A boron-oxygen-doped π-extended uracil, its synthesis method and application

Abstract

This invention discloses a boron-oxygen-doped π-extended uracil, with the following general structural formula: where R1, R2, R3, and R4 are independent substituted or unsubstituted groups, including alkyl and aryl groups; Ar 1 The groups represent different types of aryl groups. This invention synthesizes a class of boron-oxygen-doped π-extended uracils and explores their photoelectric properties, providing more solutions for obtaining more efficient organic optoelectronic materials. This invention employs an improved synthesis method that makes the reactants inexpensive and readily available, avoids the use of toxic reagents, and is simple and easy to perform. The compounds have wide applications in organic light-emitting diodes, organic solar cells, organic field-effect transistors, organic lasers, organic sensors, molecular switches, and pharmaceutical intermediates.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis and organic functional molecule technology, and in particular to a boron-oxygen-doped π-extended uracil and its synthesis method and application. Background Technology

[0002] Uralazine is a 16π-electron nitrogen-containing heterocyclic system, isoelectronic with pyrene. Its π-electron cycloene resonance structure, where in-plane nitrogen provides the electron cloud density and concentrates positive charges, illustrates the potential donor strength and electronic stability of this nitrogen-containing heterocycle. Initial anionic and cation stability studies, along with computational comparisons with pyrene, suggest that urazine may be a promising candidate material for π-conjugated materials in optoelectronic applications.

[0003] With the successful synthesis of urazine, research on its derivatives has also made continuous progress, enriching the applications of urazine derivatives in many fields, such as organic solar cells, n-type semiconductors, dyes, and organic light-emitting materials. Among these studies, the π extensions on both sides and the top of the urazine parent structure have been extensively studied, while the π extensions at the bottom have been relatively less studied. Therefore, the property changes brought about by the π extension at the bottom of urazine have gradually attracted attention.

[0004] In recent years, researchers have continuously innovated, building upon previous work and progressing from introducing a single heteroatom into conjugated polycyclic aromatic hydrocarbon (PAH) systems to incorporating two or more different heteroatoms. Various heteroatom-doped PAHs have emerged. Boron-doped PAHs, in particular, are well-known examples. Boron atoms have an empty p orbital, which allows them to combine with other electron-rich heteroatoms, enabling charge movement within the molecule.

[0005] In recent years, researchers have continuously innovated, building upon previous work and progressing from introducing a single heteroatom into conjugated polycyclic aromatic hydrocarbon (PAH) systems to incorporating two or more different heteroatoms. Various heteroatom-doped PAHs have emerged. Boron-doped PAHs, in particular, are well-known. Boron atoms possess an empty p orbital, allowing them to combine with other electron-rich heteroatoms and generate charge transfer within the molecule. However, boron atoms are unstable, and their empty p orbital is highly susceptible to nucleophilic attack. Therefore, in designing and synthesizing boron-based PAHs, sterically hindered groups are often introduced to stabilize the boron atom.

[0006] It is worth noting that replacing C=C bonds with isoelectronic and isostructural BN bonds can lead to the development of various polycyclic aromatic hydrocarbons with different optical and electronic properties, while maintaining their spatial conformation almost identical to that of all-carbon compounds. These unique properties of BN-doped polycyclic aromatic hydrocarbons make them important for organic optoelectronic devices; however, due to the lack of suitable synthetic methods and their instability, polycyclic aromatic hydrocarbons containing BO bonds have not been well studied.

[0007] A search revealed no patent publications related to this invention's patent application. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a boron-oxygen-doped π-extended uracil, its synthesis method, and its application.

[0009] The technical solution adopted by this invention to solve its technical problem is:

[0010] A boron-oxygen-doped π-extended ursine has the following general structural formula:

[0011]

[0012] Wherein, R1, R2, R3, and R4 are independent substituted or unsubstituted groups, including alkyl and aryl groups;

[0013] Ar 1 The groups represent different types of aryl groups.

[0014] Further, the aryl groups in R1, R2, R3, and R4 are benzene rings, thiophene rings, furan rings, pyrrole, pyridine, benzothiophene, benzofuran, benzopyrrole, benzopyridine, naphthyl rings, anthracene rings, phenaene, tetraphenylene, pyrene, etc. Linear or angled pentabenzene, hexabenzene, indene, or fluorene;

[0015] Ar 1 The aryl group in the group is a benzene ring, thiophene ring, furan ring, pyrrole, pyridine, benzothiophene, benzofuran, benzopyrrole, benzopyridine, naphthalene ring, anthracene ring, phenaene, tetraphenylene, pyrene, Linear or angular pentadienylbenzene, hexabenzene, indene, or fluorene.

[0016] Furthermore, the boron-oxygen-doped π-extended urazine has a structure selected from one of 2BO-1 to 2BO-84:

[0017]

[0018]

[0019]

[0020]

[0021] The method for synthesizing boron-oxygen-doped π-extended uracil as described above includes the following steps:

[0022] The reaction involves six steps: starting with p-bromoaniline, a substitution reaction yields compound 1, namely 2,6-diiodo,4-bromoaniline; compound 1 undergoes a Sonogashira coupling reaction to generate compound 2; compound 2 undergoes a one-step Paal-Knorr reaction to generate compound 3; compound 3 undergoes a one-step metal-catalyzed cyclization to generate compound 4; compound 4 undergoes a Suzuki coupling reaction to generate compound 5; and compound 5 undergoes a one-step oxygen-directed borylation cyclization reaction to generate compound 2BO.

[0023] Its synthetic route is as follows:

[0024]

[0025] Furthermore, the method specifically includes the following steps:

[0026] Synthesis of Compound 1: p-bromoaniline, iodine monochloride, and solvent were added to a round-bottom flask and heated to 60-70℃ for 12-24 h. After the product was cooled to room temperature, it was extracted with dichloromethane and water. The organic phase was dried with anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. Compound 1 was obtained by column chromatography.

[0027] Synthesis of compound 2: Compound 1, R1 and R2 alkynes involved in coupling, catalyst, base, and solvent were added to a dry Schlenk flask; the reaction was carried out at room temperature for 3-24 h; after the reaction was completed, the mixture was extracted with dichloromethane and water, and the resulting organic phase was dried with anhydrous magnesium sulfate. The solvent was removed under reduced pressure, and compound 2 was obtained by column chromatography.

[0028] Synthesis of compound 3: Compound 2, catalyst and solvent were added to a round-bottom flask and heated to 100-140℃ for 12-48 h under nitrogen protection. After the product was cooled to room temperature, it was extracted with dichloromethane and water. The organic phase was dried with anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. Compound 3 was obtained by column chromatography.

[0029] Synthesis of compound 4: Compound 3, catalyst and solvent were added to a dry reaction tube and heated to 30-140℃ for 3-24 h under nitrogen protection. After the product was cooled to room temperature, it was extracted with dichloromethane and water. The organic phase was dried with anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. Compound 4 was obtained by column chromatography.

[0030] Synthesis of compound 5: Compound 4, 2,6-dimethoxyphenylboronic acid, catalyst, ligand, base, and solvent were added to a dry reaction tube under nitrogen protection and stirred at 90-140℃ for 12-36 h. After the product cooled to room temperature, it was extracted with dichloromethane and water. The resulting organic phase was dried with anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. Compound 5 was then obtained by column chromatography.

[0031] Synthesis of compound 2BO: Compound 5, boron source reagent, tetrabutylammonium iodide, base, and solvent were added to a dry reaction tube under nitrogen protection and stirred at 130-180℃ for 12-36 h. After the product cooled to room temperature, Grignard reagent was added, and the mixture was stirred at room temperature for 5-24 h. The product was then extracted with dichloromethane and water. The resulting organic phase was dried with anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. Compound 2BO was then obtained by column chromatography.

[0032] Furthermore, in the synthesis of compound 1, the molar ratio of p-bromoaniline to iodine monochloride is 29.1:64.0;

[0033] The solvent is methanol;

[0034] In the synthesis of compound 2, the R1 and R2 alkynes are phenylacetylene and 4-pentylphenylacetylene, respectively, and their amounts are 200%-300% of the molar percentage of compound 1.

[0035] The catalyst is two of palladium acetate, tetratriphenylphosphine palladium, bistriphenylphosphine palladium dichloride, cuprous iodide, or cuprous chloride, and its amount is 1%-10% molar percentage of compound 1.

[0036] The base is one of triethylamine and diisopropylamine, and its amount is 2%-10% molar percentage of compound 1;

[0037] The solvent is one of toluene, tetrahydrofuran, and triethylamine;

[0038] Alternatively, in the synthesis of compound 3, the catalyst is 2,5-dimethoxytetrahydrofuran, which is used in an amount of 100%-120% molar percentage of compound 2.

[0039] The solvent is one or a mixture of two of glacial acetic acid and 1,2-dichloroethane;

[0040] Alternatively, during the synthesis of compound 4, the catalyst is either platinum dichloride or indium trichloride, used in an amount of 30-90% molar percentage of compound 3.

[0041] The solvent is one of tetrahydrofuran, toluene, and trichlorobenzene;

[0042] Alternatively, during the synthesis of compound 5, the catalyst is one of tetratetraphenylphosphine palladium, tris(dibenzylideneacetone)palladium, or [1,1-bis(diphenylphosphine)ferrocene]palladium dichloride, used in an amount of 1-10% molar percentage of compound 4.

[0043] The ligand is one of triphenylphosphine, tricyclohexylphosphine, and 4,5-bis(diphenylphosphine)-9,9-dimethyloxanthracene, and its amount is 10-50% molar percentage of compound 4.

[0044] The alkali is one of potassium phosphate, potassium tert-butoxide, sodium tert-butoxide, and potassium carbonate, and its amount is 100-500% molar percentage of compound 4.

[0045] The solvent is one of toluene, N,N-dimethyl sulfoxide, and trichlorobenzene;

[0046] Alternatively, in the synthesis of compound 2BO, the boron source reagent is one of boron trichloride and boron tribromide, and its amount is 200-300% of the molar percentage of compound 5.

[0047] The amount of the tetrabutylammonium iodide used is 200-300% molar percentage of compound 5;

[0048] The base is one of triethylamine and diisopropylamine, and its amount is 200-300% molar percentage of compound 5;

[0049] The solvent is one of chlorobenzene, dichlorobenzene, and trichlorobenzene.

[0050] Applications of boron-oxygen-doped π-extended uracil in optics and / or optoelectronics, as described above.

[0051] The applications of boron-oxygen-doped π-extended uracil as described above in the preparation of luminescent materials.

[0052] The above-described applications of boron-oxygen-doped π-extended uracil in the preparation of luminescent and / or host materials for optical or optoelectronic devices.

[0053] Furthermore, the optical or optoelectronic device includes optoelectronic materials, solar cells, electroluminescent devices, and sensors.

[0054] The advantages and positive effects of this invention are as follows:

[0055] 1. This invention synthesizes a class of boron-oxygen-doped π-extended uracil and explores its photoelectric properties, providing more solutions for obtaining more efficient organic optoelectronic materials. The improved synthesis method employed in this invention makes the reactants inexpensive and readily available, avoids the use of toxic reagents, and is simple and easy to implement. The compounds have wide applications in organic light-emitting diodes, organic solar cells, organic field-effect transistors, organic lasers, organic sensors, molecular switches, and pharmaceutical intermediates.

[0056] 2. This invention provides more solutions for obtaining more efficient organic optoelectronic materials. The synthesis method of the target product is simple to operate, has a high yield, and exhibits excellent green light emission characteristics (emission spectrum peak at 546 nm) and a high fluorescence quantum yield (fluorescence quantum yield of 87%). Therefore, this type of boron-oxygen-doped π-extended uracil has broad potential application prospects in the field of organic optoelectronic materials, such as in the fabrication of optoelectronic materials, solar cells, electroluminescent devices, and sensors.

[0057] 3. The synthesis methods of this invention include Sonogashira coupling reaction, Paal-Knorr reaction, indium trichloride-catalyzed cyclization reaction, Suzuki coupling reaction, substitution reaction, etc.; the boron-oxygen-doped π-extended urazine prepared can be applied in the preparation of optoelectronic materials, solar cells, electroluminescent devices, and sensors.

[0058] 4. This invention relates to boron-oxygen-doped π-extended uracil, which has broad application prospects in organic chemistry, such as in hydrogen storage materials, organic synthesis, catalysis, optoelectronic materials, sensors, probes, and bioactive molecules. By constructing boron-oxygen-doped π-extended uracil derivatives, their photoelectric physical properties are tested, and their potential application areas are explored. Attached Figure Description

[0059] Figure 1 This is a single-crystal structure diagram of compound 2BO in this invention;

[0060] Figure 2 The compound 2BO in this invention is at a concentration of 1×10⁻⁶. -5 Absorption spectrum of M in dichloromethane solution;

[0061] Figure 3 The compound 2BO in this invention is at a concentration of 1×10⁻⁶. -5 Emission spectrum of M in dichloromethane solution;

[0062] Figure 4 This is the hydrogen nuclear magnetic resonance spectrum of compound 2BO in this invention.

[0063] Figure 5 This is the carbon NMR spectrum of compound 2BO in this invention. Detailed Implementation

[0064] The present invention will be further described below with reference to the embodiments. The following embodiments are descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0065] The various experimental operations involved in the specific embodiments are all conventional techniques in the field. For parts not specifically annotated in this document, those skilled in the art can refer to various commonly used reference books, scientific and technological documents or related instructions and manuals prior to the filing date of this invention to carry out the operations.

[0066] A boron-oxygen-doped π-extended ursine has the following general structural formula:

[0067]

[0068] Wherein, R1, R2, R3, and R4 are independent substituted or unsubstituted groups, including alkyl and aryl groups;

[0069] Ar 1 The groups represent different types of aryl groups.

[0070] Preferably, the aryl group in R1, R2, R3, and R4 is a benzene ring, a thiophene ring, a furan ring, a pyrrole, a pyridine, a benzothiophene, a benzofuran, a benzopyrrole, a benzopyridine, a naphthyl ring, an anthracene ring, a phenaene, a tetraphenylene oxide, or a pyrene ring. Linear or angled pentabenzene, hexabenzene, indene, or fluorene;

[0071] Ar 1 The aryl group in the group is a benzene ring, thiophene ring, furan ring, pyrrole, pyridine, benzothiophene, benzofuran, benzopyrrole, benzopyridine, naphthalene ring, anthracene ring, phenaene, tetraphenylene, pyrene, Linear or angular pentadienylbenzene, hexabenzene, indene, or fluorene.

[0072] Preferably, the boron-oxygen-doped π-extended urazine has a structure selected from one of 2BO-1 to 2BO-84:

[0073]

[0074]

[0075]

[0076]

[0077] The method for synthesizing boron-oxygen-doped π-extended uracil as described above includes the following steps:

[0078] The reaction involves six steps: starting with p-bromoaniline, a substitution reaction yields compound 1, namely 2,6-diiodo,4-bromoaniline; compound 1 undergoes a Sonogashira coupling reaction to generate compound 2; compound 2 undergoes a one-step Paal-Knorr reaction to generate compound 3; compound 3 undergoes a one-step metal-catalyzed cyclization to generate compound 4; compound 4 undergoes a Suzuki coupling reaction to generate compound 5; and compound 5 undergoes a one-step oxygen-directed borylation cyclization reaction to generate compound 2BO.

[0079] Its synthetic route is as follows:

[0080]

[0081] Preferably, the method specifically includes the following steps:

[0082] Synthesis of Compound 1: p-bromoaniline, iodine monochloride, and solvent were added to a round-bottom flask and heated to 60-70℃ for 12-24 h. After the product was cooled to room temperature, it was extracted with dichloromethane and water. The organic phase was dried with anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. Compound 1 was obtained by column chromatography.

[0083] Synthesis of compound 2: Compound 1, R1 and R2 alkynes involved in coupling, catalyst, base, and solvent were added to a dry Schlenk flask; the reaction was carried out at room temperature for 3-24 h; after the reaction was completed, the mixture was extracted with dichloromethane and water, and the resulting organic phase was dried with anhydrous magnesium sulfate. The solvent was removed under reduced pressure, and compound 2 was obtained by column chromatography.

[0084] Synthesis of compound 3: Compound 2, catalyst and solvent were added to a round-bottom flask and heated to 100-140℃ for 12-48 h under nitrogen protection. After the product was cooled to room temperature, it was extracted with dichloromethane and water. The organic phase was dried with anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. Compound 3 was obtained by column chromatography.

[0085] Synthesis of compound 4: Compound 3, catalyst and solvent were added to a dry reaction tube and heated to 30-140℃ for 3-24 h under nitrogen protection. After the product was cooled to room temperature, it was extracted with dichloromethane and water. The organic phase was dried with anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. Compound 4 was obtained by column chromatography.

[0086] Synthesis of compound 5: Compound 4, 2,6-dimethoxyphenylboronic acid, catalyst, ligand, base, and solvent were added to a dry reaction tube under nitrogen protection and stirred at 90-140℃ for 12-36 h. After the product cooled to room temperature, it was extracted with dichloromethane and water. The resulting organic phase was dried with anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. Compound 5 was then obtained by column chromatography.

[0087] Synthesis of compound 2BO: Compound 5, boron source reagent, tetrabutylammonium iodide, base, and solvent were added to a dry reaction tube under nitrogen protection and stirred at 130-180℃ for 12-36 h. After the product cooled to room temperature, Grignard reagent was added, and the mixture was stirred at room temperature for 5-24 h. The product was then extracted with dichloromethane and water. The resulting organic phase was dried with anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. Compound 2BO was then obtained by column chromatography.

[0088] Preferably, in the synthesis of compound 1, the molar ratio of p-bromoaniline to iodine monochloride is 29.1:64.0;

[0089] The solvent is methanol;

[0090] In the synthesis of compound 2, the R1 and R2 alkynes are phenylacetylene and 4-pentylphenylacetylene, respectively, and their amounts are 200%-300% of the molar percentage of compound 1.

[0091] The catalyst is two of palladium acetate, tetratriphenylphosphine palladium, bistriphenylphosphine palladium dichloride, cuprous iodide, or cuprous chloride, and its amount is 1%-10% molar percentage of compound 1.

[0092] The base is one of triethylamine and diisopropylamine, and its amount is 2%-10% molar percentage of compound 1;

[0093] The solvent is one of toluene, tetrahydrofuran, and triethylamine;

[0094] Alternatively, in the synthesis of compound 3, the catalyst is 2,5-dimethoxytetrahydrofuran, which is used in an amount of 100%-120% molar percentage of compound 2.

[0095] The solvent is one or a mixture of two of glacial acetic acid and 1,2-dichloroethane;

[0096] Alternatively, during the synthesis of compound 4, the catalyst is either platinum dichloride or indium trichloride, used in an amount of 30-90% molar percentage of compound 3.

[0097] The solvent is one of tetrahydrofuran, toluene, and trichlorobenzene;

[0098] Alternatively, during the synthesis of compound 5, the catalyst is one of tetratetraphenylphosphine palladium, tris(dibenzylideneacetone)palladium, or [1,1-bis(diphenylphosphine)ferrocene]palladium dichloride, used in an amount of 1-10% molar percentage of compound 4.

[0099] The ligand is one of triphenylphosphine, tricyclohexylphosphine, and 4,5-bis(diphenylphosphine)-9,9-dimethyloxanthracene, and its amount is 10-50% molar percentage of compound 4.

[0100] The alkali is one of potassium phosphate, potassium tert-butoxide, sodium tert-butoxide, and potassium carbonate, and its amount is 100-500% molar percentage of compound 4.

[0101] The solvent is one of toluene, N,N-dimethyl sulfoxide, and trichlorobenzene;

[0102] Alternatively, in the synthesis of compound 2BO, the boron source reagent is one of boron trichloride and boron tribromide, and its amount is 200-300% of the molar percentage of compound 5.

[0103] The amount of the tetrabutylammonium iodide used is 200-300% molar percentage of compound 5;

[0104] The base is one of triethylamine and diisopropylamine, and its amount is 200-300% molar percentage of compound 5;

[0105] The solvent is one of chlorobenzene, dichlorobenzene, and trichlorobenzene.

[0106] Applications of boron-oxygen-doped π-extended uracil in optics and / or optoelectronics, as described above.

[0107] The applications of boron-oxygen-doped π-extended uracil as described above in the preparation of luminescent materials.

[0108] The above-described applications of boron-oxygen-doped π-extended uracil in the preparation of luminescent and / or host materials for optical or optoelectronic devices.

[0109] Preferably, the optical or optoelectronic device includes optoelectronic materials, solar cells, electroluminescent devices, and sensors.

[0110] Specifically, the relevant preparation and testing methods are as follows:

[0111] The present invention discloses a boron-oxygen-doped π-extended uracil and its synthesis method, which includes the following synthesis route and steps.

[0112]

[0113] (1) Synthesis of Compound 1: p-Bromoaniline (1.0 equiv, 29.1 mmol, 5.00 g) was weighed into a 500 mL round-bottom flask, and 300 mL of methanol (MeOH) was added to dissolve the reactants. After stirring at room temperature for 3 min, iodine monochloride (2.2 equiv, 64.0 mmol, 10.40 g) was weighed and slowly added to the round-bottom flask. The above reaction system was slowly heated to 65 °C and stirred for 12 h. After the reaction was complete, 100 mL of saturated sodium thiosulfate solution was added and stirred for 5 min. The organic phase was suspended to dryness, extracted three times with 300 mL of dichloromethane (DCM), the organic layers were combined, dried with anhydrous magnesium sulfate, and filtered to obtain the organic phase. The organic phase was concentrated by rotary evaporation to obtain the crude product. Finally, silica gel column chromatography was used for separation (elution: petroleum ether (PE) / acetic acid ester (EA) = 20 / 1), and the white target compound 1 (8.6 g, yield 70%) was finally obtained. 1 H NMR (400MHz, CDCl3): δ7.73(s,2H,Ar),4.63(s,2H,br).

[0114]

[0115] (2) Synthesis of Compound 2: 2,6-Diiodo,4-bromoaniline (1.0 equiv, 11.8 mmol, 5.02 g), tetrakis(triphenylphosphine)palladium (0.04 equiv, 0.5 mmol, 0.49 g), and cuprous iodide (0.04 equiv, 0.5 mmol, 0.11 g) were weighed into a 100 mL Schlenk flask. The flask was purged three times under nitrogen protection. Then, triethylamine (4.0 equiv, 47.2 mmol, 6.6 mL), THF solvent (25 mL), and 4-pentylphenylacetylene (2.1 equiv, 24.8 mmol, 4.8 mL) were added sequentially using a syringe. After the additions were complete, the reaction system was stirred at room temperature for 16 h. After the reaction was complete, the solvent was suspended, and the mixture was extracted three times with 30 mL each of water and DCM. The organic layers were combined, dried over anhydrous magnesium sulfate, and filtered to obtain the organic phase. The organic phase was concentrated by rotary evaporation to obtain a crude product, which was then separated by silica gel column chromatography (elution buffer: PE / EA = 50 / 1) to finally obtain the target compound 2 (5.4 g, yield 90%), which was a pale yellow oil. 1 HNMR (400MHz, CDCl3): δ7.42-7.44(m,6H,Ar),7.18(d,J=8.2Hz,4H,Ar),4.89(br,2H,NH2),2.62 (t,J=7.6Hz,4H,CH2),1.55-1.66(m,4H,CH2),1.30-1.37(m,8H,CH2),0.90(t,J=6.8Hz,6H,CH3).

[0116]

[0117] (3) Synthesis of Compound 3: Compound 2 (1.0 equiv, 11.37 mmol, 4.23 g) was weighed into a 250 mL round-bottom flask. Then, 30 mL of 1,2-dichloroethane (DCE) and 30 mL of glacial acetic acid were added sequentially using a syringe. Finally, 2,5-dimethoxytetrahydrofuran (1.2 equiv, 13.64 mmol, 1.8 mL) was added using a syringe. After reflux, the reaction system was slowly heated to 120 °C and reacted for 4 h. After the reaction was complete, most of the solvent was evaporated using a rotary evaporator. Then, 40 mL each of water and DCM were added for extraction three times. The organic layers were combined and dried with anhydrous magnesium sulfate. The organic phase was filtered to obtain the organic phase. Finally, the organic phase was concentrated by rotary evaporation to obtain the crude product. The crude product was separated by silica gel column chromatography (elution buffer: PE / EA = 50 / 1) to finally obtain the yellow target compound 3 (4.2 g, yield 87%). 1 H NMR (400MHz, CDCl3): δ7.71(s,2H,Ar),7.29(d,J=8.1Hz,4H,Ar),7.15(d,J=8.1Hz,4H,Ar),7.07(t,J=2.1Hz,2H,Ar),6.41 (t,J=2.1Hz,2H,Ar),2.62(t,J=7.5Hz,4H,CH2),1.59-1.66(m,4H,CH2),1.29-1.39(m,8H,CH2),0.92(t,J=6.8Hz,6H,CH3).

[0118]

[0119] (4) Synthesis of Compound 4: Compound 3 (1.0 equiv, 4.56 mmol, 2.0 g) and anhydrous indium trichloride (0.62 equiv, 2.82 mmol, 0.62 g) were weighed into a 100 mL Schlenk flask. The mixture was purged three times under nitrogen protection. Then, 20 mL of anhydrous toluene was added using a syringe, and the reaction system was slowly heated to 110 °C. After 24 h of reaction, most of the toluene was evaporated by rotary evaporation. Then, 40 mL each of water and DCM were added for extraction three times. The organic layers were combined, dried with anhydrous magnesium sulfate, and filtered to obtain the organic phase. The filtrate was evaporated to dryness to obtain the crude product. The crude product was purified by silica gel column chromatography (elution buffer: PE / EA = 20 / 1), finally yielding the yellow target compound 4 (1.9 g, yield 95%). 1H NMR (400MHz, CDCl3): δ7.69(d,J=8.1Hz,4H,Ar),7.54(s,2H,Ar),7.34(d,J=8.1Hz,4H,Ar),7.14(s,4H,A r),2.71(t,J=7.6Hz,4H,CH2),1.68-1.75(m,4H,CH2),1.38-1.42(m,8H,CH2),0.95(t,J=6.9Hz,6H,CH3).

[0120]

[0121] (5) Synthesis of compound 5: First, weigh compound 4 (1.0 equiv, 0.84 mmol, 500 mg), 2,6-dimethoxyphenylboronic acid (2.0 equiv, 1.7 mmol, 311 mg), tris(dibenzylacetone) dipalladium-chloroform adduct (0.05 equiv, 0.04 mmol, 43 mg), 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (0.1 equiv, 0.08 mmol, 34 mg), and potassium phosphate (3.0 equiv, 2.5 mmol, 534 mg) into a 50 mL Schlenk flask, evacuate the gas three times, and protect with nitrogen. Then, add solvent Tol (8 mL) using a syringe. After the addition was complete, the reaction system was slowly heated to 110℃. After reacting for 24 hours, most of the solvent was evaporated using a rotary evaporator. Then, 40 mL each of water and DCM were added for extraction three times. The organic layers were combined and dried with anhydrous magnesium sulfate. The organic phase was filtered to obtain the organic phase, which was then concentrated by rotary evaporation to obtain the crude product. The crude product was separated by silica gel plate chromatography (developing solvent: PE / EA = 20 / 1) to finally obtain the yellow target compound 5 (452 ​​mg, yield 87%). 1 HNMR (400MHz, CDCl3): δ7.73(d,J=8.1Hz,4H,Ar),7.44(s,2H,Ar),7.30-7.36(m,5H,Ar),7.22(s,2H,Ar),7.05(s,2H,Ar),6.71(d,J=8 .4Hz,4H,Ar),3.76(s,6H,OCH3),2.70(t,J=7.6Hz,4H,CH2),1.66-1.74(m,4H,CH2),1.35-1.42(m,8H,CH2),0.93(t,J=6.9Hz,6H,CH3).

[0122]

[0123] (6) Synthesis of compound 2BO: Compound 5 (1.0 equiv, 0.16 mmol, 100 mg) and tetrabutylammonium iodide (2.4 equiv, 0.39 mmol, 143 mg) were weighed into a 15 mL sealed tube. The system was placed in a glove box and the transition chamber was evacuated three times. Then, 3 mL of anhydrous dichlorobenzene (DCB) was added to the system in the glove box to dissolve the reactants. Triethylamine (2.0 equiv, 0.32 mmol, 35 mg) and boron trichloride (1.0 M in toluene, 2.5 equiv, 0.40 mmol, 0.40 mL) were added to the system sequentially. The reaction system was then slowly heated to 135 °C. After reacting for 24 h and cooling to room temperature, 2,4,6-trimethylphenyl magnesium bromide (1.0 M in THF, 9 equiv, 1.44 mmol, 1.44 mL) was added to the system in the glove box, and the reaction was stirred at room temperature for 5 h. After the reaction was complete, 40 mL each of water and DCM were added for extraction three times. The organic layers were combined, dried with anhydrous magnesium sulfate, and filtered to obtain the organic phase. Finally, the organic phase was concentrated by rotary evaporation to obtain the crude product. The crude product was separated by neutral alumina column chromatography (evolving solvent: PE / EA = 20 / 1) to finally obtain the yellow target compound 2BO (95 mg, yield 70%). 1 H NMR (400MHz, CDCl3): δ8.00 (s, 2H, Ar), 7.63 (dd, J1=8.6Hz, J2=7.5Hz, 1H, Ar), 7.5 6(s,2H,Ar),7.48(d,J=7.9Hz,2H,Ar),7.37(d,J=8.2Hz,4H,Ar),7.22(d,J=8.1Hz ,4H,Ar),7.06(s,4H,Ar),2.69(t,J=7.6Hz,4H,CH2),2.46(s,6H,CH3),2.30(s,12 H,CH3),1.66-1.74(m,4H,CH2),1.39-1.43(m,8H,CH2),0.96(t,J=6.8Hz,6H,CH3).

[0124] The structural characteristics and photophysical properties of these compounds were further investigated, including single-crystal structure analysis and ultraviolet fluorescence spectroscopy.

[0125] Figures 1 to 5 The single crystals of 2BO were characterized by UV absorption, fluorescence emission, and 1H and 1C NMR spectra. Figure 1 The single-crystal structure diagram shows that 2BO exhibits a good planar structure, proving that 2BO has potential charge transport properties; through Figure 2 , Figure 3The UV absorption and fluorescence emission patterns show that 2BO exhibits good absorption at 500 nm and relatively pure green emission at 516 nm, thus demonstrating the potential applications of 2BO in the field of optoelectronic materials; through Figure 4 , Figure 5 The 1H and 1C NMR spectra can prove the correctness of the 2BO structure.

[0126] Although embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations, and modifications are possible without departing from the spirit and scope of the invention and the appended claims. Therefore, the scope of the invention is not limited to the contents disclosed in the embodiments.

Claims

1. A boron-oxygen-doped pi-extended purazine, characterized by: The structural formula is as follows:

2. Use of a boron-oxygen-doped π-extended purazine according to claim 1 as a light emitting material.

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