CN112724374B

CN112724374B - Preparation of novel conjugated microporous polymer based on boron-containing fluorescent dye and photocatalytic application of novel conjugated microporous polymer

Info

Publication number: CN112724374B
Application number: CN202011485085.9A
Authority: CN
Inventors: 贡卫涛; 邓潇荣
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 2020-12-16
Filing date: 2020-12-16
Publication date: 2021-10-22
Anticipated expiration: 2040-12-16
Also published as: CN112724374A

Abstract

The invention belongs to the technical field of fine chemical engineering, and discloses preparation and photocatalytic application of a novel conjugated microporous polymer based on a boron-containing fluorescent dye. The polymer is prepared by a Sonogashira-Hagihara reaction, a boron-containing fluorescent dye structure is introduced into 1,3, 5-tri (difluoroboroxy) -2,4, 6-tri ((4-bromophenylimino) methyl) -benzene to increase the photocatalytic performance, and 1,3, 5-tri (difluoroboroxy) -2,4, 6-tri ((4-bromophenylimino) methyl) -benzene and 1,3, 5-tri- (4-ethynylphenyl) benzene are added into a Schlenk tube and react for 48-72h at 80 ℃ under the protection of nitrogen, so that the novel catalyst based on the boron-containing fluorescent dye is obtained. The catalyst prepared by the invention has good chemical and thermal stability and higher catalytic performance, and the catalytic yield of the p-benzylamine derivative can reach more than 99%.

Description

Preparation of novel conjugated microporous polymer based on boron-containing fluorescent dye and photocatalytic application of novel conjugated microporous polymer

Technical Field

The invention relates to the technical field of fine chemical engineering, in particular to preparation of a novel conjugated microporous polymer based on boron-containing fluorescent dye and photocatalytic application thereof.

Background

Energy crisis and environmental pollution have become worldwide problems. One of the main reasons is the use of fossil fuels, a non-renewable energy source. Solar energy has been the focus of research as a clean and renewable energy source due to its advantages of abundant reserves and no pollution. Among them, photocatalysis is a relatively successful and effective example of the use of solar energy, while conventional inorganic semiconductors are one of the relatively mature examples of applications. However, in the field of photocatalysis, they are also limited by low catalytic efficiency and single structural properties. Therefore, developing a novel material with high specific surface area, adjustable structure and good stability as a high-efficiency photocatalyst has important significance, and is a great challenge for researchers.

The boron-containing dye has good luminescence characteristics such as high light and chemical stability, high molar extinction coefficient, high absorption and emission, high fluorescence quantum yield and the like, so that the application of the complex in the field of organic functional materials is rapidly developed due to the excellent properties, but the complex is difficult to separate and has low reusability as a homogeneous catalyst, and further application of the complex is limited. The boron-containing conjugated porous polymer has been developed to a certain extent due to the combination of the advantages of the porous material and the boron-containing dye, and has become one of the most promising functional materials due to the adjustable geometric structure, the unique Lewis acid boron center and the very abundant physical properties, such as high specific surface, charged scaffold, strong photoluminescence, intramolecular charge transfer and the like.

The boron-containing polymer synthesized at present is an organic porous polymer mainly based on boron dipyrromethene (BODIPY) derivatives, which shows abundant photophysical properties including high absorption coefficient, good fluorescence quantum yield and relatively narrow absorption and emission bands, so that the boron-containing polymer is an important functional building group and is applied to aspects of organic solar cells, organic light-emitting diodes, sensing, imaging and the like. However, another organic porous polymer containing the boron dye aniline and its corresponding boron difluoride complex (Boranil) has not been reported. Researches find that the heterocyclic ring in the Boranil can effectively increase the conjugated region, so that the fluorescence emitted by the series of complexes can be observed by naked eyes, and meanwhile, the ultraviolet absorption and fluorescence intensity of the compounds are greatly improved, so that the application of the Boranil compounds in fluorescent materials has great potential. Therefore, there is a need to design and synthesize a Boranil-based conjugated microporous polymer and use it as a high-efficiency photocatalyst.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide preparation of a novel conjugated microporous polymer based on boron-containing fluorescent dye and photocatalytic application thereof. The polymer catalyst prepared by the invention has good chemical and thermal stability and higher catalytic performance, and the catalytic yield of the p-benzylamine derivative can reach more than 99%. The design of heterogeneous catalysts provides a more efficient process and direction of research.

The above purpose of the invention is realized by the following technical scheme:

a novel boron-containing fluorescent dye-based conjugated microporous polymer has a structure shown in formula I:

a benzylamine compound has a structural formula shown in formula II:

in the formula, R is H, Me or OMe or F or Cl.

According to the preparation method of the novel boron-containing fluorescent dye-based conjugated microporous polymer, the polymer is prepared through a Sonogashira-Hagihara reaction, a boron-containing fluorescent dye structure is introduced into 1,3, 5-tri (difluoroboroxy) -2,4, 6-tri ((4-bromophenylimino) methyl) -benzene to increase the photocatalytic performance, 1,3, 5-tri (difluoroboroxy) -2,4, 6-tri ((4-bromophenylimino) methyl) -benzene and 1,3, 5-tri- (4-ethynylphenyl) benzene are added into a Schlenk tube and react for 48-72 hours at 80 ℃ under the protection of nitrogen, and the catalyst based on the boron-containing fluorescent dye is obtained.

Further, a preparation method of the novel conjugated microporous polymer based on the boron-containing fluorescent dye comprises the following specific steps:

(1) preparation of compound a:

under the protection of argon, hexamethylenetetramine and phloroglucinol are sequentially added into a 250mL schlenk bottle. Then 30-50mL of trifluoroacetic acid is added into an ice water bath, the reaction mixture is placed in an oil bath at 90-110 ℃ and stirred for 3-6 hours at constant temperature, then 60-80mL of 3M hydrochloric acid is added into a schlenk bottle, and the heating and stirring are continued for 2-4 hours. After the reaction is finished, purifying to obtain a monomer structure compound A, wherein the structural formula of the monomer structure compound A is shown as a formula IV;

preparation of compound a the reaction formula is shown below:

(2) preparation of Compound B

Under the protection of argon, p-bromobenzylamine and the monomer compound A are sequentially added into a 50mL schlenk bottle. Then adding an organic solvent, and placing the reaction mixture in an oil bath at the temperature of 90-110 ℃ and stirring at constant temperature for 48-72 hours. After the reaction is finished, purifying to obtain a monomer structure compound B, wherein the structural formula of the monomer structure compound B is shown as a formula V;

preparation of compound B the reaction formula is shown below:

(3) preparation of Compound C

Monomer compound B was added to the schlenk bottle at 0 ℃ atmosphere. Pure boron trifluoride diethyl etherate was then added. Lithium diisopropylamide was added dropwise. The mixture was stirred at room temperature under argon for 12-48 hours. After the reaction is finished, purifying to obtain a monomer structure compound C, wherein the structural formula of the monomer structure compound C is shown as a formula VI;

preparation of compound C the reaction scheme is shown below:

(4) preparation of Compound D

4-bromoacetophenone and p-toluenesulfonic acid were thoroughly ground in a mortar and 4-aminobenzonitrile was added to the schlenk bottle. Then trifluoromethanesulfonic acid was added dropwise. The mixture was transferred to a 100mL round bottom flask and stirred at 130-150 ℃ for 24-48 hours. After the reaction is finished, purifying to obtain a monomer structure compound D, wherein the structural formula of the monomer structure compound D is shown as a formula VII;

preparation of compound D the reaction scheme is shown below:

(5) preparation of Compound E

The monomer compound D, copper iodide, triphenylphosphine and bis (triphenylphosphine) palladium chloride were added to a 250mL schlenk bottle in this order under an argon atmosphere. Then the organic solvent is added. The mixture was stirred at 40-60 ℃ for 20-40 minutes under argon. Then under the protection of argon gas, dropwise adding trimethylsilyl acetylene, and stirring at 80-120 ℃ for 24-48 hours. After the reaction is finished, purifying to obtain a monomer structure compound E, wherein the structural formula of the monomer structure compound E is shown as a formula VIII;

preparation of compound E the reaction scheme is shown below:

(6) preparation of Compound F

Monomer compound E was added to a 100mL round bottom flask. Then adding dichloromethane/methanol solution with the volume ratio of 1: 1-4. Solid potassium carbonate was then added. The mixture was stirred at room temperature for 12-48 hours. After the reaction is finished, purifying to obtain

The structural formula of the monomer structural compound F is shown as a formula IX;

preparation of compound F the reaction scheme is shown below:

(7) compound C, compound F, tetrakis (triphenylphosphine) palladium and copper iodide were added in succession to a 100mL schlenk bottle under argon protection. Then 5-30mL of N, N-dimethylformamide/triethylamine in a volume ratio of 2:1 were added and degassed in schlenk bottles by three freeze-thaw cycles. Then, the reaction mixture was stirred in an oil bath at 80-100 ℃ for 48-72 hours at constant temperature. Purifying after the reaction is finished to obtain a novel catalyst based on the boron-containing fluorescent dye;

the mole ratio of the hexamethylene tetramine to the phloroglucinol in the step (1) is as follows: 1-1.5:1.

The molar ratio of the p-bromobenzylamine in the step (2) to the monomer compound A is 3-4: 1. The organic solvent is ethanol.

The molar ratio of the monomer compound B and the lithium diisopropylamide in the step (3) is 1: 4-10.

The molar ratio of the 4-bromobenzophenone to the p-toluenesulfonic acid in the step (4) is 8-10: 1.

The molar ratio of the monomer compound D in the step (5), copper iodide, triphenylphosphine, bis (triphenylphosphine) palladium chloride and trimethylsilyl acetylene is 40:1:4:2: 180. The organic solvent is triethylamine.

The molar ratio of the monomer compound E and the solid potassium carbonate in the step (6) is 1: 4-8.

And (3) the molar ratio of the compound C, the compound F, the tetrakis (triphenylphosphine) palladium and the copper iodide in the step (7) is 25:25:2: 1.

Further, after the reaction in the step (7) was completed, the reaction mixture was filtered, the solid was washed with an organic solvent several times, and finally, the crude product was extracted with an organic solvent in a soxhlet extractor for 24 hours and dried under vacuum at 120 ℃ overnight to obtain a reddish brown solid powder catalyst. And repeatedly washing the solid generated by the reaction with an organic solvent for multiple times, specifically, respectively adding acetone, N, N-dimethylformamide, tetrahydrofuran and water into the solid generated by the reaction for washing. The organic solvent used in the Soxhlet extractor is tetrahydrofuran and methanol.

The catalyst prepared by the preparation method is applied to catalyzing amine oxide coupling reaction and thioether oxidation reaction.

A test method for catalyzing amine oxide coupling reaction:

adding the catalyst prepared by the method and benzylamine with different substituents into an organic solvent according to a certain proportion, irradiating by using a 26W blue LED lamp at room temperature and in the air, and stirring. By TLC and¹the reaction progress was monitored by H NMR and stopped after disappearance of the starting material. The catalyst was then removed by centrifugation, filtration and the filtrate was concentrated and evaporated to give the crude product. Crude product is taken¹H NMR, ratio of integrated peaks of starting material and product and by-product was used to calculate yield and conversion.

The benzyl amine with different substituents is 4-methylbenzylamine, 4-methoxyaniline, 4-fluorobenzylamine and 4-chloro-benzylamine. The organic solvent is acetonitrile. The ratio of the catalyst to benzylamine is 0.5%: 1.

compared with the prior art, the invention has the beneficial effects that:

the invention has the advantages and effects that the novel conjugated microporous polymer based on the boron-containing fluorescent dye can be prepared by utilizing the Sonogashira-Hagihara coupling reaction, the boron fluorescent group is introduced into the structure as a key light collecting part and an electron absorbing body, the transfer of energy and electrons is effectively regulated and controlled, the catalytic performance of the catalyst is improved, and the yield of the catalytic amine oxide coupling reaction is up to 99%. And the catalytic reaction has mild reaction conditions, green, simple and convenient reaction, high yield and wide application range. The compound generated by catalysis has stable structure and higher application value.

Drawings

The invention is further illustrated with reference to the following figures and examples:

FIG. 1 is an infrared spectrum of the polymer prepared in example 1.

FIG. 2 is N of the polymer prepared in example 1₂Adsorption-removal of attached figure.

FIG. 3 is a graph showing the pore size distribution of the polymer prepared in example 1.

FIG. 4 is a solid nuclear magnetic map of the polymer prepared in example 1.

FIG. 5 is a thermogram of the polymer prepared in example 1.

FIG. 6 is an XPS plot of the polymer prepared in example 1.

FIG. 7 is an SEM photograph of the polymer prepared in example 1.

FIG. 8 is a solid UV picture of the polymer prepared in example 1.

Detailed Description

The invention is described in more detail below with reference to specific examples, without limiting the scope of the invention. Unless otherwise specified, the experimental methods adopted by the invention are all conventional methods, and experimental equipment, materials, reagents and the like used in the experimental method can be obtained from commercial sources.

Example 1

A preparation method of a novel catalyst based on boron-containing fluorescent dye comprises the following steps:

(1) preparation of compound a: 2,4, 6-trihydroxy-1, 3, 5-benzenetricarboxylic acid;

hexamethylenetetramine (7.549g, 54mmol) and phloroglucinol (3.007g, 24.5mmol) were added successively to a 250mL Schlenk bottle under argon. Then 45mL of trifluoroacetic acid was added to the ice-water bath and the reaction mixture was stirred in a 100 ℃ oil bath for 4 hours at constant temperature, then 75mL of 3M hydrochloric acid was added to the schlenk flask and stirring was continued with heating for 3 hours. After the reaction was complete, the mixture was cooled to room temperature and the suspension was filtered. Dichloromethane (3 × 50mL) was then added to the filtrate, the two phases were separated, and the organic layer was dried over anhydrous magnesium sulfate and filtered. The solvent was evaporated by rotation to give a yellow solid. Finally, the resulting yellow solid was washed with hot ethanol to give the purified orange solid product compound a.

(2) Preparation of compound B: 2,4, 6-tris ((4-bromophenylamino) methylene) cyclohexane-1, 3, 5-trione;

para-bromobenzylamine (210mg, 1mmol) and 2,4, 6-trihydroxy-1, 3, 5-benzenetricarboxylic acid (860mg, 5mmol) were added to a 50mL Schlenk bottle in this order under the protection of argon. Then, 15mL of an absolute ethanol solution was added, and the reaction mixture was stirred in an oil bath at 90 ℃ for 48 hours at a constant temperature. After the reaction was completed, it was cooled to room temperature, and the suspension was filtered, followed by washing the precipitate with hot ethanol. The resulting solid product was dried under vacuum at 60 ℃ for 12 hours to give compound B as a bright yellow solid.

(3) Preparation of compound C: 1,3, 5-tris (difluoroboryloxy) -2,4, 6-tris ((4-bromophenylimino) methyl) -benzene;

2,4, 6-Tris ((4-bromophenylamino) methylene) cyclohexane-1, 3, 5-trione (335.5mg, 0.5mmol) was charged to a 50mL Schlenk's flask under argon and neat boron trifluoride etherate (13mL) was added. The reaction mixture was stirred for 5 minutes and cooled to 0 ℃. Lithium diisopropylamide (10mmol in 1M THF) was then added dropwise. The mixture was stirred at room temperature for 24 hours under argon. After this time, the reaction was cooled to 0 ℃ and quenched by the addition of water (60 mL). The solid product was isolated by filtration, washed with water and methanol, and dried under vacuum at 60 ℃ for 12 hours. Compound C was obtained as a bright yellow solid.

(4) Preparation of compound D: 1,3, 5-tris (4-bromophenyl) benzene;

4-bromoacetophenone (1g, 5.02mmol) and p-toluenesulfonic acid (0.1g, 0.58mmol) were placed in a mortar and ground well. Then transferred to a 100mL round bottom flask and the mixture was heated at 140 ℃ for 24 hours. After that, the reaction mixture was washed with a saturated sodium carbonate solution and extracted with dichloromethane. The organic phase was dried over anhydrous magnesium sulfate, the solvent was removed under rotary vacuum, and the crude product was washed with diethyl ether to give compound D as a brown solid.

(5) Preparation of compound E: 1,3, 5-tris- (4-trimethylsilylethynylphenyl) benzene;

1,3, 5-tris (4-bromophenyl) benzene (1g, 1.83mmol), copper iodide (10.52mg, 0.053mmol), triphenylphosphine (48.27mg, 0.183mmol) and bis (triphenylphosphine) palladium chloride (64.6mg, 0.09mmol) were added to a 250mL Schlenk flask, in that order, under an argon atmosphere. Triethylamine (80mL) was then added. The mixture was stirred at 50 ℃ for 30 minutes under argon. Trimethylsilylacetylene (1.13mL, 8.27mmol) was then added dropwise under argon and stirred at 100 ℃ for 36 hours. After the reaction was complete, the solvent was removed under rotary vacuum and the crude product was purified by column chromatography using Petroleum Ether (PE) as eluent. Compound E was obtained as a white solid.

(6) Preparation of compound F: 1,3, 5-tris- (4-ethynylphenyl) benzene;

1,3, 5-tris- (4-trimethylsilylethynyl phenyl) benzene (2.0g, 3.36mmol) was added to a 100mL round bottom flask. Then a 1:1 volume ratio dichloromethane/methanol solution was added. Solid potassium carbonate (2.04g, 14.76mmol) was then added. The mixture was stirred at room temperature for 24 hours. After completion of the reaction, water (80ml) was added to the reaction mixture, followed by extraction with methylene chloride three times. The organic phase was removed in rotary vacuum and the crude product was purified by column chromatography using Petroleum Ether (PE) as eluent. Compound F was obtained as a white solid.

The reaction equations of the step (1), the step (2), the step (3), the step (4), the step (5) and the step (6) are as follows:

(7) preparing a novel conjugated microporous polymer based on a boron-containing fluorescent dye;

compound C (250mg, 0.31mmol), compound F (116mg, 0.31mmol), tetrakis (triphenylphosphine) palladium (60mg, 0.05mmol) and copper iodide (24mg, 0.126mmol) were added sequentially under argon into a 100mL schlenk flask. Then 35mL of 2:1 by volume N, N-dimethylformamide/triethylamine were added and degassed in a Schlenk flask by three freeze-thaw cycles. Thereafter, the reaction mixture was stirred in an oil bath at 80 ℃ for 72 hours at constant temperature. After the reaction is finished, the reaction mixture is filtered, the solid is washed for a plurality of times by using organic solvents such as acetone, N, N-dimethylformamide, tetrahydrofuran, water and the like, and finally, the crude product is respectively extracted by using tetrahydrofuran and methanol in a Soxhlet extractor for 24 hours and is dried in vacuum at 60 ℃ overnight, so that the reddish brown solid powder catalyst is obtained. Purifying after the reaction is finished to obtain a novel catalyst based on the boron-containing fluorescent dye; infrared, N of the catalyst₂The results of adsorption-desorption, pore size distribution, solid nuclear magnetism, thermogravimetry, XPS, SEM, and solid uv analysis are shown in fig. 1, fig. 2, fig. 3, fig. 4, fig. 5, fig. 6, fig. 7, and fig. 8. As can be seen from fig. 1, 4 and 6, the polymer was successfully synthesized; the synthesized polymer has good channel structure as shown in fig. 2 and fig. 3. As can be seen from fig. 5, the synthesized polymer has good thermal stability; as can be seen from fig. 7, the synthesized polymer has a sheet-like structure; as can be seen from fig. 8, the absorption peak of the polymer incorporating the boron-containing fluorescent dye occurs at a higher wavelength in the visible light range.

The test method for the novel catalyst based on the boron-containing fluorescent dye to catalyze the amine oxide coupling reaction is as follows:

the catalyst (2.5. mu. mol, 0.5 mol%) and benzylamine (0.5mmol) were added to a quartz tube under air, followed by acetonitrile (5mL) to disperse the benzylamine uniformly, irradiated with a 26W blue LED lamp at room temperature, and stirred. By TLC and¹H the reaction progress was monitored by NMR and stopped after disappearance of the starting material. The catalyst was then removed by centrifugation, filtration and the filtrate was concentrated and evaporated to give the crude product. Crude product is taken¹H NMR analysis, the ratio of the integrated peaks of starting material, product and by-product was used to calculate yield, conversion. Characterization data:¹H NMR(500MHz，CDCl₃) Delta (ppm) 4.86(s, 2H), 7.26-7.33 (m, 1H), 7.33-7.41 (m, 4H), 7.42-7.47 (m, 3H), 7.77-7.85 (m, 2H), 8.43(s, 1H).

The structural formula is as follows:

application example 1

The test method for the boron-containing fluorescent dye-based novel catalyst catalyzed amine oxide coupling reaction prepared in example 1 is as follows:

the catalyst prepared in example 1 (2.5. mu. mol, 0.5 mol%) and 4-methylbenzylamine (0.5mmol) were added to a quartz tube under air, and then acetonitrile (5mL) was added to disperse the benzylamine uniformly, and irradiated with a 26W blue LED lamp at room temperature with stirring. The progress of the reaction was monitored by TLC and 1H NMR, and the reaction was stopped after disappearance of the starting material. The catalyst was then removed by centrifugation, filtration and the filtrate was concentrated and evaporated to give the crude product. The crude product was analyzed by 1H NMR and the ratio of the integrated peaks of starting material, product and by-product was used to calculate yield, conversion. Characterization data:¹H NMR(500MHz，CDCl₃) δ (ppm):2.36(s, 3H), 2.41(s, 3H), 4.79(s, 2H), 7.17(d, J ═ 8.0Hz, 2H), 7.25(d, J ═ 4.0Hz, 4H), 7.69(d, J ═ 8.0Hz, 2H), 8.37(s, 1H). the product was (E) -N- (4-methylbenzyl) -1- (p-tolyl) azomethine.

The structural formula is as follows:

application example 2

the catalyst prepared in example 1 (2.5. mu. mol, 0.5 mol%) and 4-methoxybenzylamine (0.5mmol) were added to a quartz tube under air, followed by addition of acetonitrile (5mL) to disperse the benzylamine uniformly, irradiated with a 26W blue LED lamp at room temperature, and stirred. The progress of the reaction was monitored by TLC and 1H NMR, and the reaction was stopped after disappearance of the starting material. The catalyst was then removed by centrifugation, filtration and the filtrate was concentrated and evaporated to give the crude product. The crude product was analyzed by 1H NMR and the ratio of the integrated peaks of starting material, product and by-product was used to calculate yield, conversion. Characterization data:¹H NMR(500MHz，CDCl₃) δ (ppm):3.82(s, 3H), 3.86(s, 3H), 4.75(s, 2H), 6.93(m, 4H), 7.27(d, J ═ 8.0Hz, 2H), 7.74(d, J ═ 8.0Hz, 2H), 8.32(s, 1H). the product was (E) -N- (4-methoxybenzyl) -1- (4-methoxyphenyl) azomethine.

The structural formula is as follows:

application example 3

the catalyst prepared in example 1 (2.5. mu. mol, 0.5 mol%) and 4-fluorobenzylamine (0.5mmol) were added to a quartz tube under air, and then acetonitrile (5mL) was added to disperse the benzylamine uniformly, and irradiated with a 26W blue LED lamp at room temperature with stirring. The progress of the reaction was monitored by TLC and 1H NMR, and the reaction was stopped after disappearance of the starting material. The catalyst was then removed by centrifugation, filtration and the filtrate was concentrated and evaporated to give the crude product. The crude product was analyzed by 1H NMR and the ratio of the integrated peaks of starting material, product and by-product was used to calculate yield, conversion. Characterization data:¹H NMR(500MHz，CDCl₃)δ(ppm):4.7(s，2H)，7.05(t，J＝8.0Hz，2H)，7.13(t，J＝8.0Hz，2H)，7.31(dd，J₁＝12.0Hz，J₂＝8.0Hz，2H)，7.80(dd，J₁＝8.0Hz，J₂4.1Hz, 2H), 8.37(s, 1H), the product is (E) -N- (4-fluorobenzyl) -1- (4-fluorophenyl) azomethine.

The structural formula is as follows:

application example 4

the catalyst prepared in example 1 (2.5. mu. mol, 0.5 mol%) and 4-chlorobenzylamine (0.5mmol) were added to a quartz tube under air, followed by addition of acetonitrile (5mL) to disperse the benzylamine uniformly, irradiated with a 26W blue LED lamp at room temperature, and stirred. The progress of the reaction was monitored by TLC and 1H NMR, and the reaction was stopped after disappearance of the starting material. The catalyst was then removed by centrifugation, filtration and the filtrate was concentrated and evaporated to give the crude product. The crude product was analyzed by 1H NMR and the ratio of the integrated peaks of starting material, product and by-product was used to calculate yield, conversion. Characterization data:¹H NMR(500MHz，CDCl₃) δ (ppm) 4.80(s, 2H), 7.25 to 7.32(m, 2H), 7.32 to 7.38(m, 2H), 7.42(d, J ═ 12.0Hz, 2H), 7.74(d, J ═ 8.0Hz, 2H), 8.37(s, 1H).

The structural formula is as follows:

the catalytic reaction formula for amine oxide coupling of the catalyst prepared in example 1 is shown below:

the catalytic performance of the amine oxide coupling of example 1 and the catalyst catalysts prepared from example 1 in application examples 1-4 are shown in table 1 below:

TABLE 1 catalytic performance of the catalyst for amine oxide coupling

The embodiments described above are merely preferred embodiments of the invention, rather than all possible embodiments of the invention. Any obvious modifications to the above would be obvious to those of ordinary skill in the art, but would not bring the invention so modified beyond the spirit and scope of the present invention.

Claims

1. A boron-containing fluorescent dye-based conjugated microporous polymer is characterized in that the structure is shown as formula I:

。

2. the method for preparing the boron-containing fluorescent dye-based conjugated microporous polymer according to claim 1, which comprises the following steps:

(1) preparation of compound a:

under the protection of argon, sequentially adding hexamethylenetetramine and phloroglucinol into a 250mL schlenk bottle; then adding 30-50mL of trifluoroacetic acid into an ice water bath, placing the reaction mixture in an oil bath at 90-110 ℃ and stirring for 3-6 hours at constant temperature, then adding 60-80mL of 3M hydrochloric acid into a schlenk bottle, and continuing heating and stirring for 2-4 hours; after the reaction is finished, the monomer structure compound A is obtained by purification, and the structural formula is shown in the formula

Shown;

preparation of compound a the reaction formula is shown below:

(2) Preparation of Compound B

Under the protection of argon, sequentially adding p-bromobenzylamine and a monomer compound A into a 50mL schlenk bottle; then adding an organic solvent, and placing the reaction mixture in an oil bath at the temperature of 90-110 ℃ and stirring at constant temperature for 48-72 hours; after the reaction is finished, the monomer structure compound B is obtained by purification, and the structural formula is shown in the formula

Shown;

preparation of compound B the reaction formula is shown below:

(3) preparation of Compound C

Adding the monomer compound B into a schlenk bottle at 0 ℃ in an atmosphere; then adding pure boron trifluoride ethyl ether; dropwise adding lithium diisopropylamide; stirring the mixture at room temperature for 12-48 hours under the protection of argon; after the reaction is finished, the monomer structure compound C is obtained by purification, and the structural formula is shown in the formula

Shown;

preparation of compound C the reaction scheme is shown below:

(4) preparation of Compound D

4-bromoacetophenone and p-toluenesulfonic acid are put into a mortar for full grinding, and then trifluoromethanesulfonic acid is added dropwise; transferring the mixture into a 100mL round-bottom flask and stirring at 130-150 ℃ for 24-48 hours; after the reaction is finished, the monomer structure compound D is obtained by purification, and the structural formula is shown in the formula

Shown;

preparation of compound D the reaction scheme is shown below:

(5) preparation of Compound E

Sequentially adding the monomer compound D, cuprous iodide and bis (triphenylphosphine) palladium chloride into a 250mL schlenk bottle under the argon atmosphere; then adding an organic solvent; stirring the mixture for 20-40 minutes at 40-60 ℃ under the protection of argon; then under the protection of argon, dropwise adding trimethylsilyl acetylene, and stirring at 80-120 ℃ for 24-48 hours; after the reaction is finished, the monomer structure compound E is obtained by purification, and the structural formula is shown in the formula

Shown;

preparation of compound E the reaction scheme is shown below:

(6) preparation of Compound F

Adding monomer compound E into a 100mL round-bottom flask; then adding dichloromethane/methanol solution with the volume ratio of 1: 1-4; then adding solid potassium carbonate; stirring the mixture at room temperature for 12-48 hours; after the reaction is finished, the monomer structure compound F is obtained by purification, and the structural formula is shown in the formula

Shown;

preparation of compound F the reaction scheme is shown below:

(7) under the protection of argon, adding the compound C, the compound F, tetrakis (triphenylphosphine) palladium and cuprous iodide into a 100mL schlenk bottle in sequence; then adding 5-30mL of N, N-dimethylformamide/triethylamine with the volume ratio of 2:1, and degassing in a schlenk bottle through three times of freezing-unfreezing cycles; then stirring the reaction mixture in an oil bath kettle at the temperature of 80-100 ℃ for 48-72 hours at constant temperature; and purifying after the reaction is finished to obtain the catalyst based on the boron-containing fluorescent dye.

3. The method according to claim 2, wherein the molar ratio of hexamethylenetetramine to phloroglucinol in step (1) is: 1-1.5: 1;

the molar ratio of the p-bromobenzylamine in the step (2) to the monomer compound A is 3-4: 1; the organic solvent is ethanol;

the molar ratio of the monomer compound B to lithium diisopropylamide in the step (3) is 1: 4-10;

the molar ratio of the 4-bromoacetophenone to the p-toluenesulfonic acid in the step (4) is 8-10: 1;

the molar ratio of the monomer compound D, cuprous iodide, bis (triphenylphosphine) palladium chloride and trimethylsilyl acetylene in the step (5) is 40:1:4:2: 180; the organic solvent is tetrahydrofuran;

the molar ratio of the monomer compound E to the solid potassium carbonate in the step (6) is 1: 4-8;

and (3) the molar ratio of the compound C, the compound F, the tetrakis (triphenylphosphine) palladium and the cuprous iodide in the step (7) is 25:25:2: 1.

4. The use of the boron-containing fluorescent dye-based conjugated microporous polymer of claim 1 to catalyze amine oxide coupling reactions.

5. The method for testing the amine oxide coupling reaction catalyzed by the boron-containing fluorescent dye-based conjugated microporous polymer as the catalyst according to claim 1, wherein the catalyst and the benzylamine with different substituents are added into the organic solvent according to a certain proportion, and are irradiated by a 26W blue LED lamp at room temperature and under air and stirred; the progress of the reaction was monitored by TLC and 1H NMR, and the reaction was stopped after disappearance of the starting material; then centrifuging, filtering to remove the catalyst, concentrating the filtrate, and evaporating to obtain a crude product; the crude product was subjected to 1H NMR and the ratio of the integrated peaks of starting material, product and by-product was used to calculate yield, conversion.

6. The test method according to claim 5, wherein the different substituent benzylamines are 4-methylbenzylamine, 4-methoxybenzylamine, 4-fluorobenzylamine, 4-chlorobenzylamine; the organic solvent is acetonitrile; the ratio of the catalyst to benzylamine is 0.5%: 1.