Thiazolinyl chiral covalent organic framework material as well as preparation method and application thereof

Abstract

A precursor of the thiazolinyl chiral covalent organic framework material is designed and synthesized, and the thiazolinyl chiral covalent organic framework material is obtained after bivalent copper salt is loaded. A precursor of the thiazolinyl chiral covalent organic framework material has the properties of high crystallinity, large porosity and good chemical stability, so that the thiazolinyl chiral covalent organic framework material has the potential of serving as a catalyst. The copper complex is synthesized from the thiazolinyl chiral covalent organic framework material obtained after loading of the cupric salt, and the copper complex has excellent Henry reaction catalysis efficiency due to the special electronic property and geometric configuration of the copper complex. Structural repeating unit of precursor of thiazolinyl chiral covalent organic framework material: # imgabs0 #

Description

Technical Field

[0001] The invention relates to the field of covalent organic framework functional materials, and in particular to a thiazoline-based chiral covalent organic framework material and a preparation method and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Henry reaction refers to an organic chemical reaction in which a nitro compound with α-active hydrogen undergoes nucleophilic addition with the carbonyl group of an aldehyde or ketone under the action of a base to generate a β-nitro alcohol. Henry reaction has been widely developed and applied in the fields of organic synthesis, drug preparation, natural product synthesis, etc. Although Henry reaction was well-known in the 19th century, the rise of chiral asymmetric Henry reaction has only occurred in recent decades. The Shibasaki research group of the University of Tokyo in Japan began to study asymmetric Henry reaction as early as 1992, and they obtained a catalytic reaction result with an enantiomeric excess (ee value) of 90%. Since then, the catalytic research of asymmetric Henry reaction has received widespread attention and great interest from workers in the field of chemistry, and many systems such as metal complex catalysts, enzyme catalysts, and organic small molecule catalysts have been developed. The development of new chiral catalysts is crucial for the development of efficient metal-catalyzed asymmetric Henry reactions.

[0004] Covalent organic framework materials (COF) are a new type of molecular sieve-like materials. They are crystalline porous polymers with a periodic network structure formed by organic small molecules containing light elements (C, H, N, O, B, etc.) connected by covalent bonds. This type of crystalline porous material has many advantages such as light weight, low density, regular structure, high specific surface area, adjustable skeleton size and modifiable pores, and has potential application value in gas storage, chemical sensing, drug release, heterogeneous catalysis, and optoelectronic materials. In recent years, chiral covalent organic framework materials have attracted great attention from chemists because of their good application prospects in asymmetric catalysis and separation of chiral compounds. Summary of the invention

[0005] In order to overcome the above problems, the present invention provides a thiazoline-based chiral covalent organic framework material and a preparation method and application thereof.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0007] The first aspect of the present invention provides a precursor of a thiazoline-based chiral covalent organic framework material, wherein the precursor has a structure represented by formula (I) as a structural repeating unit;

[0008]

[0009] The second aspect of the present invention provides a method for preparing the precursor according to the first aspect, comprising:

[0010] The precursor of the thiazoline-based chiral covalent organic framework material is synthesized by dissolving trialdehyde phloroglucinol and compound 3 in a solvent, adding acetic acid as a catalyst, and performing a solvothermal reaction;

[0011] Wherein, the structural formula of compound 3 is shown in formula (II),

[0012]

[0013] The third aspect of the present invention provides a thiazoline-based chiral covalent organic framework material, which uses the precursor of the thiazoline-based chiral covalent organic framework material prepared by the preparation method described in the first aspect and / or the second aspect as a matrix and is loaded with a divalent copper salt.

[0014] The fourth aspect of the present invention provides a method for preparing the thiazoline-based chiral covalent organic framework material according to the third aspect, comprising:

[0015] The precursor of the thiazoline-based chiral covalent organic framework material prepared by the preparation method described in the first aspect and / or the second aspect and a divalent copper salt are dispersed in a solvent, and the thiazoline-based chiral covalent organic framework material is obtained by stirring the reaction.

[0016] The fifth aspect of the present invention provides the use of the thiazoline-based chiral covalent organic framework material described in the third aspect and / or the thiazoline-based chiral covalent organic framework material prepared by the preparation method described in the fourth aspect as a catalyst.

[0017] The beneficial effects of the present invention are:

[0018] (1) The present invention designs and synthesizes the precursor of thiazoline-based chiral covalent organic framework materials, and obtains thiazoline-based chiral covalent organic framework materials after loading divalent copper salt. The precursor of the thiazoline-based chiral covalent organic framework material has the properties of high crystallinity, large porosity, and good chemical stability, and therefore has the potential to be used as a catalyst. The thiazoline-based chiral covalent organic framework material obtained after loading the divalent copper salt synthesizes a copper complex, which has excellent efficiency in catalyzing the Henry reaction due to its special electronic properties and geometric configuration. Specifically, the copper ions exist in the complex in an oxidation state of +2, and these complexes can interact with substrate molecules through their empty d orbitals, thereby activating carbonyls or nitroalkanes and reducing the activation energy of the reaction. The ligands in the copper complex can form stable coordination bonds with the copper center through their donor atoms (such as nitrogen, oxygen or sulfur), and this coordination can enhance the electron affinity of the copper center, so that the copper complex can more effectively catalyze nucleophilic addition reactions, thereby being able to efficiently catalyze the Henry reaction.

[0019] (2) The thiazoline-based chiral covalent organic framework material provided by the present invention can be used as a heterogeneous catalyst to effectively catalyze the asymmetric Henry reaction with an ee value of 92%; it can also be recycled, and the final ee value after five cycles is 90%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0021] Figure 1 This is the synthetic route of compound 3;

[0022] Figure 2 is the H NMR spectrum of compound 1;

[0023] Figure 3 is the NMR carbon spectrum of compound 1;

[0024] Figure 4 is the mass spectrum of compound 1;

[0025] Figure 5 is the infrared spectrum of compound 1;

[0026] Figure 6 is the H-NMR spectrum of compound 2;

[0027] Figure 7 is the NMR carbon spectrum of compound 2;

[0028] Figure 8 is the mass spectrum of compound 2;

[0029] Fig. 9is the infrared spectrum of compound 2;

[0030] Fig.10 is the H-NMR spectrum of compound 3;

[0031] Fig.11 is the NMR carbon spectrum of compound 3;

[0032] Fig.12 is the mass spectrum of compound 3;

[0033] Fig.13 is the infrared spectrum of compound 3;

[0034] Fig.14 The powder diffraction PXRD pattern of the precursor of the thiazoline-based chiral covalent organic framework material;

[0035] Fig.15 This is a scanning electron microscope image of the precursor of the thiazoline-based chiral covalent organic framework material;

[0036] Fig.16 This is a low-magnification transmission electron microscopy image of the precursor of the thiazoline-based chiral covalent organic framework material;

[0037] Fig.17 This is a high-magnification transmission electron microscopy image of the precursor of the thiazoline-based chiral covalent organic framework material;

[0038] Fig.18 This is the infrared spectrum of the precursor of the thiazoline-based chiral covalent organic framework material;

[0039] Fig.19 Macroscopic powder image of the precursor of thiazoline-based chiral covalent organic framework material;

[0040] Fig. 20 This is a structural simulation diagram of the precursor of thiazoline-based chiral covalent organic framework materials;

[0041] Fig.21 This is a thermogravimetric analysis diagram of the precursor of the thiazoline-based chiral covalent organic framework material;

[0042] Fig. 22 This is the powder diffraction PXRD pattern of thiazoline-based chiral covalent organic framework material;

[0043] Fig.23 This is the XPS graph of thiazoline-based chiral covalent organic framework material;

[0044] Fig.24 This is the mass spectrum of the product of the synthesis of nitromethane and benzaldehyde catalyzed by thiazoline-based chiral covalent organic framework materials;

[0045] Fig.25Liquid phase spectrum of the product of the synthesis of nitromethane and benzaldehyde catalyzed by thiazoline-based chiral covalent organic framework materials;

[0046] Fig.26 The powder diffraction PXRD pattern of the thiazoline-based chiral covalent organic framework material before and after 5 cycles of reaction;

[0047] Fig. 27 This is the ee value corresponding to the five-cycle reaction of the thiazoline-based chiral covalent organic framework material. DETAILED DESCRIPTION

[0048] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0049] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0050] A first typical embodiment of the present invention provides a precursor of a thiazoline-based chiral covalent organic framework material, wherein the precursor has a structure represented by formula (I) as a structural repeating unit;

[0051]

[0052] A second typical embodiment of the present invention provides a method for preparing the precursor according to the first aspect, comprising:

[0053] The precursor of the thiazoline-based chiral covalent organic framework material is synthesized by dissolving trialdehyde phloroglucinol and compound 3 in a solvent, adding acetic acid as a catalyst, and performing a solvothermal reaction;

[0054] Wherein, the structural formula of compound 3 is shown in formula (II),

[0055]

[0056] In one or more embodiments, the molar ratio of trialdehyde phloroglucinol to compound 3 is 2:2 to 4, preferably 2:3.

[0057] In one or more embodiments, the solvent includes one of o-dichlorobenzene, n-butanol, 1,4-dioxane, mesitylene, N-methylpyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide, o-dichlorobenzene / n-butanol or mesitylene / 1,4-dioxane; preferably mesitylene / 1,4-dioxane; further preferably, the volume ratio of mesitylene / 1,4-dioxane is 0.8-1.2:3, preferably 1:3.

[0058] In one or more embodiments, the concentration of compound 3 in the solvent is 0.025-0.05 mM, preferably 0.0375 mM.

[0059] In one or more embodiments, the concentration of acetic acid is 3 to 12 mol / L, preferably 9 mol / L.

[0060] In one or more embodiments, the temperature of the solvothermal reaction is 100 to 150° C., preferably 120° C.; the time of the solvothermal reaction is 72 to 168 hours, preferably 120 hours.

[0061] In one or more embodiments, the synthesis method of compound 3 comprises the following steps:

[0062] (1) dispersing terephthalonitrile and L-cysteine ​​in a solvent, stirring and reacting under alkaline conditions, and then adjusting the entire reaction system to acidity to obtain compound 1;

[0063] (2) dispersing compound 1 in a solvent and reacting with ethyl bromide in an alkaline environment to synthesize compound 2;

[0064] (3) dispersing compound 2 and hydrazine hydrate in a solvent, and reacting to obtain compound 3;

[0065] The structural formula of compound 1 is shown in formula (III),

[0066]

[0067] The structural formula of compound 2 is shown in formula (IV),

[0068]

[0069] Preferably, in step (1), terephthalonitrile, L-cysteine ​​and NaHCO3 are dispersed in a solvent, the pH is adjusted to 7.3-8, the reaction is stirred, and then the pH of the reaction system is adjusted to 1.5-3 to obtain compound 1;

[0070] Further preferably, in step (1), the solvent comprises a methanol-water solution, wherein the volume ratio of methanol to water is 4 to 6:3, preferably 5:3.

[0071] More preferably, in step (1), the molar ratio of terephthalonitrile to L-cysteine ​​is 1:2.5 to 4, preferably 1:3.

[0072] More preferably, in step (1), the concentration of terephthalonitrile in the solvent is 0.3 to 0.45 μmol / L, preferably 0.375 μmol / L.

[0073] Preferably, in step (2), compound 1 is dispersed in a solvent, potassium carbonate is added, and then ethyl bromide is added, and the mixture is stirred to react to obtain compound 2;

[0074] Further preferably, in step (2), the solvent comprises DMF.

[0075] More preferably, in step (2), compound 1 is dispersed in a solvent at 0-4°C.

[0076] Further preferably, in step (2), the molar ratio of compound 1 to ethyl bromide is 1:1.8-2.2, preferably 1:2.

[0077] Further preferably, in step (2), the concentration of ethyl bromide in the solvent is 0.36-0.44 mM, preferably 0.4 mM.

[0078] More preferably, in step (2), the stirring reaction time is 2 to 4 hours, preferably 3 hours.

[0079] Preferably, in step (3), the solvent comprises ethanol.

[0080] Preferably, in step (3), the molar ratio of compound 2 to hydrazine hydrate is 1:20 to 30, preferably 1:24.

[0081] Preferably, in step (3), the concentration of hydrazine hydrate in the solvent is 0.33-0.5 mM, preferably 0.4 mM.

[0082] Preferably, in step (3), the reaction temperature is 80-90° C., preferably 85° C.; the reaction time is 20-30 h, preferably 24 h.

[0083] A third typical embodiment of the present invention provides a thiazoline-based chiral covalent organic framework material, which is based on a precursor of the thiazoline-based chiral covalent organic framework material prepared by the preparation method described in the first aspect and / or the second aspect and is loaded with a divalent copper salt.

[0084] In one or more embodiments, the divalent copper salt includes anhydrous copper acetate.

[0085] The fourth aspect of the present invention provides a method for preparing the thiazoline-based chiral covalent organic framework material according to the third aspect, comprising:

[0086] The precursor of the thiazoline-based chiral covalent organic framework material prepared by the preparation method described in the first aspect and / or the second aspect and a divalent copper salt are dispersed in a solvent, and the thiazoline-based chiral covalent organic framework material is obtained by stirring the reaction.

[0087] In one or more embodiments, the solvent includes ethanol.

[0088] In one or more embodiments, the stirring reaction temperature is room temperature, and the stirring reaction time is 20 to 30 hours, preferably 24 hours.

[0089] A fifth typical embodiment of the present invention provides the use of the thiazoline-based chiral covalent organic framework material described in the third aspect and / or the thiazoline-based chiral covalent organic framework material prepared by the preparation method described in the fourth aspect as a catalyst.

[0090] In one or more embodiments, the use includes catalyzing an asymmetric Henry reaction as a catalyst.

[0091] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0092] Example 1

[0093] Figure 1 For the synthetic route of compound 3, refer to Figure 1 , synthesized compound 3.

[0094] Terephthalonitrile (1.92 g, 15.0 mmol), L-cysteine ​​(5.45 g, 45.0 mmol), and NaHCO3 (3.78 g, 45.0 mmol) were dispersed in a methanol aqueous solution (250 mL of methanol and 150 mL of water). The pH of the mixed solution was adjusted to 7.5 with 4 M sodium hydroxide solution and stirred at room temperature for 48 hours. Methanol was removed by evaporation under reduced pressure (40 ° C), a small amount of solid residue was removed by filtration, and the filtrate was retained. In an ice bath, the filtrate was acidified to pH 2 with hydrochloric acid (2 M). The precipitate was collected by suction, rinsed with cold water (3×20 mL), and vacuum dried to obtain white powder compound 1 with a yield of about 70%. The H NMR spectrum of compound 1 is shown as follows Figure 2 As shown, the NMR carbon spectrum is as follows Figure 3 As shown in the mass spectrometry Figure 4 As shown, the infrared spectrum is as follows Figure 5 shown.

[0095] In an ice bath, compound 1 (1.0 g, 3 mmol) was dissolved in 15 mL DMF, potassium carbonate (828 mg, 6 mmol) was added, and after stirring for 30 min, ethyl bromide (672 μL, 9 mmol) was added, and then the mixture was heated to room temperature and stirred for 3 hours. The reaction was monitored by TLC (n-hexane: ethyl acetate = 10:1). Compound 2 was obtained in a yield of 68%. The H NMR spectrum of compound 2 is shown in FIG. Figure 6 As shown, the NMR carbon spectrum is as follows Figure 7 As shown in the mass spectrometry Figure 8 As shown, the infrared spectrum is as follows Fig. 9 shown.

[0096] Compound 2 (98 mg, 0.25 mmol) and hydrazine hydrate (0.6 g, 6 mmol) were dissolved in ethanol (15 mL) and heated under reflux at 85 °C for 24 hours to obtain compound 3 with a yield of 88%. The H NMR spectrum of compound 3 is shown in Fig.10 As shown, the NMR carbon spectrum is as follows Fig.11 As shown in the mass spectrometry Fig.12 As shown, the infrared spectrum is as follows Fig.13 shown.

[0097] Example 2

[0098] Synthesis of precursors of thiazoline-based chiral covalent organic framework materials:

[0099] Trialdehyde phloroglucinol (10.5 mg, 0.05 mmol) and compound 3 (27.5 mg, 0.075 mmol) were dispersed in 1,4-dioxane / mesitylene solution (1.5 mL / 0.5 mL), 0.1 mL of acetic acid was added as a catalyst (final concentration was 9 M), and the reaction was sealed at 120°C for 120 hours. 33 mg of reddish brown powder was obtained, which was the precursor of the thiazoline-based chiral covalent organic framework material, with a yield of 93%.

[0100] The powder diffraction PXRD pattern of the precursor of thiazoline-based chiral covalent organic framework material is shown in Fig.14 As shown in the scanning electron microscope image Fig.15 As shown in the low-magnification transmission electron microscopy image Fig.16 As shown in the high magnification transmission electron microscopy image Fig.17 As shown, the infrared spectrum is as follows Fig.18 As shown, the macro powder map is shown in Fig.19 As shown in the structural simulation diagram Fig. 20 As shown in the thermogravimetric analysis diagram, Fig.21 shown.

[0101] Example 3

[0102] Synthesis of Thiazoline-based Chiral Covalent Organic Framework Materials:

[0103] The precursor of the thiazoline-based chiral covalent organic framework material (40 mg) and anhydrous copper acetate (70 mg) were dispersed in ethanol (35 mL) and stirred at room temperature for 24 hours to obtain the thiazoline-based chiral covalent organic framework material. The powder diffraction PXRD pattern of the thiazoline-based chiral covalent organic framework material is as follows: Fig. 22 As shown in the XPS diagram Fig.23 shown.

[0104] Example 4

[0105] Thiazolinyl chiral covalent organic framework material (29 mg, 3 mol% Cu equivalent) and ethanol (1.5 mL) were stirred at room temperature for 30 minutes to fully disperse the thiazolinyl chiral covalent organic framework material; nitromethane (540 μL, 10 mmol) and benzaldehyde (102 μL, 1 mmol) were added, stirred at room temperature, and the reaction progress was monitored by TLC. After the reaction was completed, the product was separated by column chromatography (ethyl acetate: petroleum ether = 1:1). The mass spectrum of the product is shown in Fig.24 As shown in the liquid phase spectrum Fig.25 As shown, the ee value is 92%.

[0106] The final ee value after 5 cycles of reaction is 90%. The powder framework before and after catalysis is shown in Fig.26 The ee value bar graph corresponding to the 5-cycle reaction is shown in Fig. 27 .

[0107] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A precursor of a thiazoline-based chiral covalent organic framework material, characterized in that: The precursor has the structure shown in formula (I) as a structural repeating unit; 2. The method for preparing the precursor according to claim 1, characterized in that: include: The precursor of the thiazoline-based chiral covalent organic framework material is synthesized by dissolving trialdehyde phloroglucinol and compound 3 in a solvent, adding acetic acid as a catalyst, and performing a solvothermal reaction; Wherein, the structural formula of compound 3 is shown in formula (II), 3. The preparation method according to claim 2, characterized in that: The molar ratio of trialdehyde phloroglucinol to compound 3 is 2:2 to 4, preferably 2:3; Or, the solvent includes one of o-dichlorobenzene, n-butanol, 1,4-dioxane, mesitylene, N-methylpyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide, o-dichlorobenzene / n-butanol or mesitylene / 1,4-dioxane; preferably mesitylene / 1,4-dioxane; further preferably, the volume ratio of mesitylene / 1,4-dioxane is 0.8-1.2:3, preferably 1:3; Or, the concentration of compound 3 in the solvent is 0.025-0.05 mM, preferably 0.0375 mM; Or, the concentration of acetic acid is 3 to 12 mol / L, preferably 9 mol / L; Alternatively, the temperature of the solvothermal reaction is 100 to 150° C., preferably 120° C.; the time of the solvothermal reaction is 72 to 168 h, preferably 120 h.

4. The preparation method according to claim 2, characterized in that: The synthesis method of compound 3 comprises the following steps: (1) dispersing terephthalonitrile and L-cysteine ​​in a solvent, stirring and reacting under alkaline conditions, and then adjusting the entire reaction system to acidity to obtain compound 1; (2) dispersing compound 1 in a solvent and reacting with ethyl bromide in an alkaline environment to synthesize compound 2; (3) dispersing compound 2 and hydrazine hydrate in a solvent, and reacting to obtain compound 3; The structural formula of compound 1 is shown in formula (III), The structural formula of compound 2 is shown in formula (IV), 5. The preparation method according to claim 4, characterized in that: In step (1), terephthalonitrile, L-cysteine ​​and NaHCO3 are dispersed in a solvent, the pH is adjusted to 7.3-8, the reaction is stirred, and then the pH of the reaction system is adjusted to 1.5-3 to obtain compound 1; Preferably, in step (1), the solvent comprises a methanol-water solution, wherein the volume ratio of methanol to water is 4 to 6:3, preferably 5:3; Preferably, in step (1), the molar ratio of terephthalonitrile to L-cysteine ​​is 1:2.5 to 4, preferably 1:3; Preferably, in step (1), the concentration of terephthalonitrile in the solvent is 0.3 to 0.45 μmol / L, preferably 0.375 μmol / L; Alternatively, compound 1 is dispersed in a solvent, potassium carbonate is added, and then ethyl bromide is added, and the mixture is stirred to react to obtain compound 2; In step (2), compound 1 is dispersed in a solvent, potassium carbonate is added, and then ethyl bromide is added, and the mixture is stirred to react to obtain compound 2; Preferably, in step (2), the solvent comprises DMF; Preferably, in step (2), compound 1 is dispersed in a solvent at 0 to 4°C; Preferably, in step (2), the molar ratio of compound 1 to ethyl bromide is 1:1.8-2.2, preferably 1:2; Or, in step (3), the solvent comprises ethanol; Or, in step (3), the molar ratio of compound 2 to hydrazine hydrate is 1:20 to 30, preferably 1:24; Or, in step (3), the concentration of hydrazine hydrate in the solvent is 0.33-0.5 mM, preferably 0.4 mM; Alternatively, in step (3), the reaction temperature is 80-90° C., preferably 85° C.; the reaction time is 20-30 h, preferably 24 h.

6. A thiazoline-based chiral covalent organic framework material, characterized in that: The precursor of the thiazoline-based chiral covalent organic framework material prepared by the preparation method according to claim 1 and / or any one of claims 2 to 5 is used as a matrix and is loaded with a divalent copper salt.

7. The thiazoline-based chiral covalent organic framework material according to claim 6, characterized in that: The divalent copper salt includes anhydrous copper acetate.

8. The method for preparing the thiazoline-based chiral covalent organic framework material according to claim 6 or 7, characterized in that: include: The precursor of the thiazoline-based chiral covalent organic framework material prepared by the preparation method according to claim 1 and / or any one of claims 2 to 5 and a divalent copper salt are dispersed in a solvent, and the thiazoline-based chiral covalent organic framework material is obtained by stirring the reaction.

9. Use of the thiazoline-based chiral covalent organic framework material according to claim 6 or 7 and / or the thiazoline-based chiral covalent organic framework material prepared by the preparation method according to claim 8 as a catalyst.

10. The use according to claim 9, characterized in that The application includes using the catalyst to catalyze the asymmetric Henry reaction.

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