阅读说明：本技术 一种可见光激发水溶液量子点催化硫醚化合物氧化制备亚砜化合物的方法 (Method for preparing sulfoxide compound by catalyzing thioether compound oxidation 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 卫源安 刘遵超 高天翔 孙慧楠 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硫醚化合物氧化制备亚砜化合物的方法,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,硫醚化合物为底物,用可见光激发水溶液量子点活化分子氧催化氧化硫醚化合物制备亚砜化合物。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,得到亚砜化合物的收率高,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硫醚氧化得到亚砜化合物,操作简单,底物范围广,成本低。(The invention provides a method for preparing a sulfoxide compound by catalyzing the oxidation of a thioether compound with visible light excited aqueous solution quantum dots, and belongs to the technical field of photocatalytic synthesis. The method takes an aqueous solution quantum dot as a photocatalyst and a thioether compound as a substrate, and uses visible light to excite the aqueous solution quantum dot to activate molecular oxygen to catalyze and oxidize the thioether compound to prepare the sulfoxide compound. The invention uses the water solution quantum dots with low load and simple preparation as the catalyst, and the yield of the obtained sulfoxide compound is high, and the TON is up to more than ten thousand. The reaction condition is mild, water is used as a main solvent of the reaction, and the thioether can be catalyzed and oxidized to obtain the sulfoxide compound without adding a cocatalyst and the like, so that the method is simple to operate, wide in substrate range and low in cost.)

1. a method for preparing a sulfoxide compound by catalyzing a thioether compound to be oxidized through exciting a water solution quantum dot by visible light is characterized in that the water solution quantum dot is used as a photocatalyst, and the sulfoxide compound is prepared by catalyzing the thioether compound to be oxidized through activating molecular oxygen by the water solution quantum dot excited by the visible light;

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

the thioether compound is shown as a formula I:wherein R is₁And R₂Is alkyl, cycloalkyl, aryl or heteroaromatic ring, R₁And R₂The same or different;

the sulfoxide compound is shown as a formula II:wherein R is₁And R₂Is alkyl, cycloalkyl, aryl or heteroaromatic ring, R₁And R₂The same or different.

2. The method for preparing the sulfoxide compound by catalyzing the oxidation of the thioether compound through the visible light excited aqueous quantum dot according to claim 1, wherein the preparation steps of the aqueous quantum dot 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 sulfoxide compound by catalyzing the oxidation of the thioether 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 sulfoxide compound by catalyzing the oxidation of the thioether compound by the visible light excited aqueous solution quantum dot according to the claim 1, 2 or 3, wherein when R in the thioether is₁When it is a benzene ring group, the thioether is represented by formula III:wherein R is₃And R₄Is hydrogen, halogen, alkyl, alkoxy, acyl or aryl, R₅Is alkyl, cycloalkyl, phenyl or aromatic heterocycle, R₃And R₄The same or different.

5. The method for preparing the sulfoxide compound by catalyzing the thioether compound oxidation 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 the sulfoxide compound by catalyzing the oxidation of the thioether compound through the visible light excited aqueous solution quantum dots according to claim 4, 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; the mercapto aliphatic carboxylic acid ligand is 3-mercaptopropionic acid, 4-mercaptobutyric acid, 3-mercaptobutyric acid or thioglycolic acid.

7. According to the rightThe method for preparing the sulfoxide compound by catalyzing the oxidation of the thioether compound through the visible light excited aqueous solution quantum dots according to the claims 1, 2, 3 or 6, wherein the concentration of the aqueous solution quantum dots is 5 x 10^-8The mol/L is more than, and the quantity ratio of the quantum dots in the water solution quantum dots to the thioether substances is more than 0.0000125.

8. The method for preparing the sulfoxide compound by catalyzing the oxidation of the thioether compound through the visible light excited aqueous solution quantum dots according to claim 4, wherein the concentration of the aqueous solution quantum dots is 5 x 10^-8The mol/L is more than, and the quantity ratio of the quantum dots in the water solution quantum dots to the thioether substances is more than 0.0000125.

9. The method for preparing the sulfoxide compound by catalyzing the oxidation of the thioether compound through the visible light excited aqueous solution quantum dots according to claim 5, wherein the concentration of the aqueous solution quantum dots is 5 x 10^-8The mol/L is more than, and the quantity ratio of the quantum dots in the water solution quantum dots to the thioether substances is more than 0.0000125.

10. The method for preparing the sulfoxide compound by catalyzing the oxidation of the thioether compound by the visible light excited aqueous solution quantum dot according to claim 1, 2, 3, 6, 8 or 9, wherein the visible light wavelength is 365-700 nm; the temperature of the photocatalytic reaction is-20 to 50 ℃.

Technical Field

The invention belongs to the technical field of photocatalytic synthesis, and particularly relates to a method for preparing a sulfoxide compound by catalyzing the oxidation of a thioether compound by using aqueous solution quantum dots.

Background

Semiconductor quantum dots have been found to be excellent photocatalysts due to their unique optical properties, high catalytic activity and limitation of organic solvents during the reaction. At present, aqueous CdSe quantum dots have been used to catalyze various chemical transformations because of their advantages of simple preparation, high efficiency, environmental protection, etc. The aqueous CdSe quantum dots have synthesis value in photocatalytic organic reaction. For example, the prepared aqueous CdSe quantum dot can make thiol form disulfide (Angew. chem. Int. Ed.2014,53, 2085-Photocatalytic activity. In addition, water-soluble CdSe quantum dots are used for boroacylation reaction of diazonium salt under mild acidic condition and water as solvent, wherein TON value is as high as 13600(chem.Commun.2019,55,6201). At the same time, quantum dots also have superior ability to generate Reactive Oxygen Species (ROS), including superoxide (O)₂ ^·-) Singlet oxygen (a)¹O₂) And hydroxyl radicals (HO. cndot.), play an important role in the oxidation reaction.

The sulfoxide is a medical active molecule with high value, is used as an important synthetic intermediate, and is widely applied to the fields of pharmacy or fine chemical engineering. At present, photocatalysis is a novel synthesis strategy, which can successfully oxidize thioether into sulfoxide, and is synthesized by selectively oxidizing thioether under oxygen environment and visible light irradiation. However, the challenge of current photocatalysis is the high loading of catalyst in the reaction, resulting in low catalytic efficiency. Secondly, in general, thioether needs to be oxidized in an organic solvent to generate sulfoxide, which is not green enough. Therefore, in response to these problems, we developed a highly efficient catalytic system for oxidizing thioether compounds with a highly efficient, low-loading catalyst and water as a solvent.

Disclosure of Invention

Aiming at the defects of the prior art, a method for preparing a sulfoxide compound by catalyzing the oxidation of a thioether compound by using quantum dots in a visible light excited aqueous solution is provided.

The technical scheme of the invention is as follows:

a method for preparing a sulfoxide compound by catalyzing a thioether compound to be oxidized through exciting aqueous solution quantum dots by visible light takes the aqueous solution quantum dots as a photocatalyst, and the sulfoxide compound is prepared by activating molecular oxygen and catalyzing the thioether compound to be oxidized through the aqueous solution quantum dots excited by the visible light.

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 a VI group element, 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 mercaptoaliphatic carboxylic acid, and the mercaptoaliphatic carboxylic acid ligand is 3-mercaptopropionic acid, 4-mercaptobutyric acid, 3-mercaptobutyric acid or mercaptoacetic acid.

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

Further, the thioether compounds are of formula I:wherein R is₁And R₂Is alkyl, cycloalkyl, aryl or heteroaromatic ring, R₁And R₂The same or different;

the sulfoxide compound is shown as a formula II:wherein R is₁And R₂Is alkyl, cycloalkyl, aryl or heteroaromatic ring, R₁And R₂The same or different;

preferably, R in the thioether compound₁When the aryl is benzene ring group, the thioether compound is shown as formula III:wherein R is₃And R₄Is hydrogen, halogen, alkyl, alkoxy, acyl or aryl, R₅Is alkyl, cycloalkyl, phenyl or aromatic heterocycle, R₃And R₄The same or different;

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^-8more than mol/L, and the mass ratio of the quantum dots in the aqueous solution quantum dots to the thioether compounds is more than 0.0000125.

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

In particular, when the reaction substrate thioether compound is a solid at room temperature, it is necessary to add a solvent to dissolve the thioether compound, and the thioether compound is preferably mixed with the aqueous solution quantum dots, wherein 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 a photocatalyst, the reaction solvent is mainly water, the sulfoxide 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, low cost, low catalyst loading capacity, high efficiency, cleanness and environmental protection, and is a sustainable photocatalysis method for preparing the sulfoxide compound by oxidizing the thioether compound.

Detailed Description

The preparation method of the aqueous CdSe 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-neck flask and degassed by bubbling nitrogen for 30 min. Then, the transparent solution was refluxed for about 3h to promote the growth of CdSe nanocrystals. Finally, prepareColloidal water-soluble CdSe quantum dots.

The reaction formula is as follows:

the specific embodiment is as follows:

example 1: toluene sulfide (0.5mmol) and 2.5ml of aqueous 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 toluene sulfoxide in 84% yield. The reaction product of toluene and sulfoxide is shown in the specification,¹H NMR(400MHz,Chloroform-d)δ7.71–7.62(m,2H),7.59–7.48(m,3H),2.73(s,3H).¹³C NMR(126MHz,Chloroform-d)δ145.82,131.02,129.35,123.50,43.99.

example 2: 4-fluorophenyl methyl sulfide (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10) were added into 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 using petroleum ether/ethyl acetate as eluent to obtain 1-fluoro-4- (methylsulfinyl) benzene in 60% yield.

1-fluoro-4- (methylsulfinyl) benzene,¹H NMR(400MHz,Chloroform-d)δ7.70–7.61(m,2H),7.30–7.21(m,2H),2.72(s,3H).¹³C NMR(101MHz,Chloroform-d)δ165.60,163.10,125.89,125.80,116.81,116.59,44.20.

example 3: 4-bromophenylmethyl sulfide (0.5 m) was added to a 10ml reaction tube containing magnetonsmol), 2.5ml water-soluble CdSe quantum dots (5X 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 using petroleum ether/ethyl acetate as eluent to obtain 1-bromo-4- (methylsulfinyl) benzene in 81% yield. 1-bromo-4- (methylsulfinyl) benzene, 1H NMR (400MHz, Chloroform-d) δ 7.68(d, J ═ 8.5Hz,2H),7.53(d, J ═ 8.5Hz,2H),2.72(s,3H), 13C NMR (101MHz, Chloroform-d) δ 144.97,132.59,125.47,125.16,44.02.

Example 4: 4-Methoxyphenylmethyl sulfide (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10 mol) were put into a 10ml reaction tube containing magnetons^-6M), followed by the addition of 0.5ml of CHCl₃As 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 using petroleum ether/ethyl acetate as an eluent, to obtain 1-methoxy-4- (methylsulfinyl) benzene in a yield of 52%. 1-methoxy-4- (methylsulfinyl) benzene,¹H NMR(400MHz,Chloroform-d)δ7.60(d,J＝8.8Hz,2H),7.04(d,J＝8.8Hz,2H),3.86(s,3H),2.70(s,3H).¹³C NMR(101MHz,Chloroform-d)δ162.00,136.75,125.47,114.88,55.54,44.05.

example 5: 2-bromophenyl methyl sulfide (0.5mmol) and 2.5ml of water-soluble CdSe quantum dot (5X 10) were put in 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 purified by column chromatography with petroleum ether/ethyl acetateThe crude mixture was purified using an ester eluent to give 1-bromo-2- (methylsulfinyl) benzene in 73% yield. 1-bromo-2- (methylsulfinyl) benzene,¹H NMR(400MHz,Chloroform-d)δ7.95(dd,J＝7.8,1.7Hz,1H),7.65–7.52(m,2H),7.44–7.34(m,1H),2.83(s,3H).¹³C NMR(101MHz,Chloroform-d)δ145.47,132.93,132.26,128.75,125.72,125.71,118.43,41.94.

example 6: 2-pyridylmethyl sulfide (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10 mol) 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-pyridylmethyl sulfoxide in 64% yield. 2-pyridyl-methyl sulfoxide, a salt thereof,¹H NMR(400MHz,Chloroform-d)δ8.63(d,J＝4.7Hz,1H),8.04(dt,J＝7.9,1.0Hz,1H),7.96(td,J＝7.7,1.6Hz,1H),7.39(ddd,J＝7.5,4.8,1.2Hz,1H),2.86(d,J＝0.8Hz,3H).¹³C NMR(101MHz,Chloroform-d)δ166.08,149.56,138.12,124.58,119.30,41.31.

example 7: in a 10ml reaction tube containing magnetons were added thiophenyl ether (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 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 ethyl benzene sulfoxide in 77% yield. The sulfoxide of ethylbenzene is used as a starting material,¹H NMR(400MHz,Chloroform-d)δ7.66–7.56(m,2H),7.58–7.43(m,3H),2.99–2.67(m,2H),1.20(t,J＝7.4Hz,3H).¹³C NMR(101MHz,Chloroform-d)δ143.42,130.91,129.13,124.19,50.32,5.95.

example 8: is provided with a magnet4-Benzoylphenylmethylsulfide (0.5mmol) and 2.5ml of a water-soluble CdSe quantum dot (5X 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 using petroleum ether/ethyl acetate as an eluent, to obtain 1-benzoyl-4- (methylsulfinyl) benzene in a yield of 51%. 1-benzoyl-4- (methylsulfinyl) benzene,¹H NMR(400MHz,Chloroform-d)δ8.03–7.90(m,2H),7.85–7.72(m,4H),7.69–7.59(m,1H),7.52(dd,J＝8.3,7.0Hz,2H),2.80(s,3H).¹³C NMR(101MHz,Chloroform-d)δ195.56,150.02,140.08,136.88,133.02,130.76,130.08,128.53,123.52,43.85.

example 9: dipropyl sulfide (0.5mmol) and 2.5ml of water-soluble CdSe quantum dots (5X 10 mol) 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 dipropyl sulfoxide in 75% yield. The compound is a compound of dipropyl sulfoxide and dimethyl sulfoxide,¹H NMR(400MHz,Chloroform-d)δ2.73-2.66(m,2H),2.64-2.56(m,2H),1.87-1.78(m,4H),1.11-1.08(t,6H).¹³C NMR(101MHz,Chloroform-d)δ54.41,16.25,13.38.

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 10: toluene sulfide (0.5mmol) and 2.5ml of aqueous CdS 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 toluene sulfoxide in 79% yield. The reaction product of toluene and sulfoxide is shown in the specification,¹H NMR(400MHz,Chloroform-d)δ7.71–7.62(m,2H),7.59–7.48(m,3H),2.73(s,3H).¹³C NMR(126MHz,Chloroform-d)δ145.82,131.02,129.35,123.50,43.99.

example 11: dipropyl sulfide (0.5mmol) and 2.5ml of water-soluble CdS 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 dipropyl sulfoxide in 71% yield. The compound is a compound of dipropyl sulfoxide and dimethyl sulfoxide,¹H NMR(400MHz,Chloroform-d)δ2.73-2.66(m,2H),2.64-2.56(m,2H),1.87-1.78(m,4H),1.11-1.08(t,6H).¹³C NMR(101MHz,Chloroform-d)δ54.41,16.25,13.38.

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 12: toluene sulfide (0.5mmol) and 2.5ml of aqueous ZnS quantum dot (5X 10) were put into 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 ultraviolet light (365nm) 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 toluene sulfoxide in 80% yield. The reaction product of toluene and sulfoxide is shown in the specification,¹H NMR(400MHz,Chloroform-d)δ7.71–7.62(m,2H),7.59–7.48(m,3H),2.73(s,3H).¹³C NMR(126MHz,Chloroform-d)δ145.82,131.02,129.35,123.50,43.99.

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 13: toluene sulfide (0.5mmol) and 2.5ml of aqueous CdS 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 toluene sulfoxide in 88% yield. The reaction product of toluene and sulfoxide is shown in the specification,¹H NMR(400MHz,Chloroform-d)δ7.71–7.62(m,2H),7.59–7.48(m,3H),2.73(s,3H).¹³C NMR(126MHz,Chloroform-d)δ145.82,131.02,129.35,123.50,43.99.