A method for heterogeneous photocatalytic preparation of β-hydroxy ketones

Abstract

This invention discloses a heterogeneous photocatalytic method for preparing β-hydroxy ketones. Using 1,3-diphenyl-2,3-epoxy-1-propanone compounds as raw materials, a ruthenium-supported covalent organic framework material as a heterogeneous photocatalyst, and hansyl ester 1,4-dihydropyridine as a hydrogen source, a series of β-hydroxy ketone products are obtained through photocatalytic hydrogenation of epoxy groups under visible light irradiation. This invention utilizes a heterogeneous photocatalyst, which has good recyclability; the reaction is carried out at room temperature under mild conditions; the reaction exhibits good tolerance to substituent groups and has a wide range of applicable substrates; and the use of visible light as the light source provides advantages such as simple operation, short reaction time, and high product yield. This method not only has high academic research value but also shows promise for large-scale production.

Description

Technical Field

[0001] This invention relates to a heterogeneous photocatalytic method for preparing β-hydroxy ketones, specifically a simple, mild, and economical photocatalytic reduction method for preparing β-hydroxy ketones, belonging to the field of organic synthesis chemistry. Background Technology

[0002] The selective reduction of 1,3-diphenyl-2,3-epoxy-1-propanone and its derivatives to prepare β-hydroxy ketones is an important method for preparing secondary alcohols. Secondary alcohols, as important organic intermediates, have significant research and application value in pharmaceuticals, fragrances, agrochemicals, and chemical industries. Traditional methods mostly use metal hydrides as reducing agents to obtain secondary alcohol products by reducing the carbonyl group. However, these methods not only require excessive reducing agents and generate large amounts of inorganic salts and other byproducts, causing environmental pollution, but also lack selectivity in the reduction reaction. (a) M. Miranda, MJS; M. Sae, LM; N.Campos, AS Tetrahedron Lett. 1993, 34, 353-356; b) ICLennon, JA Ramsden, Org. Process Res. Dev. 2005, 9, 110-112; c) M. Miyagi, J. Takehara, S. Collet, K. Okano, Org. Process Res. Dev. 2000, 4, 346-348; d) E. Hasegawa, K. Ishiyama, T. Kato, T. Horagushi, T. Shimizu, J. Org. Chem.1992, 57, 5352-5359.)

[0003] In recent years, photocatalysis has attracted widespread attention and research due to its advantages such as mild reaction conditions, simple operation, safe and controllable reaction, and environmental friendliness. Organic dyes are commonly used photocatalysts, and their relatively low cost and ability to be precisely designed have garnered significant attention and research. However, these catalysts are mostly used under homogeneous reaction conditions, which not only makes them difficult to recycle but also increases the difficulty of product separation and purification. Furthermore, transition metal photocatalysts possess advantages such as high catalytic activity and a wide variety, playing an important role in photocatalytic reactions. However, the use of precious metals and their non-recyclability limit the further application of these catalysts. (e) NA Romero, DA Nicewicz, Chem. Rev. 2016, 116, 10075-10166; f) J. 2013, 15, 4398-4401; h) MY Qi,ZR Tang, YJ Xu, ACS Catal. 2023, 13, 3971-3982; i) Y. Zhang, MY Qi,ZR Tang, YJ Xu, ACS Catal. 2023, 13, 3575-3590.)

[0004] As early as 2011, Ollivier et al. reported a photocatalytic selective reduction method for 1,3-diphenyl-2,3-epoxy-1-propanone and its derivatives to prepare β-hydroxy ketones. This method used a transition metal photocatalyst [Ru(bpy)3]Cl2·(H2O)6 and 1,4-dihydropyridine hansyl ester as the hydrogen source, successfully preparing a series of β-hydroxy ketones under 14 W white light irradiation. This method can be carried out under mild conditions and has good substrate applicability. However, the metal catalyst is not only expensive but also cannot be recycled, resulting in low economic efficiency. Due to the difficulty in achieving high yields of β-hydroxy ketones through the selective reduction of 1,3-diphenyl-2,3-epoxy-1-propanone and its derivatives, there has been limited research on this type of reaction in recent years. (j)MH Larraufie, R. Pellet, L. Fensterbank, JP Goddard, E. Lacôte, M. Malacria, C. Ollivier, Angew. Chem. Int. Edit. 2011, 50, 4463-4466.)

[0005] Therefore, it is of great research value to continue developing a method for preparing β-hydroxy ketones that has mild reaction conditions, is simple and safe to operate, is economical, and has high selectivity. Summary of the Invention

[0006] The purpose of this invention is to provide a heterogeneous photocatalytic method for preparing β-hydroxy ketones. This method prepares β-hydroxy ketones by selectively reducing 1,3-diphenyl-2,3-epoxy-1-propanone compounds via photocatalysis. The photocatalyst is recyclable, the reaction conditions are mild, the operation is simple and safe, and the substrates have a wide range of applicability, providing a new approach for the preparation of β-hydroxy ketones.

[0007] This invention is achieved through the following technical solution:

[0008] A heterogeneous photocatalytic method for preparing β-hydroxy ketones, comprising using 1,3-diphenyl-2,3-epoxy-1-propanone compounds of Formula II as raw materials, 1,4-dihydropyridine of Hans ester of Formula III as a hydrogen source, and Ru-COF as a photocatalyst, to obtain β-hydroxy ketones of Formula I through photocatalytic selective reduction under visible light irradiation; the reaction formula is as follows:

[0009]

[0010] Furthermore, in Formulas I and II above, R1 is selected from hydrogen, methyl, methoxy, halogen, trifluoromethyl, or nitro; R2 is selected from hydrogen, methoxy, halogen, or ester.

[0011] Furthermore, the Ru-COF photocatalyst is made from sp 2 Carbon-conjugated COF (sp 2 The preparation method involves reacting carbon-conjugated COF with Ru(bpy)₂Cl₂, and the steps include: under N₂ protection, reacting sp(bpy) with Ru(bpy)₂Cl₂ to form a carbon-conjugated COF. 2 Carbon-conjugated COF and Ru(bpy)2Cl2 were dispersed in an organic solvent and reacted with stirring at room temperature for 20-22 h to obtain Ru-COF.

[0012] Furthermore, in the above-mentioned catalyst preparation method, sp 2 The mass ratio of carbon-conjugated COF to Ru(bpy)2Cl2 is 2:1-1.5.

[0013] Furthermore, in the above-mentioned method for preparing the catalyst, the organic solvent can be tetrahydrofuran, etc.

[0014] Furthermore, in the above-mentioned catalyst preparation method, sp 2 Carbon-conjugated COFs can be prepared using methods reported in existing technologies, or by the following method: 1,3,5-tris(p-formylphenyl)benzene (TFPB), 2,2'-([2,2'-bipyridine]-5,5'-diyl)acetonitrile (BDYDAN), an aqueous solution of Cs₂CO₃, and DMAc are added to a glass tube. The glass tube is rapidly frozen at 77 K (liquid N₂), then evacuated, and subsequently flame-sealed. The sealed glass tube is allowed to thaw naturally at room temperature, followed by ultrasonic dispersion, and then heated to 115-125 °C for 3-4 days. After heating, it is cooled to room temperature, and the resulting solid is washed and dried to obtain sp. 2 Carbon-conjugated COF.

[0015] In a specific embodiment of the present invention, a method for preparing a Ru-COF photocatalyst is provided, the process route of which is shown below:

[0016]

[0017] Furthermore, the photocatalytic selective reduction reaction described in this invention refers to the reduction and ring-opening reaction of 1,3-diphenyl-2,3-epoxy-1-propanone compounds with hensyl ester 1,4-dihydropyridine induced by visible light, thereby yielding a β-hydroxy ketone. In this photocatalytic selective reduction reaction, a ruthenium-supported covalent organic framework material (Ru-COF) is used as the photocatalyst, and hensyl ester 1,4-dihydropyridine is used as the hydrogen source, and the photocatalytic selective reduction reaction is carried out under ultraviolet light irradiation.

[0018] Furthermore, the molar ratio of 1,3-diphenyl-2,3-epoxy-1-propanone compounds to hans ester 1,4-dihydropyridine is 1:1.0-2.0, preferably 1:1.1.

[0019] Furthermore, the amount of Ru-COF photocatalyst used is 1-3 mol% of 1,3-diphenyl-2,3-epoxy-1-propanone compounds, preferably 1-2 mol%.

[0020] Furthermore, the power of the visible light is 5-10W, and the visible light can be achieved through a visible light lamp.

[0021] Furthermore, the visible light is preferably violet light, and the power of the violet light is also 5-10W. The violet light can be achieved by a violet lamp with a power of 5-10W.

[0022] Furthermore, the photocatalytic reaction is carried out in the presence of a solvent. The solvent provides the reaction environment and can be an organic solvent such as N,N-dimethylformamide (DMF), acetonitrile (CH3CN), tetrahydrofuran (THF), or dimethyl sulfoxide (DMSO). In addition, experiments have shown that different solvents have a certain impact on the reaction yield; DMSO is the preferred solvent. The amount of solvent can be adjusted as needed.

[0023] Furthermore, the reaction temperature is room temperature, and the reaction time is 1-5 h.

[0024] In a specific embodiment of the present invention, a specific step for synthesizing β-hydroxy ketone is provided as follows: 1,3-diphenyl-2,3-epoxy-1-propanone compound, hans ester 1,4-dihydropyridine, Ru-COF photocatalyst and solvent are mixed, and the resulting mixture is reacted under irradiation with a 5-10 W visible light lamp to obtain β-hydroxy ketone.

[0025] This invention uses Ru-COF as a photocatalyst to induce the selective ring-opening reduction reaction of 1,3-diphenyl-2,3-epoxy-1-propanone compounds with hensyl ester 1,4-dihydropyridine to synthesize β-hydroxy ketones under visible light irradiation. Compared with existing technologies, this method exhibits the following significant advantages:

[0026] 1. The use of heterogeneous photocatalysts enables catalyst recycling and reduces reaction costs;

[0027] 2. The reaction is carried out under mild conditions, under visible light and at room temperature;

[0028] 3. Simple and safe to operate, with a short reaction time, and is environmentally friendly.

[0029] 4. The substrate has a wide range of applicability, the reaction has high selectivity, and the product yield is high.

[0030] 5. This method not only has high academic value, but also has certain industrialization prospects. Attached Figure Description

[0031] Figure 1 sp 2 Infrared spectrum of carbon-conjugated COF.

[0032] Figure 2 sp 2 PXRD pattern of carbon-conjugated COF.

[0033] Figure 3 sp 2 PXRD spectra of carbon-conjugated COF and Ru-COF.

[0034] Figure 4 The image shows the 1H NMR spectrum of the product from Example 3.

[0035] Figure 5 The image shows the carbon NMR spectrum of the product from Example 3. Detailed Implementation

[0036] The present invention will be further illustrated below through embodiments. It should be understood that the following description is only for explaining the present invention and does not limit its content.

[0037] Example 1: sp 2 Carbon-conjugated COF (sp 2 Preparation of carbon-conjugated COF

[0038] 1,3,5-tris(p-formylphenyl)benzene (TFPB, 9.6 mg, 25.6 µmol), 2,2'-([2,2'-bipyridine]-5,5'-diyl)acetonitrile (BDYDAN, 8.92 mg, 38.42 µmol), Cs₂CO₃ (0.1 M, 1.0 mL aqueous solution), and DMAc (1.0 mL) were added to a 25 mL glass tube. The glass tube was rapidly frozen at 77 K (liquid N₂), then evacuated, and flame-sealed. The total length of the sealed glass tube was reduced by 4-5 cm. The sealed glass tube was allowed to thaw naturally at room temperature, followed by sonication for 10 mins to ensure homogeneous mixing of the components. The temperature was then raised to 120 °C and heated for 3 days. After heating, the solid was cooled to room temperature, filtered, and washed three times with THF. The resulting powder was then vacuum-dried at 100 °C for 3 h to obtain sp. 2 Carbon-conjugated COF, which is a yellow powder (13.6 mg, 73% yield).

[0039] Figure 1 For sp 2 The infrared spectrum of carbon-conjugated COF shows that sp 2 Carbon-conjugated COF at 2217 cm −1 It exhibits the characteristic vibrational band of C≡N (C≡N of vinyl groups). Furthermore, the aldehyde group in the precursor reaction exhibits a vibrational band at 2822 cm⁻¹ after polycondensation. −1 and 2743 cm −1 The absence of these features indicates a high degree of polymerization.

[0040] Figure 2 For sp 2 The PXRD spectrum of carbon-conjugated COF shows that sp 2 The carbon-conjugated COF is at 2.28. ◦ The strong low-angle diffraction peaks at the sp[i] indicate the crystallinity of the material. Furthermore, sp[i]... 2 The simulated diffraction curves of the carbon-conjugated COF using the AA superposition model agree well with the experimental PXRD data. Experimental results show that the unit cell parameters are a = b = 44.966 Å, c = 4.005 Å, α = β = 90°. ◦ γ = 120 ◦ It exhibits good consistency (Rp = 11.43%, Rwp = 14.57%).

[0041] Example 2: Preparation of Ru-COF

[0042] The required sp was prepared according to the method in Example 1. 2 Carbon-conjugated COF will sp 2 100 mg of carbon-conjugated COF was added to dry tetrahydrofuran (THF) and sonicated for 10 mins to achieve complete dispersion. 50 mg of Ru(bpy)₂Cl₂ was then added under nitrogen protection. The mixture was vigorously stirred at room temperature for 20 h, and the solid was collected by centrifugation. The solid was washed three times with THF and dried under vacuum at room temperature for 12 h to obtain Ru-COF, with a mass of 120 mg. ICP-OES analysis showed that the Ru content in Ru-COF was 5.37 wt%.

[0043] Figure 3 For sp 2 PXRD spectra of carbon-conjugated COF and Ru-COF. The figures show that the crystallinity of the prepared Ru-COF is similar to that of sp. 2 The crystallinity of carbon-conjugated COFs is basically consistent, indicating that sp 2 The carbon-conjugated COF did not change its crystal structure after being supported on a Ru catalyst.

[0044] Example 3: 1,3-Diphenyl-3-hydroxy-1-propanone

[0045] 3-hydroxy-1,3-diphenylpropan-1-one

[0046]

[0047] 1,3-Diphenyl-2,3-epoxy-1-propanone (22.2 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was complete, the solvent was removed by rotary evaporation, and then the pure, colorless, oily target compound (21.0 mg) was obtained by column chromatography (electrolyte: petroleum ether / ethyl acetate volume ratio = 100:1), with a yield of 93% based on 1,3-diphenyl-2,3-epoxy-1-propanone.

[0048] The NMR spectrum of the product is as follows Figure 4 and 5 As shown, the details are as follows:

[0049] 1 H NMR (400 MHz, CDCl3): δ 7.97-7.95 (d, J = 7.8 Hz, 2H), 7.60 (t, J = 7.1Hz, 1H), 7.49-7.44 (m, 4H), 7.41-7.37 (m, 2H), 7.31-7.29 (m, 1H), 5.38-5.34(m, 1H), 3.62-3.59 (m, 1H) 3.39-3.38 (m, 2H); 13 C NMR (100 MHz, CDCl3) δ 200.2,142.8, 136.5, 133.7, 128.7, 128.6, 128.1, 127.7, 125.7, 70.0, 47.4.

[0050] Example 4: 1-Phenyl-3-(4-methylphenyl)-3-hydroxy-1-propanone

[0051] 3-hydroxy-1-phenyl-3-(p-tolyl)propan-1-one

[0052]

[0053] 1-Phenyl-3-(4-methylphenyl)-2,3-epoxy-1-propanone (23.8 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was complete, the solvent was removed by rotary evaporation, and then the purified target compound was obtained by column chromatography (evolving solvent: petroleum ether / ethyl acetate, volume ratio = 100:1), which was a white solid (19.0 mg), yield: 79%.

[0054] 1 H NMR (400 MHz, CDCl3): δ 7.96-7.94 (m, 2H), 7.60-7.56 (m, 1H), 7.48-7.44 (m, 2H), 7.34-7.32 (m, 2H), 7.20-7.18 (m, 2H), 5.33-5.29 (m, 1H), 3.55(s, 1H) 3.42-3.32 (m, 2H); 13 C NMR (100 MHz, CDCl3) δ 200.2, 140.0, 137.3,136.6, 133.6, 129.2, 128.7, 128.1, 125.7, 69.9, 47.4, 21.1.

[0055] Example 5: 1-Phenyl-3-(4-methoxyphenyl)-3-hydroxy-1-propanone

[0056] 3-hydroxy-3-(4-methoxyphenyl)-1-phenylpropan-1-one

[0057]

[0058] 1-Phenyl-3-(4-methoxyphenyl)-2,3-epoxy-1-propanone (25.4 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was complete, the solvent was removed by rotary evaporation, and then the solution was purified by column chromatography (evolving solvent: petroleum ether / ethyl acetate, volume ratio = 100:1) to obtain a pure, colorless, oily target compound (18.2 mg), yield: 71%.

[0059] 1 H NMR (400 MHz, CDCl3): δ 7.97-7.95 (m, 2H), 7.49-7.45 (m, 2H), 7.38-7.35 (m, 3H), 6.93-6.90 (m, 2H), 5.32-5.29 (m, 1H), 3.81 (s, 3H) 3.54 (s,1H), 3.37-3.35 (m, 2H); 13 C NMR (100 MHz, CDCl3) δ 200.3, 159.1, 136.5, 135.1,133.6, 128.7, 128.1, 127.0, 113.9, 69.7, 55.3, 47.3.

[0060] Example 6: 1-Phenyl-3-(4-chlorophenyl)-3-hydroxy-1-propanone

[0061] 3-(4-chlorophenyl)-3-hydroxy-1-phenylpropan-1-one

[0062]

[0063] 1-Phenyl-3-(4-chlorophenyl)-2,3-epoxy-1-propanone (25.8 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was complete, the solvent was removed by rotary evaporation, and then the pure, colorless, oily target compound (22.7 mg) was obtained by column chromatography (evolving solvent: petroleum ether / ethyl acetate, volume ratio = 100:1), yield: 87%.

[0064] 1 H NMR (400 MHz, CDCl3): δ 7.96-7.93 (m, 2H), 7.62-7.58 (m, 1H), 7.49-7.45 (m, 2H), 7.39-7.33 (m, 4H), 5.34-5.31 (m, 1H), 3.689 (s, 1H) 3.38-3.28(m, 2H); 13 C NMR (100 MHz, CDCl3) δ 200.0, 141.4, 136.3, 133.8, 133.3, 128.7,128.7, 128.1, 127.1, 69.4, 47.2.

[0065] Example 7: 1-Phenyl-3-(4-bromophenyl)-3-hydroxy-1-propanone

[0066] 3-(4-bromophenyl)-3-hydroxy-1-phenylpropan-1-one

[0067]

[0068] 1-Phenylacetyl-3-(4-bromophenyl)-2,3-epoxy-1-propanone (30.3 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was complete, the solvent was removed by rotary evaporation, and then the pure, colorless, oily target compound (25.9 mg) was obtained by column chromatography (evolving solvent: petroleum ether / ethyl acetate volume ratio = 100:1), yield: 85%.

[0069] 1 H NMR (400 MHz, CDCl3): δ 7.96-7.94 (m, 2H), 7.62-7.58 (m, 1H), 7.52-7.46 (m, 4H), 7.33-7.31 (m, 2H), 5.33-5.29 (m, 1H), 3.68-3.67 (m, 1H) 3.40-3.28 (m, 2H); 13C NMR (101 MHz, CDCl3) δ 199.0, 142.7, 135.2, 132.8, 129.6,128.9, 128.6, 127.8, 125.7, 69.9, 47.4.

[0070] Example 8: 1-Phenyl-3-(4-trifluoromethylphenyl)-3-hydroxy-1-propanone

[0071] 3-hydroxy-1-phenyl-3-(4-(trifluoromethyl)phenyl)propan-1-one

[0072]

[0073] 1-Phenyl-3-(4-trifluoromethylphenyl)-2,3-epoxy-1-propanone (29.2 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was complete, the solvent was removed by rotary evaporation, and then the purified target compound was obtained by column chromatography (evolving solvent: petroleum ether / ethyl acetate, volume ratio = 100:1), which was a white solid (23.5 mg), yield: 80%.

[0074] 1 H NMR (400 MHz, CDCl3): δ 7.97-7.94 (m, 2H), 7.66-7.56 (m, 5H), 7.50-7.46 (m, 2H), 5.44-7.40 (m, 1H), 3.75 (d, J = 3.0 Hz, 1H), 3.43-3.31 (m, 2H); 13 CNMR (100 MHz, CDCl3) δ 199.8, 146.8, 136.2, 133.9, 129.7, 128.1 (q, J C-F = 240.0Hz), 125.6, 125.5, 69.4, 47.2.

[0075] Example 9: 1-Phenyl-3-(4-nitrophenyl)-3-hydroxy-1-propanone

[0076] 3-hydroxy-3-(4-nitrophenyl)-1-phenylpropan-1-one

[0077]

[0078] 1-Phenyl-3-(4-nitrophenyl)-2,3-epoxy-1-propanone (26.9 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was complete, the solvent was removed by rotary evaporation, and then the purified target compound was obtained by column chromatography (evolving solvent: petroleum ether / ethyl acetate, volume ratio = 100:1), which was a white solid (19.3 mg), yield: 71%.

[0079] 1 H NMR (400 MHz, CDCl3): δ 8.13-8.09 (m, 2H), 7.95-7.92 (m, 2H), 7.72-7.67 (m, 1H), 7.59-7.55 (m, 2H), 7.29-7.27 (m, 2H), 5.41-5.36 (m, 1H), 3.83-3.82 (m, 1H) 3.34-3.30 (m, 1H), 3.03-2.99 (m, 1H); 13 C NMR (100 MHz, CDCl3) δ200.2, 147.0, 144.0, 134.5, 133.3, 130.4, 129.2, 128.5, 123.4, 72.9, 41.5.

[0080] Example 10: 1-(4-methoxyphenyl)-3-phenyl-3-hydroxy-1-propanone

[0081] 3-hydroxy-3-phenyl-1-( p -tolyl)propan-1-one

[0082]

[0083] 1-(4-methoxyphenyl)-3-phenyl-2,3-epoxy-1-propanone (25.4 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was complete, the solvent was removed by rotary evaporation, and then the pure, colorless, oily target compound (15.6 mg) was obtained by column chromatography (evolving solvent: petroleum ether / ethyl acetate volume ratio = 100:1), yield: 61%.

[0084] 1 H NMR (400 MHz, CDCl3): δ 7.94-7.90 (m, 2H), 7.44-7.42 (m, 2H), 7.39-7.35 (m, 2H), 7.30-7.27 (m, 1H), 6.93-6.90 (m, 2H), 5.33-5.30 (m, 1H), 3.85(s, 1H), 3.82 (s, 1H) 3.34-3.25 (m, 2H); 13 C NMR (100 MHz, CDCl3) δ 198.7,163.9, 143.0, 130.4, 129.5, 128.5, 127.5, 125.7, 113.8, 70.1, 55.5, 46.9.

[0085] Example 11: 1-(4-fluorophenyl)-3-phenyl-3-hydroxy-1-propanone

[0086] 1-(4-fluorophenyl)-3-hydroxy-3-phenylpropan-1-one

[0087]

[0088] 1-(4-fluorophenyl)-3-phenyl-2,3-epoxy-1-propanone (24.2 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was complete, the solvent was removed by rotary evaporation, and then the pure, colorless, oily target compound (21.0 mg) was obtained by column chromatography (evolving solvent: petroleum ether / ethyl acetate volume ratio = 100:1), yield: 86%.

[0089] 1 H NMR (400 MHz, CDCl3): δ 8.01-7.96 (m, 2H), 7.45-7.42 (m, 2H), 7.40-7.36 (m, 2H), 7.32-7.28 (m, 1H), 7.15-7.10 (m, 2H), 5.36-5.32 (m, 1H), 3.54(s, 1H) 3.40-3.28 (m, 2H); 13 C NMR (100 MHz, CDCl3) δ 198.4, 167.3, 164.7,142.8, 133.0, 132.9, 130.9, 130.8, 128.6, 127.7, 125.7, 115.9, 115.7, 70.0,47.3.

[0090] Example 12: 1-(4-chlorophenyl)-3-phenyl-3-hydroxy-1-propanone

[0091]

[0092] 1-(4-chlorophenyl)-3-phenyl-2,3-epoxy-1-propanone (25.8 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was complete, the solvent was removed by rotary evaporation, and then the pure, colorless, oily target compound (22.4 mg) was obtained by column chromatography (evolving solvent: petroleum ether / ethyl acetate volume ratio = 100:1), yield: 86%.

[0093] 1 H NMR (400 MHz, CDCl3): δ 7.91-7.87 (m, 2H), 7.45-7.43 (m, 4H), 7.40-7.36 (m, 2H), 7.33-7.29 (m, 1H), 5.35-5.33 (m, 1H), 3.48-3.47 (m, 1H) 3.40-3.28 (m, 2H); 13 C NMR (100 MHz, CDCl3) δ 198.8, 142.8, 140.1, 134.9, 129.5, 129.0, 128.6, 127.8, 125.7, 69.9, 47.4.

[0094] Example 13: 1-(4-bromophenyl)-3-phenyl-3-hydroxy-1-propanone

[0095] 1-(4-bromophenyl)-3-hydroxy-3-phenylpropan-1-one

[0096]

[0097] 1-(4-bromophenyl)-3-phenyl-2,3-epoxy-1-propanone (30.3 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was complete, the solvent was removed by rotary evaporation, and then the pure, colorless, oily target compound (26.5 mg) was obtained by column chromatography (evolving solvent: petroleum ether / ethyl acetate, volume ratio = 100:1), yield: 87%.

[0098] 1 H NMR (400 MHz, CDCl3): δ 7.84-7.80 (m, 2H), 7.63-7.60 (m, 2H), 7.45-7.37 (m, 4H), 7.33-7.29 (m, 1H), 5.37-5.33 (m, 1H), 3.45-3.44 (m, 1H), 3.40-3.28 (m, 2H); 13C NMR (100 MHz, CDCl3) δ 199.0, 142.7, 135.2, 132.0, 129.6,128.9, 128.6, 127.8, 125.7, 69.9, 47.4.

[0099] Example 14: 1-(4-methyl carbamate phenyl)-3-phenyl-3-hydroxy-1-propanone

[0100] methyl 4-(3-hydroxy-3-phenylpropanoyl)benzoate

[0101]

[0102] 1-(methyl 4-carboxylate phenyl)-3-phenyl-2,3-epoxy-1-propanone (28.2 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was complete, the solvent was removed by rotary evaporation, and then the pure, colorless, oily target compound (17.3 mg) was obtained by column chromatography (electrolyte: petroleum ether / ethyl acetate volume ratio = 100:1), yield: 61%.

[0103] 1 H NMR (400 MHz, CDCl3): δ 7.93-7.90 (m, 2H), 7.45-7.42 (m, 2H), 7.38-7.35 (m, 2H), 7.31-7.27 (m, 1H), 6.93-6.90 (m, 2H), 5.33-5.30 (m, 1H), 3.85(s, 3H), 3.81 (s, 1H) 3.32-3.25 (m, 2H); 13 C NMR (100 MHz, CDCl3) δ 198.5,166.2, 143.0, 139.8, 134.3, 130.1, 129.8, 128.7, 128.2, 127.9, 125.8, 70.0,52.5, 47.9.

[0104] Example 15: 1,3-Diphenyl-3-hydroxy-1-propanone

[0105] 3-hydroxy-1,3-diphenylpropan-1-one

[0106]

[0107] 1,3-Diphenyl-2,3-epoxy-1-propanone (22.2 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature under ultraviolet light for 3 h. After the reaction was completed, the solvent was removed by rotary evaporation, and then the pure, colorless, oily target compound was obtained by column chromatography (evolving solvent: petroleum ether / ethyl acetate volume ratio = 100:1).

[0108] The following are the results of changing the wattage of the UV lamp:

[0109]

[0110] Example 16: 1,3-Diphenyl-3-hydroxy-1-propanone

[0111] 3-hydroxy-1,3-diphenylpropan-1-one

[0112]

[0113] 1,3-Diphenyl-2,3-epoxy-1-propanone (22.2 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine, Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was complete, the solvent was removed by rotary evaporation, and then the pure, colorless, oily target compound was obtained by column chromatography (evolving solvent: petroleum ether / ethyl acetate volume ratio = 100:1).

[0114] By varying the amount of hansyl ester 1,4-dihydropyridine, the following product was obtained:

[0115]

[0116] Example 17: 1,3-Diphenyl-3-hydroxy-1-propanone

[0117] 3-hydroxy-1,3-diphenylpropan-1-one

[0118]

[0119] 1,3-Diphenyl-2,3-epoxy-1-propanone (22.2 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature under a 10 W UV lamp for a certain period of time. After the reaction was completed, the solvent was removed by rotary evaporation, and then the pure, colorless, oily target compound was obtained by column chromatography (evolving solvent: petroleum ether / ethyl acetate volume ratio = 100:1).

[0120] The following are the results of changing the reaction time:

[0121]

[0122] Example 18: 1,3-Diphenyl-3-hydroxy-1-propanone

[0123] 3-hydroxy-1,3-diphenylpropan-1-one

[0124]

[0125] 1,3-Diphenyl-2,3-epoxy-1-propanone (22.2 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2 (2.0 mg, 0.00112 mmol), and solvent (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was complete, the solvent was removed by rotary evaporation, and then the pure, colorless, oily target compound was obtained by column chromatography (evolving solvent: petroleum ether / ethyl acetate volume ratio = 100:1).

[0126] Changing the type of solvent results in the following product:

[0127]

[0128] Example 19: 1,3-Diphenyl-3-hydroxy-1-propanone

[0129] 3-hydroxy-1,3-diphenylpropan-1-one

[0130]

[0131] 1,3-Diphenyl-2,3-epoxy-1-propanone (22.2 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru-COF from Example 2, and DMSO (2 mL) were sequentially added to a 15 mL reaction tube. The reaction mixture was reacted at room temperature under ultraviolet light for 3 h. After the reaction was completed, the solvent was removed by rotary evaporation, and then the pure, colorless, oily target compound was obtained by column chromatography (evolving solvent: petroleum ether / ethyl acetate volume ratio = 100:1).

[0132] The following are the results of changing the amount of Ru-COF photocatalyst used:

[0133]

[0134] Comparative Example 1: 1,3-Diphenyl-3-hydroxy-1-propanone

[0135] 3-hydroxy-1,3-diphenylpropan-1-one

[0136]

[0137] 1,3-Diphenyl-2,3-epoxy-1-propanone (22.2 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru(bpy)3Cl2 (0.00112 mmol), and DMSO (2 mL) were added sequentially to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was complete, the solvent was removed by rotary evaporation, and then the pure, colorless, oily target compound (15.6 mg) was obtained by column chromatography (electrolyte: petroleum ether / ethyl acetate, volume ratio = 100:1), with a yield of 69% based on 1,3-diphenyl-2,3-epoxy-1-propanone.

[0138] Comparative Example 2: 1,3-Diphenyl-3-hydroxy-1-propanone

[0139] 3-hydroxy-1,3-diphenylpropan-1-one

[0140]

[0141] 1,3-Diphenyl-2,3-epoxy-1-propanone (22.2 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), Ru(bpy)3Cl2 (0.00112 mmol), sp 2Carbon-conjugated COF (1.2 mg) and DMSO (2 mL) were added sequentially to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was completed, the solvent was removed by rotary evaporation, and then the pure, colorless, oily target compound (14.7 mg) was obtained by column chromatography (electrolyte: petroleum ether / ethyl acetate volume ratio = 100:1), with a yield of 65% based on 1,3-diphenyl-2,3-epoxy-1-propanone.

[0142] Comparative Example 3: 1,3-Diphenyl-3-hydroxy-1-propanone

[0143] 3-hydroxy-1,3-diphenylpropan-1-one

[0144]

[0145] 1,3-Diphenyl-2,3-epoxy-1-propanone (22.2 mg, 0.1 mmol), hansyl ester 1,4-dihydropyridine (27.9 mg, 0.11 mmol), sp 2 Carbon-conjugated COF (2 mg) and DMSO (2 mL) were added sequentially to a 15 mL reaction tube. The reaction mixture was reacted at room temperature for 3 h under 10 W UV light. After the reaction was completed, the solvent was removed by rotary evaporation. TLC analysis showed that no target product was obtained.

Claims

1. A method for heterogeneous photocatalytic preparation of β-hydroxy ketones, characterized in that: Using 1,3-diphenyl-2,3-epoxy-1-propanone compounds as shown in Formula II as raw materials, Hans ester 1,4-dihydropyridine as shown in Formula III as a hydrogen source, and Ru-COF as a photocatalyst, a photocatalytic selective reduction reaction was carried out under visible light irradiation to obtain the β-hydroxy ketone shown in Formula I; the reaction formula is as follows: ； In Formula I and Formula II, R1 is selected from hydrogen, methyl, methoxy, halogen, trifluoromethyl, or nitro; R2 is selected from hydrogen, methoxy, halogen, or ester. The preparation method of Ru-COF photocatalyst is as follows: under N2 protection, sp... 2 Carbon-conjugated COF and Ru(bpy)2Cl2 were dispersed in an organic solvent at a mass ratio of 2:1-1.5 and reacted with stirring at room temperature for 20-22 h to obtain Ru-COF photocatalyst.

2. The method according to claim 1, characterized in that: The visible light mentioned is violet light.

3. The method according to claim 1 or 2, characterized in that: The molar ratio of 1,3-diphenyl-2,3-epoxy-1-propanone compounds to hans ester 1,4-dihydropyridine is 1:1.0-2.

0.

4. The method according to claim 3, characterized in that: The molar ratio of 1,3-diphenyl-2,3-epoxy-1-propanone compounds to hans ester 1,4-dihydropyridine is 1:1.

1.

5. The method according to claim 1 or 2, characterized in that: Ru The amount of COF photocatalyst used is 1-3 mol of 1,3-diphenyl-2,3-epoxy-1-propanone compound.

6. The method according to claim 5, characterized in that: Ru The amount of COF photocatalyst used is 1-2 mol of 1,3-diphenyl-2,3-epoxy-1-propanone compound.

7. The method according to claim 1 or 2, characterized in that: The power of visible light is 5-10W.

8. The method according to claim 1 or 2, characterized in that: The reaction is carried out at room temperature for 1-5 hours.

9. The method according to claim 1 or 2, characterized in that: The reaction proceeds in the presence of a solvent.

10. The method according to claim 9, characterized in that: The solvent is acetonitrile, DMSO, tetrahydrofuran, or DMF.

11. The method according to claim 9, characterized in that: Including the following Specific steps: 1,3-Diphenyl-2,3-epoxy-1-propanone compounds, hans ester 1,4-dihydropyridine, Ru-COF, and a solvent are mixed. The resulting mixture is reacted under visible light irradiation to obtain... β -Hydroxyketone.

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