A method for electrochemically catalyzing the sulfonylation of organic boronic acids

Abstract

The application provides a method for electrochemically catalyzing the sulfonylation of organic boric acid and belongs to the technical field of electrochemical synthesis of sulfones. The method can be reacted at room temperature in air, electrolyte, organic boric acid, sodium aryl sulfinate and solvent are sequentially added, and the reaction can be carried out after current is passed. The method for electrochemically catalyzing the sulfonylation of organic boric acid is simple in operation, green and environment-friendly, raw materials are cheap and easy to obtain, the conversion rate of products is high, the substrate expansion range is wide, and the method has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of organic compound synthesis technology, specifically relating to an electrochemically catalytic sulfonation reaction method for organoboronic acids. Background Technology

[0002] Diaryl sulfones, as a unique structural motif, exist in various drugs and active compounds, exhibiting antifungal, antibacterial, or antitumor activities. Therefore, developing an efficient reaction method for preparing diaryl sulfones under mild reaction conditions is desirable and practical. For example, in 2007, Tse reported a method for synthesizing asymmetric aryl sulfones by sulfonation of arylboronic acid and sodium arylsulfinate using copper acetate as a catalyst (Schareina T, Zapf A, ...). W, Müller N, Beller M, Chem-Eur J. 2007, 13(21), 6249-6254). In 2014, Sreedhar reported a method for synthesizing diaryl sulfones using magnetically separable copper ferrite (CuFe2O4) nanoparticles (Srinivas BTV, Rawat VS, Konda K, Sreedhar B. Adv Synth Catal 2014, 356(4), 805-817). Although the synthesis of diaryl sulfones has been reported in many ways, all of the above reports used metal catalysts. The development of metal catalysts is limited by their high cost, large environmental pollution, and complex synthesis. Therefore, we are trying to find an environmentally friendly and economical synthesis method. Electrochemistry has attracted great interest and widespread attention from researchers due to its green and environmentally friendly characteristics. At the same time, there are no reports in the literature on the electrochemical sulfonation reaction of organoboronic acids. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide an electrochemically catalytic sulfonation method for organoboronic acids. This method is simple to operate, requires no exogenous redox agents, exhibits high reactivity, has broad substrate applicability, high yield, and uses readily available and simple raw materials.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0005] An electrochemically catalytic sulfonation method for organoboronic acids involves adding a mixture of organoboronic acid and sodium arylsulfinate and an electrolyte, followed by the addition of a mixed solvent of acetonitrile and water, and then inserting electrodes to conduct the electrochemical sulfonation reaction by applying a constant current of 10–20 mA.

[0006] The electrochemical catalytic sulfonation reaction of organoboronic acids, "constant current" refers to a current whose direction and magnitude do not change with time, and "stirring" refers to continuous magnetic stirring.

[0007] The electrochemically catalyzed sulfonation reaction of organoboronic acids uses tetraethylammonium tetrafluoroborate as the electrolyte.

[0008] The electrochemically catalyzed sulfonation reaction of organoboronic acids uses CH3CN and H2O as mixed solvents in a volume ratio of 5 mL:1 mL.

[0009] In the electrochemical catalytic sulfonation reaction of organoboronic acids, graphite felt serves as the anode and platinum sheet as the cathode.

[0010] The electrochemically catalytic sulfonation reaction of organoboronic acid involves an organoboronic acid to sodium arylsulfite molar ratio of 1 to 3:10.

[0011] The electrochemically catalytic sulfonation reaction of organoboronic acid involves a mixture of organoboronic acid and sodium arylsulfinate being stirred at 25°C for 5 hours with a constant current of 15 mA.

[0012] The electrochemically catalyzed sulfonation reaction of the organoboronic acid, wherein the organoboronic acid is one of 4-methoxyphenylboronic acid, 3-methoxyphenylboronic acid, 2-methoxyphenylboronic acid, phenylboronic acid, 4-methylphenylboronic acid, 3-methylphenylboronic acid, 2-methylphenylboronic acid, 4-isopropylphenylboronic acid, 4-tert-butylphenylboronic acid, 4-phenylphenylboronic acid, 4-chlorophenylboronic acid, 1-naphthoboronic acid, 2-naphthoboronic acid, 9-phenanthrolineboronic acid, 4-pyreneboronic acid, benzofuran-2-boronic acid, benzothiophene-2-boronic acid, styrylboronic acid, and cyclohexene-1-boronic acid. The sodium arylsulfinate is one of sodium benzenesulfinate, sodium 4-methylbenzenesulfinate, sodium 4-chlorobenzenesulfinate, and sodium 4-fluorobenzenesulfinate.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] The method of this invention uses electrochemical technology and green, clean electricity, which is safe and environmentally friendly. The raw materials are inexpensive and readily available. The reaction can be carried out at room temperature in air. The operation is simple, the reaction activity is high, the yield is high, and the purification is convenient. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0016] Figure 1 The hydrogen nuclear magnetic resonance spectrum of the product prepared in Example 1 of this invention;

[0017] Figure 2The image shows the carbon NMR spectrum of the product prepared in Example 1 of this invention. Detailed Implementation

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0019] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0020] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0021] Example 1

[0022] The electrochemical catalytic reaction of 4-methoxyphenylboronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0023] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 4-methylphenylboronic acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 76%. The structure of the product was confirmed by NMR spectroscopy.

[0024] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ7.86 (d, J=8.5Hz, 2H, ArH), 7.79 (d, J=8.0Hz, 2H, ArH), 7.27 (d , J=8.5Hz, 2H, ArH), 6.95 (d, J=8.5Hz, 2H, ArH), 3.83 (s, 3H, OCH3), 2.38 (s, 3H, CH3); 13 C{ 1H}NMR (125MHz, CDCl3): δ163.23, 143.74, 139.44, 133.56, 129.83, 129.71, 127.37, 114.45, 55.63, 21.53

[0025] The product structural formula is:

[0026]

[0027] Example 2

[0028] The electrochemical catalytic reaction of 3-methoxyphenylboronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0029] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 3-methylphenylboronic acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 70%. The structure of the product was confirmed by NMR spectroscopy.

[0030] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ7.82 (d, J=8.5Hz, 2H, ArH), 7.48-7.50 (m, 1H, ArH), 7.43-7.44 (m, 1H, ArH), 7.37-7.40 ( m, 1H, ArH), 7.30 (d, J=8.0Hz, 2H, ArH), 7.06 (dd, J=8.5, 2.5Hz, 1H, ArH), 3.84 (s, 3H, OCH3), 2.40 (s, 3H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ159.95, 144.16, 143.06, 138.55, 130.29, 129.88, 127.68, 119.75, 119.36, 112.05, 55.65, 21.55.

[0031] The product structural formula is:

[0032]

[0033] Example 3

[0034] The electrochemical catalytic reaction of 2-methoxyphenylboronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0035] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 2-methylphenylboronic acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 71%. The structure of the product was confirmed by NMR spectroscopy.

[0036] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ8.14 (dd, J=8.0, 2.0Hz, 1H, ArH), 7.85 (d, J=8.0Hz, 2H, ArH), 7.51-7.54 (m, 1H, ArH), 7.27 ( d, J=8.0Hz, 2H, ArH), 7.09 (t, J=7.5Hz, 1H, ArH), 6.90 (d, J=8.5Hz, 1H, ArH), 3.77 (s, 3H, OCH3), 2.41 (s, 3H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ156.99, 143.73, 138.50, 135.30, 129.74, 129.24, 129.08, 128.43, 120.44, 112.38, 55.82, 21.56.

[0037] The product structural formula is:

[0038]

[0039] Example 4

[0040] The electrochemical catalytic reaction of phenylboronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0041] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of phenylboronic acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 65%. The structure of the product was confirmed by NMR spectroscopy.

[0042] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ7.93 (d, J=7.5Hz, 2H, ArH), 7.83 (d, J=8.5Hz, 2H, ArH), 7.55 (t, J= 7.5Hz, 1H, ArH), 7.49 (t, J=8.0Hz, 2H, ArH), 7.30 (d, J=8.0Hz, 2H, ArH), 2.40 (s, 3H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ144.13, 141.96, 138.62, 132.96, 129.89, 129.19, 127.70, 127.48, 21.54.

[0043] The product structural formula is:

[0044]

[0045] Example 5

[0046] The electrochemical catalytic reaction of 4-methylphenylboronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0047] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 4-methylphenylboronic acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 73%. The structure of the product was confirmed by NMR spectroscopy.

[0048] The product was characterized as a white solid. 1H NMR (500MHz, CDCl3): δ7.81 (d, J=8.5Hz, 4H, ArH), 7.28 (d, J=8.0Hz, 4H, ArH), 2.39 (s, 6H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ143.89, 139.05, 129.82, 127.54, 21.52.

[0049] The product structural formula is:

[0050]

[0051] Example 6

[0052] The electrochemical catalytic reaction of 3-methylphenylboronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0053] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 3-methylphenylboronic acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 63%. The structure of the product was confirmed by NMR spectroscopy.

[0054] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ7.82 (d, J=8.0Hz, 2H, ArH), 7.72-7.73 (m, 2H, ArH), 7.32-7.39 (m, 2H, ArH), 7.29 (d, J=8.5Hz, 2H, ArH), 2.39 (s, 6H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ144.02, 141.75, 139.44, 138.75, 133.78, 129.85, 129.05, 127.76, 127.65, 124.64, 21.53, 21.31.

[0055] The product structural formula is:

[0056]

[0057] Example 7

[0058] The electrochemical catalytic reaction of 2-methylphenylboronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0059] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 2-methylphenylboronic acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 68%. The structure of the product was confirmed by NMR spectroscopy.

[0060] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ8.19 (d, J=7.5Hz, 1H, ArH), 7.75 (d, J=8.0Hz, 2H, ArH), 7.45-7.48 (m, 1H, ArH), 7.37- 7.40 (m, 1H, ArH), 7.29 (d, J=8.0Hz, 2H, ArH), 7.22 (d, J=7.5Hz, 1H, ArH), 2.44 (s, 3H, CH3), 2.41 (s, 3H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ143.91, 139.11, 138.23, 137.82, 133.40, 132.57, 129.60, 129.22, 127.70, 126.37, 21.53, 20.14.

[0061] The product structural formula is:

[0062]

[0063] Example 8

[0064] The electrochemical catalytic reaction of 4-isopropylphenylboronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0065] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 4-isopropylphenylboronic acid, 1.0 mmol of sodium 4-methylbenzenesulfonate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 85%. The structure of the product was confirmed by NMR spectroscopy.

[0066] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ7.82-7.85 (m, 4H, ArH), 7.33 (d, J=8.5Hz, 2H, ArH), 7.29 (d, J=8.0 Hz, 2H, ArH), 2.94 (sept, J=7.0Hz, 1H, CH), 2.39 (s, 3H, CH3), 1.23 (d, J=7.0Hz, 6H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ154.53, 143.88, 139.22, 138.96, 129.80, 127.60, 127.57, 127.30, 34.12, 23.55, 21.50.

[0067] The product structural formula is:

[0068]

[0069] Example 9

[0070] The electrochemical catalytic reaction of 4-tert-butylphenylboronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0071] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 4-tert-butylphenylboronic acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 64%. The structure of the product was confirmed by NMR spectroscopy.

[0072] The product was characterized as a white solid. 1H NMR (500MHz, CDCl3): δ7.82-7.85 (m, 4H, ArH), 7.49 (d, J=8.5Hz, 2H, ArH), 7.29 (d, J=8.5Hz, 2H, ArH), 2.39 (s, 3H, CH3), 1.30 (s, 9H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ156.81, 143.89, 138.97, 138.89, 129.82, 127.62, 127.32, 126.21, 35.11, 31.00, 21.52.

[0073] The product structural formula is:

[0074]

[0075] Example 10

[0076] The electrochemical catalytic reaction of 4-phenylphenylboronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0077] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 4-phenylphenylboronic acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 66%. The structure of the product was confirmed by NMR spectroscopy.

[0078] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ7.98 (d, J=7.0Hz, 2H, ArH), 7.86 (d, J=7.5Hz, 2H, ArH), 7.67 (d, J=7.5Hz, 2H, ArH), 7.55 (d, J= 8.0Hz, 2H, ArH), 7.45 (t, J=8.0Hz, 2H, ArH), 7.40 (d, J=8.0Hz, 1H, ArH), 7.31 (d, J=7.5Hz, 2H, ArH), 2.40 (s, 3H, CH3); 13 C{ 1H}NMR (125MHz, CDCl3): δ145.97, 144.12, 140.55, 139.23, 138.82, 131.47 , 130.36, 129.92, 129.00, 128.50, 128.01, 127.84, 127.69, 127.30, 21.52.

[0079] The product structural formula is:

[0080]

[0081] Example 11

[0082] The electrochemical catalytic reaction of 4-chlorophenylboronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0083] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 4-chlorophenylboronic acid, 1.0 mmol of sodium 4-methylbenzenesulfonate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 56%. The structure of the product was confirmed by NMR spectroscopy.

[0084] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ7.86 (d, J=8.5Hz, 2H, ArH), 7.81 (d, J=8.0Hz, 2H, ArH), 7.45 (d, J=8.5Hz, 2H, ArH), 7.30 (d, J=8.5Hz, 2H, ArH), 2.40 (s, 3H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ144.47, 140.48, 139.62, 138.18, 130.01, 129.50, 128.93, 127.65, 21.54.

[0085] The product structural formula is:

[0086]

[0087] Example 12

[0088] The electrochemical catalytic reaction of 1-naphthoboric acid with sodium 4-methylbenzenesulfinate is as follows:

[0089] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 1-naphtholic boric acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 78%. The structure of the product was confirmed by NMR spectroscopy.

[0090] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ8.64 (d, J=9.0Hz, 1H, ArH), 8.49 (d, J=7.0Hz, 1H, ArH), 8.06 (d, J=8.5Hz, 1H, ArH), 7.87 (d, J =8.0Hz, 1H, ArH), 7.84 (d, J = 8.5Hz, 2H, ArH), 7.50-7.60 (m, 3H, ArH), 7.24 (d, J = 8.0Hz, 2H, ArH), 2.33 (s, 3H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ143.92, 138.76, 136.10, 134.94, 134.15, 129.68, 128.95, 128.36, 128.21, 127.39, 126.77, 124.33, 124.31, 21.45.

[0091] The product structural formula is:

[0092]

[0093] Example 13

[0094] The electrochemical catalytic reaction of 2-naphthylboronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0095] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 2-naphthylboronic acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 80%. The structure of the product was confirmed by NMR spectroscopy.

[0096] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ8.56 (s, 1H, ArH), 7.97 (d, J=7.5Hz, 1H, ArH), 7.83-7.92 ( m, 5H, ArH), 7.57-7.64 (m, 2H, ArH), 7.29 (d, J=8.5Hz, 2H, ArH), 2.38 (s, 3H, CH3); 13 C{ 1 H}NMR (125MHz, CDCl3): δ144.12, 138.75, 138.64, 134.89, 132.18, 129.89 , 129.54, 129.33, 129.00, 128.78, 127.86, 127.73, 127.53, 122.60, 21.51.

[0097] The product structural formula is:

[0098]

[0099] Example 14

[0100] The electrochemically catalytic reaction of 9-phenanthreneboronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0101] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 9-phenanthroline, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 79%. The structure of the product was confirmed by NMR spectroscopy.

[0102] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ8.88 (s, 1H, ArH), 8.61-8.66 (m, 3H, ArH), 8.05 (d, J=7.5Hz, 1H, ArH), 7.87 (d, J=8.5 Hz, 2H, ArH), 7.75-7.78 (m, 1H, ArH), 7.56-7.69 (m, 3H, ArH), 7.22 (d, J=8.0Hz, 2H, ArH), 2.32 (s, 3H, CH3); 13 C{ 1H}NMR (125MHz, CDCl3): δ143.99, 138.58, 134.52, 132.64, 131.19, 130.66, 129.95 , 129.71, 129.27, 127.58, 127.56, 127.41, 125.93, 125.39, 123.24, 122.69, 21.45.

[0103] The product structural formula is:

[0104]

[0105] Example 15

[0106] The electrochemical catalytic reaction of 4-pyreneboronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0107] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 4-pyreneboronic acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 82%. The structure of the product was confirmed by NMR spectroscopy.

[0108] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ8.98 (d, J=9.5Hz, 1H, ArH), 8.90 (d, J=8.5Hz, 1H, ArH), 8.13-8.24 (m, 5H, ArH ), 8.01-8.04 (m, 2H, ArH), 7.90 (d, J=8.5Hz, 2H, ArH), 7.22 (d, J=8.0Hz, 2H, ArH), 2.30 (s, 3H, CH3); 13 C{ 1 H}NMR (125MHz, CDCl3): δ143.75, 139.62, 135.27, 132.35, 130.77, 130.44, 130.06, 129.93, 129.68 , 128.58, 127.32, 127.11, 126.98, 126.93, 126.89, 126.72, 125.05, 124.12, 123.83, 122.87, 21.44.

[0109] The product structural formula is:

[0110]

[0111] Example 16

[0112] The electrochemical catalytic reaction of benzofuran-2-boric acid with sodium 4-methylbenzenesulfinate is as follows:

[0113] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of benzofuran-2-boric acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 74%. The structure of the product was confirmed by NMR spectroscopy.

[0114] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ7.96 (d, J=8.5Hz, 2H, ArH), 7.66 (d, J=8.0Hz, 1H, ArH), 7.53 (s, 1H, ArH), 7.49 (d, J=8 .5Hz, 1H, ArH), 7.40-7.44 (m, 1H, ArH), 7.34 (d, J=8.0Hz, 2H, ArH), 7.28-7.32 (m, 1H, ArH), 2.41 (s, 3H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ156.28, 151.86, 145.23, 136.28, 129.99, 128.25, 127.86, 125.92, 124.20, 123.04, 112.83, 112.35, 21.62.

[0115] The product structural formula is:

[0116]

[0117] Example 17

[0118] The electrochemical catalytic reaction of benzothiophene-2-boric acid with sodium 4-methylbenzenesulfinate is as follows:

[0119] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of benzothiophene-2-boric acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 86%. The structure of the product was confirmed by NMR spectroscopy.

[0120] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ7.95 (s, 1H, ArH), 7.92 (d, J=8.5Hz, 2H, ArH), 7.85 (d, J=7.0Hz, 1H, ArH), 7.80 (d, J=8.0Hz, 1H, ArH), 7.40-7.46 (m, 2H, ArH), 7.32 (d, J=8.0Hz, 2H, ArH), 2.40 (s, 3H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ144.67, 143.41, 142.64, 138.41, 137.70, 129.97, 127.65, 127.34, 125.85, 125.47, 122.70, 21.58.

[0121] The product structural formula is:

[0122]

[0123] Example 18

[0124] The electrochemical catalytic reaction of styrylboronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0125] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of styrenicboric acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 69%. The structure of the product was confirmed by NMR spectroscopy.

[0126] The product was characterized as a white solid. 1H NMR (500MHz, CDCl3): δ7.83 (d, J=8.0Hz, 2H, ArH), 7.66 (d, J=15.0Hz, 1H, =CH), 7.46-7.48 (m, 2H, ArH ), 7.38-7.40 (m, 3H, ArH), 7.34 (d, J=8.0Hz, 2H, ArH), 6.85 (d, J=15.0Hz, 1H, =CH), 2.43 (s, 3H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ144.35, 141.89, 137.72, 132.42, 131.05, 129.93, 129.02, 128.47, 127.67, 127.61, 21.56.

[0127] The product structural formula is:

[0128]

[0129] Example 19

[0130] The electrochemical catalytic reaction of cyclohexene-1-boronic acid with sodium 4-methylbenzenesulfinate is as follows:

[0131] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of cyclohexene-1-boric acid, 1.0 mmol of sodium 4-methylbenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 56%. The structure of the product was confirmed by NMR spectroscopy.

[0132] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ7.73 (d, J=8.0Hz, 2H, ArH), 7.31 (d, J=8.0Hz, 2H, ArH), 7.03 (s, 1H, =CH), 2.43 (s, 3H, CH3), 2.25-2.27 (m, 2H, CH2), 2.15-2.16 (m, 2H, CH2), 1.61-1.65 (m, 2H, CH2), 1.55-1.59 (m, 2H, CH2); 13 C{ 1H} NMR (125MHz, CDCl3): δ143.92, 140.00, 137.82, 136.42, 129.64, 128.00, 25.39, 22.75, 21.76, 21.52, 20.76.

[0133] The product structural formula is:

[0134]

[0135] Example 20

[0136] The electrochemically catalytic reaction of 4-methylphenylboronic acid with sodium benzenesulfinate proceeds as follows:

[0137] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 4-methylphenylboronic acid, 1.0 mmol of sodium benzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 42%. The structure of the product was confirmed by NMR spectroscopy.

[0138] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ7.93 (d, J=7.0Hz, 2H, ArH), 7.83 (d, J=8.0Hz, 2H, ArH), 7.55 (t, J= 7.5Hz, 1H, ArH), 7.49 (t, J=8.0Hz, 2H, ArH), 7.30 (d, J=8.0Hz, 2H, ArH), 2.40 (s, 3H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ144.13, 141.95, 138.61, 132.96, 129.88, 129.18, 127.69, 127.47, 21.54.

[0139] The product structural formula is:

[0140]

[0141] Example 21

[0142] The electrochemically catalytic reaction of 4-isopropylphenylboronic acid with sodium benzenesulfinate is as follows:

[0143] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 4-isopropylphenylboronic acid, 1.0 mmol of sodium benzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 54%. The structure of the product was confirmed by NMR spectroscopy.

[0144] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ7.95 (d, J=7.5Hz, 2H, ArH), 7.86 (d, J=8.0Hz, 2H, ArH), 7.55 (t, J=7.5Hz, 1H, ArH), 7.5 0 (t, J=8.0Hz, 2H, ArH), 7.34 (d, J=8.5Hz, 2H, ArH), 2.95 (sept, J=7.0Hz, 1H, CH), 1.23 (d, J=7.0Hz, 6H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ154.78, 141.93, 138.85, 132.96, 129.19, 127.80, 127.55, 127.39, 34.17, 23.57.

[0145] The product structural formula is:

[0146]

[0147] Example 22

[0148] The electrochemical catalytic reaction of 4-chlorophenylboronic acid with sodium benzenesulfinate is as follows:

[0149] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 4-chlorophenylboronic acid, 1.0 mmol of sodium benzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 48%. The structure of the product was confirmed by NMR spectroscopy.

[0150] The product was characterized as a white solid. 1H NMR (500MHz, CDCl3): δ7.93 (d, J=7.5Hz, 2H, ArH), 7.88 (d, J=8.5Hz, 2H, ArH), 7. 59 (t, J=7.5Hz, 1H, ArH), 7.52 (t, J=8.0Hz, 2H, ArH), 7.48 (d, J=8.5Hz, 2H, ArH); 13 C{ 1 H} NMR (125MHz, CDCl3): δ141.16, 140.09, 139.87, 133.42, 129.59, 129.39, 129.09, 127.61.

[0151] The product structural formula is:

[0152]

[0153] Example 23

[0154] The electrochemical catalytic reaction of 2-naphthylboronic acid with sodium benzenesulfinate is as follows:

[0155] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 2-naphthylboronic acid, 1.0 mmol of sodium benzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 62%. The structure of the product was confirmed by NMR spectroscopy.

[0156] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ8.58 (s, 1H, ArH), 7.97-8.01 (m, 3H, ArH), 7.92 (d, J=8.5Hz, 1H, ArH), 7.85-7.88 (m, 2H, ArH), 7.48-7.65 (m, 5H, ArH); 13 C{ 1 H} NMR (125MHz, CDCl3): δ141.58, 138.34, 134.96, 133.15, 132.16, 129.62, 129.36, 129.26, 129.12, 129.05, 127.88, 127.67, 127.61, 122.63.

[0157] The product structural formula is:

[0158]

[0159] Example 24

[0160] The electrochemical catalytic reaction of benzofuran-2-boric acid with sodium benzenesulfinate is as follows:

[0161] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of benzofuran-2-boric acid, 1.0 mmol of sodium benzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 74%. The structure of the product was confirmed by NMR spectroscopy.

[0162] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ8.09 (d, J=7.5Hz, 2H, ArH), 7.68 (d, J=8.0Hz, 1H, ArH), 7.62-7.65 (m, 1H, Ar H), 7.55-7.58 (m, 3H, ArH), 7.50-7.52 (m, 1H, ArH), 7.42-7.46 (m, 1H, ArH), 7.30-7.33 (m, 1H, ArH); 13 C{ 1 H} NMR (125MHz, CDCl3): δ156.38, 151.52, 139.29, 134.06, 129.37, 128.21, 128.02, 125.91, 124.29, 123.12, 113.31, 112.43.

[0163] The product structural formula is:

[0164]

[0165] Example 25

[0166] The electrochemical catalytic reaction of 4-methylphenylboronic acid with sodium 4-chlorobenzenesulfinate is as follows:

[0167] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 4-methylphenylboronic acid, 1.0 mmol of sodium 4-chlorobenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 44%. The structure of the product was confirmed by NMR spectroscopy.

[0168] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ7.86 (d, J=8.5Hz, 2H, ArH), 7.81 (d, J=8.0Hz, 2H, ArH), 7.46 (d, J=9.0Hz, 2H, ArH), 7.30 (d, J=8.0Hz, 2H, ArH), 2.40 (s, 3H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ144.48, 140.50, 139.63, 138.20, 130.02, 129.51, 128.94, 127.67, 21.55.

[0169] The product structural formula is:

[0170]

[0171] Example 26

[0172] The electrochemical catalytic reaction of 4-chlorophenylboronic acid with sodium 4-chlorobenzenesulfinate is as follows:

[0173] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 4-chlorophenylboronic acid, 1.0 mmol of sodium 4-chlorobenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 50%. The structure of the product was confirmed by NMR spectroscopy.

[0174] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ7.87 (d, J=8.5Hz, 4H, ArH), 7.49 (d, J=8.5Hz, 4H, ArH);13 C{ 1 H} NMR (125MHz, CDCl3): δ140.18, 139.67, 129.72, 129.07.

[0175] The product structural formula is:

[0176]

[0177] Example 27

[0178] The electrochemical catalytic reaction of 2-naphthylboronic acid with sodium 4-chlorobenzenesulfinate is as follows:

[0179] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 2-naphthylboronic acid, 1.0 mmol of sodium 4-chlorobenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 61%. The structure of the product was confirmed by NMR spectroscopy.

[0180] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ8.56 (s, 1H, ArH), 7.97 (d, J=8.0Hz, 1H, ArH), 7.92-7.94 (m, 3H, ArH), 7.87 (d, J=8.0Hz, 1H, ArH), 7.82-7.87 (m, 1H, ArH), 7.58-7.65 (m, 2H, ArH), 7.45 (d, J=9.0Hz, 2H, ArH); 13 C{ 1 H} NMR (125MHz, CDCl3): δ144.08, 138.78, 137.86, 134.99, 132.11, 129.76, 129.54, 129.33, 129.26, 129.10, 127.88, 127.70, 122.39.

[0181] The product structural formula is:

[0182]

[0183] Example 28

[0184] The electrochemically catalytic reaction of benzofuran-2-boronic acid with sodium 4-chlorobenzenesulfinate is as follows:

[0185] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of benzofuran-2-boric acid, 1.0 mmol of sodium 4-chlorobenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 72%. The structure of the product was confirmed by NMR spectroscopy.

[0186] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ8.02 (d, J=8.5Hz, 2H, ArH), 7.68 (d, J=8.0Hz, 1H, ArH), 7.57 (s, 1H , ArH), 7.52 (t, J=8.5Hz, 3H, ArH), 7.45 (t, J=7.0Hz, 1H, ArH), 7.33 (t, J=7.5Hz, 2H, ArH); 13 C{ 1 H} NMR (125MHz, CDCl3): δ156.42, 151.04, 140.88, 137.73, 129.73, 129.69, 128.22, 125.80, 124.40, 123.18, 113.61, 112.42.

[0187] The product structural formula is:

[0188]

[0189] Example 29

[0190] The electrochemical catalytic reaction of 4-methylphenylboronic acid with sodium 4-fluorobenzenesulfinate is as follows:

[0191] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 4-methylphenylboronic acid, 1.0 mmol of sodium 4-fluorobenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 56%. The structure of the product was confirmed by NMR spectroscopy.

[0192] The product was characterized as a white solid. 1H NMR (500MHz, CDCl3): δ7.93-7.96 (m, 2H, ArH), 7.81 (d, J=8.5Hz, 2H, ArH), 7.31 (d, J=8.5Hz, 2H, ArH), 7.16 (t, J=8.5Hz, 2H, ArH), 2.40 (s, 3H, CH3); 13 C{ 1 H} NMR (125MHz, CDCl3): δ166.30, 164.27, 140.32, 138.48, 130.31, 130.23, 129.98, 127.60, 116.57, 116.39, 21.54.

[0193] The product structural formula is:

[0194]

[0195] Example 30

[0196] The electrochemical catalytic reaction of 4-chlorophenylboronic acid with sodium 4-fluorobenzenesulfinate is as follows:

[0197] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 4-chlorophenylboronic acid, 1.0 mmol of sodium 4-fluorobenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 51%. The structure of the product was confirmed by NMR spectroscopy.

[0198] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ7.94-7.97 (m, 2H, ArH), 7.87 (d, J=8.5Hz, 2H, ArH), 7.49 (d, J=8.5Hz, 2H, ArH), 7.19 (t, J=8.5Hz, 2H, ArH); 13 C{ 1 H} NMR (125MHz, CDCl3): δ166.55, 164.51, 140.33, 139.93, 137.22, 130.50, 130.42, 129.68, 129.00, 116.81, 116.63.

[0199] The product structural formula is:

[0200]

[0201] Example 31

[0202] The electrochemical catalytic reaction of 2-naphthylboronic acid with sodium 4-fluorobenzenesulfinate is as follows:

[0203] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of 2-naphthylboronic acid, 1.0 mmol of sodium 4-fluorobenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 66%. The structure of the product was confirmed by NMR spectroscopy.

[0204] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ8.57 (s, 1H, ArH), 8.00-8.04 (m, 2H, ArH), 7.97 (d, J=8.0Hz, 1H, ArH), 7.92 (d, J=8.5Hz, 1H, ArH), 7.82-7.87 (m, 2H, ArH), 7.58-7.65 (m, 2H, ArH), 7.16 (t, J=8.5Hz, 2H, ArH); 13 C{ 1 H}NMR (125MHz, CDCl3): δ166.34, 164.31, 138.13, 137.65, 137.63, 134.93, 132.10, 130 .50, 130.42, 129.72, 129.31, 129.19, 128.96, 127.87, 127.67, 122.40, 116.62, 116.44.

[0205] The product structural formula is:

[0206]

[0207] Example 32

[0208] The electrochemical catalytic reaction of benzofuran-2-boronic acid with sodium 4-fluorobenzenesulfinate is as follows:

[0209] In a 25 mL three-necked round-bottom flask, 0.2 mmol of tetraethylammonium tetrafluoroborate (Et4NBF4), 0.2 mmol of benzofuran-2-boric acid, 1.0 mmol of sodium 4-fluorobenzenesulfinate, 5 mL of acetonitrile (CH3CN), and 1 mL of water (H2O) were added sequentially. The anode was a graphite felt, and the cathode was a platinum sheet. The mixture was stirred at a constant current of 15 mA for 5 h at 25 °C. After removing the solvent under vacuum, the pure product was obtained by rapid chromatography on silica gel using petroleum ether and ethyl acetate as eluents, with a yield of 64%. The structure of the product was confirmed by NMR spectroscopy.

[0210] The product was characterized as a white solid. 1 H NMR (500MHz, CDCl3): δ8.10-8.12 (m, 2H, ArH), 7.69 (d, J=8.0Hz, 1H, ArH), 7.57 (s, 1H, ArH), 7.51 (d, J=8.5Hz, 1H, ArH), 7.45 (t, J=8.0Hz, 1H, ArH), 7.33 (t, J=7.5Hz, 1H, ArH), 7.24 (t, J=8.5Hz, 2H, ArH); 13 C{ 1 H}NMR (125MHz, CDCl3): δ167.05, 165.00, 156.41, 151.30, 135.33, 135.31, 131 .24, 131.17, 128.16, 125.85, 124.38, 123.17, 116.86, 116.68, 113.35, 112.43.

[0211] The product structural formula is:

[0212]

[0213] Example 33

[0214] Example 33 optimizes the reaction conditions based on Example 1, and the optimization results are shown in Table 1.

[0215] Table 1

[0216]

[0217] *Note: In this embodiment, "yield" refers to NMR yield, i.e., the yield obtained from NMR spectra. The yield in parentheses is the separation yield.

[0218] The results of the above optimization conditions show that, under the same reaction conditions, the highest yield is achieved when the electrolyte is tetrabutylammonium tetrafluoroborate (Bu4NBF4). No product is formed without the addition of an electrolyte.

[0219] Under the same reaction conditions, the yield is not directly proportional to the time; the highest yield is achieved when the reaction time is 5 hours.

[0220] Under the same reaction conditions, a higher current intensity is not necessarily better; the reaction yield is highest when the reaction current is 15 mA. Without an electric current, no target product is formed.

[0221] Under the same reaction conditions, the highest yield was obtained when a mixed solvent was used and MeCN:H2O = 5 mL:1 mL. When other volume ratios of mixed solvents or pure acetonitrile were used, the yield was significantly lower than that under standard conditions.

[0222] Under the same reaction conditions, the electrode pair with graphite felt as the anode and platinum sheet as the cathode yields the highest reaction rate. Reactions with both graphite felt or platinum sheet as the anode and cathode yield significantly lower than under standard conditions.

[0223] This invention provides an electrochemically catalytic method for the sulfonation of organoboronic acids. The method is simple and easy to operate, uses only a small amount of solvent, and the required materials are of low toxicity, making it safe and environmentally friendly. It also achieves high product conversion and can be stored at room temperature. Furthermore, this electrochemically catalytic method for the sulfonation of organoboronic acids exhibits high reactivity and a broad substrate scope.

[0224] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for the electrochemical catalytic sulfonation reaction of organoboronic acids, characterized in that: Under ambient air and room temperature conditions, a mixture of organoboronic acid and sodium arylsulfinate is reacted in an electrolytic system via electrochemical anodic oxidation at a constant current of 10–20 mA for 4–6 hours with stirring at 25°C to obtain the product. The electrolytic system includes an electrolyte, a solvent, an anode, and a cathode. The molar ratio of the organoboronic acid to the sodium arylsulfinate is 1–3:

10. The organoboronic acid is 4-methoxyphenylboronic acid, 3-methoxyphenylboronic acid, 2-methoxyphenylboronic acid, phenylboronic acid, 4-methylphenylboronic acid, 3-methylphenylboronic acid, 2-methylphenylboronic acid. The electrolyte comprises one of the following: 4-isopropylphenylboronic acid, 4-tert-butylphenylboronic acid, 4-phenylphenylboronic acid, 4-chlorophenylboronic acid, 1-naphthoboronic acid, 2-naphthoboronic acid, 9-phenanthrolineboronic acid, 4-pyreneboronic acid, benzofuran-2-boronic acid, benzothiophene-2-boronic acid, styrylboronic acid, and cyclohexene-1-boronic acid; the sodium arylsulfinate is one of sodium benzenesulfinate, sodium 4-methylbenzenesulfinate, sodium 4-chlorobenzenesulfinate, and sodium 4-fluorobenzenesulfinate; the electrolyte comprises at least one of tetraethylammonium tetrafluoroborate, tetrabutylammonium tetrafluoroborate, tetrabutylammonium acetate, or potassium iodide.

2. The electrochemically catalytic sulfonation reaction method for organoboronic acids as described in claim 1, characterized in that: The mixture of the organoboronic acid and the sodium arylsulfinate was stirred and reacted for 5 hours under a constant current of 15 mA.

3. The electrochemically catalytic sulfonation reaction method for organoboronic acids as described in claim 1, characterized in that: The anode is a graphite felt, and the cathode is a platinum sheet.

4. The electrochemically catalytic sulfonation method for organoboronic acids according to any one of claims 1, 2, and 3, characterized in that: The stirring reaction is carried out in a solvent, namely CH3CN and H2O.

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