Method for preparing internal olefin (1, 2-disubstituted olefin) compound through visible light catalysis

Abstract

The invention provides a method for preparing an internal olefin (1, 2-disubstituted olefin) compound through visible light catalysis, which comprises the following steps of: mixing an organic silicon salt compound, brominated vinyl triphenylphosphine, a photosensitizer, an aldehyde compound, an alkaline substance and an organic solvent in an inert gas atmosphere, stirring and reacting for 12-48 hours at 25-35 DEG C under illumination, adding tetrahydrofuran into the obtained reaction liquid A, and reacting for 2-4 hours at the temperature of 25-35 DEG C to obtain the internal olefin (1, 2-disubstituted olefin) compound. Stirring and reacting for 10-24 hours at the temperature of 50-70 DEG C without illumination to obtain reaction liquid B, and post-treating the reaction liquid B to obtain the internal olefin (1, 2-disubstituted olefin) compound. According to the method, the polysubstituted olefin which is difficult to prepare by the existing method can be synthesized, the photooxidation reduction reaction and the wittig reaction are fused in a catalytic cycle, a ylide reagent does not need to be prepared, one-pot synthesis is realized, the catalyst is cheap and easy to obtain, the toxicity is low, the reaction conditions are mild, the energy consumption is saved, the yield is high, the substrate universality is strong, and the operation is simple.

Description

Technical Field

[0001] This invention relates to a method for synthesizing organic compounds, specifically a method for preparing olefinic compounds. Background Technology

[0002] Molecular diversity is often achieved through the construction of carbon-carbon bonds, and the formation of carbon-carbon double bonds (C=C) is a significant transformation in organic chemistry. Alkenes are widely used in pharmaceuticals, fine chemicals, and optoelectronic materials. Many bioactive molecules use carbon-carbon double bonds as their core framework, such as β-carotene, coumarin derivatives, anticancer drugs, polyene antifungal drugs, polyunsaturated fatty acids, and pheromones.

[0003] Therefore, the research and development of olefin synthesis technology has broad application prospects. Although chemists at home and abroad have developed a variety of efficient methods for synthesizing olefins, such as the Wittig olefination reaction, the Peterson reaction, the Takai-Utimoto olefination reaction, the Julia olefination reaction, and transition metal-catalyzed cross-coupling reactions (Chem. Rev. 2013, 113, 1313), these methods still have drawbacks such as low atom economy, the required alkenylating reagents being too reactive or highly toxic, unsuitability for sterically hindered substrates, and the need for expensive metal catalysts.

[0004] In recent years, visible light photoredox catalysis has provided economical and sustainable opportunities for the development of novel and special organic reactions. In 2021, Dario Filippini et al. used vinyl phosphine salts to cross-couple complex molecules containing carboxylic acids and aldehydes, achieving a combination of photocatalytic radical addition and Wittig reactions in a single catalytic cycle (Nature Chemistry, 2022, 14(1):66-70). However, the above reaction uses the organic photosensitizer 4CzIPN, which has harsh reaction conditions, high production costs, and is not environmentally friendly. Furthermore, some carboxylic acids also have the disadvantage of high toxicity. Currently, relatively mature alkyl precursors include alkyl halides, carboxylic acids and their derivatives, organoborides, organosilicones, Katritzkysalts, and Hantzsch ester derivatives. Organosilicon salts have high applications and advantages in synthetic chemistry due to their unique physical and chemical properties. Their easy availability and abundant transformations are promoting the development of organosilicon chemistry (European Journal of Organic Chemistry, 2024, 27(8):e202301280).

[0005] The methods for constructing carbon-carbon double bonds have continuously evolved from traditional elimination to modern catalytic strategies, becoming indispensable in the synthesis of drugs, materials, and natural products. In the future, highly selective catalytic systems with low environmental impact will be the main development direction; therefore, it is essential to develop a synthetic method with mild reaction conditions, simple operation, and high yield. Summary of the Invention

[0006] To address the limitations of current synthesis technologies, this invention provides a synthesis method different from existing technologies. It employs a combination of photo-oxidation-reduction catalysis and Wittig olefination, replacing traditional metal catalysis. This avoids a series of problems in olefin synthesis, such as complex operation, high temperature, and large catalyst dosage. It is a green synthesis method for olefin compounds with mild reaction conditions, simple operation, and high yield.

[0007] This invention provides a method for the photocatalytic preparation of internal olefin (1,2-disubstituted olefin) compounds under visible light, the method being as follows:

[0008] Under an inert gas atmosphere, an organosilicon salt compound of Formula I, vinyltriphenylphosphine bromide, a photosensitizer, an aldehyde compound of Formula II, an alkaline substance, and an organic solvent are mixed and reacted under light at 25°C–35°C (preferably 25°C) with stirring for 12–48 hours (preferably 24 hours). Tetrahydrofuran is added to the resulting reaction solution A, and the reaction is carried out under no light at 50–70°C (preferably 60°C) with stirring for 10–24 hours (preferably 20 hours). The resulting reaction solution B is then post-treated to obtain the internal compound of Formula III. The photosensitizer is an olefin (1,2-disubstituted olefin) compound; the photosensitizer is PS1, PS2, PS3, PS4, PS5, PS6, PS7, PS8, PS9, PS10, or PS11 (preferably PS3); the molar ratio of the organosilicon salt compound of Formula I, vinyltriphenylphosphine bromide, the aldehyde compound of Formula II, the photosensitizer, and the basic substance is 1:1~2:2~4:0.1~0.3:2~4 (preferably 1:1.5:3:0.25:3);

[0009]

[0010]

[0011] In Formula I, R1 is cyclohexyl, cyclopentyl, n-hexyl, n-propyl, cyanoethyl, isobutyl, chloropropyl or allyl (preferably cyclohexyl, cyclopentyl, n-propyl, cyanoethyl, chloropropyl).

[0012] In Formula II, R2 is an alkyl or aryl group (preferably aryl).

[0013] In Equation III, R1 is the same as R1 in Equation I, and R2 is the same as R2 in Equation II.

[0014] Further, the post-processing is as follows: the reaction solution B is extracted with ethyl acetate, the organic phase is concentrated by rotary evaporation and then purified by silica gel column chromatography (the eluent is petroleum ether or ethyl acetate) to obtain the internal olefin (1,2-disubstituted olefin) compound represented by Formula III.

[0015] Furthermore, the organic solvent is one or more of dichloromethane, 1,2-dichloroethane, tetrahydrofuran, toluene, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, or 1,4-dioxane (preferably dimethyl sulfoxide).

[0016] Furthermore, the volume of the organic solvent, based on the amount of the brominated vinyltriphenylphosphine, is 10–20 ml / mmol (preferably 13.33 ml / mmol).

[0017] Furthermore, the alkaline substance is one or more of Na2CO3, NaHCO3, CH3COONa, K2CO3, K3PO4, t-BuOK, or Cs2CO3 (preferably K2CO3).

[0018] Furthermore, the light source for illumination is a blue LED (preferably a 30W blue LED).

[0019] Furthermore, the photosensitizer is PS3.

[0020] Furthermore, the molar ratio of the organosilicon salt compound shown in Formula I, the vinyltriphenylphosphine bromide, the aldehyde compound shown in Formula II, the photosensitizer, and the alkaline substance is 1:1.5:3:0.25:3.

[0021] Furthermore, the volume of the tetrahydrofuran, in terms of the amount of the organosilicon salt compound represented by Formula I, is 25–100 ml / mmol (preferably 50 ml / mmol).

[0022] The organosilicon salt compounds used in this invention can be prepared by those skilled in the art based on methods disclosed in existing literature.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: the method described in the present invention can synthesize polysubstituted olefins that are difficult to prepare by existing methods; the photoredox reaction and the Wittig reaction are integrated into a single catalytic cycle, eliminating the need to prepare ylide reagents, enabling one-pot synthesis; the catalyst is inexpensive, readily available, and has low toxicity; the reaction conditions are relatively mild, saving energy consumption; the yield is high, the substrate is universal, and the operation is simple. Detailed Implementation

[0024] The present invention is further described below through specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0025] The organosilicon salts used in this invention can be prepared according to literature, and the typical steps are as follows:

[0026]

[0027] Catechol (2.0 equiv, 10 mmol, 1.1 g) and 18-crown ether-6 (1.0 equiv, 5 mmol, 1.32 g) were placed in a three-necked flask. The flask was purged with nitrogen three times. Dry methanol (20 mL) was added via syringe. After stirring at room temperature for ten minutes, cyclohexyltrimethoxysilane (1.0 equiv, 5 mmol, 1.07 mL) was added dropwise, followed by potassium methoxide (1.0 equiv, 5 mmol, 0.351 g). The mixture was then placed in the dark and stirred at room temperature for 3 hours. After the reaction was complete, the solvent was removed by rotary evaporation. A small amount of acetone was added to dissolve the precipitate, followed by rapid addition of diethyl ether. A solid precipitated, was obtained by filtration, washed with a small amount of diethyl ether, and dried under vacuum to give cyclohexyl organosilicon salt (2.5 g) as a white solid, with a yield of 79%.

[0028] Examples of synthesis of olefin compounds:

[0029] Example 1:

[0030]

[0031] Cyclohexyl organosilicon salt (1.0 equiv, 0.2 mmol, 126 mg), vinyltriphenylphosphine bromide (1.5 equiv, 0.3 mmol, 111 mg), 4-phenylbenzaldehyde (3 equiv, 0.6 mmol, 110 mg), copper-based photosensitizer PS3 (5 mol%, 15 mg), and potassium carbonate (3 equiv, 0.6 mmol, 83 mg) were added to a dry Schlenk reaction tube. After purging with nitrogen three times, dimethyl sulfoxide (4 mL) was added via syringe. The temperature was maintained at 25 °C, and the mixture was irradiated with a 30 W blue light lamp for 24 hours with moderate stirring (700 rpm). The Schlenk reaction tube was then removed, and tetrahydrofuran (10 mL) was added via syringe. The mixture was heated to 60 °C in the absence of light and stirred vigorously (1100 rpm) for 20 hours. After the reaction was complete, the mixture was extracted with ethyl acetate, the organic phase was collected, the solvent was removed by rotary evaporation, and the product was purified by column chromatography (eluent PE) to obtain the corresponding 4-(3-cyclohexylprop-1-en-1-yl)-1,1'-biphenyl. The substance was a white solid, yielded 43 mg, with a yield of 78%, and a Z / E ratio > 7:3.

[0032] Characterization data:1 1H NMR (400 MHz, Chloroform-d) δ 7.68 - 7.56 (m, 4H), 7.51 - 7.35 (m, 5H), 6.51 (d, J = 11.8 Hz, 0.7H), 6.44 (d, J = 15.8 Hz, 0.3H), 6.32 (dt, J = 15.7, 7.2 Hz, 0.3H), 5.78 (dt, J = 11.8, 7.3 Hz, 0.7H), 2.33 (td, J = 7.1, 1.9 Hz, 1.4H), 2.17 (t, J = 6.9 Hz, 0.6H), 1.86 - 1.67 (m, 5H), 1.49 - 1.41 (m, 1H), 1.31 - 1.17 (m, 3H), 0.95 - 0.90 (m, 2H).

[0033] 13 13C NMR (101 MHz, Chloroform-d) δ 140.92, 140.90, 139.53, 139.11, 137.02, 136.98, 132.24, 130.26, 130.04, 129.27, 128.81, 128.78, 127.20, 127.14, 126.99, 126.91, 126.80, 126.34, 41.18, 38.79, 38.27, 36.48, 33.30, 33.26, 26.61, 26.58, 26.43, 26.41.

[0034] Example 2:

[0035]

[0036] Cyclopentyl organosilicon salt (1.0 equiv, 0.2 mmol, 124 mg), vinyltriphenylphosphine bromide (1.5 equiv, 0.3 mmol, 111 mg), 4-phenylbenzaldehyde (3 equiv, 0.6 mmol, 110 mg), copper-based photosensitizer PS3 (5 mol%, 15 mg), and potassium carbonate (3 equiv, 0.6 mmol, 83 mg) were added to a dry Schlenk reaction tube. After purging with nitrogen three times, dimethyl sulfoxide (4 mL) was added via syringe. The temperature was maintained at 25 °C, and the mixture was irradiated with a 30 W blue light lamp for 24 hours with moderate stirring (700 rpm). The Schlenk reaction tube was then removed, and tetrahydrofuran (10 mL) was added via syringe. The mixture was heated to 60 °C in the absence of light and stirred vigorously (1100 rpm) for 20 hours. After the reaction was complete, the mixture was extracted with ethyl acetate, the organic phase was collected, the solvent was removed by rotary evaporation, and the product was purified by column chromatography (eluent PE) to obtain the corresponding 4-(3-cyclopentylprop-1-en-1-yl)-1,1'-biphenyl. This substance was a colorless liquid, with a yield of 36 mg, a yield of 68%, and a Z / E ratio > 3:1.

[0037] Characterization data: 1 H NMR(400MHz,Chloroform-d)δ7.62(td,J=14.5,13.6,7.8Hz,4H),7.51-7.35(m,5H),6.53-6.42(m,1H),6.33(dt,J=15.8,7.0Hz,0.25H),5.78(dt,J=11 .8,7.2Hz,0.75H),2.45(td,J=7.2,1.9Hz,1.5H),2.28(t,J=7.1Hz,0.5H), 2.05-1.94(m,1H),1.90-1.78(m,2H),1.70-1.56(m,4H),1.29-1.16(m,2H).

[0038] 13 C NMR(101MHz,Chloroform-d)δ140.92,140.89,139.53,139.14,137.07,136.97,132.87,130.81,129.70,129.27,128.79,1 28.77,128.42,127.21,127.15,127.00,126.92,126.82,126.36,40.65,40.07,39.55,34.94,32.43,32.38,25.22,25.21.

[0039] Example 3:

[0040]

[0041] Add cyanoacetonitrile-based organosilicon salt (1.0 equiv, 0.2 mmol, 121 mg), vinyltriphenylphosphine bromide (1.5 equiv, 0.3 mmol, 111 mg), 4-phenylbenzaldehyde (3 equiv, 0.6 mmol, 110 mg), copper-based photosensitizer PS3 (5 mol%, 15 mg), and potassium carbonate (3 equiv, 0.6 mmol, 83 mg) to a dry Schlenk reaction tube. After purging with nitrogen three times, add dimethyl sulfoxide (4 mL) via a syringe. Maintain the temperature at 25 °C and irradiate with a 30 W blue light lamp for 24 hours with moderate stirring (700 rpm). Then remove the Schlenk reaction tube and add tetrahydrofuran (10 mL) via a syringe. Heat the mixture to 60 °C in the dark and stir vigorously (1100 rpm) for 20 hours. After the reaction was complete, the mixture was extracted with ethyl acetate, the organic phase was collected, the solvent was removed by rotary evaporation, and the product was purified by column chromatography (eluent PE:EA = 40:1) to obtain the corresponding 6-([1,1'-biphenyl]-4-yl)hex-5-enonitrile. This substance was a pale yellow solid, with a yield of 34.5 mg (70%) and a Z / E ratio > 3:2.

[0042] Characterization data: 1 H NMR(400MHz,Chloroform-d)δ7.67-7.55(m,4H),7.52-7.32(m,5H),6.62-6.49(m,1H),6.21(dt,J=15.7,7.1Hz ,0.4H),5.65(dt,J=11.6,7.2Hz,0.6H),2.57(qd,J=7.3,1.9Hz,1.2H),2.49-2.35(m,2.8H),1.95-1.81(m,2H).

[0043] 13 C NMR(101MHz,Chloroform-d)δ140.69,140.67,140.14,139.73,136.12,136.03,131.61,130.54,129.93,129.14,128.81,12 8.80,127.75,127.35,127.30,127.29,127.01,126.92,126.51,119.57,119.55,31.76,27.62,25.72,25.03,16.76,16.49.

[0044] Example 4:

[0045]

[0046] Cyclohexyl organosilicon salt (1.0 equiv, 0.2 mmol, 124 mg), vinyltriphenylphosphine bromide (1.5 equiv, 0.3 mmol, 111 mg), copper-based photosensitizer PS3 (5 mol%, 15 mg), and potassium carbonate (3 equiv, 0.6 mmol, 83 mg) were added to a dry Schlenk reaction tube. After purging with nitrogen three times, dimethyl sulfoxide (4 mL) and benzaldehyde (3 equiv, 0.6 mmol, 62 μL) were added via syringe. The temperature was maintained at 25 °C, and the mixture was irradiated with a 30 W blue light lamp for 24 hours with moderate stirring (700 rpm). The Schlenk reaction tube was then removed, and tetrahydrofuran (10 mL) was added via syringe. The mixture was heated to 60 °C in the absence of light and stirred vigorously (1100 rpm) for 20 hours. After the reaction was complete, the mixture was extracted with ethyl acetate, the organic phase was collected, the solvent was removed by rotary evaporation, and the product was purified by column chromatography (eluent PE) to obtain the corresponding (3-cyclohexylprop-1-en-1-yl)benzene. The substance was a colorless liquid, with a yield of 22 mg, a yield of 55%, and a Z / E ratio > 4:1.

[0047] Characterization data: 1 H NMR(400MHz,Chloroform-d)δ7.40-7.29(m,4H),7.27-7.19(m,1H),6.47(d,J= 11.7Hz,0.8H),6.39(d,J=15.8Hz,0.2H),6.26(dt,J=15.7,7.2Hz,0.2H),5.73 (dt,J=11.7,7.3Hz,0.8H),2.26(td,J=7.1,1.9Hz,1.6H),2.14(t,J=6.9Hz,0. 4H),1.84-1.66(m,5H),1.36-1.46(m,1H),1.31-1.19(m,3H),1.0-0.90(m,2H).

[0048] 13 C NMR(101MHz,Chloroform-d)δ137.94,137.90,131.94,130.68,129.79,129.22,128.81,128.47,128 .08,126.75,126.36,125.92,41.09,38.73,38.22,36.29,33.25,33.23,26.59,26.56,26.41,26.39.

[0049] Example 5:

[0050]

[0051] Cyclohexyl organosilicon salt (1.0 equiv, 0.2 mmol, 124 mg), vinyltriphenylphosphine bromide (1.5 equiv, 0.3 mmol, 111 mg), copper-based photosensitizer PS3 (5 mol%, 15 mg), and potassium carbonate (3 equiv, 0.6 mmol, 83 mg) were added to a dry Schlenk reaction tube. After purging with nitrogen three times, dimethyl sulfoxide (4 mL) and o-tolualdehyde (3 equiv, 0.6 mmol, 69.4 μL) were added via syringe. The temperature was maintained at 25 °C, and the mixture was irradiated with a 30 W blue light lamp for 24 hours with moderate stirring (700 rpm). The Schlenk reaction tube was then removed, and tetrahydrofuran (10 mL) was added via syringe. The mixture was heated to 60 °C in the absence of light and stirred vigorously (1100 rpm) for 20 hours. After the reaction was complete, the mixture was extracted with ethyl acetate, the organic phase was collected, the solvent was removed by rotary evaporation, and the product was purified by column chromatography (eluent PE) to obtain the corresponding 1-(3-cyclohexylpropyl-1-en-1-yl)-2-methylbenzene. This substance was a colorless liquid, with a yield of 17 mg (40%) and a Z / E ratio > 3:1.

[0052] Characterization data: 1 H NMR(400MHz,Chloroform-d)δ7.45(d,J=6.9Hz,0.25H),7.24-7.12(m,3.75H),6.57(d,J=15 .2Hz,0.25H),6.49(d,J=11.5Hz,0.75H),6.12(dt,J=15.2,7.3Hz,0.25H),5.77(dt,J=11.5, 7.4Hz, 0.75H), 2.37 (s, 0.7H), 2.28 (s, 2.3H), 2.16 (td, J=7.1, 1.4Hz, 0.5H), 2.07 (td, J=7. 1,1.8Hz,1.5H),1.85-1.62(m,5H),1.47-1.32(m,1H),1.30-1.12(m,3H),0.96-0.82(m,2H).

[0053] 13C NMR(101MHz,Chloroform-d)δ137.12,137.02,136.25,134.85,131.58,131.13,130.13,129.67,129.14,128.59,128.47 ,126.72,126.63,125.98,125.47,125.22,41.38,38.43,38.22,35.97,33.22,33.15,26.61,26.55,26.40,19.93,19.89.

[0054] Example 6:

[0055]

[0056] Cyclohexyl organosilicon salt (1.0 equiv, 0.2 mmol, 124 mg), vinyltriphenylphosphine bromide (1.5 equiv, 0.3 mmol, 111 mg), copper-based photosensitizer PS3 (5 mol%, 15 mg), and potassium carbonate (3 equiv, 0.6 mmol, 83 mg) were added to a dry Schlenk reaction tube. After purging with nitrogen three times, dimethyl sulfoxide (4 mL) and m-methylbenzaldehyde (3 equiv, 0.6 mmol, 70 μL) were added via syringe. The temperature was maintained at 25 °C, and the mixture was irradiated with a 30 W blue light lamp for 24 hours with moderate stirring (700 rpm). The Schlenk reaction tube was then removed, and tetrahydrofuran (10 mL) was added via syringe. The mixture was heated to 60 °C in the absence of light and stirred vigorously (1100 rpm) for 20 hours. After the reaction was complete, the mixture was extracted with ethyl acetate, the organic phase was collected, the solvent was removed by rotary evaporation, and the product was purified by column chromatography (eluent PE) to obtain the corresponding 1-(3-cyclohexylprop-1-en-1-yl)-3-methylbenzene. This substance was a colorless liquid, with a yield of 25 mg, a yield of 58%, and a Z / E ratio > 3:1.

[0057] Characterization data: 11H NMR (400 MHz, Chloroform-d) δ 7.32 - 7.11 (m, 3H), 7.12 - 7.03 (m, 1H), 6.46 (d, J = 11.7 Hz, 0.75H), 6.38 (d, J = 15.8 Hz, 0.25H), 6.26 (dt, J = 15.8, 7.1 Hz, 0.25H), 5.73 (dt, J = 11.7, 7.3 Hz, 0.75H), 2.40 (d, J = 7.2 Hz, 3H), 2.28 (td, J = 7.1, 1.9 Hz, 1.5H), 2.15 (td, J = 7.0, 1.1 Hz, 0.5H), 1.86 - 1.65 (m, 5H), 1.51 - 1.35 (m, 1H), 1.34 - 1.14 (m, 3H), 1.07 - 0.90 (m, 2H).

[0058] 13 13C NMR (101 MHz, Chloroform-d) δ 137.98, 137.90, 137.86, 137.58, 131.78, 130.77, 129.63, 129.57, 129.31, 128.40, 127.98, 127.56, 127.15, 126.65, 125.86, 123.12, 41.12, 38.78, 38.26, 36.34, 33.28, 33.25, 26.62, 26.60, 26.45, 26.42, 21.53, 21.45.

[0059] Example 7:

[0060]

[0061] Cyclohexyl organosilicon salt (1.0 equiv, 0.2 mmol, 124 mg), vinyltriphenylphosphine bromide (1.5 equiv, 0.3 mmol, 111 mg), copper-based photosensitizer PS3 (5 mol%, 15 mg), and potassium carbonate (3 equiv, 0.6 mmol, 83 mg) were added to a dry Schlenk reaction tube. After purging with nitrogen three times, dimethyl sulfoxide (4 mL) and p-tolualdehyde (3 equiv, 0.6 mmol, 71 μL) were added via syringe. The temperature was maintained at 25 °C, and the mixture was irradiated with a 30 W blue light lamp for 24 hours with moderate stirring (700 rpm). The Schlenk reaction tube was then removed, and tetrahydrofuran (10 mL) was added via syringe. The mixture was heated to 60 °C in the absence of light and stirred vigorously (1100 rpm) for 20 hours. After the reaction was complete, the mixture was extracted with ethyl acetate, the organic phase was collected, the solvent was removed by rotary evaporation, and the product was purified by column chromatography (eluent PE) to obtain the corresponding 1-(3-cyclohexylprop-1-en-1-yl)-4-methylbenzene. The substance was a colorless liquid, with a yield of 23 mg, a yield of 53%, and a Z / E ratio > 3:1.

[0062] Characterization data: 1 H NMR(400MHz,Chloroform-d)δ7.25(d,J=7.6Hz,0.5H),7.20(d,J=8.0Hz,1.5H),7.18-7.08(m,2 H),6.42(d,J=11.7Hz,0.75H),6.33(d,J=15.9Hz,0.25H),6.18(dt,J=15.7,7.2Hz,0.25H),5.6 6(dt,J=11.7,7.3Hz,0.75H),2.35(d,J=8.8Hz,3H),2.23(td,J=7.1,1.9Hz,1.5H),2.10(td,J= 7.1,1.2Hz,0.5H),1.81-1.62(m,5H),1.45-1.32(m,1H),1.30-1.10(m,3H),1.00-0.86(m,2H).

[0063] 13 C NMR(101MHz,Chloroform-d)δ136.41,136.00,135.17,135.04,131.23,130.50,129.16,129.06,128.79 ,128.73,125.81,41.08,38.76,38.27,36.34,33.26,33.23,26.61,26.58,26.42,26.40,21.19,21.15.

[0064] Example 8:

[0065]

[0066] Cyclohexyl organosilicon salt (1.0 equiv, 0.2 mmol, 124 mg), vinyltriphenylphosphine bromide (1.5 equiv, 0.3 mmol, 111 mg), 4-chlorobenzaldehyde (3 equiv, 0.6 mmol, 84.4 mg), copper-based photosensitizer PS3 (5 mol%, 15 mg), and potassium carbonate (3 equiv, 0.6 mmol, 83 mg) were added to a dry Schlenk reaction tube. After purging with nitrogen three times, dimethyl sulfoxide (4 mL) was added via syringe. The temperature was maintained at 25 °C, and the mixture was irradiated with a 30 W blue light lamp for 24 hours with moderate stirring (700 rpm). The Schlenk reaction tube was then removed, and tetrahydrofuran (10 mL) was added via syringe. The mixture was heated to 60 °C in the absence of light and stirred vigorously (1100 rpm) for 20 hours. After the reaction was complete, the product was extracted with ethyl acetate, the organic phase was collected, the solvent was removed by rotary evaporation, and the product was purified by column chromatography (eluent PE) to obtain the corresponding 1-chloro-4-(3-cyclohexylprop-1-en-1-yl)benzene. The substance was a colorless liquid, with a yield of 34.5 mg, a yield of 73%, and a Z / E ratio > 7:3.

[0067] Characterization data: 1 H NMR(400MHz,Chloroform-d)δ7.35-7.19(m,4H),6.41(d,J=11.7Hz,0.7H),6.33(d,J=15.7Hz,0.3H),6.22(dt,J=15.7,7.1Hz,0.3H),5.74(dt,J=11.7, 7.3Hz,0.7H),2.21(td,J=7.1,1.9Hz,1.4H),2.12(td,J=6.9,1.1Hz,0.6H), 1.82-1.60(m,5H),1.47-1.33(m,1H),1.32-1.12(m,3H),1.02-0.87(m,2H).

[0068] 13 C NMR(101MHz,Chloroform-d)δ136.42,136.31,132.64,132.25,132.05,130.55,130.07,129. 52,128.57,128.22,128.09,127.11,41.05,38.64,38.15,36.24,33.22,26.55,26.51,26.36.

[0069] Example 9:

[0070]

[0071] Cyclohexyl organosilicon salt (1.0 equiv, 0.2 mmol, 124 mg), vinyltriphenylphosphine bromide (1.5 equiv, 0.3 mmol, 111 mg), copper-based photosensitizer PS3 (5 mol%, 15 mg), and potassium carbonate (3 equiv, 0.6 mmol, 83 mg) were added to a dry Schlenk reaction tube. After purging with nitrogen three times, dimethyl sulfoxide (4 mL) and 3-bromobenzaldehyde (3 equiv, 0.6 mmol, 70 μL) were added via syringe. The temperature was maintained at 25 °C, and the mixture was irradiated with a 30 W blue light lamp for 24 hours with moderate stirring (700 rpm). The Schlenk reaction tube was then removed, and tetrahydrofuran (10 mL) was added via syringe. The mixture was heated to 60 °C in the absence of light and stirred vigorously (1100 rpm) for 20 hours. After the reaction was complete, the product was extracted with ethyl acetate, the organic phase was collected, the solvent was removed by rotary evaporation, and the product was purified by column chromatography (eluent PE) to obtain the corresponding 1-bromo-3-(3-cyclohexylprop-1-en-1-yl)benzene. The substance was a colorless liquid, with a yield of 41.5 mg, a yield of 74%, and a Z / E ratio > 7:3.

[0072] Characterization data: 1 H NMR (400MHz, Chloroform-d) δ7.55-7.41(m,1H),7.41-7.13(m,3H),6.39(d,J=11.8Hz,0.7H),6.36-6.19(m,0.6H),5.77(dt,J=11.7,7.4Hz ,0.7H),2.22(td,J=7.1,1.9Hz,1.4H),2.13(t,J=6.4Hz,0.6H),1.79- 1.60(m,5H),1.47-1.34(m,1H),1.31-1.15(m,3H),1.02-0.90(m,2H).

[0073] 13 C NMR(101MHz,Chloroform-d)δ140.12,139.98,133.38,131.67,131.52,129.96,129.59,129.36,129.33,128. 75,127.91,127.36,124.63,122.72,122.21,41.02,38.64,38.12,36.19,33.21,26.55,26.51,26.37,26.35.

[0074] Example 10:

[0075]

[0076] Cyclohexyl organosilicon salt (1.0 equiv, 0.2 mmol, 124 mg), vinyltriphenylphosphine bromide (1.5 equiv, 0.3 mmol, 111 mg), 4-cyanobenzaldehyde (3 equiv, 0.6 mmol, 78.7 mg), copper-based photosensitizer PS3 (5 mol%, 15 mg), and potassium carbonate (3 equiv, 0.6 mmol, 83 mg) were added to a dry Schlenk reaction tube. After purging with nitrogen three times, dimethyl sulfoxide (4 mL) was added via syringe. The temperature was maintained at 25 °C, and the mixture was irradiated with a 30 W blue light lamp for 24 hours with moderate stirring (700 rpm). The Schlenk reaction tube was then removed, and tetrahydrofuran (10 mL) was added via syringe. The mixture was heated to 60 °C in the absence of light and stirred vigorously (1100 rpm) for 20 hours. After the reaction was complete, the mixture was extracted with ethyl acetate, the organic phase was collected, the solvent was removed by rotary evaporation, and the product was purified by column chromatography (eluent PE:EA = 50:1) to obtain the corresponding 4-(3-cyclohexylprop-1-en-1-yl)benzonitrile. The substance was a colorless liquid, with a yield of 34 mg, a yield of 75%, and a Z / E ratio > 2:1.

[0077] Characterization data: 1 H NMR(400MHz,Chloroform-d)δ7.60(dd,J=17.0,8.3Hz,2H),7.40(dd,J=21.2,8.3Hz,2H),6.45(d,J=11.7Hz,0.7H),6.40-6.37(m,0.6H),5.87(dt,J= 11.8,7.4Hz,0.7H),2.21(td,J=7.1,1.9Hz,1.4H),2.17-2.13(m,0.6H),1 .78-1.64(m,5H),1.47-1.36(m,1H),1.29-1.11(m,3H),1.02-0.85(m,2H).

[0078] 13C NMR(101MHz,Chloroform-d)δ142.56,142.38,135.26,134.25,132.33,131.92,129.39,129.33,127.86,126.37,119.17,119.10,109.90,109.83,41.12,38.55,38.01,36.37,33.21,33.19,26.47,26.42,26.29。

Claims

1. A method for the photocatalytic preparation of internal olefin (1,2-disubstituted olefin) compounds by visible light, characterized in that, The method is as follows: Under an inert gas atmosphere, the organosilicon salt compound of Formula I, vinyltriphenylphosphine bromide, photosensitizer, aldehyde compound of Formula II, alkaline substance, and organic solvent are mixed and reacted under light and at 25°C–35°C for 12–48 hours with stirring. Tetrahydrofuran is added to the resulting reaction solution A, and the reaction is carried out under no light and at 50–70°C with stirring for 10–24 hours. The resulting reaction solution B is then post-treated to obtain the internal olefin (1,2-disubstituted olefin) compound of Formula III. The photosensitizer is PS1, PS2, PS3, PS4, PS5, PS6, PS7, PS8, PS9, PS10, or PS11. The molar ratio of the organosilicon salt compound of Formula I, vinyltriphenylphosphine bromide, aldehyde compound of Formula II, photosensitizer, and alkaline substance is 1:1–2:2–4:0.1–0.3:2–4. In Formula I, R1 is cyclohexyl, cyclopentyl, n-hexyl, n-propyl, cyanoethyl, isobutyl, chloropropyl, or allyl. In formula II, R2 is an alkyl or aryl group; In Equation III, R1 is the same as R1 in Equation I, and R2 is the same as R2 in Equation II.

2. The method for preparing internal olefin (1,2-disubstituted olefin) compounds by visible light photocatalysis as described in claim 1, characterized in that, The post-processing is as follows: the reaction solution B is extracted with ethyl acetate, the organic phase is concentrated by rotary evaporation, and then purified by silica gel column chromatography to obtain the internal olefin (1,2-disubstituted olefin) compound represented by Formula III.

3. The method for preparing internal olefin (1,2-disubstituted olefin) compounds by visible light photocatalysis as described in claim 1, characterized in that, The organic solvent is one or more of dichloromethane, 1,2-dichloroethane, tetrahydrofuran, toluene, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, or 1,4-dioxane.

4. The method for preparing internal olefin (1,2-disubstituted olefin) compounds by visible light photocatalysis as described in claim 1, characterized in that, The volume of the organic solvent, based on the amount of the brominated vinyltriphenylphosphine, is 10–20 ml / mmol.

5. The method for preparing internal olefin (1,2-disubstituted olefin) compounds by visible light photocatalysis as described in claim 1, characterized in that, The alkaline substance is one or more of Na2CO3, NaHCO3, CH3COONa, K2CO3, K3PO4, t-BuOK, or Cs2CO3.

6. The method for preparing internal olefin (1,2-disubstituted olefin) compounds by visible light photocatalysis as described in claim 1, characterized in that, The light source for the illumination is a blue LED.

7. The method for preparing internal olefin (1,2-disubstituted olefin) compounds by visible light photocatalysis as described in claim 1, characterized in that, The photosensitizer is PS3.

8. The method for preparing internal olefin (1,2-disubstituted olefin) compounds by visible light photocatalysis as described in claim 1, characterized in that, The molar ratio of the organosilicon salt compound shown in Formula I, the vinyltriphenylphosphine bromide, the aldehyde compound shown in Formula II, the photosensitizer, and the alkaline substance is 1:1.5:3:0.25:

3.

9. The method for preparing internal olefin (1,2-disubstituted olefin) compounds by visible light photocatalysis as described in claim 1, characterized in that, The volume of the tetrahydrofuran, expressed as the amount of the organosilicon salt compound represented by Formula I, is 25–100 ml / mmol.

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