0.3 mmol), dihydropyridine (76 mg, 0.3 mmol), and 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile (8 mg, 0.01 mmol). The crude product was rapidly purified by silica gel chromatography (eluting with petroleum ether: ethyl acetate = 50:1) to give the product (21.5 mg, 85% yield, 90% ee) as a pale yellow oil.1 H NMR (400MHz, CHCl3) δ: 7.21 (d, J=8.6Hz, 2H), 6.86 (d, J=8.7Hz, 2H), 3.80 (s, 3H), 3.75 (q, J=7.1Hz, 1H), 1.46 (d, J=7.1Hz, 3H), 1.41 (s, 9H)ppm. 13 C{ 1 H} NMR (101MHz, CDCl3) δ: 202.1, 158.7, 132.4, 128.8, 113.9, 55.2, 53.7, 47.9, 29.7, 18.6ppm.

[0037] Example 5

[0038] Following the general procedure, Ni(COD)2 (2.8 mg, 0.01 mmol), (4R, 4'R)-4-((R)-sec-butyl)-4'-((S)-sec-butyl ester)-1,1'-bis(3-(tert-butyl)phenyl)4,4',5,5'-tetrahydro-1H,1'H-2,2·-bisimidazole (5.4 mg, 0.011 mmol), THF (2 mL), S-(tert-butyl)-2-chloropropanethioester (1a) (17 μL, 0.1 mmol), 1-(4-iodophenyl)ethane-1-one (2i) (73.8 mg, 0.3 mmol), Et3N (42 μL, 0.3 mmol), dihydropyridine (76 mg, 0.3 mmol) and 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile (8 mg, 0.01 mmol). The crude product was rapidly purified by silica gel chromatography (eluting with petroleum ether: ethyl acetate = 50:1) to give a white solid product (22.7 mg, 88% yield, 90% ee). 1 H NMR (400MHz, CDCl3) δ: 7.90 (d, J=8.6Hz, 2H), 7.37 (d, J=8.4Hz, 2H), 3.85 (q, J=7.1Hz, 1H), 2.57 (s, 3H), 1.48 (d, J=6.5Hz, 3H), 1.39 (s, 9H)ppm. 13 C{ 1 H} NMR (101MHz, CDCl3) δ: 200.7, 197.7, 145.6, 136.0, 128.7, 127.9, 54.4, 48.3, 29.6, 26.6, 18.3ppm.

[0039] Example 6

[0040] Following the standard procedure, Ni(COD)2 (2.8 mg, 0.01 mmol), (4R, 4'R)-4-((R)-sec-butyl)-4'-((S)-sec-butyl ester)-1,1'-bis(3-(tert-butyl)phenyl)4,4',5,5'-tetrahydro-1H,1'H-2,2'-bisimidazole (5.4 mg, 0.011 mmol), THF (2 mL), and S-(tert-butyl) were added. 2-Chlorothiopropane ester (1a) (18 mg, 117 μL, 0.1 mmol), 1-(3-iodophenyl)ethane-1-one (2k) (73.8 mg, 0.3 mmol), Et3N (42 μL, 0.3 mmol), dihydropyridine (76 mg, 0.3 mmol), and 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile (8 mg, 0.01 mmol). The crude product was purified by rapid silica gel chromatography (eluting with petroleum ether:ethyl acetate = 50:1) to give a product (21.2 mg, 80% yield, 90% ee) as a pale yellow oil. 1 H NMR (400MHz, CDCl3) δ: 7.87 (d, J=12.6Hz, 2H), 7.52 (d, J=6.2Hz, 1H), 7.44 (t, J=7.7 Hz, 1H), 3.88 (q, J=7.1Hz, 1H), 2.62 (s, 3H), 1.52 (d, J=7.1Hz, 3H), 1.42 (s, 9H)ppm. 13 C{ 1 H} NMR (101MHz, CDCl3) δ: 201.2, 198.0, 140.8, 137.4, 132.4, 128.9, 127.7, 127.3, 54.3, 48.2, 29.7, 26.7, 18.6ppm.

[0041] Example 7

[0042] The reaction was carried out according to the general procedure, using Ni(COD)2 (2.8 mg, 0.01 mmol), (4R, 4'R)-4-((R)-sec-butyl)-4'-((S)-sec-butyl ester)-1,1'-bis(3-(tert-butyl)phenyl)-4,4',5,5'-tetrahydro-1H,1'H-2,2'-bisimidazole (5.4 mg, 0.011 mmol), THF (2 mL), S-(tert-butyl)-2-chlorobutyrate (1b) (19.5 mg, 0.1 mmol), 1-(4-iodophenyl)ethane-1-one (2i) (73.8 mg, 0.3 mmol), Et3N (42 μL, 0.3 mmol), dihydropyridine (76 mg, 0.3 mmol), and 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile (8 mg, 0.01 mmol). The crude product was purified by rapid silica gel chromatography (eluting with petroleum ether: EtOAc = 100:1) to give a pale yellow oily product (25.0 mg, 90% yield, 90% ee). 1 HNMR (400MH) z , CDCl3) δ: 7.92-7.86 (m, 2H), 7.40-7.33 (m, 2H), 3.59 (t, J=7.5Hz, 1H), 2.57 (s, 3 H), 2.17-2.07(m, 1H), 1.77-1.73(m, 1H), 1.39(s, 9H), 0.87(t, J=7.4Hz, 3H)ppm. 13 C{ 1 H} NMR (101MHz, CDCl3) δ: 200.2, 197.7, 144.2, 136.1, 128.6, 128.3, 62.3, 48.4, 29.6, 26.7, 26.8, 12.0ppm.

[0043] Example 8

[0044] The reaction was carried out according to the usual procedure, using Ni(COD)2 (2.8 mg, 0.01 mmol), (4R, 4'R)-4-((R)-sec-butyl)-4'((S)-sec-butyl ester)-1,1'-bis(3-(tert-butyl)phenyl)-4,4',5,5'-tetrahydro-1H,1'H-2,2'-bisimidazole (5.4 mg, 0.011 mmol), THF (2 mL), S-(tert-butyl)-2-chloropentanol ester (1b) (20.9 mg, 0.1 mmol), 1-(4-iodophenyl)ethane-1-one (2i) (73.8 mg, 0.3 mmol), dihydropyridine (76 mg, 0.3 mmol) and 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile (8 mg, 0.01 mmol). The crude product was rapidly purified by silica gel chromatography (eluting with petroleum ether: ethyl acetate = 100:1) to give a pale yellow oily product (25.7 mg, yield 88%, 90% ee). 1 H NMR (400MHz, CDCl3) δ: 7.92-7.87 (m, 2H), 7.39-7.34 (m, 2H), 3.70 (t, J=7.6Hz, 1H), 2.56 (s, 3H), 2.07-2.04(m, 1H), 1.79-1.65(m, 1H), 1.39(s, 9H), 1.31-1.12(m, 2H), 0.88(t, J=7.3Hz, 3H)ppm. 13 C{ 1 H} NMR (101MHz, CDCl3) δ: 200.2, 197.7, 144.4, 136.0, 128.6, 128.3, 60.3, 48.3, 35.5, 29.6, 26.6, 20.6, 13.8ppm.

[0045] Example 9

[0046] The reaction was carried out according to a general procedure with Ni(COD)2 (2.8 mg, 0.01 mmol), (4R, 4'R)-4-((R)-sec-butyl)-4'-((S)-sec-butyl ester)-1,1'-bis(3-(tert-butyl)phenyl)-4,4',5,5'-tetrahydro-1H,1'H-2,2'-bisimidazole (5.4 mg, 0.011 mmol), THF (2 mL), S-(tert-butyl)-2-chloro-4-(methylthio)butyrate (1e) (24.1 mg, 0.1 mmol), 1-(4-iodophenyl)ethane-1-one (2i) (73.8 mg, 0.3 mmol), dihydropyridine (76 mg, 0.3 mmol) and 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile (8 mg, 0.01 mmol). The crude product was rapidly purified by silica gel chromatography (eluting with petroleum ether: EtOAc = 50:1) to give a pale yellow solid product (28.2 mg, 87% yield, 74% ee). 1 H NMR (400MHz, CDCl3) δ: 7.86 (d, J=8.4Hz, 2H), 7.34 (d, J=8.3Hz, 2H), 4.02-3.7 7(m, 1H), 2.53(s, 3H), 2.40-2.23(m, 3H), 2.06-1.89(m, 4H), 1.34(s, 9H)ppm. 13 C{ 1 H} NMR (101MHz, CDCl3) δ: 199.7, 197.7, 143.5, 136.2, 128.8, 128.4, 58.7, 48.6, 32.2, 31.5, 29.6, 26.6, 15.2ppm.

[0047] Example 10

[0048] The reaction was carried out according to the general procedure, using Ni(COD)2 (2.8 mg, 0.01 mmol), (4R, 4'R)-4-((R)-sec-butyl)-4'-((S)-sec-butyl ester)-1,1'-bis(3-(tert-butyl)phenyl)-4,4',5,5'-tetrahydro-1H,1'H-2,2'-bisimidazole (5.4 mg, 0.011 mmol), THF (2 mL), S-(tert-butyl)-2-chloro-3-(4-fluorophenyl)thiopropionate (1f) (27.5 mg, 0.1 mmol), 1-(4-iodophenyl)ethane-1-one (2i) (73.8 mg, 0.3 mmol), dihydropyridine (76 mg, 0.3 mmol) and 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile (8 mg, 0.01 mmol). The crude product was rapidly purified by silica gel chromatography (eluting with petroleum ether: EtOAc = 50:1) to give a pale yellow solid product (29.4 mg, 82% yield, 80% ee). 1 HNMR (400MHz, CDCl3) δ: 7.88 (d, J=8.3Hz, 2H), 7.34 (d, J=8.3Hz, 2H), 7.00 (dd, J=8.5, 5.5Hz, 2H), 6.88 (t, J=8.7Hz, 2H), 3.91 (t, J=7.7Hz, 1H), 3.39 (dd, J=13.7, 7.9Hz, 1H), 2.95 (dd, J=13.7, 7.3Hz, 1H), 2.57 (s, 3H), 1.35 (s, 9H)ppm. 13 C{ 1 H}NMR (101MHz, CDCl3) δ: 199.6, 197.9, 161.6 (d, J 1 C-F =231.5Hz), 143.5, 136.3, 134.0, 130.5 (d, J 4 C-F =8.0Hz), 128.5 (d, J) 2 C-F =39.6Hz), 115.3 (d, J) 3 C-F =21.2Hz), 115.2, 62.4, 48.8, 38.8, 29.7, 26.8ppm.

Claims

1. A method for synthesizing chiral α-aryl thioesters, characterized in that: In an inert gas environment, the racemic α-chlorothioester compound shown in Formula 1 and the aryl iodide compound shown in Formula 2 were synthesized by a reductive cross-coupling reaction with the organic solvent tetrahydrofuran in the presence of a nickel catalyst bis-(1,5-cyclooctadiene)nickel, a nitrogen ligand (4R,4′R)-4-((R)-sec-butyl)-4′-((S)-sec-butyl ester)-1,1′-bis(3-(tert-butyl)phenyl)-4,4′,5,5′-tetrahydro-1H,1'H-2,2'-bisimidazole, a photocatalyst 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile, a base triethylamine, and a reducing agent dihydropyridine; wherein R 1 Selected from any one of methyl, ethyl, n-propyl, methylthioethyl, and 4-fluorobenzyl, R 2 It is selected from any one of methyl, tert-butyl, methoxy, and acetyl groups.

2. The synthesis method according to claim 1, characterized in that, The inert gas mentioned is nitrogen.

3. The synthesis method according to claim 1, characterized in that, The reaction temperature is 25°C.

4. The synthesis method according to claim 1, characterized in that, The racemic α-chlorothioester, aryl iodide, and product α-aryl thioester are listed in one of the following tables:

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