Alpha-furan boron compound and three-component strategy synthesis method thereof

Abstract

The invention provides an alpha-furan borane compound and a three-component strategy synthesis method thereof, and the alpha-furan borane compound is synthesized by taking a ketone compound, an alkyne aldehyde compound and a borane complex as raw materials through a one-step reaction under the catalysis of cuprous chloride. Compared with the prior art, the method has the advantages of economical steps, efficient atom utilization, environmental protection and the like, and is a unique method for preparing the alpha-furan borane compound. In addition, the raw materials are convenient and easy to obtain, the operation steps are simple, the reaction conditions are mild, and the method is suitable for large-scale industrial production.

Description

Technical Field

[0001] The invention belongs to the field of fine chemical synthesis, and specifically relates to an alpha-furan boron compound and a three-component strategy synthesis method thereof. Background Art

[0002] Furan and boron structural units are important pharmacophoric groups in drug molecules. Therefore, the development of compounds with both furan and boron structural units has important research value. In 2017, Zhou Qilin's team at Nankai University reported a method for synthesizing α-furan borane compounds from two components of metal-catalyzed conjugated alkyne enone and borane (J.Am.Chem.Soc.2017,139,3784-3789). This method uses the conjugated alkyne enone obtained in advance by the reaction of ketone and alkyne aldehyde in the presence of additives such as acetic acid, piperidine and magnesium sulfate and post-treatment purification as raw materials, and then inserts the boron hydrogen bond through α-furan metal carbene to synthesize a series of α-furan borane compounds.

[0003] Multicomponent cascade reactions are simple to operate, highly efficient, and atom-economical, and are a direct and effective way to construct complex and diverse molecules. However, the complexity of the reactions and the diversity of the products make the design of synthons and the screening of conditions for this strategy extremely challenging. So far, there has been no report on the one-step synthesis of α-furan borane compounds through the insertion of boron-hydrogen bonds by a multicomponent strategy using α-furan metal carbenes. Summary of the invention

[0004] The purpose of the present invention is to provide an α-furan borane compound and a three-component strategy synthesis method thereof, so as to overcome the problems of cumbersome operation, low efficiency and poor atom economy in the prior art. The present invention uses commercially available ketones, acetylene aldehydes and borane complexes as raw materials, and synthesizes α-furan borane compounds in one step through an α-furan carbene boron hydrogen bond insertion pathway under copper catalysis. The raw materials are readily available, the operation is simple, the conditions are mild, and it is suitable for the needs of large-scale industrial production.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme:

[0006] An α-furan borane compound, wherein the structural formula of the α-furan borane compound is as shown in formula (1):

[0007]

[0008] Among them, R 1 is alkyl or aryl; R 2 is COMe, COEt, CO2Me or SO2Ph; R 3 is alkyl or aryl; LB is NMe3, NMe(C4H8) or NMe(C5H 10 ).

[0009] A three-component strategy synthesis method for an α-furan borane compound, wherein a ketone compound as shown in formula (2), an acetylene aldehyde compound as shown in formula (3) and a borane compound as shown in formula (4) are used to synthesize an α-furan borane compound as shown in formula (1) through a one-step reaction under the catalysis of cuprous chloride as shown in formula (5);

[0010]

[0011] Furthermore, the specific steps include: adding a catalyst CuCl and a reaction solvent in a reaction container in sequence under room temperature and air conditions, and stirring evenly; then adding a ketone compound, an acetylene aldehyde compound and a borane complex in sequence to react, and after the reaction is completed, separating by silica gel column chromatography to obtain an α-furan borane compound.

[0012] Furthermore, the molar ratio of the ketone compound, the acetylene aldehyde compound, the borane complex and cuprous chloride is 1:1.5:4:0.1.

[0013] Furthermore, the reaction solvent is dichloromethane, and 0.4 mmol of ketone compound is added to every 1.0 mL of the reaction solvent.

[0014] Furthermore, the reaction time is 10-20 hours.

[0015] Furthermore, the reaction temperature is 55°C.

[0016] Furthermore, after the reaction is completed, silica gel column chromatography is directly performed for separation.

[0017] Furthermore, when separating by silica gel column chromatography, the eluent is petroleum ether and ethyl acetate, and the volume ratio of petroleum ether to ethyl acetate is 2:1 to 4:1.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] The prior art method for obtaining α-furan borane compounds is to use a ketone and an acetylenic aldehyde to react in the presence of additives such as acetic acid, piperidine and magnesium sulfate, and to obtain a conjugated acetylenone in advance through post-treatment and purification as a raw material. The synthesis of this raw material consumes a large amount of additives, has poor atom economy, and the post-treatment process consumes a lot of time and energy.

[0020] The present invention can synthesize α-furan borane compounds in one step through a three-component strategy, avoiding the use of additives required for raw material synthesis and the consumption of reagents required for post-processing purification in a two-component strategy, saving time and labor costs, and thus having the advantages of being green and economical. At the same time, the method of the present invention has easy-to-obtain raw materials, simple operation, mild conditions, and is suitable for the needs of large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the reaction for the three-component strategy to synthesize α-furanborane compounds. DETAILED DESCRIPTION

[0022] The present invention is described in further detail below:

[0023] An α-furan borane compound, such as formula (1), has the following structural formula:

[0024]

[0025] A three-component strategy for synthesizing α-furan borane compounds, such as Figure 1 As shown, the specific preparation scheme is as follows: using a ketone compound as shown in formula (2), an acetylene aldehyde compound as shown in formula (3) and a borane compound as shown in formula (4), under the catalysis of cuprous chloride as shown in formula (5), an α-furan borane compound as shown in formula (1) is synthesized by a one-step reaction;

[0026]

[0027] A method for synthesizing α-furan borane compounds by a three-component strategy specifically comprises: adding a catalyst CuCl and a reaction solvent dichloromethane to a reaction container at room temperature and air conditions, stirring evenly; then adding a ketone compound, an acetylene aldehyde compound and a borane complex in sequence, reacting at 55°C; finally, directly separating by silica gel column chromatography, using an eluent of petroleum ether: ethyl acetate = 2:1 to 4:1 (volume ratio) to obtain an α-furan borane compound. The molar ratio of the ketone compound, the acetylene aldehyde compound, the borane complex and the cuprous chloride catalyst is 1:1.5:4:0.1; the reaction solvent is dichloromethane, and 0.4 mmol of the ketone compound is added to every 1.0 mL of the reaction solvent; and the reaction time is 10-20 hours.

[0028] The specific equation is as follows:

[0029]

[0030] The present invention is described in detail below in conjunction with the embodiments and drawings to facilitate a more comprehensive understanding of the present invention by those skilled in the art, but the present invention is not limited to the scope of all embodiments. All other embodiments obtained without creative work are within the scope of protection of the present invention.

[0031] Example 1

[0032] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0033]

[0034] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, the catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and the reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then the ketone compound 2a (20.0 mg, 0.2 mmol, 1.0 eq), the acetylene aldehyde compound 3a (39.0 mg, 0.3 mmol, 1.5 eq) and the borane complex 4a (58.4 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C for 10 hours in a sealed state; finally, the α-furan borane compound 1a (45.6 mg, yield 80%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). According to NMR analysis, the NMR data are as follows: 1 H NMR (500MHz, CDCl3): δ7.32-7.26(m,2H),7.22(t,J=7.5Hz,2H),7.07(t,J=7 .2Hz,1H),6.29(s,1H),3.35(s,1H),2.50(s,3H),2.46(s,9H),2.35(s,3H). 13 C NMR (125MHz, CDCl3): δ195.0,160.9,156.1,147.4,128.5,128.3,124.6,122.1,104.6,52.6,38.0,29.2,14.6.

[0035] Example 2

[0036] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0037]

[0038] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, the catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and the reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then the ketone compound 2a (20.0 mg, 0.2 mmol, 1.0 eq), the acetylene aldehyde compound 3b (48.0 mg, 0.3 mmol, 1.5 eq) and the borane complex 4a (58.4 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C for 10 hours in a sealed state; finally, the α-furan borane compound 1b (49.7 mg, yield 79%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). According to NMR analysis, the NMR data are as follows: 1 H NMR (500MHz, CDCl3): δ7.21(d,J=8.6Hz,2H),6.79(d,J=8.6Hz,2H),6.23(s,1 H),3.76(s,3H),3.30(t,J=4.9Hz,1H),2.50(s,3H),2.47(s,9H),2.34(s,3H). 13 C NMR (125MHz, CDCl3): δ195.0,161.3,157.0,156.3,139.4,129.2,122.2,113.8,104.3,55.4,52.7,36.8,29.3,14.6.

[0039] Example 3

[0040] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0041]

[0042] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, the catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and the reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then the ketone compound 2a (20.0 mg, 0.2 mmol, 1.0 eq), the acetylene aldehyde compound 3c (44.4 mg, 0.3 mmol, 1.5 eq) and the borane complex 4a (58.4 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C for 10 hours in a sealed state; finally, the α-furan borane compound 1c (47.2 mg, yield 78%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). According to NMR analysis, the NMR data are as follows: 1H NMR (500MHz, CDCl3): δ7.24-7.21(m,2H),6.91(t,J=8.7Hz,2H),6.26(s,3H),3.33(t,J=4.8Hz,1H),2.50(s,2H),2.48(s,9H),2.35(s,3H). 13 C NMR (125MHz, CDCl3): δ195.0, 160.7, 160.6 (d, J = 242.7Hz), 156.3, 143.0, 129.4 (d,J=7.6Hz),122.2,115.0(d,J=20.9Hz),114.9,104.7,52.7,37.0,29.3,14.6. 11 B NMR (160MHz,CDCl3):δ-1.1. 19 F NMR (471MHz,CDCl3):δ-119.8.High resolution data:Calculated for [C 17 H 24 BFNO2,M+H] + :304.1879,found:304.1885.

[0043] Example 4

[0044] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0045]

[0046] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, the catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and the reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then the ketone compound 2a (20.0 mg, 0.2 mmol, 1.0 eq), the acetylene aldehyde compound 3d (43.2 mg, 0.3 mmol, 1.5 eq) and the borane complex 4a (58.4 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C for 10 hours in a sealed state; finally, the α-furan borane compound 1d (47.2 mg, yield 79%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). According to NMR analysis, the NMR data are as follows: 1H NMR (500MHz, CDCl3): δ7.14-7.08(m,3H),6.88(d,J=6.9Hz,1H),6.29(s,1H),3.32(s,1H),2.50(s,3H),2.46(s,9H),2.36(s,3H),2.30(s,3H). 13 C NMR (125MHz, CDCl3): δ195.0,161.0,156.1,147.3,137.7,129.0,128.2,125.43,125.36,122.2,104.6,52.7,37.7,29.3,21.7,14.6.

[0047] Example 5

[0048] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0049]

[0050] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, the catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and the reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then the ketone compound 2a (20.0 mg, 0.2 mmol, 1.0 eq), the acetylene aldehyde compound 3e (59.4 mg, 0.3 mmol, 1.5 eq) and the borane complex 4a (58.4 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C for 10 hours in a sealed state; finally, the α-furan borane compound 1e (44.5 mg, yield 63%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). According to NMR analysis, the NMR data are as follows: 1 H NMR (500MHz, CDCl3): δ7.51 (s, 1H), 7.45-7.43 (m, 1H), 7.32 (d, J = 5.0Hz, 2H) ,6.33(s,1H),3.41(t,J=4.7Hz,1H),2.50(s,3H),2.51(s,9H),2.37(s,3H). 13 C NMR (125MHz, CDCl3): δ194.9, 159.8, 156.5, 148.5, 131.5, 130.3 (q, J = 31.3Hz), 128.6, 124.8, (q, J=3.8Hz), 124.6 (q, J=272.0Hz), 122.3, 121.8 (q, J=3.8Hz), 105.3, 52.7, 38.0, 29.3, 14.6.11 B NMR (160MHz,CDCl3):δ-1.5. 19 F NMR (471MHz,CDCl3):δ-62.30. High resolution data: Calculated for [C 18 H 24 BF3NO2,M+H] + :354.1847,found:354.1855.

[0051] Example 6

[0052] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0053]

[0054] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, the catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and the reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then the ketone compound 2a (20.0 mg, 0.2 mmol, 1.0 eq), the acetylene aldehyde compound 3f (43.2 mg, 0.3 mmol, 1.5 eq) and the borane complex 4a (58.4 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C for 10 hours in a sealed state; finally, the α-furan borane compound 1f (48.1 mg, yield 80%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). According to NMR analysis, the NMR data are as follows: 1 H NMR (500MHz, CDCl3): δ7.31(d,J=7.6Hz,1H),7.08(t,J=7.3Hz,2H),6.97(t,J=7.5Hz ,1H),6.33(s,1H),3.55(s,1H),2.53(s,9H),2.51(s,3H),2.42(s,3H),2.36(s,3H). 13 C NMR (125MHz, CDCl3): δ194.9,161.1,156.1,145.2,134.1,130.2,128.1,126.0,124.4,122.3,105.4,52.8,32.7,29.3,20.4,14.7.

[0055] Example 7

[0056] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0057]

[0058] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, the catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and the reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then the ketone compound 2a (20.0 mg, 0.2 mmol, 1.0 eq), the acetylene aldehyde compound 3g (54.0 mg, 0.3 mmol, 1.5 eq) and the borane complex 4a (58.4 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C for 10 hours in a sealed state; finally, the α-furan borane compound 1g (42.3 mg, yield 63%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). According to NMR analysis, the NMR data are as follows: 1 H NMR (500MHz, CDCl3): δ7.79-7.71(m,3H),7.66(s,1H),7.52(d,J=8.4Hz,1H),7.40(t,J=6.7Hz,1H) ,7.35(t,J=7.2Hz,1H),6.35(s,1H),3.54(t,J=4.4Hz,1H),2.49(s,3H),2.48(s,9H),2.37(s,3H). 13 CNMR (125MHz, CDCl3): δ195.0,160.6,156.4,145.2,134.0,131.7,128.0,127 .8,127.7,127.4,125.7,125.6,124.7,122.2,105.0,52.8,38.0,29.3,14.6.

[0059] Example 8

[0060] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0061]

[0062] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, the catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and the reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then the ketone compound 2a (20.0 mg, 0.2 mmol, 1.0 eq), the acetylene aldehyde compound 3h (28.2 mg, 0.3 mmol, 1.5 eq) and the borane complex 4a (58.4 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C for 10 hours in a sealed state; finally, the α-furan borane compound 1h (39.8 mg, yield 80%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). After NMR analysis, the NMR data are as follows: 1 H NMR (500MHz, CDCl3): δ6.08(s,1H),2.52(s,3H),2.49(s,9H),2.35(s,3H),1.25(s ,1H),0.92-0.84(m,1H),0.52-0.46(m,1H),0.38-0.35(m,1H),0.13-0.03(m,2H). 13 C NMR (125MHz, CDCl3): δ195.1,163.5,155.5,122.2,102.9,52.5,34.7,29.2,16.0,14.6,6.5,5.2. 11 B NMR (160MHz, CDCl3): δ-1.8. High resolution data: Calculated for [C 14 H 25 BNO2,M+H] + :250.1973,found:250.1977.

[0063] Example 9

[0064] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0065]

[0066] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, the catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and the reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then the ketone compound 2a (20.0 mg, 0.2 mmol, 1.0 eq), the acetylene aldehyde compound 3i (40.8 mg, 0.3 mmol, 1.5 eq) and the borane complex 4a (58.4 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C for 10 hours in a sealed state; finally, the α-furan borane compound 1i (35.0 mg, yield 60%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). According to NMR analysis, the NMR data are as follows: 1 H NMR (500MHz, CDCl3): δ6.14(s,1H),2.53(s,3H),2.43(s,9H),2.36(s,3H),1.76-1.63(m,6H),1.47-1.41(m,1H),1.21-0.86(m,5H). 13 C NMR (125MHz, CDCl3): δ195.3,163.1,155.5,122.2,105.1,52.5,43.0,35.7,33.4,31.7,29.3,27.3,27.2,26.9,14.7.

[0067] Example 10

[0068] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0069]

[0070] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then ketone compound 2a (20.0 mg, 0.2 mmol, 1.0 eq), acetylene aldehyde compound 3j (33.0 mg, 0.3 mmol, 1.5 eq) and borane complex 4a (58.4 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C under sealing for 10 hours; finally, the α-furan borane compound 1j (41.0 mg, yield 77%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). According to NMR analysis, the NMR data are as follows: 1H NMR (500MHz, CDCl3): δ6.19 (s, 1H), 2.53 (s, 3H), 2.42 (s, 9H), 2.37 (s, 3H), 1.57 (d, J = 6.7Hz, 1H), 0.88 (s, 9H). 13 C NMR (125MHz, CDCl3): δ195.4,164.0,155.0,122.3,105.4,52.5,40.9,34.6,29.8,29.3,14.6.

[0071] Embodiment 11

[0072] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0073]

[0074] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, the catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and the reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then the ketone compound 2b (25.6 mg, 0.2 mmol, 1.0 eq), the acetylene aldehyde compound 3a (39.0 mg, 0.3 mmol, 1.5 eq) and the borane complex 4a (58.4 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C for 10 hours in a sealed state; finally, the α-furan borane compound 1k (31.4 mg, yield 50%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). According to NMR analysis, the NMR data are as follows: 1 H NMR (500MHz, CDCl3): δ7.29(d,J=7.6Hz,2H),7.23(t,J=7.5Hz,2H),7.07(t,J=7.3Hz,1H),6.27(s,1H)3.38(t,J= 5.0Hz,1H),3.01-2.88(m,2H),2.70(q,J=7.2Hz,2H),2.47(s,9H),1.18(t,J=7.5Hz,3H),1.12(t,J=7.2Hz,3H),. 13 C NMR (125MHz, CDCl3): δ197.9,161.1,160.6,147.4,128.3,124.6,120.6,104.1,52.7,38.0,34.4,21.8,12.5,8.1.

[0075] Example 12

[0076] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0077]

[0078] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, the catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and the reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then the ketone compound 2c (23.2 mg, 0.2 mmol, 1.0 eq), the acetylene aldehyde compound 3a (39.0 mg, 0.3 mmol, 1.5 eq) and the borane complex 4a (58.4 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C for 10 hours in a sealed state; finally, the α-furan borane compound 1l (54.4 mg, yield 90%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). According to NMR analysis, the NMR data are as follows: 1 H NMR (500MHz, CDCl3): δ7.25(d,J=7.2Hz,2H),7.20(t,J=7.4Hz,2H),7.05(t,J=7.3 Hz,1H),6.33(s,1H),3.77(s,3H),3.34(t,J=4.6Hz,1H),2.49(s,3H),2.46(s,9H). 13 C NMR (125MHz, CDCl3): δ165.3,160.9,157.0,147.5,128.21,128.18,124.4,113.5,104.9,52.6,51.1,38.0,13.9.

[0079] Embodiment 13

[0080] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0081]

[0082] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, the catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and the reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then the ketone compound 2d (37.6 mg, 0.2 mmol, 1.0 eq), the acetylene aldehyde compound 3a (39.0 mg, 0.3 mmol, 1.5 eq) and the borane complex 4a (58.4 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C for 10 hours in a sealed state; finally, the α-furan borane compound 1m (45.7 mg, yield 63%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). After NMR analysis, the NMR data are as follows: 1 H NMR (500MHz, CDCl3): δ7.97(d,J=7.1Hz,2H),7.39(t,J=7.3Hz,2H),7.35-7.30(m,3H),7.23(t,J =7.3Hz,2H),7.07(t,J=7.3Hz,1H),6.51(s,1H),3.79(s,3H),3.47(t,J=4.9Hz,1H),2.50(s,9H). 13 C NMR (125MHz, CDCl3): δ164.8,162.1,155.1,147.1,130.7,128.6,128.34,128.30,128.1,114.2,107.3,52.7,51.5,38.3. 11 B NMR (160MHz, CDCl3): δ-0.8. High resolution data: Calculated for [C 22 H 27 BNO3,M+H] + :364.2079,found:364.2086.

[0083] Embodiment 14

[0084] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0085]

[0086] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, the catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and the reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then the ketone compound 2e (39.6 mg, 0.2 mmol, 1.0 eq), the acetylene aldehyde compound 3a (39.0 mg, 0.3 mmol, 1.5 eq) and the borane complex 4a (58.4 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C for 10 hours in a sealed state; finally, the α-furan borane compound 1n (41.5 mg, yield 54%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). According to NMR analysis, the NMR data are as follows: 1 H NMR (500MHz, CDCl3): δ7.88 (d, J = 7.2Hz, 2H), 7.55-7.45 (m, 3H), 7.23-7.18 (m, 4H) ,7.07-7.04(m,1H),6.26(s,1H),3.30(t,J=4.5Hz,1H),2.48(s,3H),2.43(s,9H). 13 C NMR (125MHz, CDCl3): δ162.1,154.3,146.7,143.1,132.8,129.2,128.3,126.9,124.8,122.4,104.0,52.7,38.0,13.2.

[0087] Embodiment 15

[0088] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0089]

[0090] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, the catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and the reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then the ketone compound 2a (20.2 mg, 0.2 mmol, 1.0 eq), the acetylene aldehyde compound 3a (39.0 mg, 0.3 mmol, 1.5 eq) and the borane complex 4b (79.2 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C for 10 hours in a sealed state; finally, the α-furan borane compound 1o (44.2 mg, yield 71%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). After NMR analysis, the NMR data are as follows: 1H NMR (500MHz, CDCl3): δ7.29(d,J=7.6Hz,2H),7.22(t,J=7.5Hz,2H),7.07(t,J=7.3Hz,1H),6.29(s,1H),3.38(t,J=4.9Hz ,1H),3.15-3.09(m,1H),2.95-2.90(m,1H),2.72-2.68(m,1H),2.50(s,3H),2.46(s,3H),2.35(s,3H),2.00-1.80(m,5H). 13 C NMR (125MHz, CDCl3): δ195.0,161.1,156.1,147.6,128.24,128.22,124.5,122.1,104.5,62.0,61.6,47.6,37.9,29.2,22.4,22.1,14.6. 11 BNMR (160MHz, CDCl3):δ-2.6. High resolution data: Calculated for [C 19 H 27 BNO2,M+H] + :312.2130,found:312.2138.

[0091] Example 16

[0092] A three-component strategy for synthesizing α-furan borane compounds, the reaction equation is as follows:

[0093]

[0094] A three-component strategy for synthesizing α-furan borane compounds, the implementation scheme is as follows: under room temperature and air conditions, the catalyst CuCl (2.0 mg, 0.02 mmol, 0.1 eq) and the reaction solvent dichloromethane (0.5 mL) are added to the reaction container in sequence and stirred evenly; then the ketone compound 2a (20.0 mg, 0.2 mmol, 1.0 eq), the acetylene aldehyde compound 3a (39.0 mg, 0.3 mmol, 1.5 eq) and the borane complex 4c (90.4 mg, 0.8 mmol, 4.0 eq) are added in sequence, and the reaction is carried out at 55°C for 10 hours in a sealed state; finally, the α-furan borane compound 1p (48.1 mg, yield 74%) is obtained by direct silica gel column chromatography separation (according to the volume ratio, petroleum ether: ethyl acetate = 4:1). According to NMR analysis, the NMR data are as follows: 1H NMR (500MHz, CDCl3): δ7.28(d,J=7.3Hz,2H),7.22(t,J=7.4Hz,2H),7.06(t,J=7.2Hz,1H),6.29(s,1H),3.39(t,J=4.4Hz,1H),2.9 4-2.84(m,1H),2.86-2.80(m,1H),2.63-2.56(m,2H),2.50(s,3H),2.43(s,3H),2.35(s,3H),1.80-1.70(m,2H),1.61-1.43(m,4H). 13 C NMR (125MHz, CDCl3): δ195.0,161.2,156.1,147.9,128.21,128.19,124.4,122.2,104.5,59.0,58.9,46.3,37.1,29.3,22.7,20.3,20.2,14.6. 11 B NMR (160MHz, CDCl3): δ-2.4. High resolution data: Calculated for [C 20 H 29 BNO2,M+H] + :326.2286,found:326.2292.

[0095] The embodiments described above are only preferred technical solutions of the present invention and should not be regarded as limitations of the present invention. The embodiments and features in the embodiments of the present application can be arbitrarily combined with each other without conflict. The protection scope of the present invention shall be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. An α-furan boron compound, characterized in that The structural formula of the α-furan borane compound is shown in formula (1): Among them, R 1 is alkyl or aryl; R 2 is COMe, COEt, CO2Me or SO2Ph; R 3 is alkyl or aryl; LB is NMe3, NMe(C4H8) or NMe(C5H 10 ).

2. A three-component strategy synthesis method of the α-furan boron compound according to claim 1, characterized in that: A ketone compound as shown in formula (2), an acetylene aldehyde compound as shown in formula (3) and a borane compound as shown in formula (4) are used to synthesize an α-furan borane compound as shown in formula (1) through a one-step reaction under the catalysis of cuprous chloride as shown in formula (5); 3. The three-component strategy synthesis method of α-furan boron compound according to claim 2, characterized in that: The specific steps include: adding a catalyst CuCl and a reaction solvent in a reaction container in sequence under room temperature and air conditions, and stirring evenly; then adding a ketone compound, an acetylene aldehyde compound and a borane complex in sequence to react, and after the reaction is completed, separating by silica gel column chromatography to obtain an α-furan borane compound.

4. The three-component strategy synthesis method of α-furan boron compound according to claim 3, characterized in that: The molar ratio of the ketone compound, the acetylene aldehyde compound, the borane complex and cuprous chloride is 1:1.5:4:0.

1.

5. The three-component strategy synthesis method of the α-furan boron compound according to claim 2 or 3, characterized in that: The reaction solvent is dichloromethane, and 0.4 mmol of ketone compound is added to every 1.0 mL of the reaction solvent.

6. The three-component strategy synthesis method of α-furan boron compound according to claim 3, characterized in that: The reaction time is 10-20 hours.

7. The three-component strategy synthesis method of α-furan boron compound according to claim 6, characterized in that: The temperature of the reaction was 55°C.

8. The three-component strategy synthesis method of α-furan boron compound according to claim 3, characterized in that: After the reaction is completed, silica gel column chromatography is directly performed for separation.

9. The three-component strategy synthesis method of α-furan boron compound according to claim 3, characterized in that: When separating by silica gel column chromatography, the eluent is petroleum ether and ethyl acetate, and the volume ratio of petroleum ether to ethyl acetate is 2:1 to 4:1.

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