Luminescent nematic liquid crystal material as well as preparation method and application thereof

Abstract

The invention discloses a light-emitting nematic liquid crystal material as well as a preparation method and application thereof. The structural formula of the light-emitting nematic liquid crystal material is as shown in formula 1, wherein R1 independently represents C4-C10 straight chain or branched chain alkyl; r < 2 > independently represents a C3-C8 linear chain or branched chain alkyl group, and Ar represents an aryl group or a substituted aryl group. The chiral nematic liquid crystal is formed after the chiral inducer is added into the high-quantum-yield luminescent nematic liquid crystal material, and a high circular polarization luminescent asymmetric factor can be obtained. The chiral nematic liquid crystal formed by adding the chiral inducer into the luminous nematic liquid crystal has high luminous efficiency and high circular polarization luminous asymmetry factor. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a class of luminescent nematic liquid crystal materials, their preparation methods and applications, belonging to the field of organic luminescent materials. Background Art

[0002] Chiral liquid crystals (also known as chiral nematic liquid crystals) have self-organized helical superstructures and many unique optical activities, such as optical rotation, CD, and selective reflection, etc., and thus have attracted increasing attention. Compared with other types of chiral supramolecular assemblies, chiral nematic liquid crystals are easy to obtain and have low costs, and are ideal materials for obtaining a high circularly polarized luminescence asymmetry factor (glum, glum = 2×(IL–IR) / (IL+IR), -2 < glum < +2, where IL and IR represent the intensities of left-handed and right-handed circularly polarized light, respectively). It has wide application values in the fields of anti-counterfeiting and information security, chiral optical sensors, 3D optical displays, photoinduced asymmetric synthesis, organic light-emitting diodes, etc. Therefore, developing nematic liquid crystals with high luminescence quantum yields and constructing circularly polarized luminescent nematic liquid crystals by combining the characteristics of highly long-range ordered orientation of nematic liquid crystals with chiral inductors has important scientific significance and application values. Summary of the Invention

[0003] The purpose of the present invention is to provide a class of luminescent nematic liquid crystals with high quantum yields, their preparation methods and applications. The synthesis method of the luminescent nematic liquid crystals of the present invention is simple, the product yield is high, and large-scale preparation can be carried out; the chiral nematic liquid crystals formed by adding chiral inductors to the luminescent nematic liquid crystals of the present invention have a high circularly polarized luminescence asymmetry factor.

[0004] The nematic liquid crystals provided by the present invention have a structural formula as shown in Formula 1:

[0005]

[0006] In Formula 1, each R1 independently represents a straight-chain or branched-chain alkyl group with C4-C 10 ; each R2 independently represents a straight-chain or branched-chain alkyl group with C3-C8; the group Ar includes but is not limited to any one of the following groups:

[0007]

[0008] Among them, is the connection position.

[0009] Preferably, the nematic liquid crystals provided by the present invention include but are not limited to any one of the compounds shown in Formulas LC1-LC36:

[0010]

[0011]

[0012] The present invention further provides a method for preparing the nematic liquid crystal, comprising the following steps:

[0013] 1) Formula A R The compound shown is the same as formula B R The compound shown in the figure is reacted to obtain formula C R The compounds shown;

[0014]

[0015] 2) Formula C R The compound shown in the figure reacts with an isopropoxyboronic acid pinacol ester compound to obtain a compound of formula D R The compounds shown;

[0016]

[0017] 3) Formula E and D R The compounds shown in formula 1 are subjected to coupling reaction to obtain the nematic liquid crystal shown in formula 1;

[0018] Br-Ar-Br

[0019] Formula E

[0020] In formula E, Ar has the same meaning as above, and R1 and R2 have the same meanings as above.

[0021] In step 1) of the above method, the reaction is carried out in the presence of Pd(PPh3)4 and potassium carbonate;

[0022] The Pd(PPh3)4, the potassium carbonate and the formula A R The molar ratio of the compounds shown may be 0.1 to 0.01:6:1, preferably 0.01:6:1;

[0023] Formula A R Compound B R The molar ratio of the compound can be 1:1 to 4, preferably 1:1.5;

[0024] The reaction is carried out in a solvent; specifically, the solvent is a mixture of toluene, ethanol and water, preferably in a volume ratio of 4:2:1;

[0025] The reaction temperature may be 70 to 120° C., and the reaction time may be 5 to 12 hours, preferably 12 hours;

[0026] The reaction is carried out under the protection of an inert gas, and the inert gas is preferably nitrogen.

[0027] In step 2) of the above method, the reaction is carried out in the presence of n-butyl lithium and isopropoxy boric acid pinacol ester;

[0028] The n-butyl lithium, the isopropoxy boric acid pinacol ester and the R The molar ratio of the compounds shown may be 1 to 1.5:1.5:1, preferably 1.2:1.5:1;

[0029] The reaction is carried out in a solvent; preferably at least one of tetrahydrofuran and diethyl ether;

[0030] The reaction process is as follows: n-butyl lithium is added to the reaction system in sequence, the reaction temperature is -78°C, the reaction time can be 1 to 3 hours, preferably 3 hours, and then isopropoxyboronic acid pinacol ester is added for reaction, the reaction temperature is room temperature, and the reaction time is 12 to 36 hours;

[0031] The reaction is carried out under the protection of an inert gas, and the inert gas is preferably nitrogen.

[0032] In step 3) of the above method, the coupling reaction is carried out in the presence of Pd(PPh3)4 and potassium carbonate;

[0033] The molar ratio of the Pd(PPh3)4, the potassium carbonate and the compound represented by formula E may be 0.1 to 0.01:6:1, preferably 0.01:6:1;

[0034] The compound of formula E and D R The molar ratio of the compounds can be 1:2 to 4, preferably 1:2.2;

[0035] The coupling reaction is carried out in a solvent; specifically, the solvent is a mixture of toluene, ethanol and water, preferably, the volume ratio may be 4:2:1;

[0036] The coupling reaction temperature may be 70-120°C, preferably 90°C, and the reaction time may be 12-24 hours, preferably 24 hours;

[0037] The coupling reaction is carried out under the protection of an inert gas, and the inert gas is preferably nitrogen.

[0038] The chiral nematic liquid crystal formed by adding a chiral inducing agent to the high quantum yield luminescent nematic liquid crystal material provided by the present invention can obtain a high circularly polarized luminescent asymmetry factor.

[0039]

[0040] The chiral inducing agent may be R5011 or S5011, and the structural formula is shown above;

[0041] The mass ratio of the chiral inducing agent to the nematic liquid crystal is 1:5-20.

[0042] The present invention has the following advantages:

[0043] (1) The synthesis method of the nematic liquid crystal of the present invention is simple, the product yield is high, and it can be prepared on a large scale;

[0044] (2) The chiral nematic liquid crystal formed by adding a chiral inducing agent to the luminescent nematic liquid crystal of the present invention has high luminescence efficiency and high circularly polarized luminescence asymmetry factor. DETAILED DESCRIPTION

[0045] The present invention is further described in detail below in conjunction with specific embodiments, and the examples provided are only for illustrating the present invention, rather than for limiting the scope of the present invention. The examples provided below can be used as a guide for further improvements by those of ordinary skill in the art, and do not constitute a limitation of the present invention in any way.

[0046] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0047] Example 1. Preparation of the compound represented by formula LC1

[0048]

[0049]

[0050] (1) Under nitrogen protection, add compound A to a 500 mL double-necked round-bottom flask in sequence. R 1 554 mg (1.95 mmol), B R 1 1.71g (2.92mmol), Pd (PPh3) 4 225mg (0.195mmol), potassium carbonate 1.62g (11.5mmol), and 40mL toluene, 20mL ethanol, 10mL water, reflux at 70°C for 12 hours. After the reaction system is cooled to room temperature, 1000mL water and 1000mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), and 977mg of white powder is obtained. The white powder is C R 1, with a yield of 71%.

[0051] C R The structural confirmation data of 1 are as follows: HRMS (MALDI TOF) m / z calcd for C 46 H 59 BrO[M] +706.3749, found 706.3758.

[0052] (2) Under nitrogen protection, add compound C to a 250 mL double-necked round-bottom flask. R 1 900mg (1.38mmol) and 50mL anhydrous THF, add n-butyl lithium (2.5M n-hexane, 0.66mL, 1.65mmol) at -78°C and stir for 3h, then add isopropoxyboronic acid pinacol ester (385mg, 2.07mol) dropwise. After complete addition, the reaction is stirred at room temperature for 24h. After the reaction is completed, 500mL of water and 500mL of dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled to obtain a crude product. The crude product is purified by recrystallization with methanol to obtain 957mg of white powder. The white powder is D R 1, with a yield of 92%.

[0053] D R The structural confirmation data of 1 are as follows: HRMS (MALDI TOF) m / z calcd for C 52 H 71 BO3[M] + 754.5496, found 754.5482.

[0054] (3) Under nitrogen protection, 92 mg (0.39 mmol) of 1,4-dibromobenzene, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), to obtain 467mg of white powder. The white powder is LC1, and the yield is 90%.

[0055] The structural confirmation data of LC1 are as follows: HRMS (MALDI TOF) m / z calcd for C 98 H 122 O2[M] + 1332.0520, found 1332.0511.

[0056] Example 2, Preparation of the compound represented by formula LC2

[0057]

[0058] Under nitrogen protection, 112 mg (0.39 mmol) of 1,4-dibromonaphthalene, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), and 469mg of white powder is obtained. The white powder is LC2, and the yield is 87%.

[0059] The structural confirmation data of LC2 are as follows: HRMS (MALDI TOF) m / z calcd for C 102 H 124 O2[M] + 1381.9635, found 1381.9651.

[0060] Example 3, Preparation of the compound represented by formula LC3

[0061]

[0062] Under nitrogen protection, 127 mg (0.39 mmol) of compound 4,4'-dibromobiphenyl, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (3:1), to obtain 467mg of white powder. The white powder is LC3, and the yield is 85%.

[0063] The structural confirmation data of LC3 are as follows: HRMS (MALDI TOF) m / z calcd for C 104 H 126 O2[M] +1407.9791, found 1407.9805.

[0064] Example 4. Preparation of the compound represented by formula LC4

[0065]

[0066] Under nitrogen protection, 112 mg (0.39 mmol) of compound 5,8-dibromoquinoline, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), to obtain 458mg of white powder. The white powder is LC4, and the yield is 85%.

[0067] The structural confirmation data of LC4 are as follows: HRMS (MALDI TOF) m / z calcd for C 101 H 123 NO2[M] + 1382.9587, found 1382.9610.

[0068] Example 5. Preparation of the compound represented by formula LC5

[0069]

[0070] Under nitrogen protection, 151 mg (0.39 mmol) of compound 4,4-dibromoterphenyl, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (5:1), and 504mg of white powder is obtained. The white powder is LC5, and the yield is 87%.

[0071] The structural confirmation data of LC5 are as follows: HRMS (MALDI TOF) m / z calcd for C 110 H 130 O2[M] + 1484.0104, found 1484.0155.

[0072] Example 6. Preparation of the compound represented by formula LC6

[0073]

[0074] Under nitrogen protection, 112 mg (0.39 mmol) of compound 5,8-dibromoisoquinoline, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), to obtain 453mg of white powder. The white powder is LC6, and the yield is 84%.

[0075] The structural confirmation data of LC6 are as follows: HRMS (MALDI TOF) m / z calcd for C 101 H 123 NO2[M] + 1382.9587, found 1382.9546.

[0076] Example 7. Preparation of the compound represented by formula LC7

[0077]

[0078] Under nitrogen protection, 93 mg (0.39 mmol) of 2,5-dibromopyridine, D R1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), and 463mg of white powder is obtained. The white powder is LC7, and the yield is 89%.

[0079] The structural confirmation data of LC7 are as follows: HRMS (MALDI TOF) m / z calcd for C 97 H 121 NO2[M] + 1332.9431, found 1332.9428.

[0080] Example 8, Preparation of the compound represented by formula LC8

[0081]

[0082] Under nitrogen protection, 112 mg (0.39 mmol) of compound 5,8-dibromobenzopyrazine, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (3:1), to obtain 459mg of a turquoise powder. The turquoise powder is LC8, and the yield is 85%.

[0083] The structural confirmation data of LC8 are as follows: HRMS (MALDI TOF) m / z calcd for C 100 H 122 N2O2[M] + 1383.9540, found 1383.9574.

[0084] Example 9, Preparation of the compound represented by formula LC9

[0085]

[0086] Under nitrogen protection, 93 mg (0.39 mmol) of compound 2,5-dibromopyrazine, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (3:1), to obtain 447mg of cyan powder. The cyan powder is LC9, and the yield is 86%.

[0087] The structural confirmation data of LC9 are as follows: HRMS (MALDI TOF) m / z calcd for C 96 H 120 N2O2[M] + 1333.9383, found 1333.9372.

[0088] Example 10. Preparation of the compound represented by formula LC10

[0089]

[0090] Under nitrogen protection, 112 mg (0.39 mmol) of compound 3,7-dibromo-1,5-naphthyridine, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90℃ for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (3:1), and 470mg of cyan powder is obtained. The cyan powder is LC10, and the yield is 87%.

[0091] The structural confirmation data of LC10 are as follows: HRMS (MALDI TOF) m / z calcd for C 100 H 122 N2O2[M] +1383.9540, found 1383.9527.

[0092] Example 11, Preparation of the compound represented by formula LC11

[0093]

[0094] Under nitrogen protection, 286 mg (0.39 mmol) of 2,5-dibromoterephthalonitrile, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), to obtain 453mg of a turquoise powder. The turquoise powder is LC11, and the yield is 84%.

[0095] The structural confirmation data of LC11 are as follows: HRMS (MALDI TOF) m / z calcd for C 100 H 120 N2O2[M] + 1381.9383, found 1381.9356.

[0096] Example 12: Preparation of the compound represented by formula LC12

[0097]

[0098] Under nitrogen protection, 112 mg (0.39 mmol) of compound 3,8-dibromoquinoline, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), to obtain 475mg of white powder. The white powder is LC12, and the yield is 88%.

[0099] The structural confirmation data of LC12 are as follows: HRMS (MALDI TOF) m / z calcd for C 101 H 123 NO2[M] + 1382.9587, found 1382.9576.

[0100] Example 13. Preparation of the compound represented by formula LC13

[0101]

[0102] Under nitrogen protection, 131 mg (0.39 mmol) of 1,4-dibromoanthracene, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1) to obtain 474mg of white powder. The white powder is LC13, and the yield is 85%.

[0103] The structural confirmation data of LC13 are as follows: HRMS (MALDI TOF) m / z calcd for C 106 H 126 O2[M] + 1431.9791, found 1431.9782.

[0104] Example 14. Preparation of the compound represented by formula LC14

[0105]

[0106] Under nitrogen protection, 131 mg (0.39 mmol) of compound 3,8-dibromophenanthridine, D R1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (3:1), to obtain 497mg of white powder. The white powder is LC14, and the yield is 89%.

[0107] The structural confirmation data of LC14 are as follows: HRMS (MALDI TOF) m / z calcd for C 105 H 125 NO2[M] + 1432.9744, found 1432.9761.

[0108] Example 15. Preparation of the compound represented by formula LC15

[0109]

[0110] Under nitrogen protection, 131 mg (0.39 mmol) of compound 9,10-dibromoanthracene, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), and 491mg of white powder is obtained. The white powder is LC15, and the yield is 88%.

[0111] The structural confirmation data of LC15 are as follows: HRMS (MALDI TOF) m / z calcd for C 106 H 126 O2[M] + 1431.9791, found 1431.9754.

[0112] Example 16. Preparation of the compound represented by formula LC16

[0113]

[0114] Under nitrogen protection, 131 mg (0.39 mmol) of 2,7-dibromophenanthrene, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), to obtain 475mg of white powder. The white powder is LC16, and the yield is 85%.

[0115] The structural confirmation data of LC16 are as follows: HRMS (MALDI TOF) m / z calcd for C 106 H 126 O2[M] + 1431.9791, found 1431.9780.

[0116] Example 17. Preparation of the compound represented by formula LC17

[0117]

[0118] Under nitrogen protection, 131 mg (0.39 mmol) of 2,6-dibromoanthracene, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1) to obtain 458mg of white powder. The white powder is LC17, and the yield is 82%.

[0119] The structural confirmation data of LC17 are as follows: HRMS (MALDI TOF) m / z calcd for C 106 H 126 O2[M] + 1431.9791, found 1431.9775.

[0120] Example 18, Preparation of the compound represented by formula LC18

[0121]

[0122] Under nitrogen protection, 132 mg (0.39 mmol) of compound 3,8-dibromo-1,10-phenanthroline, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (3:1), to obtain 492mg of cyan powder. The cyan powder is LC18, and the yield is 88%.

[0123] The structural confirmation data of LC18 are as follows: HRMS (MALDI TOF) m / z calcd for C 104 H 124 N2O2[M] + 1433.9696, found 1433.9675.

[0124] Example 19, Preparation of the compound represented by formula LC19

[0125]

[0126] Under nitrogen protection, 132 mg (0.39 mmol) of compound 2,7-dibromophenazine, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (3:1), to obtain 481mg of cyan powder. The cyan powder is LC19, and the yield is 86%.

[0127] The structural confirmation data of LC19 are as follows: HRMS (MALDI TOF) m / z calcd for C 104 H 124 N2O2[M] + 1433.9696, found 1433.9705.

[0128] Example 20, Preparation of the compound represented by formula LC20

[0129]

[0130] Under nitrogen protection, 137 mg (0.39 mmol) of 2,7-dibromo-9,9-dimethylfluorene, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), and 497mg of white powder is obtained. The white powder is LC20, and the yield is 88%.

[0131] The structural confirmation data of LC20 are as follows: HRMS (MALDI TOF) m / z calcd for C 107 H 130 O2[M] + 1448.0104, found 1448.0125.

[0132] Example 21. Preparation of the compound represented by formula LC21

[0133]

[0134] Under nitrogen protection, 114 mg (0.39 mmol) of compound 4,7-dibromo-2,1,3-benzothiadiazole, D R1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (3:1), to obtain 477mg of yellow powder. The yellow powder is LC21, and the yield is 88%.

[0135] The structural confirmation data of LC21 are as follows: HRMS (MALDI TOF) m / z calcd for C 98 H 120 N2O2S[M] + 1389.9104, found 1389.9152.

[0136] Example 22, Preparation of the compound represented by formula LC22

[0137]

[0138] Under nitrogen protection, 108 mg (0.39 mmol) of compound 4,7-dibromo-2,1,3-benzoxadiazole, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (3:1), to obtain 466mg of yellow powder. The yellow powder is LC22, and the yield is 87%.

[0139] The structural confirmation data of LC22 are as follows: HRMS (MALDI TOF) m / z calcd for C 98 H 120 N2O3[M] + 1373.9333, found 1373.9321.

[0140] Example 23. Preparation of the compound represented by formula LC23

[0141]

[0142] Under nitrogen protection, 133 mg (0.39 mmol) of compound 4,7-dibromo-2,1,3-benzoselenadiazole, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (3:1), to obtain 477mg of orange powder. The orange powder is LC23, and the yield is 85%.

[0143] The structural confirmation data of LC23 are as follows: HRMS (MALDI TOF) m / z calcd for C 98 H 120 N2O2Se[M] + 1437.8549, found 1437.8565.

[0144] Example 24. Preparation of the compound represented by formula LC24

[0145]

[0146] Under nitrogen protection, 197 mg (0.39 mmol) of compound 4,7-bis(5-bromo-2-thienyl)-2,1,3-benzoselenadiazole, D R 1 649mg (0.86mmol), Pd (PPh3) 445mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (3:1), and 543mg of red powder is obtained. The red powder is LC24, and the yield is 87%.

[0147] The structural confirmation data of LC24 are as follows: HRMS (MALDI TOF) m / z calcd for C 106 H 124N2O2S2Se[M] + 1601.8303, found 1601.8287.

[0148] Example 25. Preparation of the compound represented by formula LC25

[0149]

[0150] Under nitrogen protection, 179 mg (0.39 mmol) of compound 4,7-bis(5-bromo-2-thienyl)-2,1,3-benzoselenadiazole, D R 1 649mg (0.86mmol), Pd (PPh3) 445mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (3:1), and 509mg of red powder is obtained. The red powder is LC25, and the yield is 84%.

[0151] The structural confirmation data of LC25 are as follows: HRMS (MALDI TOF) m / z calcd for C 106 H 124 N2O2S3[M] + 1553.8858, found 1553.8867.

[0152] Example 26. Preparation of the compound represented by formula LC26

[0153]

[0154] Under nitrogen protection, 172 mg (0.39 mmol) of compound 4,7-bis(5-bromo-2-thienyl)-2,1,3-benzoxadiazole, D R1 649mg (0.86mmol), Pd (PPh3) 445mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (3:1), and 516mg of red powder is obtained. The red powder is LC26, and the yield is 86%.

[0155] The structural confirmation data of LC26 are as follows: HRMS (MALDI TOF) m / z calcd for C 106 H 124 N2O3S2[M] + 1537.9087, found 1537.9061.

[0156] Example 27. Preparation of the compound represented by formula LC27

[0157]

[0158] Under nitrogen protection, 133 mg (0.39 mmol) of compound 3,7-dibromodibenzothiophene, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), and 499mg of white powder is obtained. The white powder is LC27, and the yield is 89%.

[0159] The structural confirmation data of LC27 are as follows: HRMS (MALDI TOF) m / z calcd for C 104 H 124 O2S[M] + 1437.9356, found 1437.9381.

[0160] Example 28, Preparation of the compound represented by formula LC28

[0161]

[0162] Under nitrogen protection, 127 mg (0.39 mmol) of compound 3,7-dibromodibenzofuran, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), and 482mg of white powder is obtained. The white powder is LC28, and the yield is 87%.

[0163] The structural confirmation data of LC28 are as follows: HRMS (MALDI TOF) m / z calcd for C 104 H 124 O3[M] + 1421.9584, found 1421.9568.

[0164] Example 29. Preparation of the compound represented by formula LC29

[0165]

[0166] Under nitrogen protection, 148 mg (0.39 mmol) of compound 3,7-dibromodibenzoselenol, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), and 498mg of white powder is obtained. The white powder is LC29, and the yield is 86%.

[0167] The structural confirmation data of LC29 are as follows: HRMS (MALDI TOF) m / z calcd for C 104 H 124 O2Se[M] +1485.8800, found 1485.8838.

[0168] Example 30, Preparation of the Compound Represented by Formula LC30

[0169]

[0170] Under nitrogen protection, 156 mg (0.39 mmol) of 2,7-dibromo-9-phenylcarbazole, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), to obtain 484mg of white powder. The white powder is LC30, and the yield is 83%.

[0171] The structural confirmation data of LC30 are as follows: HRMS (MALDI TOF) m / z calcd for C 110 H 129 NO2[M] + 1497.0057, found 1497.0028.

[0172] Example 31, Preparation of the compound represented by formula LC31

[0173]

[0174] Under nitrogen protection, 132 mg (0.39 mmol) of 2,7-dibromo-9-methylcarbazole, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), to obtain 476mg of white powder. The white powder is LC31, and the yield is 85%.

[0175] The structural confirmation data of LC31 are as follows: HRMS (MALDI TOF) m / z calcd for C 105 H 127 NO2[M] + 1434.9900, found 1434.9875.

[0176] Example 32, Preparation of the compound represented by formula LC32

[0177]

[0178] Under nitrogen protection, 143 mg (0.39 mmol) of 2,7-dibromo-9-ethylcarbazole, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), to obtain 496mg of white powder. The white powder is LC32, and the yield is 87%.

[0179] The structural confirmation data of LC32 are as follows: HRMS (MALDI TOF) m / z calcd for C 107 H 131 NO2[M] + 1463.0213, found 1463.0248.

[0180] Example 33. Preparation of the compound represented by formula LC33

[0181]

[0182] Under nitrogen protection, 151 mg (0.39 mmol) of 2,8-dibromo-fused dinaphthalene, D R1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1) to obtain 491mg of white powder. The white powder is LC33, and the yield is 85%.

[0183] The structural confirmation data of LC33 are as follows: HRMS (MALDI TOF) m / z calcd for C 110 H 128 O2[M] + 1481.9948, found 1481.9921.

[0184] Example 34. Preparation of the compound represented by formula LC34

[0185]

[0186] Under nitrogen protection, 151 mg (0.39 mmol) of compound 6,12-dibromo-fused dinaphthalene, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), to obtain 480mg of white powder. The white powder is LC34, and the yield is 83%.

[0187] The structural confirmation data of LC34 are as follows: HRMS (MALDI TOF) m / z calcd for C 110 H 128 O2[M] + 1481.9948, found 1481.9959.

[0188] Example 35. Preparation of the compound represented by formula LC35

[0189]

[0190] Under nitrogen protection, 140 mg (0.39 mmol) of 2,7-dibromopyrene, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), to obtain 488mg of white powder. The white powder is LC35, and the yield is 86%.

[0191] The structural confirmation data of LC35 are as follows: HRMS (MALDI TOF) m / z calcd for C 108 H 126 O2[M] + 1455.9791, found 1455.9805.

[0192] Example 36. Preparation of the compound represented by formula LC36

[0193]

[0194] Under nitrogen protection, 140 mg (0.39 mmol) of 1,6-dibromopyrene, D R 1 649mg (0.86mmol), Pd(PPh3)4 45mg (0.039mmol), potassium carbonate 324mg (2.3mmol), and 8mL toluene, 4mL ethanol, 2mL water, reflux at 90°C for 24 hours. After the reaction system is cooled to room temperature, 300mL water and 300mL dichloromethane are added thereto for extraction. The organic phase after extraction is dried with anhydrous sodium sulfate, filtered, and then the organic liquid phase is distilled off to obtain a crude product. The crude product is purified by column chromatography, and the elution solvent is petroleum ether: dichloromethane (4:1), to obtain 483mg of white powder. The white powder is LC36, and the yield is 85%.

[0195] The structural confirmation data of LC36 are as follows: HRMS (MALDI TOF) m / z calcd for C 108 H 126 O2[M] + 1455.9791, found 1455.9780.

[0196] Example 37: Preparation of Chiral Nematic Liquid Crystal

[0197] The chiral nematic liquid crystals obtained in Examples 1 to 36 of the present invention are added with a chiral inducing agent to form the chiral nematic liquid crystals, and their performance is evaluated.

[0198] (I) The steps for preparing chiral nematic liquid crystal by adding a chiral inducing agent to the nematic liquid crystal are as follows:

[0199] Dissolve 20-50 mg of sample (LC1-LC36: R5011 or S5011 = 9:1) in 1.0 mL of toluene. Stir at room temperature for 1 hour. Then, spin-coat the mixed solution on a quartz plate (3 cm × 3 cm) at 3000 rpm for 60 s to form a chiral nematic liquid crystal film.

[0200] (ii) Performance evaluation of chiral nematic liquid crystals prepared by adding chiral inducers R5011 or S5011 to nematic liquid crystals LC1 to LC36: The fluorescence quantum yield of the prepared chiral nematic liquid crystal film was measured using an integrating sphere method; the circularly polarized luminescence asymmetry factor was measured using a JASCO CPL-300 spectrometer.

[0201] The prepared chiral nematic liquid crystal film has a fluorescence quantum yield and a circularly polarized luminescence asymmetry factor (g lum ) as shown in Table 1 and Table 2.

[0202] Table 1 Performance data of adding chiral perturbant R5011 to nematic liquid crystal prepared from Examples 1-36

[0203]

[0204] Table 2 Performance data of adding chiral perturbant S5011 to nematic liquid crystal prepared from Examples 1-36

[0205]

[0206]

[0207] It can be seen from the data in Table 1 and Table 2 that the film formed by the chiral nematic liquid crystal of the present invention has high fluorescence quantum efficiency and high circularly polarized luminescence asymmetry factor, and has wide application value in the fields of anti-counterfeiting and information security, hand light sensors, 3D optical displays, light-induced asymmetric synthesis, organic light-emitting diodes, etc.

[0208] The present invention has been described in detail above. For those skilled in the art, without departing from the purpose and scope of the present invention, and without the need to carry out unnecessary experimental conditions, the present invention can be implemented in a wide range under equivalent parameters, concentrations and conditions. Although the present invention provides specific embodiments, it should be understood that the present invention can be further improved. In a word, according to the principles of the present invention, the application is intended to include any changes, uses or improvements to the present invention, including departure from the disclosed scope in the application, and changes made with conventional techniques known in the art.

Claims

1. Formula C R The compounds shown; Formula C R In the above, R1 each independently represents C4-C 10 R2 each independently represents a C3-C8 straight chain or branched chain alkyl group.

2. Formula D R The compounds shown; Formula D R In the above, R1 each independently represents C4-C 10 R2 each independently represents a C3-C8 straight chain or branched chain alkyl group.

3. A nematic liquid crystal, the structural formula of which is shown in Formula 1; Formula C R In the above, R1 each independently represents C4-C 10 R2 each independently represents a C3-C8 straight chain or branched chain alkyl group; Ar represents an aryl group or a substituted aryl group.

4. The nematic liquid crystal according to claim 3, characterized in that: Ar is selected from but not limited to any one of the following groups: in, For the connection location.

5. The nematic liquid crystal according to claim 3 or 4, characterized in that: The nematic liquid crystal represented by Formula 1 includes but is not limited to any one of the compounds represented by Formulas LC1-LC36:

6. The method for preparing the nematic liquid crystal according to any one of claims 3 to 5, comprising the following steps: The compound represented by formula E and the compound represented by formula D in claim 2 R The compounds shown in formula 1 are subjected to coupling reaction to obtain the nematic liquid crystal shown in formula 1; Br-Ar-Br Formula E In Formula E, Ar is defined the same as Ar in Formula 1.

7. The preparation method according to claim 6, characterized in that: The coupling reaction is carried out in the presence of Pd(PPh3)4 and potassium carbonate; The molar ratio of the Pd(PPh3)4, the potassium carbonate and the compound represented by formula E is 0.1-0.01:6:1; The compound represented by formula E and formula D R The molar ratio of the compounds shown is 1:2-4; The coupling reaction is carried out in a solvent, and the solvent is a mixture of toluene, ethanol and water; The coupling reaction temperature is 70-120°C and the time is 12-24 hours; The coupling reaction is carried out under the protection of inert gas.

8. The preparation method according to claim 6 or 7, characterized in that: Claim 1 Chinese formula C R The compound shown in the figure reacts with an isopropoxyboronic acid pinacol ester compound to obtain a compound of formula D R The compounds shown; The reaction is carried out in the presence of n-butyl lithium and isopropoxy boric acid pinacol ester; The n-butyl lithium, the isopropoxy boric acid pinacol ester and the formula C R The molar ratio of the compounds shown is 1 to 1.5:1.5:1; The reaction is carried out in a solvent, and the solvent is at least one of tetrahydrofuran and diethyl ether; The reaction process is as follows: n-butyl lithium is sequentially added into the reaction system, reacted at -78°C for 1 to 3 hours, and then isopropoxyboronic acid pinacol ester is added, reacted at room temperature for 12 to 36 hours. The reaction is carried out under the protection of inert gas.

9. The preparation method according to claim 8, characterized in that: Formula A R The compound shown is the same as formula B R The compound shown in the figure is reacted to obtain formula C R The compounds shown; Wherein, R1 and R2 are defined as in Formula C R ; The reaction is carried out in the presence of Pd(PPh3)4 and potassium carbonate; The Pd(PPh3)4, the potassium carbonate and the formula A R The molar ratio of the compounds shown is 0.1-0.01:6:1; Formula A R The compounds shown are R The molar ratio of the compounds shown is 1:1 to 4; The reaction is carried out in a solvent, which is a mixture of toluene, ethanol and water; The reaction temperature is 70-120°C, and the reaction time is 5-12 hours; The reaction is carried out under the protection of inert gas.

10. A chiral nematic liquid crystal, consisting of the nematic liquid crystal described in any one of 3-5 and a chiral inducing agent.

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