Chiral recognition material and its preparation method and application

Abstract

The present application discloses a chiral recognition material, a preparation method, and an application thereof. The chiral recognition material disclosed in the present application is obtained by chemically modifying a dihydrodibenzophenazine derivative as a parent material. The chiral recognition material has the functions of both chiral recognition of natural chiral compounds using luminescence color differences and ee value detection of natural chiral compounds using ratiometric fluorescence. The chiral recognition effect is obvious and the environmental requirements are less restricted.

Description

Technical Field

[0001] The present invention relates to the technical field of organic luminescent materials, and in particular to a chiral recognition material and a preparation method and application thereof. Background Art

[0002] The enantiomers of naturally occurring chiral compounds often exhibit distinct properties. In some specific compounds, the disparity between enantiomers can be even more pronounced, with one enantiomer exhibiting a pronounced effect while the other is inactive or even toxic. Therefore, chiral identification and determination of the enantiomeric purity of naturally occurring chiral compounds are of great importance.

[0003] Light, due to its non-invasive nature, has become a key method for amplifying microscopic molecular chirality to macroscopic manifestations. However, most current methods for chiral identification using luminescence rely on changes in luminescence intensity, which is difficult to discern visually and generally requires the use of expensive spectrometers. In contrast, changes in luminescence wavelength, particularly those in the visible light band, are easily detected by the human eye as shifts in luminescence color, facilitating chiral identification. Furthermore, current methods that use changes in light intensity to measure enantiomeric excess (EE) have high environmental requirements, and the intensity obtained in different environments often varies significantly. Using ratiometric fluorescence to measure EE can significantly reduce environmental impacts, making it a promising development direction.

[0004] However, currently, there are few materials that can simultaneously use the difference in luminescence color to identify the chirality of natural chiral compounds and use ratiometric fluorescence to detect the ee value of natural chiral compounds. Summary of the Invention

[0005] The present application provides a chiral recognition material, a preparation method and an application thereof. The chiral recognition material has the functions of both chiral recognition of natural chiral compounds using luminescent color differences and ee value detection of natural chiral compounds using ratiometric fluorescence.

[0006] In a first aspect, the present invention provides a chiral recognition material having a chemical structure shown in formula (I) or (II):

[0007]

[0008] Wherein, n represents the number of methylene groups, and n is any integer between 1 and 10. The R group has a chemical structure shown in any one of formulas (A1) to (A4):

[0009]

[0010] In some embodiments, the chiral material has dual emission capabilities, and the chiral recognition material has luminescence properties at wavelengths of 460 nm and 600 nm.

[0011] In some embodiments, the chiral recognition material exhibits different luminescence intensities in ethyl acetate, methanol, acetonitrile, and N,N-dimethylformamide.

[0012] In a second aspect, the present invention provides a method for preparing a chiral recognition material, comprising the following steps:

[0013] (1) Preparation of dihydrodibenzophenazine derivatives;

[0014] (2) Chemically modifying the dihydrodibenzophenazine derivative to obtain the chiral recognition material.

[0015] In a third aspect, the present invention provides an application method of a chiral recognition material, comprising the following steps:

[0016] (1) mixing a chiral recognition material and a chiral acid in an organic solvent to obtain a mixed solution;

[0017] (2) Based on the mixed solution, detecting the chiral enantiomer type and enantiomeric excess percentage of the chiral acid.

[0018] In some embodiments, the organic solvent comprises at least one of cyclohexane, acetone, chloroform, dichloromethane, ethyl acetate, and tetrahydrofuran.

[0019] In some embodiments, the organic solvent includes cyclohexane and acetone, and the ratio of the cyclohexane to the acetone is 5:1 by mass.

[0020] In some embodiments, the ratio of the chiral recognition material to the chiral acid is 0.1-10 by mass percentage.

[0021] In some embodiments, in step (2), the chiral enantiomer type of the chiral acid is determined based on the luminescence wavelength of the mixed solution.

[0022] In some embodiments, in step (2), the enantiomeric excess percentage of the chiral acid in the mixed solution is determined based on the ratiometric fluorescence ratio of the mixed solution.

[0023] As can be seen from the above technical solution, this specification provides a chiral recognition material, which is obtained by chemically modifying a dihydrodibenzophenazine derivative as a parent material. The raw materials are pure organic compounds with a wide source, easy availability, low price, simple synthesis, and convenient preparation. In addition, the chiral recognition material has stable luminescence properties and can be used in air without the need for inert gas protection or a vacuum environment. In addition, the chiral recognition material has the functions of chiral recognition of natural chiral compounds using luminescence color differences and ee value detection of natural chiral compounds using ratiometric fluorescence. The chiral recognition effect is obvious, the environmental requirements are less restricted, and it is suitable for chiral recognition of natural chiral compounds, enantiomeric purity analysis, and other aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 Fluorescence spectra of chiral recognition materials provided in some embodiments of the present application obtained when dissolved in different solvents;

[0026] Figure 2 Pictures of different mixed solutions provided in some application examples of this application after being irradiated by 365nm UV lamp;

[0027] Figure 3 Fluorescence spectra of different solutions provided for some application examples of this application;

[0028] Figure 4 Schematic diagram of a curve showing the ratio fluorescence as the ordinate and the ee value as the abscissa after the chiral recognition material provided in some application examples of this application is mixed with a chiral acid;

[0029] Figure 5 Images of the chiral recognition material (1S,2R)-DPAC provided in some application examples of this application mixed with chiral acids (B-5) with different ee values ​​and processed using standard colorimetric software;

[0030] Figure 6 Images of the chiral recognition material (1R,2S)-DPAC provided in some application examples of this application mixed with chiral acids (B-5) with different ee values ​​and processed using standard colorimetric software;

[0031] Figure 7 Pictures of different mixed solutions provided in some application examples of this application after being irradiated by 365nm UV lamp;

[0032] Figure 8 Fluorescence spectra of different solutions provided for some application examples of this application;

[0033] Figure 9 Pictures of different mixed solutions provided in some application examples of this application after being irradiated by 365nm UV lamp;

[0034] Figure 10 Fluorescence spectra of different solutions provided for some application examples of this application. DETAILED DESCRIPTION

[0035] To facilitate understanding of this specification, a more comprehensive description of the specification will be provided below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of this specification. However, this specification can be implemented in many different forms without departing from the core spirit of this specification and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of this specification.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this specification pertains. The terms used herein in this specification are for the purpose of describing specific embodiments only and are not intended to limit this specification. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0037] In a first aspect, the present invention provides a chiral recognition material having a chemical structure shown in formula (I) or (II):

[0038]

[0039] Wherein, n represents the number of methylene groups, and n is any integer between 1 and 10. The R group has a chemical structure shown in any one of formulas (A1) to (A4):

[0040]

[0041] The chiral recognition materials provided in the present embodiments exhibit dual emission properties, exhibiting luminescence at 460 nm and 600 nm. Furthermore, when the chiral recognition materials are dissolved in different solvent systems, the corresponding fluorescence intensities at the two emission wavelengths vary. This indicates that different solvent systems may affect the fluorescence emission intensity of the chiral recognition materials.

[0042] In some embodiments, the chiral recognition material exhibits different luminescence intensities in ethyl acetate, methanol, acetonitrile, and N,N-dimethylformamide, and the absolute fluorescence quantum yield of the chiral recognition material is ≥0.1%.

[0043] In a second aspect, the present invention provides a method for preparing a chiral recognition material, comprising the following steps:

[0044] (1) Preparation of dihydrodibenzophenazine derivatives. The chemical reaction equation involved in the process of preparing dihydrodibenzophenazine derivatives can be as follows:

[0045]

[0046] (2) Chemically modifying the dihydrodibenzophenazine derivative to obtain a chiral recognition material. The chemical reaction equation for chemical modification using the dihydrodibenzophenazine derivative as the parent is as follows:

[0047]

[0048] In the above synthesis process, compound 2 is a dihydrodibenzophenazine derivative, and compound 3 is a synthesized chiral recognition material. The chemical structure of the chiral recognition material is consistent with formula (I), and the modifying group is formula (A1). It should be understood that if compound 1 containing only one hydroxyl group is used as the reaction raw material in the above synthesis process, the chiral recognition material represented by formula (II) can be synthesized according to the above synthesis route.

[0049] In a third aspect, an embodiment of the present application provides an application method of a chiral recognition material, comprising the following steps: (1) mixing a chiral recognition material and a chiral acid in an organic solvent to obtain a mixed solution; and (2) detecting the type of chiral enantiomer and the enantiomeric excess percentage of the chiral acid based on the mixed solution.

[0050] The chiral acid can be selected from any one of the compounds of formula (B-1) to (B-25):

[0051]

[0052]

[0053] In some embodiments, the organic solvent comprises at least one of cyclohexane, acetone, chloroform, dichloromethane, ethyl acetate, and tetrahydrofuran. In the embodiments of the present application, after mixing the chiral recognition material and the chiral acid in the aforementioned organic solvent, the resulting mixed solution can be subjected to a luminescence color difference test to achieve chiral recognition of the natural chiral compound. Furthermore, the resulting mixed solution can be subjected to ratiometric fluorescence detection to determine the ee value of the natural chiral compound.

[0054] In some embodiments, the organic solvent includes cyclohexane and acetone, and the ratio of cyclohexane to acetone is 5:1 by mass. The inventors have discovered through extensive experiments that by mixing cyclohexane and acetone in the aforementioned ratio to form a mixed solvent, dissolving a chiral recognition material and a chiral acid in the mixed solvent, and then performing chiral recognition of natural chiral compounds using luminescence color differences and EE value detection of natural chiral compounds using ratiometric fluorescence, respectively, a strong detection signal and high signal responsiveness can be achieved, thereby improving detection accuracy.

[0055] In some embodiments, the ratio of the chiral recognition material to the chiral acid is 0.1-10 by weight. When using the chiral recognition material and the chiral acid for the above-mentioned detection, the amount of both added has a certain impact on the detection results. Excessive or insufficient addition of either substance will lead to signal weakening, affecting the accuracy of the detection results. The inventors have found through experiments that controlling the ratio of the chiral recognition material to the chiral acid within the range of 0.1-10 can maintain a good detection signal level.

[0056] In some embodiments, in step (2), the chiral enantiomer species of the chiral acid is determined based on the luminescence wavelength of the mixed solution.

[0057] In some embodiments, in step (2), the enantiomeric excess percentage of the chiral acid in the mixed solution is determined based on the ratiometric fluorescence ratio of the mixed solution.

[0058] The following are specific preparation examples related to the above-mentioned content of this disclosure. It should be understood that the following examples are merely illustrative of the dual-component doped optical materials disclosed above, their preparation methods, and applications. The specific implementation methods and parameters used herein are merely one or more of the numerous processes and methods described above. Those skilled in the art can prepare dual-component doped optical materials using other parameters according to the above-mentioned methods based on the content of this specification without departing from the core spirit disclosed in the application.

[0059] Example 1

[0060] This embodiment provides a chiral recognition material, comprising the following steps:

[0061] (1) Preparation of dihydrodibenzophenazine derivatives. The chemical reaction equation involved in the process of preparing dihydrodibenzophenazine derivatives can be as follows:

[0062]

[0063] Compound 1 (300 mg, 0.61 mmol, 1 equivalent) was dissolved in 20 mL of ultra-dry tetrahydrofuran, and 2-bromoethanol (1.51 g, 12.1 mmol, 20 equivalents) and p-toluenesulfonic acid (115.5 mg, 0.67 mmol, 1.1 equivalents) were added. The reaction was stirred at room temperature for 3 hours. After the reaction, the solvent was removed in vacuo, the mixture was quenched with water, and the organic layer was extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, filtered and concentrated, and then purified by silica gel column chromatography (petroleum ether:ethyl acetate = 2:1) to obtain 350 mg of a white solid (compound 2). Compound 2 is a dihydrodibenzophenazine derivative with a mass ratio of 5.0 and a yield of 81.2%.

[0064] (2) Chemically modifying the dihydrodibenzophenazine derivative to obtain a chiral recognition material. The chemical reaction equation for chemical modification using the dihydrodibenzophenazine derivative as the parent is as follows:

[0065]

[0066] Compound 2 (400 mg, 0.56 mmol, 1 eq), (1S,2R)-2-amino-1,2-diphenylethanol (481 mg, 2.26 mmol, 4 eq), and K2CO3 (232.2 mg, 1.68 mmol, 3 eq) were added to ultra-dry acetonitrile (100 mL) and refluxed at 50°C with stirring for 10 hours. After completion of the reaction, the mixture was quenched with water and extracted with dichloromethane. The organic layer was dried over anhydrous magnesium sulfate, filtered, concentrated, and purified by silica gel column chromatography (dichloromethane:methanol = 10:1) to obtain 210 mg of a white solid (compound 3). Compound 3 was the chiral recognition material in a yield of 38.6%.

[0067] The chiral recognition material prepared in Example 1 was dissolved in ethyl acetate (EA), methanol (MeOH), acetonitrile (MeCN), and N,N-dimethylformamide (DMF), respectively, and the fluorescence luminescence of the solution was detected. Figure 1 The following graphs show the fluorescence spectra of the chiral recognition material prepared in Example 1 when dissolved in different solvents, wherein the horizontal axis is the wavelength and the vertical axis is the intensity. Figure 1 As shown, the chiral recognition material has dual emission capabilities, exhibiting luminescence characteristics at wavelengths of 460nm and 600nm respectively. In addition, the chiral recognition material exhibits different luminescence intensities in different solvents (such as ethyl acetate, methanol, acetonitrile, and N,N-dimethylformamide).

[0068] Application Example 1

[0069] The chiral recognition material prepared in Example 1 has two enantiomers, which are respectively represented as (1S, 2R)-DPAC and (1R, 2S)-DPAC for easy distinction.

[0070] In this application example, the chiral recognition material is used to recognize the chiral acid (B-5).

[0071] Cyclohexane and acetone were prepared into a mixed solvent in a mass ratio of 5:1, (1S,2R)-DPAC was dissolved in the mixed solvent, and two chiral enantiomers RB-5 and SB-5 of the chiral acid (B-5) were added to the mixed solvent respectively to obtain mixed solution 1 and mixed solution 2, wherein the chiral enantiomer RB-5 was added to mixed solution 1, and the chiral enantiomer SB-5 was added to mixed solution 2.

[0072] Mixed solution 1 and mixed solution 2 were irradiated with 365nm ultraviolet light. Figure 2 The following pictures show the two mixed solutions in Application Example 1 after being irradiated by 365nm UV lamp. Figure 2 As shown, for chiral acids with different configurations, after mixing them with chiral recognition materials, obvious differences in luminescent colors can be observed with the naked eye after irradiation with a 365nm ultraviolet lamp.

[0073] The fluorescence luminescence of mixed solution 1 and mixed solution 2 was detected. Figure 3 The fluorescence spectra of different solutions in Application Example 1 are shown, wherein the horizontal axis is the wavelength and the vertical axis is the intensity. Figure 3 As shown in the figure, compared with the case where only (1S,2R)-DPAC exists, obvious wavelength differences can be observed after mixing (1S,2R)-DPAC with chiral acid; and different mixed solutions also have obvious wavelength differences. Figure 2 、 Figure 3 The phenomenon can confirm that the chiral recognition material prepared in Example 1 can be used for chiral recognition of natural chiral compounds.

[0074] The same equivalents of (1S,2R)-DPAC and (1R,2S)-DPAC were mixed with chiral acids (B-5) with different ee values, respectively, to obtain two curves with ratio fluorescence as the horizontal axis and ee value as the vertical axis. Figure 4 The figure shows a curve diagram of the chiral recognition material mixed with the chiral acid in Application Example 1, with the ratio fluorescence as the ordinate and the ee value as the abscissa. Figure 4 As shown in the figure, the ratio fluorescence of chiral recognition materials varies at different ee values. Figure 4 The curve shown allows for ee value detection of chiral acids based on ratiometric fluorescence of unknown ee values.

[0075] Figure 5 The images are shown after (1S,2R)-DPAC in Application Example 1 was mixed with chiral acids (B-5) of different ee values ​​and processed using standard colorimetric card software. Figure 6 The images below show the mixture of (1R,2S)-DPAC and chiral acids (B-5) with different ee values ​​from Application Example 1, processed using standard colorimetric software. As the ee value changes, the color of the mixed solution changes, as can be seen with the naked eye.

[0076] Application Example 2

[0077] In this application example, the chiral recognition material is used to recognize a chiral acid (B-11).

[0078] Cyclohexane and acetone were prepared into a mixed solvent in a mass ratio of 5:1, (1S,2R)-DPAC was dissolved in the mixed solvent, and two chiral enantiomers RB-11 and SB-11 of the chiral acid (B-11) were added to the mixed solvent, respectively, to obtain mixed solution 3 and mixed solution 4, wherein the chiral enantiomer RB-11 was added to mixed solution 3, and the chiral enantiomer SB-11 was added to mixed solution 4.

[0079] Mixed solution 3 and mixed solution 4 were irradiated with 365nm ultraviolet light. Figure 7 The following pictures show the two mixed solutions in Application Example 2 after being irradiated by 365nm UV light. Figure 7 As shown, for chiral acids with different configurations, after mixing them with chiral recognition materials, obvious differences in luminescent colors can be observed with the naked eye after irradiation with a 365nm ultraviolet lamp.

[0080] The fluorescence luminescence of mixed solution 3 and mixed solution 4 was detected. Figure 8 The fluorescence spectra of different solutions in Application Example 2 are shown, wherein the horizontal axis is the wavelength and the vertical axis is the intensity. Figure 8 As shown in the figure, compared with the case where only (1S,2R)-DPAC exists, obvious wavelength differences can be observed after mixing (1S,2R)-DPAC with chiral acid; and different mixed solutions also have obvious wavelength differences. Figure 7 、 Figure 8 The phenomenon can confirm that the chiral recognition material prepared in Example 1 can be used for chiral recognition of natural chiral compounds.

[0081] Application Example 3

[0082] In this application example, the chiral recognition material is used to recognize a chiral acid (B-20).

[0083] Cyclohexane and acetone were prepared into a mixed solvent in a mass ratio of 5:1, (1S,2R)-DPAC was dissolved in the mixed solvent, and two chiral enantiomers of the chiral acid (B-20), RB-20 and SB-20, were added to the mixed solvent, respectively, to obtain mixed solution 5 and mixed solution 6, wherein the chiral enantiomer RB-20 was added to mixed solution 5, and the chiral enantiomer SB-20 was added to mixed solution 6.

[0084] Mixed solution 5 and mixed solution 6 were irradiated with 365nm ultraviolet light. Figure 9 The following pictures show the two mixed solutions in Application Example 3 after being irradiated by 365nm UV light. Figure 9 As shown, for chiral acids with different configurations, after mixing them with chiral recognition materials, obvious differences in luminescent colors can be observed with the naked eye after irradiation with a 365nm ultraviolet lamp.

[0085] The mixed solutions 5 and 6 were tested for fluorescence luminescence. Figure 10 The fluorescence spectra of different solutions in Application Example 3 are shown, wherein the horizontal axis is the wavelength and the vertical axis is the intensity. Figure 10 As shown in the figure, compared with the case where only (1S,2R)-DPAC exists, obvious wavelength differences can be observed after mixing (1S,2R)-DPAC with chiral acid; and different mixed solutions also have obvious wavelength differences. Figure 9 、 Figure 10 The phenomenon can confirm that the chiral recognition material prepared in Example 1 can be used for chiral recognition of natural chiral compounds.

[0086] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0087] The embodiments described above only express several embodiments of the present invention, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, several variations and improvements can be made, which all fall within the scope of protection of the present invention. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided by the present invention are all within the scope of protection of the claims attached to the present invention. Therefore, the scope of protection of the patent of the present invention shall be based on the attached claims, and the description and drawings can be used to interpret the content of the claims.

Claims

1. A chiral recognition material, characterized in that Having the chemical structure shown in formula (I) or (II): Wherein, n represents the number of methylene groups, and n is any integer between 1 and 10. The R group has a chemical structure shown in any one of formulas (A1) to (A4):

2. The chiral recognition material according to claim 1, wherein The chiral recognition material has a dual emission function, and the chiral recognition material has luminescence characteristics at wavelengths of 460 nm and 600 nm.

3. The chiral recognition material according to claim 1, wherein The chiral recognition material exhibits different luminescence intensities in ethyl acetate, methanol, acetonitrile and N,N-dimethylformamide.

4. A method for preparing a chiral recognition material, characterized in that: The following steps are involved: (1) Preparation of dihydrodibenzophenazine derivatives; (2) Chemically modifying a dihydrodibenzophenazine derivative to obtain the chiral recognition material. The preparation route of the chiral recognition material is as follows:

5. A method for using the chiral recognition material according to claim 1, characterized in that: The following steps are involved: (1) mixing a chiral recognition material and a chiral acid in an organic solvent to obtain a mixed solution; (2) Based on the mixed solution, detecting the chiral enantiomer type and enantiomeric excess percentage of the chiral acid, wherein the chiral acid is selected from any one of the following compounds:

6. The method for using the chiral recognition material according to claim 5, wherein: The organic solvent is selected from at least one of cyclohexane, acetone, chloroform, dichloromethane, ethyl acetate and tetrahydrofuran.

7. The method for using the chiral recognition material according to claim 6, wherein: The organic solvents are cyclohexane and acetone, and the ratio of the cyclohexane to the acetone is 5:1 in terms of mass percentage.

8. The method for using the chiral recognition material according to claim 5, wherein: Calculated by mass percentage, the ratio of the chiral recognition material to the chiral acid is 0.1-10.

9. The method for using the chiral recognition material according to claim 5, wherein: In the step (2), the chiral enantiomer type of the chiral acid is determined based on the luminescence wavelength of the mixed solution.

10. The method for using the chiral recognition material according to claim 5, wherein: In the step (2), the enantiomeric excess percentage of the chiral acid in the mixed solution is determined based on the ratiometric fluorescence ratio of the mixed solution.

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