阅读说明：本技术 一种含有硼原子的卤代多环芳香族化合物及其制备方法 (Halogenated polycyclic aromatic compound containing boron atom and preparation method thereof ) 是由 杨楚罗 张友明 喻明鑫 黄太安 邹洋 于 2021-08-09 设计创作，主要内容包括：本发明公开了一种含有硼原子的卤代多环芳香族化合物及其制备方法,包括：将合成前体溶解在有机溶剂中,得到合成前体溶液；在惰性气氛中,冰浴条件下,将正丁基锂加入到所述合成前体溶液中,反应第一预定时间,得到含有中间产物的混合溶液；将三溴化硼加入到所述含有中间产物的混合溶液中,反应第二预定时间后,在冰浴条件下将二异丙基乙胺注入到所述含有中间产物的混合溶液中,升温至预定温度进行反应,得到所述含有硼原子的卤代多环芳香族化合物；所述合成前体具有如下结构通式：其中,D-(1)和D-(2)分别独立地选自经修饰和未经修饰的含氮的芳香基团或含氮的杂芳香基团；X-(1、)X-(2)为卤素原子。该方法不涉及高危试剂,具有制备工艺简单,产率高的特点。(The invention discloses a halogenated polycyclic aromatic compound containing boron atoms and a preparation method thereof, wherein the preparation method comprises the following steps: dissolving a synthesis precursor in an organic solvent to obtain a synthesis precursor solution; adding n-butyllithium into the synthetic precursor solution in an inert atmosphere under an ice-bath condition, and reacting for a first preset time to obtain a mixed solution containing an intermediate product; adding boron tribromide into the mixed solution containing the intermediate product, reacting for a second preset time, injecting diisopropylethylamine into the mixed solution containing the intermediate product under an ice bath condition, and heating to a preset temperature for reaction to obtain the halogenated polycyclic aromatic compound containing boron atoms; the synthesis precursor has the following structural general formula: wherein D is 1 And D 2 Each independently selected from the group consisting of modified and unmodified nitrogen-containing aromatic groups or nitrogen-containing heteroaromatic groups; x 1、 X 2 Is a halogen atom. The method does not involve high-risk reagents, and has the characteristics of simple preparation process and high yield.)

1. A method for producing a halogenated polycyclic aromatic compound containing a boron atom, comprising:

dissolving a synthesis precursor in an organic solvent to obtain a synthesis precursor solution;

adding n-butyllithium into the synthetic precursor solution in an inert atmosphere under an ice-bath condition, and reacting for a first preset time to obtain a mixed solution containing an intermediate product;

adding boron tribromide into the mixed solution containing the intermediate product, reacting for a second preset time, injecting diisopropylethylamine into the mixed solution containing the intermediate product under an ice bath condition, and heating to a preset temperature for reaction to obtain the halogenated polycyclic aromatic compound containing boron atoms;

the synthesis precursor has the following structural general formula:

wherein D is₁And D₂Each independently selected from the group consisting of modified and unmodified nitrogen-containing aromatic groups or nitrogen-containing heteroaromatic groups; x_1、X₂Is a halogen atom.

2. The method according to claim 1, wherein the organic solvent is one or more selected from mesitylene, o-dichlorobenzene, and xylene.

3. The production method according to claim 1, wherein the addition equivalent of the n-butyllithium is 0.5 to 1.5 times the addition equivalent of the precursor.

4. The method according to claim 1, wherein D is₁And D₂Each independently selected from the group having the structure:

wherein R is_n(n ═ 1,2,3, 4,5,6,7,8) is independently hydrogen, cyano, trifluoromethyl, aryl having 6 to 30 carbon atoms, heteroaryl having 2 to 30 carbon atoms, alkyl having 1 to 12 carbon atoms, alkoxy or aryloxy having 1 to 12 carbon atoms, or a halogen atom; m is selected from any one of carbon atom, oxygen atom, sulfur atom, silicon atom and boron atom.

5. The preparation method according to claim 1, wherein the step of adding n-butyllithium to the synthesis precursor solution under an inert atmosphere and ice bath conditions to react for a first predetermined time to obtain a mixed solution containing an intermediate product comprises:

dropwise adding n-butyllithium into the synthetic precursor solution in an inert atmosphere under an ice bath condition, and reacting for 10-30min to obtain a mixed solution containing an intermediate product;

the n-pentane solvent in the mixed solution containing the intermediate product was removed under stirring.

6. The preparation method according to claim 1, wherein the step of adding boron tribromide to the mixed solution containing the intermediate product, reacting for a second predetermined time, injecting diisopropylethylamine into the mixed solution containing the intermediate product under ice bath conditions, and heating to a predetermined temperature to react to obtain the halogenated polycyclic aromatic compound containing the boron atom specifically comprises:

adding boron tribromide into the mixed solution containing the intermediate product at the temperature below-40 ℃, reacting for 10-20min, and naturally heating to 20-25 ℃;

and (3) under the ice bath condition, injecting diisopropylethylamine into the mixed solution containing the intermediate product, heating to 150-200 ℃, and reacting for 10-15 hours to obtain the halogenated polycyclic aromatic compound containing the boron atom.

7. A halogenated polycyclic aromatic compound containing a boron atom, characterized by having the following general structural formula:

wherein D is₁And D₂Each independently selected from a nitrogen-containing aromatic group or a nitrogen-containing heteroaromatic group; x₁Is a halogen atom.

8. The halogenated polycyclic aromatic compound containing a boron atom according to claim 7, wherein D is₁And D₂Each independently selected from an aromatic group or a heteroaromatic group having a nitrogen atom as a terminal group and being singly bonded to a boron atom.

9. The halogenated polycyclic aromatic compound containing a boron atom according to claim 7 or 8, wherein D is₁Selected from nitrogen-containing aromatic groups modified by cyano, trifluoromethyl, aryl with 6-30 carbon atoms, heteroaryl with 2-30 carbon atoms, alkyl with 1-12 carbon atoms, alkoxy with 1-12 carbon atoms or aryloxy;

or said D₁Selected from cyano, trifluoromethyl, aryl with 6-30 carbon atoms, heteroaryl with 2-30 carbon atoms, alkyl with 1-12 carbon atoms, and alkoxy with 1-12 carbon atomsOr an aryloxy-modified nitrogen-containing heteroaromatic group;

said D₂Selected from nitrogen-containing aromatic groups modified by cyano, trifluoromethyl, aryl with 6-30 carbon atoms, heteroaryl with 2-30 carbon atoms, alkyl with 1-12 carbon atoms, alkoxy with 1-12 carbon atoms or aryloxy;

or said D₂Selected from nitrogen-containing heteroaromatic group modified by cyano, trifluoromethyl, aryl group with 6-30 carbon atoms, heteroaryl group with 2-30 carbon atoms, alkyl group with 1-12 carbon atoms, alkoxy group with 1-12 carbon atoms or aryloxy group.

10. The halogenated polycyclic aromatic compound containing a boron atom according to claim 8, wherein the halogenated polycyclic aromatic compound containing a boron atom comprises the following structural formula:

wherein, X₁Selected from Br or Cl.

Technical Field

The invention relates to the technical field of luminescent material preparation, in particular to a halogenated polycyclic aromatic compound containing boron atoms and a preparation method thereof.

Background

In recent years, boron-based materials have attracted considerable interest due to their potential applications in optoelectronic devices (Turkoglu et al, 2017; Mellerup and Wang, 2019). The p-orbital, which is vacant by boron atoms, has electron-deficient or Lewis-acidic properties (Brown and Dodson, 1957). Such electron deficient boron can undergo pi conjugation with an organic conjugated system via the pz orbital of the empty boron and the pi orbital of carbon. Due to its sp²The hybrid triangular planar geometry has a rigid/planar molecular structure, resulting in less non-radiative decay, showing a very high photoluminescence quantum yield (PLQY) (Elbin and Bazan, 2008; Von Grotthus et al, 2018).

Polycyclic aromatic compounds containing boron atoms exhibit excellent performance in the field of photoelectricity, but the production method thereof has three major problems. First, many conventional designs inevitably use t-butyl lithium, a high-risk reagent. Secondly, the low yield (lower than 20%) of the boronation in the traditional scheme causes huge waste of raw materials, increases the production cost and limits large-scale application. Thirdly, the traditional boronation ring-closing scheme is quite difficult to functionalize, and few groups can simultaneously bear high temperature and high pressure and strong acid and alkali environments in the reaction process.

Therefore, the prior art is still subject to further improvement.

Disclosure of Invention

In view of the above-mentioned disadvantages of the prior art, an object of the present invention is to provide a halogenated polycyclic aromatic compound containing a boron atom and a method for preparing the same, which can solve the problem of low yield of the conventional preparation of a polycyclic aromatic compound containing a boron atom.

In a first aspect, a method for producing a halogenated polycyclic aromatic compound containing a boron atom, comprising:

dissolving a synthesis precursor in an organic solvent to obtain a synthesis precursor solution;

adding n-butyllithium into the synthetic precursor solution in an inert atmosphere under an ice-bath condition, and reacting for a first preset time to obtain a mixed solution containing an intermediate product;

adding boron tribromide into the mixed solution containing the intermediate product, reacting for a second preset time, and then adding NEt (i-Pr) under ice bath condition₂Injecting the mixture into the mixed solution containing the intermediate product, and heating the mixed solution to a preset temperature for reaction to obtain the halogenated polycyclic aromatic compound containing the boron atom;

the synthesis precursor has the following structural general formula:

wherein D is₁And D₂Each independently selected from the group consisting of modified and unmodified nitrogen-containing aromatic groups or nitrogen-containing heteroaromatic groups; x_1、X₂Is a halogen atom.

Optionally, the preparation method, wherein the organic solvent is selected from one or more of mesitylene, o-dichlorobenzene and xylene.

Alternatively, the production method, wherein an addition equivalent of the n-butyllithium is 0.5 to 1.5 times an addition equivalent of the precursor.

Alternatively, the preparation method, wherein D₁And D₂Each independently selected from the group having the structure:

wherein R is_n(n ═ 1,2,3, 4,5,6,7,8) is independently hydrogen, cyano, trifluoromethyl, aryl having 6 to 30 carbon atoms, heteroaryl having 2 to 30 carbon atoms, alkyl having 1 to 12 carbon atoms, alkoxy or aryloxy having 1 to 12 carbon atoms or a halogen atom; m is selected from carbon atom, oxygen atom, sulfurAny of atoms, silicon atoms, and boron atoms.

Optionally, the preparation method, wherein the step of adding n-butyllithium to the synthesis precursor solution in an inert atmosphere under an ice bath condition, and reacting for a first predetermined time to obtain a mixed solution containing an intermediate product specifically includes:

dropwise adding n-butyllithium into the synthetic precursor solution in an inert atmosphere under an ice bath condition, and reacting for 10-30min to obtain a mixed solution containing an intermediate product;

the n-pentane solvent in the mixed solution containing the intermediate product was removed under stirring.

Optionally, the preparation method includes the steps of adding boron tribromide to the mixed solution containing the intermediate product, after reacting for a second predetermined time, injecting diisopropylethylamine into the mixed solution containing the intermediate product under an ice bath condition, and heating to a predetermined temperature to react, so as to obtain the halogenated polycyclic aromatic compound containing the boron atom, and specifically includes:

adding boron tribromide into the mixed solution containing the intermediate product at the temperature below-40 ℃, reacting for 10-20min, and naturally heating to 20-25 ℃;

and (3) under the ice bath condition, injecting diisopropylethylamine into the mixed solution containing the intermediate product, heating to 150-200 ℃, and reacting for 10-15 hours to obtain the halogenated polycyclic aromatic compound containing the boron atom.

In a second aspect, the present invention provides a halogenated polycyclic aromatic compound containing a boron atom, wherein the halogenated polycyclic aromatic compound has the following structural formula:

wherein D is₁And D₂Each independently selected from a nitrogen-containing aromatic group or a nitrogen-containing heteroaromatic group; x₁Is a halogen atom.

Optionally, said halo containing a boron atomA polycyclic aromatic compound, wherein D is₁And D₂Each independently selected from an aromatic group or a heteroaromatic group having a nitrogen atom as a terminal group and being singly bonded to a boron atom.

Optionally, the halogenated polycyclic aromatic compound containing a boron atom, wherein D is₁Selected from nitrogen-containing aromatic groups modified by cyano, trifluoromethyl, aryl with 6-30 carbon atoms, heteroaryl with 2-30 carbon atoms, alkyl with 1-12 carbon atoms, alkoxy with 1-12 carbon atoms or aryloxy;

or said D₁Selected from nitrogen-containing heteroaromatic group modified by cyano, trifluoromethyl, aryl group with carbon number of 6-30, heteroaryl group with carbon number of 2-30, alkyl group with carbon number of 1-12, alkoxy group with carbon number of 1-12 or aryloxy group;

said D₂Selected from nitrogen-containing aromatic groups modified by cyano, trifluoromethyl, aryl with 6-30 carbon atoms, heteroaryl with 2-30 carbon atoms, alkyl with 1-12 carbon atoms, alkoxy with 1-12 carbon atoms or aryloxy;

or said D₂Selected from nitrogen-containing heteroaromatic group modified by cyano, trifluoromethyl, aryl group with 6-30 carbon atoms, heteroaryl group with 2-30 carbon atoms, alkyl group with 1-12 carbon atoms, alkoxy group with 1-12 carbon atoms or aryloxy group.

Optionally, the halogenated polycyclic aromatic compound containing a boron atom includes the following structural formula:

wherein, X₁Selected from Br or Cl.

Has the advantages that: the embodiment of the invention provides a preparation method of a halogenated polycyclic aromatic compound containing boron atoms, which does not relate to high-risk reagents and has the characteristics of simple synthesis process and high production efficiency.

Detailed Description

The present invention provides a halogenated polycyclic aromatic compound containing a boron atom and a method for producing the same, and the present invention will be described in further detail below in order to make the objects, the technical means, and the effects of the present invention clearer and clearer. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

The invention provides a halogenated polycyclic aromatic compound containing boron atoms, which has the following structural general formula:

wherein D is₁And D₂Each independently selected from a nitrogen-containing aromatic group or a nitrogen-containing heteroaromatic group; or said D₁Selected from nitrogen-containing aromatic group or heteroaromatic group modified by cyano, trifluoromethyl, aryl group with 6-30 carbon atoms, heteroaryl group with 2-30 carbon atoms, alkyl group with 1-12 carbon atoms, alkoxy group with 1-12 carbon atoms or aryloxy group; said D₂Selected from nitrogen-containing aromatic group or heteroaromatic group modified by cyano, trifluoromethyl, aryl group with 6-30 carbon atoms, heteroaryl group with 2-30 carbon atoms, alkyl group with 1-12 carbon atoms, alkoxy group with 1-12 carbon atoms or aryloxy group; x₁Is F, Cl, Br or I.

Illustratively, the halogenated polycyclic aromatic compound containing a boron atom includes, but is not limited to, the following structure (in X)₁Br for example):

based on the same inventive concept, the present invention also provides a method for preparing a halogenated polycyclic aromatic compound containing a boron atom, the method comprising:

s10, dissolving the synthesis precursor in an organic solvent to obtain a synthesis precursor solution;

s20, adding n-butyllithium into the synthetic precursor solution under an ice bath condition in an inert atmosphere, and reacting for a first preset time to obtain a mixed solution containing an intermediate product;

s30, adding boron tribromide into the mixed solution containing the intermediate product, reacting for a second preset time, and then adding NEt (i-Pr) under ice bath condition₂(diisopropylethylamine) is injected into the mixed solution containing the intermediate product, and the temperature is raised to a preset temperature for reaction to obtain the halogenated polycyclic aromatic compound containing the boron atom;

the synthesis precursor has the following structural general formula:

wherein D is₁And D₂Each independently selected from the group consisting of modified and unmodified nitrogen-containing aromatic groups or nitrogen-containing heteroaromatic groups; x_1、X₂Is a halogen atom.

In this example, the synthetic precursor was obtained by electrophilic boriding using n-butyllithium as the lithium reagent, which was 0.5-1.5 times the equivalent of the synthetic precursor and was able to remove D directionally₁And D₂X between radicals₂(bromo) atom and protecting para-X thereof₁Is not affected by the lithium reagent.

Illustratively, the method for preparing a halogenated polycyclic aromatic compound containing a boron atom can be described by the following general formula, comprising the following two steps:

wherein, C₁And C₂Indicates the attachment site.

In the first step, compound comp 1 may be reacted in C by one or more chemical reactions₁And C₂Two sites and D₁And D₂The groups are connected to obtain a compound comp 2;

in the second step, compound comp 2 can be prepared by mixing n-butyllithium and D in a certain ratio₁And D₂X in between₂After directional lithium-halogen exchange of halogen atom, boronizing the ring to obtain compound comp 3. Wherein, boron tribromide with effective concentration higher than 90% is used in the ring closing boronization process.

Based on the same inventive concept, the present invention also provides an application of a halogenated polycyclic aromatic compound containing a boron atom, which is used in an optoelectronic device.

The preparation of the halogenated polycyclic aromatic compound containing a boron atom provided by the present invention is further illustrated by the following specific examples.

Example 1:

multiple resonance molecules of halogenated boron nitrogen

1) Synthesis of intermediate (1)

First, carbazole (7.36g, 44mmol) and Cs were sequentially added to a 250mL two-necked round-bottomed flask₂CO₃(32.50g, 100mmol) then, under Ar, 50mL of ultra dry DMF was injected via syringe to give a suspension which was stirred at 60 ℃ for 15 minutes. Finally, 5-bromo-2-chloro-1, 3-difluorobenzene (5.44g, 20mmol) was added all at once from the side port of the reaction flask and the temperature was raised to 155 ℃ for reaction for 12 h. After the reaction is finished, cooling to room temperature, filtering out insoluble inorganic salt, and then utilizingThe high boiling DMF solvent was removed by concentration in vacuo and the residue was purified by column chromatography using an optimized eluent formulation DCM/PE (1: 5, v/v) to afford intermediate (1).

2) Synthesis of halogenated boron-nitrogen multiple resonance molecule (I)

To a 120mL thick-walled pressure-resistant bottle with a branched mouth, intermediate (1) (2.83g, 5mmol) and ultra-dry mesitylene (50mL) were added, and the Ar atmosphere in the bottle was maintained. Then, n-butyllithium (b) was added dropwise under ice-bathⁿBuLi, 2.2mL, 5.5mmol), and after maintaining the reaction at low temperature for 20 minutes, stirring was continued at room temperature for 1 hour, during which the low-boiling n-pentane solvent in the butyllithium was pumped out by an oil pump. Then boron tribromide (0.95mL, 10mmol) was injected rapidly at-40 ℃ and after keeping at low temperature for 15 minutes, it was stirred for 0.5 hour by naturally warming to room temperature. Finally, continue to inject NEt (i-Pr) in ice bath₂(1.6mL, 10mmol), the tube was sealed, the temperature was raised to 180 ℃ and the mixture was stirred for 12 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, quenched by the addition of 5mL of ice water, extracted with 100mL of dichloromethane, and the combined organic layers were concentrated in vacuo. The residue was separated using an automatic column chromatography, the eluent was set to DCM/PE (1:10, v/v), and the product (r) was isolated. 1H NMR (500MHz, Chloroform-d) delta [ ppm]：8.55(d,J＝7.3Hz,2H),8.19(s,2H),7.94(dd,J＝8.0,1.4Hz,2H),7.50–7.58(m,4H),7.35–7.29(m,4H),7.16(ddd,J＝8.8,7.1,1.9Hz,2H).13C NMR(126MHz,Chloroform-d)δ[ppm]：145.46,143.53,135.55,126.66,125.19,124.39,122.36,121.48,120.09,119.83,119.41,116.72,111.18,109.56,105.42.HRMS:(ESI)m/z calcd for C₃₀H₁₆BBrN₂[M+H]+:495.19；found:495.21。

Example 2:

halogenated boron-nitrogen multiple resonance molecule 2

1) Synthesis of intermediate (2)

First, 3, 6-di-tert-butylcarbazole (12.29g, 44mmol), and Cs were added in this order to a 250mL two-necked round-bottomed flask₂CO₃(32.50g, 100mmol) then, under Ar, 50mL of ultra dry DMF was injected via syringe to give a suspension which was stirred at 60 ℃ for 15 minutes. Finally, 5-bromo-2-chloro-1, 3-difluorobenzene (5.44g, 20mmol) was added all at once from the side port of the reaction flask and the temperature was raised to 155 ℃ for reaction for 12 h. After the reaction was complete, the temperature was reduced to room temperature, the insoluble inorganic salt was filtered off, the high boiling DMF solvent was then removed by concentration in vacuo and the residue was purified by column chromatography with an optimized eluent formulation DCM/PE (1: 5, v/v) to give intermediate (2) as a white powder (13.61 g).

2) Synthesis of halogenated boron-nitrogen multiple resonance molecule (II)

To a 120mL thick-walled pressure-resistant bottle with a branch mouth, intermediate (2) (3.95g, 5mmmol) and ultra-dry mesitylene (50mL) were added, and the Ar atmosphere in the bottle was maintained. Then, n-butyllithium (b) was added dropwise under ice-bathⁿBuLi, 2.2mL, 5.5mmol), and after maintaining the reaction at low temperature for 20 minutes, stirring was continued at room temperature for 1 hour, during which the low-boiling n-pentane solvent in the butyllithium was pumped out by an oil pump. Then boron tribromide (0.95mL, 10mmol) was injected rapidly at-40 ℃ and after keeping at low temperature for 15 minutes, it was stirred for 0.5 hour by naturally warming to room temperature. Finally, continue to inject NEt (i-Pr) in ice bath₂(1.6mL, 10mmol), the tube was sealed, the temperature was raised to 180 ℃ and the mixture was stirred for 12 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, quenched by the addition of 5mL of ice water, extracted with 100mL of dichloromethane, and the combined organic layers were concentrated in vacuo. The residue was separated using an automatic column chromatography, the eluent was set to DCM/PE (1:10, v/v), and 1.94g of a product was isolated as a yellow powder. 1H NMR (500MHz, Chloroform-d) delta [ ppm]：8.97(d,J＝2.0Hz,2H),8.35(d,J＝1.8Hz,2H),8.14–8.09(m,4H),8.05(d,J＝8.8Hz,2H),7.57(dd,J＝8.7,2.1Hz,2H),1.67(s,18H),1.53(s,18H).13C NMR(126MHz,Chloroform-d)δ145.56,144.81,144.48,141.38,137.95,129.72,127.15,124.49,123.69,120.88,117.28,114.12,110.76,35.30,34.91,32.32,31.97.HRMS:(ESI)m/z calcd for C⁴⁶H⁴⁸BBrN₂[M+H]+:718.62；found:718.70。

Example 3:

multiple resonance molecules of halogenated boron nitrogen

1) Synthesis of intermediate (3)

First, 9-Dimethylacridine (DMAC) (9.21g, 44mmol), Cs were added in this order to a 250mL two-necked round-bottomed flask₂CO₃(32.50g, 100mmol) then, under Ar, 50mL of ultra dry DMF was injected via syringe to give a suspension which was stirred at 60 ℃ for 15 minutes. Finally, 5-bromo-2-chloro-1, 3-difluorobenzene (5.44g, 20mmol) was added all at once from the side port of the reaction flask and the temperature was raised to 155 ℃ for reaction for 12 h. After the reaction is complete, the temperature is reduced to room temperature, the insoluble inorganic salts are filtered off, the DMF solvent with high boiling point is then removed by concentration in vacuo, and the residue is purified by column chromatography, with an optimum eluent formulation DCM/PE (1: 5, v/v), giving the intermediate (3) as a white powder.

2) Synthesis of halogenated boron-nitrogen multiple resonance molecule

To a 120mL thick-walled pressure-resistant bottle with a branched mouth, the intermediate (3) (3.45g, 5mmol) and ultra-dry mesitylene (50mL) were added, and the Ar atmosphere in the bottle was maintained. Then, n-butyllithium (b) was added dropwise under ice-bathⁿBuLi，2.2mL，5.5mmol)，After the reaction was maintained at the low temperature for 20 minutes, stirring was continued at room temperature for 1 hour, during which the low-boiling n-pentane solvent in the butyllithium was pumped out by an oil pump. Then boron tribromide (0.95mL, 10mmol) was injected rapidly at-40 ℃ and after keeping at low temperature for 15 minutes, it was stirred for 0.5 hour by naturally warming to room temperature. Finally, continue to inject Net (i-Pr) in ice bath₂(1.6mL, 10mmol), the tube was sealed, the temperature was raised to 180 ℃ and the mixture was stirred for 12 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, quenched by the addition of 5mL of ice water, extracted with 100mL of dichloromethane, and the combined organic layers were concentrated in vacuo. Separating the residue with automatic column chromatography, configuring the eluate as DCM/PE (1:10, v/v), and separating to obtain product with powder. 1H NMR (500MHz, Chloroform-d) delta [ ppm]：7.61(d,J＝7.3Hz,2H),7.19(s,2H),7.17(dd,J＝8.0,1.4Hz,2H),7.00–6.95(m,4H),6.88(ddd,J＝8.8,7.1,1.9Hz,2H),1.69(s,12H).13C NMR(126MHz,Chloroform-d)δ[ppm]：144.54,141.32,135.56,132.62,132.06,131.86,130.55,125.41,124.91,123.57,123.04,116.34,115.37,30.91,22.74.HRMS:(ESI)m/z calcd for C₃₆H₂₈BBrN₂[M+H]+:579.28；found:579.35。

Example 4:

halogenated boron-nitrogen multiple resonance molecule

1) Synthesis of intermediate (4)

First, phenothiazine (8.77g, 44mmol) and Cs were added in this order to a 250mL two-necked round-bottomed flask₂CO₃(32.50g, 100mmol) then, under Ar, 50mL of ultra dry DMF was injected via syringe to give a suspension which was stirred at 60 ℃ for 15 minutes. Finally, 5-bromo-2-chloro-1, 3-difluorobenzene (5.44g, 20mmol) was added all at once from the side port of the reaction flask and the temperature was raised to 155 ℃ for reaction for 12 h. After the reaction is finished, cooling to room temperature, filtering out insoluble inorganic salt, and then concentrating by vacuumThe high boiling DMF solvent was condensed off and the residue was purified by column chromatography with an optimized eluent formulation DCM/PE (1: 5, v/v) to give intermediate (4) as a powder.

2) Synthesis of halogenated boron-nitrogen multiple resonance molecule

To a 120mL thick-walled pressure-resistant bottle with a branched mouth, intermediate (4) (3.15g, 5mmol) and ultra-dry mesitylene (50mL) were added, and the Ar atmosphere in the bottle was maintained. Then, n-butyllithium (b) was added dropwise under ice-bathⁿBuLi, 2.2mL, 5.5mmol), and after maintaining the reaction at low temperature for 20 minutes, stirring was continued at room temperature for 1 hour, during which the low-boiling n-pentane solvent in the butyllithium was pumped out by an oil pump. Then boron tribromide (0.95mL, 10mmol) was injected rapidly at-40 ℃ and after keeping at low temperature for 15 minutes, it was stirred for 0.5 hour by naturally warming to room temperature. Finally, continue to inject NEt (i-Pr) in ice bath₂(1.6mL, 10mmol), the tube was sealed, the temperature was raised to 180 ℃ and the mixture was stirred for 12 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, quenched by the addition of 5mL of ice water, extracted with 100mL of dichloromethane, and the combined organic layers were concentrated in vacuo. Separating the residue with an automatic column chromatography, configuring the eluent as DCM/PE (1:10, v/v), and separating to obtain powder product (1H NMR (500MHz, Chloroform-d) delta ppm [ ppm ]]：7.91(d,J＝7.3Hz,2H),7.87(s,2H),7.62(dd,J＝8.0,1.4Hz,2H),7.36–7.29(m,4H),7.19–7.12(m,4H),7.06(ddd,J＝8.8,7.1,1.9Hz,2H).13C NMR(126MHz,Chloroform-d)δ[ppm]：144.54,143.92,143.86,132.82,132.16,128.16,127.25,127.11,124.91,123.77,123.57,121.84,116.34.HRMS:(ESI)m/z calcd for C₃₀H₁₆BBrN₂S₂[M+H]+:559.27；found:559.31。

Example 5:

multiple resonance molecule of halogenated boron nitrogen

1) Synthesis of intermediate (5)

First, to a 250mL two-necked round bottom flask was added in order phenoxazine (8.06g, 44mmol), Cs₂CO₃(32.50g, 100mmol) then, under Ar, 50mL of ultra dry DMF was injected via syringe to give a suspension which was stirred at 60 ℃ for 15 minutes. Finally, 5-bromo-2-chloro-1, 3-difluorobenzene (5.44g, 20mmol) was added all at once from the side port of the reaction flask and the temperature was raised to 155 ℃ for reaction for 12 h. After the reaction is complete, the reaction is cooled to room temperature, the insoluble inorganic salts are filtered off, the DMF solvent with high boiling point is then removed by concentration in vacuo, and the residue is purified by column chromatography, using an optimized eluent formulation DCM/PE (1: 5, v/v), giving a powder of intermediate (5).

2) Synthesis of haloboron-nitrogen multiple resonance molecule

To a 120mL thick-walled pressure-resistant bottle with a branched mouth, intermediate (5) (3.00g, 5mmol) and ultra-dry mesitylene (50mL) were added, and the Ar atmosphere in the bottle was maintained. Then, n-butyllithium (b) was added dropwise under ice-bathⁿBuLi, 2.2mL, 5.5mmol), and after maintaining the reaction at low temperature for 20 minutes, stirring was continued at room temperature for 1 hour, during which the low-boiling n-pentane solvent in the butyllithium was pumped out by an oil pump. Then boron tribromide (0.95mL, 10mmol) was injected rapidly at-40 ℃ and after keeping at low temperature for 15 minutes, it was stirred for 0.5 hour by naturally warming to room temperature. Finally, continue to inject NEt (i-Pr) in ice bath₂(1.6mL, 10mmol), the tube was sealed, the temperature was raised to 180 ℃ and the mixture was stirred for 12 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, quenched by the addition of 5mL of ice water, extracted with 100mL of dichloromethane, and the combined organic layers were concentrated in vacuo. Separating residue with automatic column chromatography, setting eluent configuration as DCM/PE (1:10, v/v), and separating to obtain powder product with properties of (1H NMR 500MHz, Chloroform-d) delta ppm]：8.03(d,J＝7.3Hz,2H),7.82(s,2H),7.62(dd,J＝8.0,1.4Hz,2H),7.26–7.19(m,4H),7.18–7.10(m,4H),7.06(ddd,J＝8.8,7.1,1.9Hz,2H).13C NMR(126MHz,Chloroform-d)δ[ppm]：146.31,144.52,139.25,134.51,131.23,130.24,127.86,127.73,127.45,124.92,123.56,116.33,114.91,113.34.HRMS:(ESI)m/z calcd for C₃₀H₁₆BBrN₂O₂[M+H]+:527.12；found:527.18。

It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.