阅读说明：本技术 一种可见光激发水溶液量子点催化烯烃化合物氧化断裂制备羰基化合物的方法 (Method for preparing carbonyl compound by catalyzing oxidative fracture of olefin compound through visible light excited aqueous solution quantum dots ) 是由 孟庆伟 李嘉宁 赵静喃 马存飞 朱红霏 高天翔 孙慧楠 卫源安 刘遵超 于 2021-09-07 设计创作，主要内容包括：本发明提供了一种可见光激发水溶液量子点催化烯烃化合物氧化断裂制备羰基化合物的方法,属于光催化合成技术领域。该方法以水溶液量子点为光催化剂,用可见光激发水溶液量子点活化分子氧催化氧化芳香烯烃化合物裂解制备羰基化合物。本发明使用低负载量且制备简单的水溶液量子点为催化剂,得到羰基化合物的收率高,TON高达万级以上。反应条件温和,水作为反应的主要溶剂,也不需要外加助催化剂等就可催化烯烃化合物氧化裂解得到羰基化合物,操作简单,底物范围广,成本低。(The invention provides a method for preparing a carbonyl compound by catalyzing an olefin compound to be oxidized and broken through a visible light excited aqueous solution quantum dot, and belongs to the technical field of photocatalytic synthesis. The method takes aqueous quantum dots as a photocatalyst, and uses visible light to excite the aqueous quantum dots to activate molecular oxygen to catalyze and oxidize aromatic olefin compounds to prepare carbonyl compounds by cracking. The method uses the water solution quantum dots with low load and simple preparation as the catalyst, and the yield of the obtained carbonyl compound is high, and the TON is up to more than ten thousand. The method has the advantages of mild reaction conditions, simple operation, wide substrate range and low cost, and can catalyze the oxidative cracking of the olefin compound to obtain the carbonyl compound by taking water as a main solvent of the reaction without adding a cocatalyst and the like.)

1. a method for preparing carbonyl compounds by catalyzing olefin compounds to be oxidized and broken through visible light excitation aqueous solution quantum dots is characterized in that the aqueous solution quantum dots are used as a photocatalyst, and the aromatic olefin compounds are prepared by catalyzing and oxidizing the aromatic olefin compounds to be cracked through activating molecular oxygen by the visible light excitation aqueous solution quantum dots;

the quantum dots in the aqueous solution quantum dots are one or more than two of II-VI group quantum dots;

the aromatic olefin compound is shown as a formula I:wherein R is₁、R₂And R₃Is a hydrogen atom, halogen, alkyl, alkoxy, cycloalkyl or aryl, R₁、R₂And R₃The same or different; r₄Is a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group,R₅is an alkyl group;

the carbonyl compound is represented by formula II:wherein R is₁、R₂And R₃Is a hydrogen atom, halogen, alkyl, alkoxy, cycloalkyl or aryl, R₁、R₂And R₃The same or different; r₄Is a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group.

2. The method for preparing carbonyl compounds by catalyzing the oxidative cleavage of olefin compounds through the visible light excited aqueous quantum dots according to claim 1, wherein the preparation steps of the aqueous quantum dots are as follows:

dissolving a substance A in water to prepare a solution A, then adding a ligand, mixing fully in advance, purging with nitrogen to remove oxygen, then adding a substance B, and carrying out reflux reaction at a reflux temperature for 2-4 hours to obtain water solution quantum dots; the A substance is a metal salt containing VI group elements, the B substance is a precursor containing II group elements, and the ligand is a mercapto aliphatic carboxylic acid ligand.

3. The method for preparing the carbonyl compound by catalyzing the oxidative cleavage of the olefin compound by the visible light excited aqueous solution quantum dots according to claim 2, wherein the substance A is a cadmium salt or a zinc salt; the B substance is NaSeSO₃、NaHSe、Na₂S or NaHTe.

4. The method for preparing the carbonyl compound by catalyzing the oxidative cleavage of the olefin compound through the visible light excited aqueous solution quantum dots according to claim 1, wherein the oxidant is molecular oxygen, and the concentration of the oxidant is 20-100%; the II-VI group quantum dots are CdSe, CdS, ZnS or CdTe.

5. The method for preparing the carbonyl compound by catalyzing the oxidative cleavage of the olefin compound through the visible light excited aqueous solution quantum dots according to claim 2 or 3, wherein the oxidant is molecular oxygen, and the concentration is 20-100%; the II-VI group quantum dots are CdSe, CdS, ZnS or CdTe; the mercapto aliphatic carboxylic acid ligand is 3-mercaptopropionic acid, 4-mercaptobutyric acid, 3-mercaptobutyric acid or thioglycolic acid.

6. The method for preparing carbonyl compounds by catalyzing olefin compounds to be oxidized and cracked through visible light excited aqueous solution quantum dots according to claim 1, 2, 3 or 4, wherein the concentration of the aqueous solution quantum dots is 5 x 10^-8The mol/L is more than, the mass ratio of the quantum dots in the aqueous solution quantum dots to the aromatic olefin compounds is more than 0.0000125.

7. The method for preparing carbonyl compounds by catalyzing oxidative cleavage of olefin compounds through visible light excited aqueous quantum dots according to claim 5, wherein the concentration of the aqueous quantum dots is 5 x 10^-8The mol/L is more than, the mass ratio of the quantum dots in the aqueous solution quantum dots to the aromatic olefin compounds is more than 0.0000125.

8. The method for preparing the carbonyl compound by catalyzing the oxidative cleavage of the olefin compound with the visible light excited aqueous solution quantum dot according to claim 1, 2, 3, 4 or 7, wherein the temperature of the photocatalytic reaction is-20 to 50 ℃; the visible light wavelength is 365-700 nm.

9. The method for preparing the carbonyl compound by catalyzing the oxidative cleavage of the olefin compound through the visible light excited aqueous solution quantum dots according to claim 5, wherein the temperature of the photocatalytic reaction is-20 to 50 ℃; the visible light wavelength is 365-700 nm.

10. The method for preparing the carbonyl compound by catalyzing the oxidative cleavage of the olefin compound through the visible light excited aqueous solution quantum dots according to claim 6, wherein the temperature of the photocatalytic reaction is-20 to 50 ℃; the visible light wavelength is 365-700 nm.

Technical Field

The invention belongs to the technical field of photocatalytic synthesis, and particularly relates to a method for preparing a carbonyl compound by catalyzing an olefin compound to be oxidized and broken through aqueous solution quantum dots.

Background

The oxidative cleavage of olefins to aldehydes/ketones is one of the most important oxidation reactions. Industrially, carbonyl products are available from inexpensive, readily available olefins and are important precursors for the synthesis of many pharmaceuticals, natural compounds and fine chemicals. The traditional catalytic C ═ C double bond cleavage reaction is ozonolysis and Lemieux-Johnson oxidation, which are also common methods in industry. In addition, significant advances have been made in transition metal catalysis and thermally initiated free radical processes. However, the above methods generally have disadvantages of low atom economy, danger of chemical reagents, and high cost of metal catalysts.

Due to increased attention to green synthesis and environmental issues, photochemical oxidation has been recognized as a powerful technique for myriad oxidation reactions, and is also a potential route to oxidation products including ketones, alcohols, sulfoxides, and epoxides. To achieve cleaner synthetic strategies, molecular oxygen, as the best green oxidant, is often used for photochemical oxidation. Currently, some progress has been made in the field of olefin oxidative cracking by photocatalysis. Common photocatalysts, e.g. I₂Disulfide, 10-methylacridine perchlorate (AcrH)⁺ClO^4-) 5,10, 15-triphenyl-20- (4-hydroxyphenyl) -21H, 9, 10-Dicyanoanthracene (DCA), eosin Y, Polymeric Carbonitride (PCN), BiVO₄、CdS、ZnInS₄Has high photocatalytic activity. Although the advantages of photocatalysts in terms of strong catalytic ability and good applicability have been widely recognized, the high loading and inefficiency of these photocatalysts remains a problem and there is a need to find more efficient photocatalytic processes. Secondly, the second problem is that the organic solvent is used as the reaction solvent in the catalytic systems, and the requirement of green cleanness cannot be met. Therefore, in response to these problems, we developed a catalytic system for the oxidative cracking of olefins with high efficiency and low loading of catalyst and water as solvent.

Disclosure of Invention

Aiming at the defects of the prior art, the method for catalyzing the oxidative cleavage of the olefin compound by using the quantum dots in the visible light excited aqueous solution is provided.

The technical scheme of the invention is as follows:

a method for preparing carbonyl compounds by catalyzing olefin compounds to be oxidized and broken through visible light excitation aqueous solution quantum dots is characterized in that the aqueous solution quantum dots are used as a photocatalyst, and the aromatic olefin compounds are prepared by catalyzing and oxidizing the aromatic olefin compounds to be cracked through molecular oxygen activated by the visible light excitation aqueous solution quantum dots.

Furthermore, the quantum dots in the aqueous solution quantum dots are one or more of II-VI group quantum dots which are mixed, and the II-VI group quantum dots are CdSe, CdS, ZnS or CdTe.

The preparation steps of the aqueous solution quantum dot are as follows:

dissolving the substance A in water to prepare a solution A, then adding a ligand, fully mixing in advance, purging with nitrogen to remove oxygen, then adding the substance B, and carrying out reflux reaction at a reflux temperature for 2-4 hours to obtain the aqueous solution quantum dots.

Preferably, the A substance is a metal salt containing IV group elements, including cadmium salt and zinc salt;

preferably, the B substance is a precursor containing a group II element, including NaSeSO₃、NaHSe、Na₂S、NaHTe。

Preferably, when the aqueous solution quantum dot is prepared, the ligand to be adopted is mercapto aliphatic carboxylic acid, and the mercapto aliphatic carboxylic acid is 3-mercaptopropionic acid, 4-mercaptobutyric acid, 3-mercaptobutyric acid or thioglycolic acid.

Preferably, the ligand is added with premixing time of 5min and nitrogen purging time of 30 min.

Further, the aromatic olefin is of formula I:wherein R is₁、R₂And R₃Is a hydrogen atom, halogen, alkyl, alkoxy, cycloalkyl or aryl, R₁、R₂And R₃The same or different; r₄Is a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group, R₅Is an alkyl group;

the carbonyl compound is represented by formula II:wherein R is₁、R₂And R₃Is a hydrogen atom, halogen, alkyl, alkoxy, cycloalkyl or aryl, R₁、R₂And R₃The same or different; r₄Is a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group;

furthermore, the oxidant is molecular oxygen, the concentration of the oxidant is 20-100%, pure oxygen is preferred, the concentration of the oxidant is 100%, and the wavelength of the visible light is 365-700 nm.

Further, the concentration of the aqueous solution quantum dots is 5 multiplied by 10^-8The mol/L is more than, the mass ratio of the quantum dots in the aqueous solution quantum dots to the aromatic olefin is more than 0.0000125.

Further, the temperature of the photocatalytic reaction is-20-50 ℃.

In particular, when the reaction substrate aromatic olefin compound is a solid at room temperature, it is necessary to add a solvent to dissolve it, and the solvent is preferably mixed with the aqueous solution quantum dots, and the solvent may be one or more selected from toluene, n-hexane, tetrahydrofuran, ethyl acetate, acetonitrile, DMF, DMAP, DMSO, chloroform, carbon tetrachloride, dichloromethane, dioxane, petroleum ether, methanol, and ethanol.

The invention has the beneficial effects that: the aqueous solution quantum dots are simple to prepare, low in cost and long in storage time. The water solution quantum dots are used as the photocatalyst, the reaction solvent is mainly water, the carbonyl compound can be obtained under visible light, the yield is high, and the TON is up to more than ten thousand. The method has the advantages of mild reaction conditions, simple operation, wide substrate range and low cost, can efficiently catalyze the olefin to be oxidized and cracked to obtain the carbonyl compound by taking water as a main solvent of the reaction and without adding a cocatalyst and the like.

Detailed Description

The preparation method of the aqueous solution quantum dot comprises the following steps: 40mg selenium powder was added to 100mL Na₂SO₃(189mg) in aqueous solution. The resulting mixture was degassed by bubbling with nitrogen for 30 minutes and then refluxed until the selenium powder was completely dissolved to obtain transparent Na₂SeSO₃And (3) solution. Then 20mL of Na₂SeSO₃The solution was mixed with 380mL of a solution containing CdCl₂·5/2H₂A solution of O (92mg) and 3-mercaptopropionic acid (MPA, 52. mu.L) was mixed and the pH was adjusted to 11 with 1.0M NaOH. The mixture was placed in a three-necked flask and degassed by bubbling nitrogenQi for 30 min. Then, the transparent solution was refluxed for about 3h to promote the growth of CdSe nanocrystals. Finally, colloidal water-soluble CdSe quantum dots are prepared.

The reaction formula is as follows:

the specific operation steps of each embodiment are as follows:

example 1: alpha-methyl-4-chlorostyrene (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 4-chloroacetophenone in 90% yield. 4-chloro-acetophenone is added into the raw material of the ethyl acetate,¹H NMR(400MHz,Chloroform-d)δ7.89(d,J＝8.5Hz,2H),7.42(d,J＝8.6Hz,2H),2.58(s,3H).¹³C NMR(126MHz,Chloroform-d)δ196.73,139.52,135.44,129.70,128.85,26.50,26.48.

example 2: alpha-methyl-4-chlorostyrene (1mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 4-chloroacetophenone in 76% yield.

Example 3: alpha-methyl-4-chlorostyrene (1mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then suppliedOxygen to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 16 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 4-chloroacetophenone in 66% yield.

Example 4: alpha-methyl-4-chlorostyrene (1mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W blue light (450nm) for 24 hours at room temperature. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 4-chloroacetophenone in 74% yield.

Example 5: alpha-methyl-4-chlorostyrene (1mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then air was supplied to maintain a pure air atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 4-chloroacetophenone in 40% yield.

Example 6: alpha-methyl-4-chlorostyrene (1mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M), 2ml of CH are added₃CN is used as a solvent. The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and chromatographed by column chromatographyThe crude mixture was purified by chromatography using petroleum ether/ethyl acetate as eluent to obtain 4-chloroacetophenone in 61% yield.

Example 7: alpha-methyl-4-chlorostyrene (1mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M), 2ml of toluene were added as solvent. The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 4-chloroacetophenone in 33% yield.

Example 8: alpha-methyl-4-fluorostyrene (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 4-fluoroacetophenone in 92% yield. 4-fluoro acetophenone is added into the mixture of the above-mentioned raw materials,¹H NMR(400MHz,Chloroform-d)δ7.99(dd,J＝8.9,5.4Hz,2H),7.13(t,J＝8.6Hz,2H),2.59(s,3H).¹³C NMR(126MHz,DMSO-d6)δ191.19,161.53,159.50,128.35,125.72,125.64,110.47,110.30,21.26.

example 9: alpha-methyl-4-bromostyrene (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer is concentrated and the crude mixture is purified by column chromatography using petroleum ether/ethyl acetate as eluentCompound to obtain 4-bromoacetophenone in 89% yield. 4-bromoacetophenone is added into the mixture of the raw materials,¹H NMR(400MHz,Chloroform-d)δ7.87–7.76(m,2H),7.60(dd,J＝8.5,1.2Hz,2H),2.58(s,3H).¹³C NMR(126MHz,Chloroform-d)δ196.98,135.84,131.89,129.84,128.29,26.53.

example 10: alpha-methyl-4-methoxystyrene (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 4-methoxyacetophenone in 87% yield. 4-methoxy-acetophenone is added into the mixture of the four medicaments,¹H NMR(400MHz,Chloroform-d)δ7.94(d,J＝8.9Hz,2H),6.93(d,J＝8.9Hz,2H),3.87(s,3H),2.56(s,3H).¹³C NMR(126MHz,Chloroform-d)δ196.79,163.50,130.60,130.38,113.69,55.48,26.35.

example 11: alpha-methyl-4-nitrostyrene (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M), 0.5ml of CHCl was added₃As a solvent. The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 4-nitroacetophenone in 85% yield. 4-nitroacetophenone is obtained by reacting 4-nitroacetophenone,¹H NMR(400MHz,Chloroform-d)δ8.38–8.26(m,2H),8.12(d,J＝8.9Hz,2H),2.70(s,3H).¹³C NMR(126MHz,Chloroform-d)δ196.32,150.40,141.42,129.33,123.88,27.00.

example 12: alpha-methyl-3-methylstyrene (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10 mol) are placed in a 10ml reaction tube with magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 3-methylacetophenone in 75% yield. 3-methyl-acetophenone is added into the mixture of 3-methyl-acetophenone,¹H NMR(400MHz,Chloroform-d)δ7.84–7.68(m,2H),7.40–7.28(m,2H),2.56(s,3H),2.39(s,3H).¹³C NMR(126MHz,Chloroform-d)δ198.27,138.31,137.17,133.82,128.76,128.43,125.56,26.61,26.59,21.29,21.28.

example 13: alpha-methyl-2-methylstyrene (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10 mol) are placed in a 10ml reaction tube with magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 2-methylacetophenone in 40% yield. 2-methyl-acetophenone is added into the mixture of the two components,¹H NMR(400MHz,Chloroform-d)δ7.74–7.62(m,1H),7.35(tt,J＝7.4,1.4Hz,1H),7.28–7.18(m,2H),2.55(d,J＝1.4Hz,3H),2.52(s,3H).¹³C NMR(126MHz,Chloroform-d)δ201.59,138.37,137.62,132.03,131.50,129.37,125.70,29.48,21.57.

example 14: alpha-methyl-4-phenylstyrene (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M), 0.5ml of CHCl was added₃As a solvent. The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and purified by column chromatography with petroleum etherEthyl acetate was used as eluent to purify the crude mixture to obtain 4-phenylacetophenone in 66% yield. 4-phenyl-acetophenone is added into the mixture of the raw materials,¹H NMR(400MHz,Chloroform-d)δ8.09–7.99(m,2H),7.73–7.60(m,4H),7.52–7.35(m,3H),2.64(s,3H).¹³C NMR(126MHz,Chloroform-d)δ197.73,145.80,139.90,135.89,128.97,128.92,128.24,127.28,127.24,26.67,26.65.

example 15: alpha-butylstyrene (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) were added to a 10ml reaction tube containing magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain cyclopentanone in 69% yield. A pentanone-containing compound of benzene and pentanone,¹H NMR(400MHz,Chloroform-d)δ7.95(dt,J＝7.2,1.6Hz,2H),7.59–7.48(m,1H),7.44(td,J＝7.6,2.6Hz,2H),2.95(td,J＝6.3,5.3,3.7Hz,2H),1.77–1.62(m,2H),1.49–1.33(m,2H),0.95(td,J＝7.4,2.0Hz,3H).¹³C NMR(126MHz,Chloroform-d)δ200.51,137.10,132.84,128.53,128.04,38.30,26.48,22.48,13.94.

example 16: alpha-phenylstyrene (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M), 0.5ml of CHCl was added₃As a solvent. The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain benzophenone in 61% yield. The preparation method of the benzophenone comprises the steps of preparing benzophenone,¹H NMR(400MHz,Chloroform-d)δ7.88–7.75(m,4H),7.64–7.55(m,2H),7.53–7.44(m,4H).¹³C NMR(126MHz,Chloroform-d)δ196.77,137.62,132.42,130.07,128.29.

example 17: 3- (1-methyl) vinyl thiophene (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 3-acetylthiophene in 83% yield. 3-acetyl-thiophene, namely 3-acetyl-thiophene,¹H NMR(400MHz,Chloroform-d)δ8.12–7.96(m,1H),7.54(dt,J＝5.1,1.2Hz,1H),7.31(ddd,J＝5.1,2.9,1.0Hz,1H),2.54(d,J＝1.0Hz,3H).¹³C NMR(126MHz,Chloroform-d)δ192.26,142.66,132.35,126.99,126.40,27.57,27.55.

example 18: 2- (1-methyl) vinylpyridine (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) were added to a 10ml reaction tube containing magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 2-acetylpyridine with a yield of 71%. 2-acetyl pyridine, and the preparation method thereof,¹H NMR(400MHz,Chloroform-d)δ8.69(dt,J＝4.8,2.3Hz,1H),8.10–7.98(m,1H),7.84(tt,J＝7.8,1.9Hz,1H),7.53–7.43(m,1H),2.73(d,J＝2.0Hz,3H).¹³C NMR(126MHz,Chloroform-d)δ200.03,153.59,149.00,136.83,127.10,121.60,25.75.

example 19: beta-methyl-alpha-phenyl styrene (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M), 0.5ml of CHCl was added₃As a solvent. The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperatureFor 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain benzophenone in 66% yield.

Example 20: 4-Fluorostyrene (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) are added into a 10ml reaction tube filled with magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 16 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 4-fluorobenzaldehyde in a yield of 80%. 4-fluorobenzaldehyde is added into the mixture of the benzene and the formaldehyde,¹H NMR(400MHz,Chloroform-d)δ9.97(s,1H),7.91(ddd,J＝8.7,5.4,2.1Hz,2H),7.22(td,J＝8.6,2.3Hz,2H).¹³C NMR(126MHz,DMSO-d6)δ185.27,162.31,160.26,127.02,126.94,111.18,111.01.

preparing aqueous CdS quantum dots: 20mL of Na₂Solution of S (0.015M) with 380mL CdCl₂·5/2H₂A solution of O (92mg) and 3-mercaptopropionic acid (MPA, 52. mu.L) was mixed and the pH was adjusted to 11 with 1.0M NaOH. The mixture was placed in a three-neck flask and degassed by bubbling nitrogen for 30 min. Then, the transparent solution was refluxed for about 3h to promote the growth of CdS nanocrystals. Finally, colloidal water-soluble CdS quantum dots are prepared.

Example 21: adding alpha-methyl-4-chlorostyrene (0.5mmol) and 2.5ml of water-soluble CdS quantum dots (5 multiplied by 10) into a 10ml reaction tube filled with magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 4-chloroacetophenone in 88% yield. 4-chloro groupThe preparation method of the acetophenone compound comprises the following steps of,¹H NMR(400MHz,Chloroform-d)δ7.89(d,J＝8.5Hz,2H),7.42(d,J＝8.6Hz,2H),2.58(s,3H).¹³C NMR(126MHz,Chloroform-d)δ196.73,139.52,135.44,129.70,128.85,26.50,26.48.

preparation of aqueous ZnS quantum dots: 20mL of Na₂S (0.015M) solution and 380mL solution containing ZnSO₄(64mg) and a solution of 3-mercaptopropionic acid (MPA, 52. mu.L) were mixed and the pH was adjusted to 11 with 1.0M NaOH. The mixture was placed in a three-neck flask and degassed by bubbling nitrogen for 30 min. The clear solution was then refluxed for about 3h to promote the growth of ZnS nanocrystals. Finally, colloidal water-soluble ZnS quantum dots are prepared.

Example 22: alpha-methyl-4-chlorostyrene (0.5mmol) and 2.5ml of water-soluble ZnS quantum dots (5X 10) were added to a 10ml reaction tube containing magnetons^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 4-chloroacetophenone in 78% yield. 4-chloro-acetophenone is added into the raw material of the ethyl acetate,¹H NMR(400MHz,Chloroform-d)δ7.89(d,J＝8.5Hz,2H),7.42(d,J＝8.6Hz,2H),2.58(s,3H).¹³C NMR(126MHz,Chloroform-d)δ196.73,139.52,135.44,129.70,128.85,26.50,26.48.

preparing aqueous CdTe quantum dots: in an ice-water bath (0 ℃), 63.5mg of tellurium powder was added to 100mL of NaBH₄(56.7mg) in an aqueous solution, and stirred until the tellurium powder was completely dissolved, to obtain a transparent NaHTe solution. 20mL of NaHTe solution was mixed with 380mL of solution containing CdCl₂·5/2H₂A solution of O (92mg) and 3-mercaptopropionic acid (MPA, 52. mu.L) was mixed and the pH was adjusted to 11 with 1.0M NaOH. The mixture was placed in a three-neck flask and degassed by bubbling nitrogen for 30 min. The clear solution is then refluxed for about 3h to promote the growth of CdTe nanocrystals. Finally, colloid water-soluble CdTe quantum dots are prepared.

Example 23: in a 10ml reaction tube filled with magnetonsAdding alpha-methyl-4-chlorostyrene (0.5mmol) and 2.5ml of water-soluble CdTe quantum dots (5 multiplied by 10)^-6M). The reaction tube was sealed and evacuated for 5 minutes, and then oxygen was supplied to maintain a pure oxygen atmosphere. Next, the reaction tube was placed in a photoreactor and irradiated with 10W violet light (400nm) at room temperature for 24 hours. After completion of the reaction, by adding 1mL of CHCl₃Extraction was performed 3 times, and organic layers were obtained by combination. Finally, the organic layer was concentrated and the crude mixture was purified by column chromatography with petroleum ether/ethyl acetate as eluent to obtain 4-chloroacetophenone in 80% yield. 4-chloro-acetophenone is added into the raw material of the ethyl acetate,¹H NMR(400MHz,Chloroform-d)δ7.89(d,J＝8.5Hz,2H),7.42(d,J＝8.6Hz,2H),2.58(s,3H).¹³C NMR(126MHz,Chloroform-d)δ196.73,139.52,135.44,129.70,128.85,26.50,26.48.