Synthesis method of 6, 6 '-diphenyl binaphthol

Abstract

The invention belongs to the technical field of organic synthesis, and particularly relates to a synthesis method of 6, 6 '-diphenyl binaphthol, which comprises the following steps: 1) adding 6, 6'-dibromo binaphthol and phenylboronic acid into a solvent, adding alkali, and stirring; 2) adding a palladium catalyst, stirring, adjusting to a reaction temperature for reaction, and adjusting the temperature to 20-30 DEG C after the reaction; and 3) acidizing, filtering, washing, dissolving, filtering and carrying out column chromatography to obtain 6, 6 '-diphenyl binaphthol. The method has the advantages that a palladium catalysis system of a single solvent is used, the types of reaction solvents are reduced, phosphine ligands and protective gas environments are not used any more, the operation difficulty is reduced, the use conditions of the reaction are greatly broadened, and meanwhile, the conversion rate is increased.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic synthesis, and particularly relates to a synthesis method of 6,6'-diphenylbinaphthol. BACKGROUND

[0002] 6,6'-diphenylbinaphthol is a compound that has important applications in materials, catalysis and other aspects, and has important applications in optical resin materials and synthesis of new catalysts.

[0003] de Vries, J. G., et al., Tetrahedron Letters (2001), 42(39). A synthesis strategy of protecting hydroxyl with MOMCl, coupling phenylmagnesium chloride with dibromobinaphthol catalyzed by dichlorobistriphenylphosphine nickel and then deprotecting, with a yield of 71%, but this method is complex and has been eliminated. Most of the existing technologies use 6,6'-dibromobinaphthol to couple with phenylboronic acid to obtain 6,6'-diphenylbinaphthol, such as: Kozlowski, Marisa C. et al., Organic Letters (2022), 24(45). Using dichloro(1,1'-bisdiphenylphosphinylferrocene) palladium as a catalyst, cesium carbonate as a base, water and tetrahydrofuran as a solvent, a catalytic system with a yield of 85%. Wang, Tianli. et al., Angewandte Chemie, International Edition (2021), 60(27). Using tetrakis(triphenylphosphine)palladium as a catalyst, potassium carbonate as a base, water and tetrahydrofuran as a solvent, a catalytic system with a yield of 75%. Moberg, Christina. Et al., Organometallics (2016), 35(11). Using palladium acetate and tri-o-tolylphosphine as a catalyst, potassium phosphate as a base, water and dioxane as a solvent, a catalytic system with a yield of 77%. These catalytic systems using phenylboronic acid as raw material all use mixed solvents, which have low reuse rate and are not conducive to environmental protection.

[0004] To solve this problem, a single-solvent palladium catalytic system is used, and a phosphine ligand and a protective gas environment are no longer used. This system can obtain the target 6,6'-diphenylbinaphthol with a yield better than that of the prior art. SUMMARY

[0005] To overcome the shortcomings of the prior art, the purpose of the present application is to provide a synthesis method of 6,6'-diphenylbinaphthol, which uses a single-solvent palladium catalytic system, reduces the operation difficulty and improves the conversion rate.

[0006] To achieve the above-mentioned purpose, the present application realizes the following technical scheme:

[0007] A method for synthesizing 6,6'-diphenylbinaphthol, comprising the following steps:

[0008] 1) adding 6,6'-dibromobinaphthol and phenylboronic acid into a solvent, adding a base, and stirring;

[0009] 2) adding a palladium catalyst, stirring, adjusting to a reaction temperature to carry out a reaction, and adjusting the temperature to 20-30 DEG C after the reaction;

[0010] 3) further acidifying, filtering, washing with water, dissolving, filtering, and column chromatography to obtain 6,6'-diphenylbinaphthol.

[0011] The mass ratio of 6,6'-dibromobinaphthol to phenylboronic acid is 1:2-1:3, and the mass ratio of 6,6'-dibromobinaphthol to the base is 1:2-1:12.

[0012] The base is one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium acetate, and potassium acetate.

[0013] The mass ratio of 6,6'-dibromobinaphthol to the palladium catalyst is 100:1-100:5.

[0014] The palladium catalyst is one of palladium acetate, palladium chloride, and tris(dibenzylideneacetone)dipalladium.

[0015] The mass ratio of 6,6'-dibromobinaphthol to the solvent is 1:5-1:20.

[0016] The solvent is one of water, methanol, ethanol, toluene, xylene, tetrahydrofuran, diethyl ether, dimethyl sulfoxide, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0017] The reaction temperature is 0-60 DEG C, and the reaction time is 1-6 hours.

[0018] Compared with the prior art, the present application has the following beneficial effects:

[0019] The palladium catalytic system using a single solvent reduces the types of reaction solvents, does not use phosphine ligands, and does not use a protective gas environment, thereby reducing the operation difficulty, greatly widening the use conditions of the reaction, and improving the conversion rate. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is the liquid phase spectrum of Example 1. DETAILED DESCRIPTION

[0021] The present application will be described in detail below with reference to the accompanying drawings, but it should be pointed out that the implementation of the present application is not limited to the following embodiments.

[0022] A method for synthesizing 6,6'-diphenyl binaphthol, 6,6'-dibromo binaphthol, phenyl boronic acid are added to a solvent, a base is added, stirring; a palladium catalyst is added, stirring, adjusting to the reaction temperature to react, after the reaction, cooling; then acidification, filtration, water washing, dissolution, filtration, column chromatography to obtain 6,6'-diphenyl binaphthol.

[0023] The reaction equation is:

[0024]

[0025] Example 1:

[0026] A 100 mL four-necked flask is added with water 40 g, 6,6-dibromo binaphthol 4.441 g (10 mmol), phenyl boronic acid 2.438 g (20 mmol), potassium carbonate 8.306 g (60 mmol), stirring for 15 minutes, then adding palladium acetate 22.4 mg (0.1 mmol), stirring at 25°C for 2 hours, then adding 1M concentration hydrochloric acid, acidifying to the water phase pH 4, then filtering out the precipitate. The precipitate is washed with 10 mL of water, then the solid is dissolved with 20 mL of tetrahydrofuran, dried with anhydrous sodium sulfate, then the precipitate and palladium black are removed by filtration, the organic phase is concentrated, then column chromatography is performed with n-hexane and ethyl acetate as the developing agent in a volume ratio of 5:1, to obtain the product 6,6-diphenyl binaphthol 3.911 g, with a yield of 89.2%, a purity of 99.02%, and the liquid chromatogram is shown in Figure 1 .

[0027] Example 2:

[0028] A 250 mL four-necked flask is added with water 80 g, 6,6-dibromo binaphthol 4.441 g (10 mmol), phenyl boronic acid 2.438 g (20 mmol), potassium carbonate 8.306 g (60 mmol), stirring for 15 minutes, then adding palladium acetate 22.4 mg (0.1 mmol), stirring at 25°C for 2 hours, then adding 1M concentration hydrochloric acid, acidifying to the water phase pH 4, then filtering out the precipitate. The precipitate is washed with 10 mL of water, then the solid is dissolved with 20 mL of tetrahydrofuran, dried with anhydrous sodium sulfate, then the precipitate and palladium black are removed by filtration, the organic phase is concentrated, then column chromatography is performed with n-hexane and ethyl acetate as the developing agent in a volume ratio of 5:1, to obtain the product 6,6-diphenyl binaphthol 3.605 g, with a yield of 82.2%, a purity of 98.91%.

[0029] Example 3:

[0030] Into a 100 mL four-necked flask, add toluene 40 g, 6,6-dibromo- chalcone 4.441 g (10 mmol), phenyl boronic acid 2.438 g (20 mmol), potassium carbonate 16.612 g (120 mmol), stir for 15 minutes, then add palladium acetate 22.4 mg (0.1 mmol), stir at 60 °C for 2 hours, then cool to 25 °C, add 1 M concentration hydrochloric acid, acidify to the water phase pH is 4, separate the water phase, use water 3*10 mL to wash the organic phase, add anhydrous sodium sulfate to the organic phase, dry, then filter out the precipitate and palladium black, concentrate the organic phase, then use n-hexane and ethyl acetate with a volume ratio of 5:1 as the developing agent for column chromatography, to obtain the product 6,6-diphenyl chalcone 3.140 g, yield 71.6%, purity 98.97%.

[0031] Example 4:

[0032] Into a 100 mL four-necked flask, add toluene 40 g, 6,6-dibromo- chalcone 4.441 g (10 mmol), phenyl boronic acid 2.438 g (20 mmol), potassium carbonate 16.612 g (120 mmol), stir for 15 minutes, then add palladium acetate 22.4 mg (0.1 mmol), stir at 60 °C for 2 hours, then cool to 25 °C, add 1 M concentration hydrochloric acid, acidify to the water phase pH is 4, separate the water phase, use water 3*10 mL to wash the organic phase, add anhydrous sodium sulfate to the organic phase, dry, then filter out the precipitate and palladium black, concentrate the organic phase, then use n-hexane and ethyl acetate with a volume ratio of 5:1 as the developing agent for column chromatography, to obtain the product 6,6-diphenyl chalcone 3.140 g, yield 71.6%, purity 98.97%.

[0033] Example 5:

[0034] Into a 100 mL four-necked flask, add toluene 40 g, 6,6-dibromo- chalcone 4.441 g (10 mmol), phenyl boronic acid 2.438 g (20 mmol), potassium carbonate 16.612 g (120 mmol), stir for 15 minutes, then add palladium acetate 22.4 mg (0.1 mmol), stir at 60 °C for 2 hours, then cool to 25 °C, add 1 M concentration hydrochloric acid, acidify to the water phase pH is 4, separate the water phase, use water 3*10 mL to wash the organic phase, add anhydrous sodium sulfate to the organic phase, dry, then filter out the precipitate and palladium black, concentrate the organic phase, then use n-hexane and ethyl acetate with a volume ratio of 5:1 as the developing agent for column chromatography, to obtain the product 6,6-diphenyl chalcone 3.140 g, yield 71.6%, purity 98.97%.

Claims

1. A method for synthesizing 6,6'-diphenylbinaphthol, characterized in that: The following steps are involved: 1) Add 6,6'-dibromobinaphthol and phenylboric acid to a solvent, add a base, and stir; 2) adding palladium catalyst, stirring, adjusting to reaction temperature for reaction, and adjusting the temperature to 20-30° C. after the reaction; 3) Acidification, filtration, water washing, dissolution, filtration, and column chromatography are then performed to obtain 6,6'-diphenylbinaphthol.

2. A method for synthesizing 6,6'-diphenylbinaphthol according to claim 1, characterized in that, The molar ratio of 6,6'-dibromobinaphthol to phenylboric acid is 1:2 to 1:3; the molar ratio of 6,6'-dibromobinaphthol to base is 1:2 to 1:

12.

3. A method for synthesizing 6,6'-diphenylbinaphthol according to claim 1, characterized in that, The alkali is one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium acetate and potassium acetate.

4. The method for synthesizing 6,6'-diphenylbinaphthol according to claim 1, wherein The molar ratio of the 6,6'-dibromobinaphthol to the palladium catalyst is 100:1 to 100:

5.

5. The method for synthesizing 6,6'-diphenylbinaphthol according to claim 1, wherein The palladium catalyst is one of palladium acetate, palladium chloride and tris(dibenzylideneacetone)dipalladium.

6. The method for synthesizing 6,6'-diphenylbinaphthol according to claim 1, wherein: The mass ratio of the 6,6'-dibromobinaphthol to the solvent is 1:5 to 1:

20.

7. The method for synthesizing 6,6'-diphenylbinaphthol according to claim 1, wherein: The solvent is one of water, methanol, ethanol, toluene, xylene, tetrahydrofuran, ether, dimethyl sulfoxide, N,N-dimethylformamide and N,N-dimethylacetamide.

8. The method for synthesizing 6,6'-diphenylbinaphthol according to claim 1, wherein: The reaction temperature is 0-60° C., and the reaction time is 1-6 hours.

Images