A method for preparing aryl substituted alcohols
By using non-metallic catalysts such as tetrabromofluorescein and thiourea dioxide to react with aryl aldehydes under visible light, the problem of expensive metal catalysts in existing technologies has been solved, achieving efficient and mild synthesis of aryl substituted alcohols and expanding the application range of C=O double bond polarity reversal.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUIZHOU MEDICAL UNIV
- Filing Date
- 2026-02-11
- Publication Date
- 2026-05-26
AI Technical Summary
Existing visible light photocatalytic reactions require expensive and environmentally harmful metal photocatalysts, which limits the application of C=O double bond polarity inversion to construct carbon-carbon bonds.
Aryl substituted alcohols were prepared by mixing tetrabromofluorescein, thiourea dioxide, potassium carbonate, and organic solvents with aryl aldehydes and 4-cyanopyridine at room temperature and reacting under blue light irradiation with a blue LED. The mixture was then purified by vacuum distillation and silica gel column chromatography.
This method enables the efficient synthesis of aryl substituted alcohols under mild conditions, with a wide range of applicable substrates. It avoids the use of expensive and harmful metal photocatalysts and has potential application value.
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Figure CN122079871A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of organic synthesis. Background Technology
[0002] Constructing carbon-carbon bonds through the polarity reversal of the C=O double bond is an important synthetic strategy in organic chemistry. Traditional C=O double bond polarity reversal often requires harsh reaction conditions and strong reducing agents sensitive to water or air, limiting its applicability. In recent years, visible light photocatalysis, with its unique and efficient single-electron transfer characteristics, has achieved the efficient conversion of electron-depleted functional groups into nucleophilic intermediates at room temperature. This strategy has been extended to the coupling of the C=O double bond itself or with alkyl chains, yielding alkyl-substituted alcohols and amines. However, existing visible light photocatalysis requires expensive and environmentally harmful metal photocatalysts, resulting in poor techno-economic and environmental friendliness. Therefore, how to achieve C=O double bond polarity reversal to construct carbon-carbon bonds using inexpensive non-metallic photocatalysts is a problem that urgently needs to be solved. Summary of the Invention
[0003] This invention aims to address the problem that existing visible light photocatalytic reactions that construct carbon-carbon bonds by reversing the polarity of C=O double bonds require expensive and environmentally harmful metal photocatalysts, and thus provides a method for preparing aryl substituted alcohols.
[0004] A method for preparing an aryl substituted alcohol, comprising the following steps:
[0005] Aryl aldehyde, 4-cyanopyridine, tetrabromofluorescein, thiourea dioxide, potassium carbonate and organic solvent were mixed evenly at room temperature and with stirring to obtain a mixture. The mixture was then irradiated with a blue light-emitting diode at room temperature, with stirring and a light power of 30W~36W. After the reaction was complete, the solvent was removed by vacuum distillation, and then purified by silica gel column chromatography to obtain aryl substituted alcohol.
[0006] The molar ratio of the aryl aldehyde to 4-cyanopyridine is 1:(1.0~1.5); the molar ratio of the aryl aldehyde to tetrabromofluorescein is 1:(0.01~0.1); the molar ratio of the aryl aldehyde to thiourea dioxide is 1:(0.01~0.1); the molar ratio of the aryl aldehyde to potassium carbonate is 1:(1.8~2.0).
[0007] The structural formula of the aryl aldehyde is as follows: R1 is H, chloro, or bromine;
[0008] The structural formula of the 4-cyanopyridine is as follows: ;
[0009] The structural formula of the aryl substituted alcohol is as follows: R1 is H, chlorine, or bromine.
[0010] The beneficial effects of this invention are:
[0011] This invention utilizes visible light photocatalysis to directly couple C=O double bond polarity inversion with aromatic compounds, achieving efficient and mild synthesis of aryl-substituted alcohols. The reaction does not require expensive and environmentally harmful metal photocatalysts or strong reducing agents, and has a wide range of applicable substrates. This method is an important supplement to visible light photocatalysis for C=O double bond polarity inversion and has potential application value. Attached Figure Description
[0012] Figure 1 The aryl substituted alcohol prepared in Example 1 1 H NMR spectrum;
[0013] Figure 2 The aryl substituted alcohol prepared in Example 1 13 C10 NMR spectrum. Detailed Implementation
[0014] Specific Implementation Method 1: This implementation method provides a method for preparing aryl substituted alcohols, which is carried out according to the following steps:
[0015] Aryl aldehyde, 4-cyanopyridine, tetrabromofluorescein, thiourea dioxide, potassium carbonate and organic solvent were mixed evenly at room temperature and with stirring to obtain a mixture. The mixture was then irradiated with a blue light-emitting diode at room temperature, with stirring and a light power of 30W~36W. After the reaction was complete, the solvent was removed by vacuum distillation, and then purified by silica gel column chromatography to obtain aryl substituted alcohol.
[0016] The molar ratio of the aryl aldehyde to 4-cyanopyridine is 1:(1.0~1.5); the molar ratio of the aryl aldehyde to tetrabromofluorescein is 1:(0.01~0.1); the molar ratio of the aryl aldehyde to thiourea dioxide is 1:(0.01~0.1); the molar ratio of the aryl aldehyde to potassium carbonate is 1:(1.8~2.0).
[0017] The structural formula of the aryl aldehyde is as follows: R1 is H, chloro, or bromine;
[0018] The structural formula of the 4-cyanopyridine is as follows: ;
[0019] The structural formula of the aryl substituted alcohol is as follows: R1 is H, chlorine, or bromine.
[0020] The specific reaction route for the preparation of aryl substituted alcohols in this embodiment is as follows:
[0021] ;
[0022] Where R1 is H, chloro, or bromine; Eosin Y is tetrabromofluorescein; and TDO is thiourea dioxide.
[0023] The beneficial effects of this embodiment are:
[0024] This embodiment utilizes a visible-light photocatalytic reaction to directly couple C=O double bond polarity inversion with aromatic compounds, achieving efficient and mild synthesis of aryl-substituted alcohols. The reaction does not require expensive and environmentally harmful metal photocatalysts or strong reducing agents, and has a wide range of applicable substrates. This method is an important supplement to visible-light photocatalytic C=O double bond polarity inversion and has potential application value.
[0025] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the organic solvent used is acetonitrile. Everything else is the same as in Specific Implementation Method One.
[0026] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 1 or 2 in that the molar ratio of the aryl aldehyde to the volume ratio of the organic solvent is 1 mmol:(10~20) mL. Everything else is the same as in Specific Implementation Method 1 or 2.
[0027] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the solvent used for silica gel column chromatography separation and purification is a mixed solvent of petroleum ether and ethyl acetate. Everything else is the same as in Specific Implementation Methods One to Three.
[0028] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the volume ratio of petroleum ether to ethyl acetate is (10~20):1. Everything else is the same as in Specific Implementation Methods One to Four.
[0029] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that: aryl aldehyde, 4-cyanopyridine, tetrabromofluorescein, thiourea dioxide, potassium carbonate, and an organic solvent are mixed evenly at room temperature and a stirring speed of 200 r / min to 400 r / min to obtain a mixture. Everything else is the same as in Specific Implementation Methods One to Five.
[0030] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the mixture is irradiated for 12 to 24 hours at room temperature, a stirring speed of 200 to 400 r / min, and a blue LED illumination power of 30 W to 36 W. Everything else is the same as in Specific Implementation Methods One to Six.
[0031] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that the molar ratio of the aryl aldehyde to 4-cyanopyridine is 1:(1.2~1.5). Everything else is the same as in Specific Implementation Methods One to Seven.
[0032] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that the molar ratio of the aryl aldehyde to tetrabromofluorescein is 1:(0.05~0.1). Everything else is the same as in Specific Implementation Methods One to Eight.
[0033] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods One to Nine in that the molar ratio of the aryl aldehyde to thiourea dioxide is 1:(0.05~0.1). Everything else is the same as in Specific Implementation Methods One to Nine.
[0034] The beneficial effects of the present invention are verified using the following embodiments:
[0035] Example 1:
[0036] A method for preparing an aryl substituted alcohol, comprising the following steps:
[0037] At room temperature and with a stirring speed of 300 r / min, 55 mg (0.1 mmol) of aryl aldehyde, 14.0 mg (0.15 mmol) of 4-cyanopyridine, 3.1 mg (0.005 mmol) of tetrabromofluorescein, 2.2 mg (0.002 mmol) of thiourea dioxide, 27.0 mg (0.2 mmol) of potassium carbonate and 2 mL of organic solvent were mixed evenly to obtain a mixture. The mixture was then irradiated for 24 h at room temperature, with a stirring speed of 300 r / min and a blue light-emitting diode illumination power of 36 W. After the reaction was complete, the solvent was removed by vacuum distillation, and the mixture was then purified by silica gel column chromatography to obtain aryl substituted alcohol.
[0038] The structural formula of the aryl aldehyde is as follows: ;
[0039] The structural formula of the 4-cyanopyridine is as follows: ;
[0040] The aryl-substituted alcohol is phenyl(4-pyridyl)methanol, with the following structural formula: .
[0041] The organic solvent is acetonitrile.
[0042] The solvent used for silica gel column chromatography separation and purification is a mixture of petroleum ether and ethyl acetate.
[0043] The volume ratio of petroleum ether to ethyl acetate is 15:1.
[0044] The reaction route for the preparation of aryl substituted alcohols in this embodiment is as follows:
[0045] .
[0046] The purity of the aryl substituted alcohol prepared in Example 1 was tested to be 97%, and the yield was 85%.
[0047] Figure 1 The aryl substituted alcohol prepared in Example 1 1 H NMR spectrum; Figure 2 The aryl substituted alcohol prepared in Example 1 13 C NMR spectrum; NMR data analysis:
[0048] 1 H NMR (400 MHz, CDCl3): δH 7.46-7.42 (m, 2H), 7.22 – 7.16 (m, 2H), 7.12-7.07 (m, 2H), 6.74 (tt, J = 7.3, 1.1 Hz, 1H), 6.66-6.62 (m, 2H), 3.39(t, J = 7.0 Hz, 2H), 2.88 (t, J = 7.0 Hz, 2H).
[0049] 13 C NMR (101 MHz, CDCl3): δC 147.50, 138.23, 131.68, 130.55, 129.37, 120.29, 117.92, 113.23, 45.01, 34.84.
Claims
1. A method for preparing an aryl-substituted alcohol, characterized in that... It is done in the following steps: Aryl aldehyde, 4-cyanopyridine, tetrabromofluorescein, thiourea dioxide, potassium carbonate and organic solvent were mixed evenly at room temperature and with stirring to obtain a mixture. The mixture was then irradiated with a blue light-emitting diode at room temperature, with stirring and a light power of 30W~36W. After the reaction was complete, the solvent was removed by vacuum distillation, and then purified by silica gel column chromatography to obtain aryl substituted alcohol. The molar ratio of the aryl aldehyde to 4-cyanopyridine is 1:(1.0~1.5); the molar ratio of the aryl aldehyde to tetrabromofluorescein is 1:(0.01~0.1); the molar ratio of the aryl aldehyde to thiourea dioxide is 1:(0.01~0.1); the molar ratio of the aryl aldehyde to potassium carbonate is 1:(1.8~2.0). The structural formula of the aryl aldehyde is as follows: R1 is H, chloro, or bromine; The structural formula of the 4-cyanopyridine is as follows: ; The structural formula of the aryl substituted alcohol is as follows: R1 is H, chlorine, or bromine.
2. The method for preparing an aryl substituted alcohol according to claim 1, characterized in that... The organic solvent is acetonitrile.
3. The method for preparing an aryl substituted alcohol according to claim 1, characterized in that... The molar ratio of the aryl aldehyde to the volume ratio of the organic solvent is 1 mmol:(10~20) mL.
4. The method for preparing an aryl substituted alcohol according to claim 1, characterized in that... The solvent used for silica gel column chromatography separation and purification is a mixture of petroleum ether and ethyl acetate.
5. The method for preparing an aryl substituted alcohol according to claim 4, characterized in that... The volume ratio of petroleum ether to ethyl acetate is (10~20):
1.
6. The method for preparing an aryl substituted alcohol according to claim 1, characterized in that... Aryl aldehyde, 4-cyanopyridine, tetrabromofluorescein, thiourea dioxide, potassium carbonate, and organic solvent were mixed evenly at room temperature and a stirring speed of 200 r / min to 400 r / min to obtain a mixture.
7. The method for preparing an aryl substituted alcohol according to claim 1, characterized in that... The mixture was irradiated for 12 to 24 hours at room temperature, with a stirring speed of 200 to 400 r / min and a blue LED illumination power of 30 W to 36 W.
8. The method for preparing an aryl substituted alcohol according to claim 1, characterized in that... The molar ratio of the aryl aldehyde to 4-cyanopyridine is 1:(1.2~1.5).
9. The method for preparing an aryl substituted alcohol according to claim 1, characterized in that... The molar ratio of the aryl aldehyde to tetrabromofluorescein is 1:(0.05~0.1).
10. The method for preparing an aryl substituted alcohol according to claim 1, characterized in that... The molar ratio of the aryl aldehyde to thiourea dioxide is 1:(0.05~0.1).