Method for functionalizing C-H bonds of propiophenone and derivatives thereof through environment-friendly photocatalysis

Abstract

The invention discloses a method for functionalizing C-H bonds of propiophenone and derivatives thereof through environment-friendly photocatalysis. According to the method, a cadmium sulfide-based semiconductor is used as a photocatalyst, methanol is used as a carbon source under an alkaline condition, the C-H bond functionalization of the propiophenone derivative is efficiently realized to construct a C-C bond, and hydroxymethylation, methoxymethylation and methylation reactions are included. The product selectivity can be controlled by regulating reaction parameters and catalyst types, and the highest yields of the three products under visible light irradiation respectively reach 95%, 84% and 98%. The method has the remarkable advantages that high-risk toxic alkylating reagents are avoided, and the method is green and safe; the catalyst can be recycled, and cost is reduced; the operation is simple and convenient, the conditions (room temperature and normal pressure visible light) are mild, and the substrate universality is good; the reaction mechanism is novel, and an efficient new way is provided for the C (sp3)-H bond functionalization of the carbonyl compound.

Description

Technical Field

[0001] The present invention belongs to the technical field of photocatalytic oxidation, and specifically relates to the use of semiconductor materials as photocatalysts, methanol as a green carbon source under visible light excitation, to achieve the selective C (sp 3 )-H bond functionalization method to construct CC bond. Background Art

[0002] In recent decades, C1 chemistry has developed rapidly. Common C1 sources such as iodomethane, diazomethane, methyl magnesium halide, formaldehyde and CO2 have many disadvantages in practical applications, such as high toxicity, strong corrosiveness, low reactivity and harsh reaction conditions. These problems seriously limit their further conversion and application in organic synthesis. Therefore, finding a green and environmentally friendly C1 reagent has become an important research direction in the current field of chemistry. Methanol is a stable liquid at room temperature. It has abundant reserves, low cost, is green, low-toxic and biodegradable. It can be synthesized through various routes such as natural gas, coal, biomass and municipal waste. With the emphasis on non-fossil energy and carbon dioxide utilization, methanol as a green C1 source in organic reactions has attracted much attention.

[0003] Propiophenone and its derivatives are important components and synthetic intermediates of pesticides, dyes, drugs, natural products, polymers and other molecules. 3 )-H functionalization, such as hydroxymethylation, methoxymethylation and methylation, is of great significance in the fields of drug development, natural product synthesis and material science. 3 )-H functionalization has been explored to some extent, such as the use of transition metal photocatalytic strategies and organic dye photocatalytic methods (Y. Tsukamoto, S. Itoh, M. Kobayashi, Y. Obora, Org Lett 2019, 21, 3299-3303; aJ. Yang, D. Xie, H. Zhou, S. Chen, J. Duan, C. Huo, Z. Li, Advanced Synthesis & Catalysis 2018, 360, 3471-3476; bJ. Yang, C. Liu, H. Zhou, R. Fan, B. Ma, Z. Li, Org Biomol Chem 2021, 19, 5572-5576). However, these methods have problems such as high catalyst cost, difficulty in separating and recovering homogeneous photocatalysts, and poor reaction selectivity. More importantly, there is no catalyst system that can use methanol as a renewable C1 source to achieve selective C(sp) conversion of phenylacetone and its derivatives. 3)-H functionalization was performed to obtain the corresponding hydroxymethylated ketone, methylated ketone and methoxymethylated ketone products. Summary of the Invention

[0004] In view of the defects in the prior art, the present invention has developed a green synthesis method based on photocatalytic strategy, which uses cadmium sulfide-based semiconductors as catalysts and methanol as a renewable carbon source to achieve the synthesis of phenylacetone and its derivatives C (sp 3 )-H bond selective functionalization. This method can efficiently construct CC bonds by precisely controlling the reaction conditions, achieving three transformation pathways: α-hydroxymethylation, α-methoxymethylation, and α-methylation, without the use of highly dangerous and toxic alkylating agents. This technology has significant advantages such as catalyst recyclability, mild reaction conditions, and environmental friendliness. It not only solves the selectivity control problems of traditional methods, but also expands the application range of semiconductor photocatalysts in organic synthesis, showing important application prospects in the fields of fine chemicals and pharmaceutical synthesis.

[0005] To achieve the above objectives, the present invention adopts a technical solution: an environmentally friendly photocatalytic method for the functionalization of C-H bonds of propiophenone and its derivatives, which adopts a photocatalytic strategy, uses a cadmium sulfide-based semiconductor as a catalyst, and methanol as a renewable carbon source to achieve divergent C-H bond functionalization (hydroxymethylation / methoxymethylation / methylation) of propiophenone and its derivatives under alkaline conditions, including α-hydroxymethylation, α-methoxymethylation, and α-methylation. Wherein, the structural formula I of the propiophenone and its derivatives is as follows:

[0006]

[0007] R 1 is a group substituted at any position on the benzene ring; the group is selected from one of hydrogen, methyl, ethyl, methoxy, halogen, and trifluoromethyl; R 2 is selected from one of hydrogen, methyl, ethyl, and aryl (phenyl). 1 is a halogen (F / Cl / Br), trifluoromethyl, alkoxy (methoxy) or other substituent with strong electronic effect (for examples with yields > 80%); R 2 is H or methyl (steric hindrance minimization configuration);

[0008] For the technical solution described above, it is further preferred that the CH bond of the propiophenone and its derivatives is α-hydroxymethylated, and the reaction formula is A, B or C, as follows:

[0009]

[0010] For the technical solution described above, it is further preferred that the concentration of the propiophenone and its derivatives in the reaction system is 0.1-0.5 mol / L, and the optimal concentration is 0.2-0.3 mol / L.

[0011] For the technical solution described above, it is further preferred that the light in the photocatalytic reaction is ultraviolet light or visible light with a wavelength range of 220-780 nm, and an optimal wavelength of 380-400 nm.

[0012] For the technical solution described above, it is further preferred that the light intensity of the photocatalytic reaction is 1 to 60 W / cm 2 The optimal light intensity is 25-35W / cm 2 The illumination time is 1-12h, preferably 8-12h; the temperature range of the catalytic reaction is -10-80°C, preferably 25-60°C. Most preferably, the selectivity control conditions of the reaction are:

[0013] Hydroxymethylation: 25°C, methanol:water = 1:1, potassium carbonate;

[0014] Methoxymethylation: 60°C, methanol: water = 3:1, potassium carbonate;

[0015] Methylation: 60°C, pure methanol, cesium carbonate.

[0016] For the technical solution described above, it is further preferred that the semiconductor photocatalyst is selected from one of cadmium sulfide, titanium dioxide, carbon nitride, zinc oxide, zinc sulfide, zinc indium sulfide, cadmium selenide, and cadmium sulfide-nickel cobalt double hydroxide complex, and its morphology can be flake-shaped, block-shaped, flower-shaped, spherical or rod-shaped. The more preferred semiconductor photocatalyst is cadmium sulfide nanorods or rod-shaped cadmium sulfide-sheet nickel cobalt double hydroxide complex (simplified as "cadmium sulfide-nickel cobalt complex" in the embodiment).

[0017] The cadmium sulfide-nickel cobalt double hydroxide complex is a core-shell heterostructure catalyst, in which nickel cobalt double hydroxide nanosheets are in situ grown on the surface of hexagonal wurtzite-structured cadmium sulfide nanorods and tightly wrapped. The molar ratio of cadmium sulfide to nickel cobalt double hydroxide is 1:(0.07-0.35), and the molar ratio of Ni to Co in the nickel cobalt double hydroxide is 2:1.

[0018] The cadmium sulfide nanorods have a hexagonal wurtzite crystal structure, a length of 130-150 nm, and a diameter of 8-12 nm.

[0019] For the technical solution described above, it is further preferred that the amount of the semiconductor photocatalyst used in the system is 1-10 mg / mL (the amount refers to the ratio of the mass of the catalyst to the total volume of the reaction system). The most preferred amount of the semiconductor photocatalyst is 2-3 mg / mL. The activity of the catalyst is retained at >90% after three reuses.

[0020] For the technical solution described above, it is further preferred that the base is selected from one of potassium bicarbonate, sodium bicarbonate, potassium carbonate, sodium carbonate, cesium carbonate, potassium hydroxide, potassium tert-butoxide, 1,8-diazabicycloundec-7-ene, and triethylenediamine, more preferably potassium carbonate or cesium carbonate.

[0021] For the technical solution described above, it is further preferred that the molar ratio of the substrate (propiophenone and its derivatives) to the base is 1:(0.1-10), and the optimal molar ratio is 1:1.

[0022] For the technical solution described above, it is further preferred that the solvent is selected from methanol, ethanol, dichloromethane, chloroform, dimethyl sulfoxide, N,N-dimethylformamide, a mixture of acetone and water; the preferred solvent is a mixture of methanol and water, with a methanol to water ratio of (1-3):(0-1). The most preferred solvent systems are: hydroxymethylation: methanol-water (1:1); methoxymethylation: methanol-water (3:1); and methylation: pure methanol.

[0023] For the technical solution described above, it is further preferred that the gas includes air, oxygen and / or nitrogen, and the preferred gas is air or oxygen.

[0024] The reaction mechanism of the present invention is as follows: under light irradiation, a semiconductor photocatalyst is excited to form a large number of photogenerated carriers, the photogenerated holes oxidize methanol to obtain formaldehyde, the photogenerated electrons reduce oxygen to obtain reactive oxygen species (ROS), the formaldehyde and the substrate undergo aldol condensation to obtain α-hydroxymethylated ketone; the α-hydroxymethylated ketone undergoes dehydration at a relatively high temperature and a relatively strong alkaline environment to obtain an enone intermediate; the enone intermediate reacts with methanol to obtain an α-methoxymethylated ketone; and the enone intermediate reacts with hydrogen to obtain an α-methylated ketone.

[0025] The technical solution described above is further preferably further comprised of post-processing steps such as extraction, drying, and concentration of the target product mixed solution, as well as column chromatography purification steps. The green method achieves a 100% conversion rate of propiophenone, a 95% yield of the α-hydroxymethylation product, an 84% yield of the α-methoxymethylation product, and an 98% yield of the α-methylation product, demonstrating excellent green chemistry properties and industrial application potential.

[0026] Beneficial effects of the present invention

[0027] 1. Green conversion using methanol as a carbon source: The present invention adopts a semiconductor photocatalytic method, with methanol as a green and renewable carbon source, to achieve divergent C-H bond functionalization of carbonyl compounds. The reaction conditions are mild, avoiding the use of highly dangerous and toxic alkylating agents and reducing the risk of environmental pollution.

[0028] 2. Controllable Highly Selective Synthesis: By simply adjusting the catalyst type, reaction temperature, and solvent, highly selective conversion of a single ketone substrate to three target products—α-hydroxymethylated ketone, α-methoxymethylated ketone, and α-methylated ketone—can be achieved, with yields reaching up to 95%, 84%, and 98%, respectively. This reduces operational complexity and process costs, meeting atom and process economy requirements.

[0029] 3. The catalyst can be recycled and reused: Semiconductor heterogeneous catalysts exist in solid form and are stable. They can be separated, recycled and reused after the reaction, reducing process costs and improving reaction economy.

[0030] 4. Broad substrate compatibility: The method of the present invention exhibits good compatibility with different types of phenylpropiophenone derivatives, including halogenated phenylpropiophenones, alkyl-substituted phenylpropiophenones, furans, thiophenes and other aromatic heterocyclic ketones, and is highly versatile and flexible.

[0031] 5. Advantages of industrial application: The preparation method of the catalyst CdS-NiCo complex is simple and the raw materials are inexpensive.

[0032] 6. Improved green chemical indicators: Compared with traditional methylation processes, atom utilization is increased by more than 30%.

[0033] 7. Comparative Examples 1-9 show that the yield of conventional catalysts (such as titanium dioxide and carbon nitride) is only 13%-37%, while the yield of the CdS-NiCo composite of the present invention is as high as 82%-95%. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of 3-hydroxy-2-methylpropiophenone in Example 1.

[0035] Figure 2 This is the hydrogen nuclear magnetic resonance spectrum of 3-hydroxy-2-methyl-1-(thiophen-2-yl)acetone in Example 12.

[0036] Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of 3-methoxy-2-methyl-1-phenylpropanone in Example 13.

[0037] Figure 4 This is the hydrogen nuclear magnetic resonance spectrum of 1-(4-fluorophenyl)-3-methoxy-2-methyl-1-propanone in Example 14.

[0038] Figure 5 This is the hydrogen nuclear magnetic resonance spectrum of isobutyrophenone in Example 25.

[0039] Figure 6 This is the hydrogen nuclear magnetic resonance spectrum of 1-(4-trifluoromethylphenyl)-2-methyl-1-propanone in Example 27. DETAILED DESCRIPTION

[0040] The following examples are provided to illustrate the present invention but are not intended to limit its scope. Unless otherwise stated, the chemical reagents and biological materials used in the present invention were obtained from commercial sources and processed and used according to standard operating procedures. All experimental procedures were performed under conventional laboratory conditions to ensure the reproducibility and reliability of the technical solutions.

[0041] In all the following embodiments:

[0042] "eq" indicates molar equivalent relative to substrate;

[0043] The amount of catalyst is calculated based on the total volume of the reaction solution;

[0044] The yield is the actual yield of the product after separation and purification.

[0045] The cadmium sulfide-nickel cobalt double hydroxide composite is prepared using a native growth method and has the following structural characteristics: nickel cobalt double hydroxide nanosheets (thickness 3-5nm) are in situ grown on the surface of hexagonal wurtzite-structured cadmium sulfide nanorods and tightly wrapped to form a core-shell heterostructure. The cadmium sulfide-nickel cobalt double hydroxide composite used in the present invention has a specific composition ratio, wherein the molar ratio of cadmium sulfide to nickel cobalt double hydroxide is 1:(0.07-0.35), which can ensure the optimal performance of the catalyst. In particular, the molar ratio of nickel to cobalt in the nickel cobalt double hydroxide is strictly controlled at 2:1, which is crucial for maintaining catalytic activity and selectivity. In specific embodiments, different reaction types use optimized catalyst ratios: Examples 1-12 (hydroxymethylation reaction) use a molar ratio of 1:0.07; Examples 13-24 (methoxymethylation reaction) use a molar ratio of 1:0.28; the preparation method of the catalyst can refer to the prior art literature (LiS, Wang L, Li YD, et al. Novel photocatalyst incorporating Ni-Co layered doublehydroxides with P-doped CdS for enhancing photocatalytic activity towards hydrogen evolution [J]. Applied Catalysis B: Environmental, 2019, 254: 145-155.); Examples 25-38 (methylation reaction) use cadmium sulfide nanorods with a length distribution of 130-150 nm as a catalyst alone. The cadmium sulfide-nickel cobalt double hydroxide complex is prepared by the original growth method, which is a well-known technology in this field; its structural characteristics are: nickel cobalt double hydroxide nanosheets (thickness 3-5 nm) are in situ grown on the surface of hexagonal wurtzite structure cadmium sulfide (length 130-150 nm) nanorods and tightly wrapped to form a core-shell heterostructure.

[0046] Example 1

[0047] To a 10 mL reaction tube equipped with a magnetic rod, add propiophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) dissolved in a mixed solvent of methanol (1 mL) and water (1 mL). The reaction tube was sealed and evacuated for 5 minutes, then oxygen was supplied to maintain a pure oxygen atmosphere. The reaction was carried out at 25°C under 30W 395nm violet light. After 8 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 5:1) to obtain pure 3-hydroxy-2-methylpropiophenone in an 82% yield. 1 HNMR (600MHz, Chloroform-d): δ7.96(d,J=7.2Hz,2H),7.57(t,J=7.2Hz,1H),7.47(t,J=7.2Hz,2H),3.93(d d,J=10.8,7.2Hz,1H),3.80(dd,J=10.8,4.2Hz,1H),3.70–3.62(m,1H),2.22(s,1H),1.23(d,J=7.2Hz,3H). For example Figure 1 .

[0048] Example 2

[0049] In a 10 mL reaction tube equipped with a magnetic rod, p-fluoropropiophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1 mL) and water (1 mL). The tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 25°C under 30W 395nm violet light. After 8 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 5:1) to obtain pure 1-(4-fluorophenyl)-3-hydroxy-2-methyl-1-propanone in an 84% yield. 1 H NMR (400MHz, CDCl3): δ8.08–7.93(m,2H),7.22–7.07(m,2H),3.93(dd,J=11.0,7.2Hz,1H),3 .79(dd,J=11.1,4.2Hz,1H),3.64(pd,J=7.2,4.2Hz,1H),2.46(s,1H),1.23(d,J=7.2Hz,3H).

[0050] Example 3

[0051] In a 10 mL reaction tube equipped with a magnetic rod, p-chloropropiophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1 mL) and water (1 mL). The tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 25°C under 30W 395nm violet light. After 8 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 5:1) to obtain pure 1-(4-chlorophenyl)-3-hydroxy-2-methyl-1-propanone in a yield of 95%. 1 HNMR (400MHz, Chloroform-d): δ7.94–7.86(m,2H),7.51–7.41(m,2H),3.93(dd,J=11.1,7.2Hz,1 H),3.78(dd,J=11.1,4.3Hz,1H),3.62(pd,J=7.2,4.2Hz,1H),2.40(s,1H),1.22(d,J=7.2Hz,3H).

[0052] Example 4

[0053] In a 10 mL reaction tube equipped with a magnetic rod, p-methylpropiophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1 mL) and water (1 mL). The reaction tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 25°C under 30W 395nm violet light. After 8 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 5:1) to obtain pure 1-(4-methylphenyl)-3-hydroxy-2-methyl-1-propanone in a yield of 63%. 1 HNMR (400MHz, Chloroform-d): δ7.89–7.82(m,2H),7.27(d,J=8.1Hz,2H),3.95–3.88(m,1H),3.79(dd,J= 11.1,4.2Hz,1H),3.64(td,J=7.2,4.2Hz,1H),2.54(d,J=25.5Hz,1H),2.42(s,3H),1.23(d,J=7.2Hz,3H).

[0054] Example 5

[0055] In a 10 mL reaction tube equipped with a magnetic rod, m-chloropropiophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1 mL) and water (1 mL). The tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 25°C under 30W 395nm violet light. After 8 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 5:1) to obtain pure 1-(3-chlorophenyl)-3-hydroxy-2-methyl-1-propanone in an 82% yield. 1 H NMR (600MHz, Chloroform-d): δ7.93(d,J=2.0Hz,1H),7.83(d,J=7.8Hz,1H),7.55(dd,J=7.9,2.2Hz,1H),7.43(t,J=7.8Hz,1H ),3.93(dd,J=11.1,7.2Hz,1H),3.79(dd,J=11.1,4.3Hz,1H),3.62(pd,J=7.2,4.2Hz,1H),2.39(s,1H),1.22(d,J=7.2Hz,3H).

[0056] Example 6

[0057] In a 10 mL reaction tube equipped with a magnetic separator, m-bromopropiophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1 mL) and water (1 mL). The tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 25°C under 30W 395nm violet light. After 8 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 5:1) to obtain pure 1-(3-bromophenyl)-3-hydroxy-2-methyl-1-propanone in a yield of 71%. 1H NMR (600MHz, Chloroform-d): δ8.09(t,J=1.9Hz,1H),7.88(dt,J=7.9,1.4Hz,1H),7.71(ddd,J=8.0,2.1,1.0Hz,1H),7.37(t,J=7.9 Hz,1H),3.93(dd,J=11.1,7.2Hz,1H),3.79(dd,J=11.1,4.2Hz,1H),3.62(pd,J=7.2,4.2Hz,1H),2.31(s,1H),1.22(d,J=7.2Hz,3H).

[0058] Example 7

[0059] In a 10 mL reaction tube equipped with a magnetic separator, m-trifluoromethylpropiophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1 mL) and water (1 mL). The tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 25°C under 30W 395nm violet light. After 8 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 5:1) to obtain pure 3-hydroxy-2-methyl-1-(3-(trifluoromethyl)phenyl)propan-1-one in an 86% yield. 1 HNMR (600MHz, Chloroform-d): δ8.22(s,1H),8.15(d,J=7.8Hz,1H),7.84(d,J=7.8Hz,1H),7.64(d,J=7.8Hz,1H),3.96(dd ,J=11.1,7.3Hz,1H),3.81(dd,J=11.1,4.2Hz,1H),3.69(td,J=7.2,4.2Hz,1H),2.50–2.22(m,1H),1.24(d,J=7.2Hz,3H).

[0060] Example 8

[0061] In a 10 mL reaction tube equipped with a magnetic separator, phenylbutyrate (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1 mL) and water (1 mL). The tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 25°C under 30W 395nm violet light. After 8 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 5:1) to obtain pure 2-(hydroxymethyl)-1-phenyl-1-butanone in a yield of 62%. 1 H NMR (600MHz, Chloroform-d): δ8.05–7.90(m,2H),7.59(t,J=7.3Hz,1H),7.48(t,J=7.6Hz,2H),3.98(dd,J=11.1,6.8Hz,1H),3.85(dd,J=11.1 ,3.9Hz,1H),3.55(qd,J=6.8,3.9Hz,1H),2.37(s,1H),1.78(ddd,J=13.7,7.5,6.0Hz,1H),1.68(dt,J=14.2,7.3Hz,1H),0.96(t,J=7.5Hz,3H).

[0062] Example 9

[0063] In a 10 mL reaction tube equipped with a magnetic rod, valerophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1 mL) and water (1 mL). The reaction tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 25°C under 30W 395nm violet light. After 8 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 5:1) to obtain pure 2-(hydroxymethyl)-1-phenyl-1-pentanone in a yield of 55%. 1H NMR (600MHz, Chloroform-d): δ3.95 (dd, J=11.1, 6.9Hz, 1H), 3.84 (dd, J=11.0, 3.9Hz, 1H), 3.63 (qd, J=6.8, 3.8Hz, 1H), 2.49 (s, 1H ),1.69(ddt,J=13.2,10.2,6.4Hz,1H),1.64–1.50(m,1H),1.37(dddq,J=23.5,13.4,10.0,6.6,6.2Hz,2H),0.90(t,J=7.3Hz,3H).

[0064] Example 10

[0065] In a 10 mL reaction tube equipped with a magnetic rod, diphenyl ketone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1 mL) and water (1 mL). The reaction tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 25°C under 30W 395nm violet light. After 8 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 5:1) to obtain pure 3-hydroxy-1,2-diphenyl-1-propanone in a yield of 62%. 1 H NMR (600MHz, Chloroform-d): δ7.98–7.89(m,2H),7.47(t,J=7.4Hz,1H),7.36(t,J=7.6Hz,2H),7.34–7.19( m,5H),4.79(dd,J=8.4,4.8Hz,1H),4.28(dd,J=11.4,8.4Hz,1H),3.88(dd,J=11.4,4.8Hz,1H),2.55(s,1H).

[0066] Example 11

[0067] In a 10 mL reaction tube equipped with a magnetic rod, phenylbutanone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1 mL) and water (1 mL). The reaction tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 25°C under 30W 395nm violet light. After 8 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 5:1) to obtain pure 2-(hydroxymethyl)-1,4-diphenyl-1-butanone in a 40% yield. 1 H NMR (600MHz, Chloroform-d): δ7.86–7.73(m,2H),7.56(t,J=7.3Hz,1H),7.43(t,J=7.7Hz,2H),7.32–7.24(m,2H),7.24–7.19(m,1H),7.17–7.08(m,2 H),3.99(dd,J=11.3,6.4Hz,1H),3.90(dd,J=11.2,3.7Hz,1H),3.59(dtd, J=9.9,6.3,3.7Hz,1H),2.79–2.60(m,2H),2.36(s,1H),2.10–1.93(m,2H).

[0068] Example 12

[0069] In a 10 mL reaction tube equipped with a magnetic rod, 2-propionylthiophene (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1 mL) and water (1 mL). The tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 25°C under 30W 395nm violet light. After 8 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 5:1) to obtain pure 3-hydroxy-2-methyl-1-(thiophen-2-yl)acetone in a yield of 91%. 1HNMR (600MHz, Chloroform-d): δ7.77(dd,J=3.8,1.2Hz,1H),7.68(dd,J=4.9,1.2Hz,1H),7.16(dd,J=4.9,3.8Hz,1H),3.9 2(dd,J=11.1,7.2Hz,1H),3.79(dd,J=11.1,4.3Hz,1H),3.53(qt,J=7.1,3.6Hz,1H),2.45(s,1H),1.28(d,J=7.2Hz,3H). Such as Figure 2 .

[0070] Example 13

[0071] To a 10 mL reaction tube equipped with a magnetic rod, phenylacetone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1.5 mL) and water (0.5 mL). The reaction tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 60°C under 30W 395nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 10:1) to obtain pure 3-methoxy-2-methyl-1-phenylacetone in an 84% yield. 1 HNMR (600MHz, Chloroform-d): δ7.97(d,J=7.8Hz,2H),7.56(t,J=7.2Hz,1H),7.46(t,J=7.8 Hz,2H),3.80–3.74(m,2H),3.45(dd,J=8.4,5.4Hz,1H),3.32(s,3H),1.20(d,J=7.2Hz,3H). Such as Figure 3 .

[0072] Example 14

[0073] In a 10 mL reaction tube equipped with a magnetic rod, p-fluoropropiophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1.5 mL) and water (0.5 mL). The tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 60°C under 30W 395nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 10:1) to obtain pure 1-(4-fluorophenyl)-3-methoxy-2-methyl-1-propanone in an 81% yield. 1 HNMR (600MHz, Chloroform-d): δ8.06–7.97(m,2H),7.13(t,J=8.6Hz,2H),3.74(qd ,J=7.4,3.9Hz,2H),3.48–3.42(m,1H),3.31(s,3H),1.19(dd,J=7.0,5.1Hz,3H). For example Figure 4 .

[0074] Example 15

[0075] In a 10 mL reaction tube equipped with a magnetic separator, p-bromopropiophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1.5 mL) and water (0.5 mL). The tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 60°C under 30W 395 nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 10:1) to obtain pure 1-(4-bromophenyl)-3-methoxy-2-methyl-1-propanone in a yield of 49%. 1 H NMR (600MHz, Chloroform-d): δ7.84(d,J=8.2Hz,2H),7.60(d,J=8.2Hz,2H),3.72(d,J=5.4Hz,2H),3.45(d,J=3.5Hz,1H),3.31(s,3H),1.19(d,J=6.1Hz,3H).

[0076] Example 16

[0077] In a 10 mL reaction tube equipped with a magnetic separator, p-methylpropiophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1.5 mL) and water (0.5 mL). The tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 60°C under 30W 395 nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 10:1) to obtain pure 1-(4-methylphenyl)-3-methoxy-2-methyl-1-propanone in a yield of 70%. 1 H NMR (600MHz, Chloroform-d): δ7.88(d,J=8.3Hz,2H),7.26(d,J=8.1Hz,2H),3.81 –3.70(m,2H),3.49–3.40(m,1H),3.32(s,3H),2.41(s,3H),1.20(d,J=6.6Hz,3H).

[0078] Example 17

[0079] In a 10 mL reaction tube equipped with a magnetic rod, p-ethylpropiophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1.5 mL) and water (0.5 mL). The tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 60°C under 30W 395nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 10:1) to obtain pure 1-(4-ethylphenyl)-3-methoxy-2-methyl-1-propanone in a yield of 62%. 1 H NMR (600MHz, Chloroform-d): δ7.91(d,J=8.4Hz,2H),7.29(d,J=8.0Hz,2H),3.82–3.72(m,2H),3. 49–3.40(m,1H),3.32(s,3H),2.71(q,J=7.6Hz,2H),1.26(t,J=7.6Hz,3H),1.20(d,J=6.7Hz,3H).

[0080] Example 18

[0081] In a 10 mL reaction tube equipped with a magnetic rod, p-methoxypropiophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1.5 mL) and water (0.5 mL). The reaction tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 60°C under 30W 395nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 10:1) to obtain pure 1-(4-methoxyphenyl)-3-methoxy-2-methyl-1-propanone in a yield of 64%. 1 H NMR(600MHz,Chloroform-d): δ7.97(d,J=8.9Hz,2H),6.94(d,J=8.9Hz,2H),3.87(s ,3H),3.81–3.68(m,2H),3.44(d,J=3.2Hz,1H),3.32(s,3H),1.19(d,J=6.2Hz,3H).

[0082] Example 19

[0083] In a 10 mL reaction tube equipped with a magnetic separator, m-methoxypropiophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1.5 mL) and water (0.5 mL). The tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 60°C under 30W 395nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 10:1) to obtain pure 1-(3-methoxyphenyl)-3-methoxy-2-methyl-1-propanone in a yield of 67%. 1 H NMR (600MHz, Chloroform-d): δ7.56(dt,J=7.7,1.2Hz,1H),7.50(t,J=2.1Hz,1H),7.37(t,J=7.9Hz,1H),7.11(dd, J=7.9,2.7Hz,1H),3.85(s,3H),3.75(d,J=5.7Hz,2H),3.49–3.42(m,1H),3.32(s,3H),1.21(dd,J=6.7,1.8Hz,4H).

[0084] Example 20

[0085] In a 10 mL reaction tube equipped with a magnetic separator, valerophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1.5 mL) and water (0.5 mL). The reaction tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 60°C under 30W 395nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 10:1) to obtain pure 2-(methoxymethyl)-1-phenyl-1-pentanone in a yield of 56%. 1 H NMR (600MHz, Chloroform-d): δ8.02–7.90(m,2H),7.56(t,J=7.4Hz,1H),7.46(t,J=7.6Hz,2H),3.85–3.66(m,2H),3.51 (dd,J=8.6,4.9Hz,1H),3.29(s,3H),1.79–1.66(m,1H),1.57–1.46(m,1H),1.30(h,J=7.5Hz,2H),0.88(t,J=7.4Hz,3H).

[0086] Example 21

[0087] In a 10 mL reaction tube equipped with a magnetic rod, hexanophenone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1.5 mL) and water (0.5 mL). The reaction tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 60°C under 30W 395nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 10:1) to obtain pure 2-(methoxymethyl)-1-phenyl-1-hexanone in a yield of 41%. 1 HNMR (600MHz, Chloroform-d): δ7.98 (dd, J=7.9, 1.5Hz, 2H), 7.60–7.53 (m, 1H) ,7.46(t,J=7.7Hz,2H),3.80–3.67(m,2H),3.56–3.45(m,1H),3.29(s,3H),1.80

[0088] –1.64(m,1H),1.54(dp,J=14.8,5.4Hz,1H),1.27(q,J=4.2,3.6Hz,4H),0.84(t,J=6.8Hz,3H).

[0089] Example 22

[0090] In a 10 mL reaction tube equipped with a magnetic rod, diphenylacetone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1.5 mL) and water (0.5 mL). The reaction tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 60°C under 30W 395nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 10:1) to obtain pure 2-benzyl-3-methoxy-1-phenyl-1-propanone in a yield of 53%. 1 H NMR (600MHz, Chloroform-d): δ7.92–7.84(m,2H),7.50(t,J=7.2Hz,1H),7.39(t,J=7.6Hz,2H),7.22(t,J=7.5Hz,2H),7.15(d,J=7.7Hz,3H),4.00(qd ,J=7.2,5.2Hz,1H),3.70(dd,J=9.1,7.4Hz,1H),3.51(dd,J=9.1,5.3Hz,1H ), 3.26 (s, 3H), 3.06 (dd, J = 13.8, 7.4Hz, 1H), 2.88 (dd, J = 13.8, 6.8Hz, 1H).

[0091] Example 23

[0092] In a 10 mL reaction tube equipped with a magnetic rod, phenylbutanone (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1.5 mL) and water (0.5 mL). The tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 60°C under 30W 395nm violet light. The reaction was complete after 12 hours. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 10:1) to obtain pure 2-(methoxymethyl)-1,4-diphenyl-1-butanone in a yield of 43%. 1H NMR (600MHz, Chloroform-d): δ7.94–7.84(m,2H),7.54(d,J=7.4Hz,1H),7.43(t,J= 7.8Hz,2H),7.28–7.21(m,2H),7.18(d,J=7.4Hz,1H),7.14–7.08(m,2H),3.84–3.68( m,2H),3.53(dd,J=8.3,4.9Hz,1H),3.28(s,3H),2.60(ddd,J=15.7,9.3,6.3Hz,2H) ,2.10(dddd,J=13.7,9.3,7.4,6.2Hz,1H),1.87(dddd,J=13.6,9.5,6.5,5.2Hz,1H).

[0093] Example 24

[0094] In a 10 mL reaction tube equipped with a magnetic rod, 2-propionylthiophene (0.5 mmol), cadmium sulfide-nickel cobalt double hydroxide complex (5 mg), and potassium carbonate (1.0 eq) were dissolved in a mixture of methanol (1.5 mL) and water (0.5 mL). The reaction tube was sealed and evacuated for 5 minutes, followed by oxygen supply to maintain a pure oxygen atmosphere. The reaction was carried out at 60°C under 30W 395nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 10:1) to obtain pure 3-methoxy-2-methyl-1-(thiophen-2-yl)acetone in a yield of 62%. 1 H NMR (600MHz, Chloroform-d): δ7.77(s,1H),7.65(t,J=4.4Hz,1H),7.14(q,J=4.1Hz,1H),3.75(td,J=8.5 ,3.4Hz,1H),3.61(t,J=6.7Hz,1H),3.53–3.40(m,1H),3.33(d,J=3.4Hz,3H),1.23(dd,J=7.2,3.6Hz,3H).

[0095] Example 25

[0096] To a 10 mL reaction tube equipped with a magnetic separator, add propiophenone (0.5 mmol), cadmium sulfide (5 mg), and cesium carbonate (1.0 eq) dissolved in methanol (2 mL). The reaction was carried out at 60°C under air atmosphere and 30W 395 nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1) to obtain pure isobutyrophenone in an 87% yield. 1 HNMR (600MHz, Chloroform-d): δ8.01–7.91 (m, 2H), 7.54 (td, J=7.1, 1.8Hz, 1H), 7.4 5(td,J=7.7,1.9Hz,2H),3.55(pd,J=6.8,1.9Hz,1H),1.21(dd,J=7.0,2.0Hz,6H). Such as Figure 5 .

[0097] Example 26

[0098] In a 10 mL reaction tube equipped with a magnetic separator, p-chloropropiophenone (0.5 mmol), cadmium sulfide (5 mg), and cesium carbonate (1.0 eq) dissolved in methanol (2 mL) were added. The reaction was carried out at 60°C under air atmosphere and 30W 395 nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1) to obtain pure 1-(4-chlorophenyl)-2-methyl-1-propanone in a yield of 93%. 1 HNMR (600MHz, Chloroform-d): δ7.99–7.83(m,2H),7.52–7.36(m,2H),3.49(h,J=6.8Hz,1H),1.21(d,J=6.9Hz,6H).

[0099] Example 27

[0100] In a 10 mL reaction tube equipped with a magnetic rod, p-trifluoromethylpropiophenone (0.5 mmol), cadmium sulfide (5 mg), and cesium carbonate (1.0 eq) were dissolved in methanol (2 mL). The reaction was carried out at 60°C under air atmosphere and 30W 395 nm violet light. After 12 hours, the reaction was completed. The reaction solution was extracted three times with 15 mL of dichloromethane, and the organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether: ethyl acetate = 50:1) to obtain pure 1-(4-trifluoromethylphenyl)-2-methyl-1-propanone with a yield of 98%. 1HNMR (600 MHz, Chloroform-d): δ7.82 (d, J = 8.2 Hz, 2H), 7.61 (d, J = 8.2 Hz, 2H), 3.55–3.45 (m, 1H), 1.21 (d, J = 6.8 Hz, 6H). Figure 6 .

[0101] Example 28

[0102] In a 10 mL reaction tube equipped with a magnetic separator, p-methylpropiophenone (0.5 mmol), cadmium sulfide (5 mg), and cesium carbonate (1.0 eq) dissolved in methanol (2 mL) were added. The reaction was carried out at 60°C under air atmosphere and 30W 395 nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1) to obtain pure 1-(4-methylphenyl)-2-methyl-1-propanone in a yield of 72%. 1 H NMR (600MHz, Chloroform-d): δ8.00–7.72(m,2H),7.19(d,J=7.8Hz,2H),3.62–3.32(m,1H),2.35(d,J=9.5Hz,3H),1.36–1.03(m,6H).

[0103] Example 29

[0104] In a 10 mL reaction tube equipped with a magnetic separator, m-chloropropiophenone (0.5 mmol), cadmium sulfide (5 mg), and cesium carbonate (1.0 eq) dissolved in methanol (2 mL) were added. The reaction was carried out at 60°C under air atmosphere and 30W 395 nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1) to obtain pure 1-(3-chlorophenyl)-2-methyl-1-propanone in an 84% yield. 1HNMR (600MHz, Chloroform-d): δ7.92(t,J=1.9Hz,1H),7.82(dt,J=7.7,1.4Hz,1H),7 .56–7.48(m,1H),7.41(t,J=7.9Hz,1H),3.50(p,J=6.8Hz,1H),1.22(d,J=6.9Hz,6H).

[0105] Example 30

[0106] In a 10 mL reaction tube equipped with a magnetic separator, m-trifluoromethylpropiophenone (0.5 mmol), cadmium sulfide (5 mg), and cesium carbonate (1.0 eq) dissolved in methanol (2 mL) were added. The reaction was carried out at 60°C under air atmosphere and 30W 395 nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1) to obtain pure 2-methyl-1-(3-(trifluoromethyl)phenyl)propan-1-one in an 87% yield. 1 H NMR (600MHz, Chloroform-d): δ8.21(s,1H),8.14(d,J=7.8Hz,1H),7.81(d,J=7.8Hz,1H),7.62(t,J=7.8Hz,1H),3.65–3.48(m,1H),1.24(d,J=6.9Hz,6H).

[0107] Example 31

[0108] In a 10 mL reaction tube equipped with a magnetic separator, m-methoxypropiophenone (0.5 mmol), cadmium sulfide (5 mg), and cesium carbonate (1.0 eq) dissolved in methanol (2 mL) were added. The reaction was carried out at 60°C under 30W 395 nm violet light in an air atmosphere. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1) to obtain pure 1-(3-methoxyphenyl)-2-methyl-1-propanone in an 81% yield. 1H NMR (600MHz, Chloroform-d): δ7.44(d,J=7.6Hz,1H),7.40(t,J=2.1Hz,1H),7.27(td,J=8.0,1.5Hz,1H),7 .00(dd,J=8.1,2.6Hz,1H),3.76(d,J=1.5Hz,3H),3.44(pd,J=6.8,1.5Hz,1H),1.12(dd,J=6.8,1.6Hz,6H).

[0109] Example 32

[0110] In a 10 mL reaction tube equipped with a magnetic separator, o-fluoropropiophenone (0.5 mmol), cadmium sulfide (5 mg), and cesium carbonate (1.0 eq) dissolved in methanol (2 mL) were added. The reaction was carried out at 60°C under air atmosphere and 30W 395 nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1) to obtain pure 1-(2-fluorophenyl)-2-methyl-1-propanone in a 50% yield. 1 H NMR (600MHz, Chloroform-d): δ7.77(td,J=7.6,1.9Hz,1H),7.49(dq,J=7.9,2.7Hz,1H),7.22(t ,J=7.5Hz,1H),7.12(dd,J=11.2,8.3Hz,1H),3.41(pd,J=6.8,1.2Hz,1H),1.20(d,J=6.9Hz,6H).

[0111] Example 33

[0112] In a 10 mL reaction tube equipped with a magnetic separator, butyrophenone (0.5 mmol), cadmium sulfide (5 mg), and cesium carbonate (1.0 eq) dissolved in methanol (2 mL) were added. The reaction was carried out at 60°C under air atmosphere and 30W 395 nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1) to obtain pure 2-methyl-1-phenyl-1-pentanone in a yield of 53%. 1HNMR (600MHz, Chloroform-d): δ8.03–7.91(m,2H),7.60–7.51(m,1H),7.46(dd,J=8.4,7.0Hz,2H),3.40(h, J=6.8Hz,1H),1.84(tt,J=13.9,7.4Hz,1H),1.56–1.43(m,1H),1.19(d,J=6.9Hz,3H),0.92(t,J=7.5Hz,3H).

[0113] Example 34

[0114] To a 10 mL reaction tube equipped with a magnetic separator, hexanophenone (0.5 mmol), cadmium sulfide (5 mg), and cesium carbonate (1.0 eq) dissolved in methanol (2 mL) were added. The reaction was carried out at 60°C under air atmosphere and 30W 395 nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1) to obtain pure 2-methyl-1-phenyl-1-hexanone in a yield of 44%. 1 H NMR (600MHz, Chloroform-d): δ8.13–7.80(m,2H),7.48(t,J=7.5Hz,1H),7.39(t,J=7.6Hz,2H),3.39(dd,J=14.0,7.2Hz,1H), 1.73(ddd,J=9.1,6.3,3.0Hz,1H),1.46–1.29(m,1H),1.22(qt,J=10.5,4.6Hz,4H),1.12(d,J=6.9Hz,3H),0.84–0.73(m,3H).

[0115] Example 35

[0116] To a 10 mL reaction tube equipped with a magnetic separator, diphenylacetone (0.5 mmol), cadmium sulfide (5 mg), and cesium carbonate (1.0 eq) dissolved in methanol (2 mL) were added. The reaction was carried out at 60°C under air atmosphere and 30W 395 nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1) to obtain pure 2-benzyl-1-phenyl-1-propanone in a yield of 62%. 1H NMR (600MHz, Chloroform-d): δ7.86(d,J=7.7Hz,2H),7.36(t,J=7.3Hz,1H),7.27(t,J=7.6Hz, 2H),7.19(d,J=4.5Hz,4H),7.10(q,J=4.5Hz,1H),4.59(q,J=6.8Hz,1H),1.44(d,J=6.9Hz,3H).

[0117] Example 36

[0118] In a 10 mL reaction tube equipped with a magnetic separator, tetralone (0.5 mmol), cadmium sulfide (5 mg), and cesium carbonate (1.0 eq) dissolved in methanol (2 mL) were added. The reaction was carried out at 60°C under 30W 395 nm violet light in an air atmosphere. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na₂SO₄, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1) to obtain pure 2-methyl-3,4-dihydronaphthalen-1(2H)-one in a yield of 39%. 1 H NMR (600MHz, Chloroform-d): δ8.04(dd,J=7.8,1.5Hz,1H),7.45(td,J=7.5,1.4Hz,1H),7.30(t,J=7.6Hz,1H),7.23(d,J=7.6Hz,1 H),3.10–2.93(m,2H),2.65–2.54(m,1H),2.20(dq,J=13.3,4.4Hz,1H),1.89(dtd,J=13.2,11.6,4.7Hz,1H),1.28(d,J=6.8Hz,3H).

[0119] Example 37

[0120] In a 10 mL reaction tube equipped with a magnetic separator, 3,4-methylenedioxypropiophenone (0.5 mmol), cadmium sulfide (5 mg), and cesium carbonate (1.0 eq) dissolved in methanol (2 mL) were added. The reaction was carried out at 60°C under air atmosphere and 30W 395 nm violet light. The reaction was complete after 12 hours. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na₂SO₄, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1) to obtain pure 1-(benzodioxetyl[1,3]benzo[5]yl)-2-methylpropan-1-one in a 50% yield. 1H NMR (600MHz, Chloroform-d): δ7.56–7.44(m,1H),7.36(d,J=1.7Hz,1H),6.77(d,J=8.2Hz,1H),5.96(s,2H),3.39(p,J=6.8Hz,1H),1.12(d,J=6.9Hz,6H).

[0121] Example 38

[0122] In a 10 mL reaction tube equipped with a magnetic separator, 5-methyl-2-propionylfuran (0.5 mmol), cadmium sulfide (5 mg), and cesium carbonate (1.0 eq) dissolved in methanol (2 mL) were added. The reaction was carried out at 60°C under air atmosphere and 30W 395 nm violet light. After 12 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1) to obtain pure 1-(5-methylfuran-2-yl)-2-methylacetone in a yield of 76%. 1 H NMR (600MHz, Chloroform-d): δ7.11 (d, J = 3.4Hz, 1H), 6.15 (d, J = 3.4Hz, 1H), 3.28 (p, J = 6.9Hz, 1H), 2.40 (s, 3H), 1.20 (d, J = 7.0Hz, 6H).

[0123] Comparative Example 1

[0124] To a 10 mL reaction tube equipped with a magnetic rod, add propiophenone (0.5 mmol), flaky zinc indium sulfide (5 mg), and potassium carbonate (1.0 eq) dissolved in a mixed solvent of methanol (1 mL) and water (1 mL). The reaction tube was sealed and evacuated for 5 minutes, then oxygen was supplied to maintain a pure oxygen atmosphere. The reaction was carried out at 25°C under 30W 395nm violet light. After 8 hours, the reaction was complete. The reaction solution was extracted three times with 15 mL of dichloromethane. The organic phases were combined, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The mixture was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 5:1) to obtain pure 3-hydroxy-2-methylpropiophenone in a yield of 46%. 1 H NMR (600MHz, Chloroform-d): δ7.96(d,J=7.2Hz,2H),7.57(t,J=7.2Hz,1H),7.47(t,J=7.2Hz,2H),3.93(d d,J=10.8,7.2Hz,1H),3.80(dd,J=10.8,4.2Hz,1H),3.70–3.62(m,1H),2.22(s,1H),1.23(d,J=7.2Hz,3H).

[0125] Comparative Example 2-8

[0126] The experimental conditions and steps of Control Examples 2-8 were the same as those of Control 1, with only the type of semiconductor photocatalyst being changed. The reaction yields are shown in the following table:

[0127] Control Example semiconductor photocatalysts Yield % 2 Flake titanium dioxide 13 3 flake carbon nitride 27 4 Flower-like zinc oxide 30 5 Blocky zinc sulfide 22 6 Flake cadmium selenide 37 7 Spherical cadmium sulfide 34 8 Flake cadmium sulfide 50 9 Rod-shaped cadmium sulfide 58

[0128] In summary, the present invention systematically verifies the selectivity of the photocatalytic system using methanol as a green carbon source and cadmium sulfide-based semiconductor as a catalyst for phenylpropiophenone and its derivatives through Examples 1-38. 3 )-H bond functionalization method. Experimental data show that by precisely controlling the reaction temperature (25-60°C), solvent composition (methanol / water ratio) and base type (potassium carbonate / cesium carbonate), α-hydroxymethylation (maximum yield 95%), α-methoxymethylation (maximum 84%) and α-methylation products (maximum 98%) can be obtained in a targeted manner. The CdS-NiCo double metal hydroxide complex of the present invention exhibits optimal catalytic performance. Compared with traditional catalysts (such as titanium dioxide, carbon nitride, etc.), the yield is increased by 30-50%. This method is suitable for aromatic ketones and heterocyclic systems containing halogen, trifluoromethyl, alkoxy and other substituents, and the yield is generally >70%. The catalyst can be recycled 5 times with an activity retention of >90%, an atom utilization rate of more than 95%, and an E factor of <20, which is significantly better than the traditional methylation process (E factor >35). The present invention successfully solves the problems of the prior art such as non-recyclable catalysts, single selectivity, and the need to use high-risk reagents, and provides a new strategy for the green functionalization of carbonyl compounds that is efficient, economical, and environmentally friendly.

[0129] It should be understood that the above embodiments are intended only to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection thereof. Persons skilled in the art may make various modifications and variations to the above embodiments without departing from the spirit and basic principles of the present invention, but such modifications and variations shall still fall within the scope of protection of the claims of the present invention and their equivalents. The scope of protection of the present invention shall be based on the appended claims and shall not be limited to the details of the above embodiments.

Claims

1. An environmentally friendly photocatalytic method for the functionalization of C-H bonds of propiophenone and its derivatives, characterized by: A photocatalytic strategy is adopted, using cadmium sulfide-based semiconductors as catalysts and methanol as a renewable carbon source, to achieve divergent C-H bond functionalization of propiophenone and its derivatives under alkaline conditions, including hydroxymethylation / methoxymethylation / methylation; wherein, the structural formula I of the propiophenone and its derivatives is as follows: R 1 is a group substituted at any position on the benzene ring; the group is selected from one of hydrogen, methyl, ethyl, methoxy, halogen, and trifluoromethyl; R 2 One selected from hydrogen, methyl, ethyl and aryl.

2. The method according to claim 1, wherein: The CH bond α-hydroxymethylation of propiophenone and its derivatives has the reaction formula A, B or C as follows:

3. The method according to claim 1, wherein: The concentration of the propiophenone and its derivatives in the reaction system is 0.1-0.5 mol / L.

4. The method according to claim 1, wherein: The wavelength of light in the photocatalytic reaction is 220-780nm; the light intensity of the photocatalytic reaction is 1-60W / cm 2 , the illumination time is 1-12h, and the temperature of the catalytic reaction is -10~80℃.

5. The method according to claim 1, wherein: The semiconductor photocatalyst is selected from one of cadmium sulfide, titanium dioxide, cuprous oxide, zinc oxide, indium zinc sulfide, cadmium selenide, and cadmium sulfide-nickel cobalt double hydroxide complex, and its morphology is flake, block, flower, sphere or rod.

6. The method according to claim 1, wherein: The semiconductor photocatalyst is rod-shaped cadmium sulfide or a cadmium sulfide-nickel cobalt double metal hydroxide complex; wherein the cadmium sulfide-nickel cobalt double metal hydroxide complex is a core-shell heterostructure catalyst, wherein nickel cobalt double metal hydroxide nanosheets are in situ grown and wrapped on the surface of cadmium sulfide nanorods with a hexagonal wurtzite structure, the molar ratio of cadmium sulfide to nickel cobalt double metal hydroxide is 1:(0.07-0.35), and the molar ratio of Ni to Co in the nickel cobalt double metal hydroxide is 2:1; the cadmium sulfide nanorods have a hexagonal wurtzite crystal structure, a length of 130-150 nm, and a diameter of 8-12 nm.

7. The method according to claim 1, wherein: The amount of the semiconductor photocatalyst used in the system is 1-10 mg / mL.

8. The method according to claim 1, wherein: The base is selected from one of potassium bicarbonate, sodium bicarbonate, potassium carbonate, sodium carbonate, cesium carbonate, potassium hydroxide, potassium tert-butoxide, 1,8-diazabicycloundec-7-ene, and triethylenediamine.

9. The method according to claim 1, wherein: The molar ratio of the propiophenone and its derivatives to the base is 1:(0.1-10).

10. The method according to claim 1, wherein: The solvent is selected from a mixture of methanol, ethanol, dichloromethane, chloroform, dimethyl sulfoxide, N,N-dimethylformamide, acetone and water.

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