Fluorene modified expanded ring porphyrin compound, derivative, preparation method and application

Abstract

The invention relates to a fluorene modified expanded ring porphyrin compound, a derivative, a preparation method and application. The fluorene-modified expanded ring porphyrin compound has a chemical structure shown in the following general formula, or is a tautomer and a configurational isomer of the structure shown in the following general formula: in the # imgabs0 # formula, Et is ethyl; r1 and R2 are independently selected from hydrogen, C1-10 alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups and substituted or unsubstituted aralkyl groups, and OR1 and R2 are different. Compared with the prior art, successful synthesis and separation of ten-membered expanded-loop porphyrin configurational isomerism are realized by introducing sp3-hybrid carbon atoms into an expanded-loop porphyrin skeleton, and the preparation method has important significance on general synthesis strategies constructed by expanded-loop porphyrin configurational isomers and research and development of chiral optical materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic synthesis, and in particular relates to a fluorene-modified ring-expanded porphyrin compound, a derivative, a preparation method and an application thereof. Background Art

[0002] Expanded porphyrins are a class of porphyrin derivatives containing at least 17 atoms in their central conjugated pathway. They have broad application prospects in aromaticity research, near-infrared absorbing dyes, photodynamic therapy, anion sensing and transport, and have attracted widespread attention from both theoretical and experimental chemists in recent years. However, the flexible molecular skeletons of most expanded porphyrins result in complex and variable conformations, which in turn poses challenges to their isolation, purification, and characterization. Therefore, in-depth exploration of the intrinsic connection between the structure and conformation of expanded porphyrins has become an important research direction in this field.

[0003] Configurational isomerism often influences the conformation and properties of macromolecules, a phenomenon widely demonstrated in living organisms. For example, the crucial influence of peptide bond cis-trans isomerism on protein folding, including the classic proline N-terminal cis-trans isomerism. Cis- and trans-isomeric ring-expanded porphyrins also exhibit distinct conformations and optoelectronic properties. However, their building blocks are primarily planar aromatic compounds such as pyrrole, thiophene, and benzene. This results in the synthesis of these ring-expanded porphyrins focusing primarily on different ways of connecting the functional units, significantly limiting their synthetic strategies.

[0004] You et al. (Li, C.; Huang, Z.; Hu, Y.; Liang, W.; Su, R.; Chen, M.; Zhou, L.; Wu, D.; Gao, G.; You, J. Synthesis of Imidazole-Based

[30] Heptaphyrin and Stable FigureEight

[60] Tetradecaphyrins via[5+2]Condensations in One Pot. Org. Lett. 2021, 23, 3746-3750.) synthesized cis- and trans-isomers of tetradecaphyrin by introducing an asymmetric 2,5-imidazole unit, demonstrating the importance of C-H bond activation reaction, condensation strategy, and the role of hydrogen bonds and π-π interactions in conformational stabilization. The Mangalampalli Ravikanth group (Yadav, B.; Ravikanth, M. Synthesis and Studies of Structural Isomers of meso-Fused Dicarbahexaphyrins. Chem. Asian. J. 2022, 17, e202200432.) successfully synthesized fluorene-modified cis- and trans-isomers using the meso-position fusion strategy, and systematically characterized the differences in their absorption spectra and single crystal structures, providing an important reference for expanding the synthesis methods of cis- and trans-isomerized ring-expanded porphyrins.

[0005] The above-mentioned existing technologies have achieved the separation of some cis- and trans-isomers of ring-expanded porphyrins and observed significant differences in properties by introducing asymmetric 2,5-imidazole units or developing meso-position fusion strategies. However, the synthesis of the above-mentioned cis- and trans-isomers of ring-expanded porphyrins depends on specific asymmetric groups, making it difficult to perform functional modifications based on them.

[0006] Therefore, a universal method for synthesizing cis- and trans-isomers of ring-expanded porphyrin compounds remains to be developed. Summary of the Invention

[0007] The purpose of the present invention is to provide a fluorene-modified ring-expanded porphyrin compound, derivatives, preparation method and application in order to overcome the defect of the prior art that the cis and trans isomers of the ring-expanded porphyrin compound cannot be universally synthesized.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] The present invention first provides a fluorene-modified ring-expanded porphyrin compound having a chemical structure represented by the following general structural formula, or being a tautomer or configurational isomer of the structure represented by the following general structural formula:

[0010]

[0011] Wherein, Et is ethyl;

[0012] R 1 and R 2 are independently selected from hydrogen, C 1-10 alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted aralkyl, and OR 1 With R 2 Furthermore, the fluorene-modified ring-expanded porphyrin compound includes the following structural formula:

[0013]

[0014] Wherein, structural formula I and structural formula II are cis-trans isomers;

[0015] In the formula, Et is ethyl, MeO is methoxy, and Mes is mesityl.

[0016] The present invention also provides a method for preparing a fluorene-modified ring-expanded porphyrin compound, comprising the following steps:

[0017] S1: Compound 1 and R 2 -MgBr is dispersed in an organic solvent to react and generate compound 2;

[0018] S2: Compound 2, sodium hydride and R 1 -I is mixed with an organic solvent and reacted to obtain compound 3;

[0019] S3: Compound 3, compound 4, palladium acetate, triphenylphosphine, and potassium carbonate are heated under reflux in a mixed solvent to obtain compound 5;

[0020] S4: heating and mixing compound 5, sodium hydroxide, and an organic solvent, and then subjecting the mixture to a reflux reaction to obtain compound 6;

[0021] S5: Compound 6, Compound 7, methanesulfonic acid, and an organic solvent are mixed and reacted under an inert gas atmosphere; 2,3-dichloro-5,6-dicyanobenzoquinone is then added, and the mixture is reacted in air to finally obtain a fluorene-modified ring-expanded porphyrin compound;

[0022] In step S5, the molar ratio of compound 6, compound 7, methanesulfonic acid and 2,3-dichloro-5,6-dicyanobenzoquinone is 1:1:(5-15):(2-4);

[0023] The above steps S1 to S4 are all carried out under an inert gas atmosphere;

[0024] The structural formulas of compounds 1 to 7 are as follows, wherein Et is an ethyl group and Bpin is a pinacol boron group:

[0025]

[0026] Furthermore, in step S1, the compound 1 and R 2 -MgBr has a molar ratio of 1:(1.5-2.5).

[0027] Furthermore, in step S1, the reaction time is 1.5-2.5 hours, and the reaction temperature is room temperature.

[0028] Furthermore, in step S1, the solvent is one or more of tetrahydrofuran, dichloromethane, chloroform, and toluene.

[0029] Further, in step S2, the compound 2, sodium hydride and R 1 The molar ratio of -I is 1:(3.5-4.5):(2.5-3.5).

[0030] Furthermore, in step S2, the reaction time is 5-6 hours, and the reaction temperature is room temperature.

[0031] Furthermore, in step S2, the solvent is one or more of tetrahydrofuran, dichloromethane, chloroform, and toluene.

[0032] Furthermore, in step S3, the molar ratio of compound 3, compound 4, palladium acetate, triphenylphosphine and potassium carbonate is 1:(1.5-2.5):(0.05-0.1):(0.05-0.15):(2.5-3.5).

[0033] Furthermore, in step S3, the reaction time is 14-18 hours, and the reaction temperature is 85-95°C.

[0034] Furthermore, in step S3, the mixed solvent is composed of water and dioxane in a volume ratio of 1:(4-6).

[0035] Furthermore, in step S4, the molar ratio of compound 5 to sodium hydroxide is 1:(12-18).

[0036] Furthermore, in step S4, the reaction time is 1-3 hours, and the reaction temperature is 180-200°C.

[0037] Furthermore, in step S4, the solvent is ethylene glycol.

[0038] Furthermore, in step S5, the reaction time is 2-4 hours, the reaction time after adding 2,3-dichloro-5,6-dicyanobenzoquinone is 0.5-1.5 hours, and the reaction temperature is room temperature.

[0039] Furthermore, in step S5, the acid catalyst includes any one of methanesulfonic acid, trifluoroacetic acid, p-toluenesulfonic acid, hydroiodic acid, and boron trifluoride etherate.

[0040] Furthermore, in step S5, the organic solvent includes one or more of dichloromethane and chloroform.

[0041] In the preparation method of the present invention, sp 3 The introduction of hybrid carbon atoms provides a direction for the synthesis of universal ring-expanded porphyrin cis-trans isomers, which can be achieved by adjusting R 1 and R 2 The group precisely regulates the properties of the cis and trans isomers of the ring-expanded porphyrin, ultimately achieving specific applications in different fields. Furthermore, the 9-position of the fluorene group is highly reactive, facilitating the further conversion of the ring-expanded porphyrin to obtain ring-expanded porphyrin derivatives.

[0042] The present invention also provides an application of a fluorene-modified ring-expanded porphyrin compound, wherein the fluorene-modified ring-expanded porphyrin compound is used for preparing a chiral optical material.

[0043] The present invention also provides a fluorene-modified ring-expanded porphyrin compound derivative comprising the following structural formula:

[0044]

[0045] The derivative corresponding to the structural formula III is a fluorene-modified ring-expanded porphyrin compound which is reacted with OR under acidic conditions. 1 Obtained by hydrolysis.

[0046] The derivative corresponding to the structural formula IV is obtained by rearrangement of a fluorene-modified ring-expanded porphyrin compound under acidic conditions and with the participation of a cyano group.

[0047] The fluorene-modified ring-expanded porphyrin compound derivative is used for preparing chiral optical materials.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] (1) Based on the current synthetic strategy limitation of ring-expanded porphyrin configuration isomers, the present invention embeds 9,9'-disubstituted fluorene units into the ring-expanded porphyrin skeleton by introducing sp 3 -hybridized carbon atoms to achieve the successful synthesis and separation of the conformational isomers of the ten-membered ring-expanded porphyrin, which is of great significance for the general synthetic strategy of the construction of the conformational isomers of the ring-expanded porphyrin and provides a new idea for the research and development of chiral optical materials based on the ring-expanded porphyrin.

[0050] (2) Based on the acid-dependent divergent synthesis strategy, the present invention further obtained a fluorene-modified ten-membered ring-expanded porphyrin derivative, providing a new direction for the development of the synthesis strategy of ring-expanded porphyrin derivatives.

[0051] (3) The synthetic method proposed in the present invention has higher universality in constructing ring-expanded porphyrin cis-trans isomers, that is, any sp 3 -hybridized carbon atoms can be used to construct ring-expanded porphyrin cis-trans isomers. 1 and R 2 The group precisely controls the properties of the ring-expanded porphyrin, ultimately enabling specific applications in different fields. Furthermore, the 9-position of the fluorene group exhibits high reactivity, facilitating further conversion of the ring-expanded porphyrin to yield ring-expanded porphyrin derivatives with diverse properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is the H NMR spectrum (293K) of compound 5 during the preparation process of Example 1 of the present invention.

[0053] Figure 2 This is the H NMR spectrum (293K) of compound 6 during the preparation process of Example 1 of the present invention.

[0054] Figure 3 This is the H NMR spectrum (293K) of compound I in Example 1 of the present invention.

[0055] Figure 4 This is the H NMR spectrum (293K) of compound II in Example 1 of the present invention.

[0056] Figure 5 HRMS spectra of compound I (a) and compound II (b) in Example 1 of the present invention.

[0057] Figure 6 Schematic diagram of the single crystal structure of Compound I and Compound II in Example 1 of the present invention.

[0058] Figure 7 This is the absorption spectrum of methanesulfonic acid titration of Compound I and Compound II in Example 1 of the present invention.

[0059] Figure 8 The UV-visible absorption spectra of Compound I and Compound II in Example 1 of the present invention are shown.

[0060] Figure 9 The 223K H NMR spectrum and the 373K H NMR spectrum of compound III in Example 2 of the present invention are shown.

[0061] Figure 10 This is the H NMR spectrum (293K) of compound IV in Example 2 of the present invention.

[0062] Figure 11 HRMS spectra of compound III (a) and compound IV (b) in Example 2 of the present invention.

[0063] Figure 12 Schematic diagram of the single crystal structure of compound III and compound IV in Example 2 of the present invention.

[0064] Figure 13 The circular dichroism spectra (a) and (g) of compound IV in Example 2 of the present invention are abs Graph (b). DETAILED DESCRIPTION

[0065] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0066] Unless otherwise specified, the reagents, methods, instruments and equipment used in the present invention are conventional reagents, methods, instruments and equipment in the art. Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0067] In the following examples, the structural formula of compound 4 is:

[0068]

[0069] The preparation method of compound 4 can be found in https: / / doi.org / 10.1021 / jacs.2c01240. The specific preparation process is as follows:

[0070]

[0071] Propionaldehyde (107.0 g, 1.84 mol) and 1-nitropropane (125.9 g, 1.40 mol) were added sequentially to a 1L two-necked flask. 125 mL of a 1 mol / L potassium hydroxide methanol solution was added dropwise under ice bath conditions. After the addition was complete, the mixture was reacted in an ice bath for 3 h. 62.5 mL of a 0.9 mol / L sulfuric acid methanol solution was slowly added dropwise, and the mixture was stirred at room temperature for 0.5 h. After the reaction was completed, the reaction solution was extracted with ethyl acetate and water, and the organic phase was washed three times with water, once with a saturated sodium bicarbonate solution, and once with saturated brine. The organic phase was dried over anhydrous sodium sulfate and the solvent was removed by rotary evaporation under reduced pressure to obtain 166.4 g of 4-nitro-3-hexanol as a yellow oily liquid with a yield of 94.14%.

[0072] In a 1L two-necked flask, the above-prepared 4-nitro-3-hexanol (166.4g, 1.13mol), acetic anhydride (229.7g, 2.25mol) 4-dimethylaminopyridine (DMAP, 6.9g, 56.50mmol), and dichloromethane (332mL) were added in sequence and stirred at room temperature overnight. Methanol (200mL) was added and stirring was continued for 1h. Saturated sodium bicarbonate solution was slowly added dropwise to quench the reaction. The aqueous phase was extracted three times with dichloromethane, and the organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed by vacuum rotary evaporation to obtain a light green oily liquid 4-nitro-3-hexyl acetate.

[0073] To a 2L two-necked flask, the above-prepared 4-nitrohexyl 3-acetate (134.7 g), ethyl isocyanoacetate (69.8 g, 0.62 mol), tetrahydrofuran (400 mL), and isopropanol (160 mL) were added sequentially. 1,8-diazobisspiro[5.4.0]undec-7-ene (DBU, 202.3 g, 1.33 mol) dissolved in tetrahydrofuran (320 mL) was added dropwise in an ice-water bath and stirred overnight at room temperature. The mixture was extracted with ethyl acetate and water, and the organic phase was dried over anhydrous sodium sulfate. The solvent was removed by rotary evaporation under reduced pressure, and the product was purified by silica gel column chromatography (PE:EA = 20:1) to obtain 94.0 g of 8 as a yellow oily liquid with a yield of 67.64%.

[0074] Compound 8 (20.0 g, 0.10 mol), ethanol (100 mL), and potassium bicarbonate (25.0 g, 0.25 mol) dissolved in water (70 mL) were added sequentially to a 1L two-necked flask. After thorough stirring until completely dissolved, potassium iodide (25.0 g, 0.15 mol) and elemental iodine (38.0 g, 0.15 mol) dissolved in a mixture of ethanol (130 mL) and water (65 mL) were slowly added dropwise to the reaction system using a separatory funnel. After the addition was complete, the reaction mixture was refluxed in an 80°C oil bath for 2 hours, cooled naturally to room temperature, and a sufficient amount of saturated sodium sulfite aqueous solution was added all at once. The mixture was filtered under reduced pressure using a Buchner funnel to obtain a white or yellow solid. Purification by silica gel column chromatography (petroleum ether / ethyl acetate = 30:1) gave 17.0 g of 9 as a white solid in a yield of 51.84%.

[0075] Under nitrogen, compound 9 (3.2 g, 10.00 mol), bistriphenylphosphine palladium dichloride (70 mg, 0.10 mmol), tetrahydrofuran (32 mL), and triethylamine (3 mL) were added sequentially to a dry 100 mL two-necked flask. After thorough stirring, pinacol borane (2 mL, 12.00 mmol) was slowly added dropwise to the reaction system using a syringe. After the addition was complete, the reaction was refluxed in an 80°C oil bath for 3 hours, extracted three times with ethyl acetate and water, and the organic phase was dried over anhydrous sodium sulfate. The solvent was then dried and purified by silica gel column chromatography (petroleum ether / ethyl acetate = 30:1) to give 1.4 g of 4 as a yellow oily liquid with a yield of 43.61%.

[0076] In the following examples, the structural formula of compound 7 is:

[0077]

[0078] The preparation method of compound 7 can be found in https: / / doi.org / 10.1055 / s-1998-2041. The specific preparation process is as follows:

[0079]

[0080] To a 50 mL two-necked flask, compound 8 (2.0 g, 10.30 mmol), sodium hydroxide (1.1 g, 27.50 mmol) dissolved in water (8 mL), and ethanol (20 mL) were added sequentially. The mixture was refluxed at 80°C overnight. After completion of the reaction, hydrochloric acid solution was slowly added dropwise to adjust the pH of the reaction system to 4.5-5.5. The mixture was filtered and washed with water to obtain 1.7 g of an off-white solid 10 with a yield of 82.67%. The solid was carried on to the next step without further purification.

[0081] Compound 10 (3.0 g, 18.00 mmol) and trifluoroacetic acid (80 mL) were added sequentially to a 500 mL two-necked flask, stirred in the dark for 5 min until completely dissolved. Triethyl orthoformate (80 mL) was then added dropwise in an ice-water bath, and the mixture was allowed to react in the dark for 1 h. After the reaction, saturated sodium bicarbonate solution was added until the system was neutral. The organic phase was extracted with dichloromethane, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation under reduced pressure. The product was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 8:1) and washed with petroleum ether to obtain 1.9 g of 7 as a white solid with a yield of 59.90%. The product was directly used in the next step without further purification.

[0082] Example 1:

[0083] This embodiment provides a fluorene-modified ring-expanded porphyrin compound and its preparation method. The fluorene-modified ring-expanded porphyrin compound of this embodiment has the structural formula:

[0084]

[0085] Both structural formulas I and II are cis-trans isomers, with the mesityl (Mes) and methoxy (MeO) groups located on the same and opposite sides of the macrocyclic skeleton, respectively. The synthetic route for the aforementioned fluorene-modified isomeric ring-expanded porphyrin compounds is as follows:

[0086]

[0087] S1: Synthesis of compound 2

[0088] A 250mL two-necked flask was filled with a polytetrafluoroethylene stirring magnet and then replaced with nitrogen three times. The mixture was then baked under negative pressure to remove water. Under a nitrogen atmosphere, compound 1, dibromofluorenone (3.4g, 10mmol) and 40mL of tetrahydrofuran were added. After stirring and dissolving, a 1mmol / mL solution of mesityl magnesium bromide in tetrahydrofuran (20mL) was added dropwise using a syringe. The mixture was stirred and reacted at 25°C for 2h. After the reaction, an appropriate amount of water was added and the reaction solution was extracted with ethyl acetate several times. The organic phase was dried over anhydrous sodium sulfate and the solvent was removed by vacuum rotary evaporation to obtain a light yellow solid powder. Impurities were washed with n-hexane to obtain 4.3g of white solid powder 2, with a yield of 94%.

[0089] The structures of compound 1 and compound 2 are as follows:

[0090]

[0091] S2: Synthesis of compound 3:

[0092] Take a 250mL two-necked flask, load it with a polytetrafluoroethylene stirring magnet, replace nitrogen three times, and bake under negative pressure to remove water. Under a nitrogen atmosphere, add compound 2 (4.7g, 10mmol) and 60% sodium hydride (0.9g, 40mmol), slowly add 60mL tetrahydrofuran, stir for 0.5h, slowly add iodomethane (1.9mL, 30mmol) dropwise with a syringe, and react at room temperature for 5h. After the reaction is completed, add appropriate amount of water, use ethyl acetate to extract the reaction solution several times, the organic phase is dried over anhydrous sodium sulfate and then evaporated under reduced pressure to remove the solvent to obtain a light yellow solid powder, and use n-hexane to wash out impurities to obtain 4.2g white solid powder 3, with a yield of 89%.

[0093] The structure of compound 3 is as follows:

[0094]

[0095] S3: Synthesis of compound 5:

[0096] Take a 25mL two-necked flask, install a polytetrafluoroethylene stirring magnet, and replace the nitrogen atmosphere three times. Under a nitrogen atmosphere, add compound 3 (0.5g, 1mmol), pyrrole borane compound 4 (0.7g, 2mmol), triphenylphosphine (26mg, 0.1mmol), palladium acetate (11mg, 0.05mmol) and 10mL dioxane. After stirring until completely dissolved, potassium carbonate (0.4g, 3mmol) in water (2mL) was added dropwise with a syringe. The reaction was refluxed at 90°C for 16h. After the reaction was completed and cooled, an appropriate amount of water was added and the mixture was extracted with dichloromethane several times. The organic phase was dried over anhydrous sodium sulfate and the solvent was removed by vacuum rotary evaporation to obtain a dark solid powder. The product was further purified by silica gel column chromatography with an eluent of n-hexane:ethyl acetate = 10:1 to obtain 550mg of white solid powder 4 with a yield of 78%.

[0097] The structure of compound 5 is as follows:

[0098]

[0099] Compound 5 was used as a sample for experimental analysis, and its H NMR spectrum (293K) was as follows Figure 1 As shown:

[0100] 1 H NMR(400MHz,CHLOROFORM-D)δ9.02(s,2H),7.75(d,J=7.8Hz,2H),7.54(d,J=7.8Hz,2H),7.42(s,2H),7.01(s,1H),6.61(s,1H),4.34(q,J=7.1Hz,4H) ,2.94(s,3H),2.89–2.73(m,7H),2.60(q,J=7.5Hz,4H),2.25(s,3H),1.38( t,J=7.1Hz,6H),1.31(s,3H),1.22(t,J=7.4Hz,6H),1.16(t,J=7.4Hz,6H).

[0101] S4: Synthesis of compound 6:

[0102] A 25 mL two-necked flask was filled with a polytetrafluoroethylene stirring magnet and the atmosphere was replaced with nitrogen three times. Compound 5 (0.7 g, 1 mmol), sodium hydroxide (0.6 g, 15 mmol), and 15 mL of ethylene glycol were added under a nitrogen atmosphere and refluxed at 190°C for 2 h. After cooling, an appropriate amount of water was added, and the mixture was ultrasonically shaken and filtered to yield 534 mg of a yellow-brown solid 6 (96% yield).

[0103] The structure of compound 6 is as follows:

[0104]

[0105] Compound 6 was used as a sample for experimental analysis, and its H NMR spectrum (293K) was as follows Figure 2 As shown:

[0106] 1H NMR (600MHz, CDCl3) δ8.0(s,2H),7.7(d,J=7.8Hz,2H),7.5(d,J=7.8Hz,2H),7.3(s,2H),7.0(s,1H),6.6(s,1H),6.6(s,2H),2.9( s,3H),2.8(s,3H),2.6(q,J=7.5Hz,4H),2.5(q,J=7.5Hz,4H),2.2(s,3H),1.3(s,3H),1.3(t,J=7.5Hz,6H),1.2(t,J=7.5Hz,6H).

[0107] S5: Synthesis of Compounds I and II

[0108] A 250 mL two-necked flask was filled with a polytetrafluoroethylene stirring magnet and then replaced with nitrogen three times. Compound 6 (56 mg, 0.1 mmol), pyrrole dialdehyde compound 7 (18 mg, 0.1 mmol), and 100 mL of dichloromethane were added under a nitrogen atmosphere. Methanesulfonic acid (33 μL, 0.5 mmol) was added dropwise via syringe. After a 3-hour reaction, dicyanodichlorobenzoquinone (68 mg, 0.3 mmol) was added. The reaction was continued at room temperature for 0.5 hours, followed by an excess of triethylamine and a 0.5-hour reaction. After completion of the reaction, the product was initially purified by alumina column chromatography and then purified by column chromatography using triethylamine-treated silica gel to obtain a crude product. After multiple silica gel column chromatography purifications, the products of different polarities were prepared as saturated dichloromethane solutions. An appropriate amount of n-hexane was added and slowly evaporated and recrystallized to obtain a small amount of black powder. The yields of compounds I and II were 35% and 24%, respectively.

[0109] Compounds I and II obtained in this example were characterized as follows:

[0110] (1) NMR characterization

[0111] Compound I was used as a sample for experimental analysis, and its H NMR spectrum (293K) was as follows Figure 3 As shown:

[0112] 1H NMR (600MHz, CDCl3) δ7.93(d,J=7.9Hz,4H),7.57(s,4H),7.35(d,J=7.9Hz,4H),6.80(s,6H),6.40(s,2H),2.78(s,6H),2.68(q,J=7.6Hz,8 H),2.63(q,J=7.7Hz,8H),2.61–2.53(m,8H),2.40(s,6H),2.09(s,6H),1.22(td,J=7.6,2.8Hz,24H),1.16(s,6H),1.00(t,J=7.5Hz,12H).

[0113] Compound II was used as a sample for experimental analysis, and its H NMR spectrum (293K) was as follows Figure 4 As shown:

[0114] 1 H NMR (600MHz, CDCl3) δ7.67(d,J=7.8Hz,4H),7.58(s,4H),7.21(d,J=7.8Hz,4H),6.92(s,2H),6.81(s,4H),6.51(s,2H),2.87(s,6H),2 .86(s,6H),2.69(q,J=7.6Hz,8H),2.60(q,J=7.5Hz,8H),2.37–2.29(m,8H),2.20(s,6H),1.24–1.18(m,30H),0.77(t,J=7.4Hz,12H).

[0115] (2) Mass spectrometry characterization

[0116] The HRMS spectra of compound Ⅰ and compound Ⅱ are as follows Figure 5 shown.

[0117] Compound I (m / z): [M+H] + Calcd.for C 98 H 107 N6O2 1400.8469; Found 1400.8576.

[0118] Compound II (m / z): [M+H] + Calcd.for C 98 H 107 N6O2 1400.8469; Found 1400.8563.

[0119] The experimental results are consistent with the theoretical values, verifying the accuracy of the structure.

[0120] (3) Single crystal structure analysis

[0121] The single crystal structures of compound I and compound II are shown in Figure 2. Figure 6 For the sake of clarity, the outer ethyl group and some outer hydrogen atoms are omitted, where white represents hydrogen atoms, yellow represents carbon atoms, blue represents nitrogen atoms, and red represents oxygen atoms.

[0122] The aforementioned NMR and single-crystal X-ray diffraction analyses confirmed that Compounds I and II are cis-trans isomers. Compound I forms a unique distorted figure-8 conformation in the solid state, but in solution, it transforms into a rectangular conformation with its two methoxy groups arranged in a cis configuration. In stark contrast, Compound II maintains a stable rectangular conformation in both the solid and solution states, with the methoxy groups in a perfect trans configuration.

[0123] (4) Differences in acidity and alkalinity

[0124] The difference in acidity and alkalinity between compound I and compound II was determined by methanesulfonic acid (MSA) titration absorption spectroscopy.

[0125] Figure 7 The absorption spectra of methanesulfonic acid titration of cis- and trans-isomers I (a) and II (b) show significant differences in the amount of acid required for complete protonation: 3 equivalents of MSA and 14 equivalents of MSA, respectively. This indicates a significant difference in acidity and alkalinity between the two, allowing for intuitive identification of complete protonation based on the color difference. This suggests promising applications in acidity detection for specific applications. Furthermore, after protonation, the absorption extends into the near-infrared region around 1000 nm, demonstrating potential for bioimaging applications.

[0126] (5) Differences in optical properties

[0127] The absorption spectra of compound I and compound II were obtained in dichloromethane solution at a test concentration of 1×10 -5 M. The two have different colors in solution, compound I is yellow-green and compound II is gray-blue. Figure 8 As shown, both have Soret bands and Q bands in their absorption spectra, and the Q band absorption intensity of compound II is about 40% stronger than that of compound I, reflecting the significant influence of cis-trans isomerism on properties.

[0128] Example 2:

[0129] This embodiment provides a fluorene-modified ring-expanded porphyrin compound derivative and its preparation method. The fluorene-modified ring-expanded porphyrin derivative compound of this embodiment has the structural formula:

[0130]

[0131] The synthetic route of the above-mentioned fluorene-modified configurational isomerization ring-expanded porphyrin compound is as follows:

[0132]

[0133] The above-mentioned synthetic route is substantially the same as that in Example 1, except that, in step S5 of the present embodiment, the addition amount of methanesulfonic acid is different. Specifically, in S5 of the present embodiment, a 250mL two-necked flask is taken, and nitrogen is replaced three times after a polytetrafluoroethylene stirring magnet is loaded. 6 (56mg, 0.1mmol), pyrrole dialdehyde 7 (18mg, 0.1mmol) and 100mL dichloromethane are added under a nitrogen atmosphere, and methanesulfonic acid (98 μL, 1.5mmol) is added dropwise with a syringe. After reacting for 3h, dicyanodichlorobenzoquinone (68mg, 0.3mmol) is added, and after reacting for 0.5h under a normal temperature atmospheric environment, excessive triethylamine is added and reacted for 0.5h. After the reaction, the product was initially purified by alumina column chromatography and then purified by column chromatography using silica gel treated with triethylamine to obtain a crude product. After multiple silica gel column chromatography purifications, the products of different polarities were prepared as saturated dichloromethane solutions, and an appropriate amount of n-hexane was added. The solution was slowly evaporated and recrystallized to obtain a small amount of black powder. The yields of compounds III and IV were 19% and 4%, respectively.

[0134] Compounds III and IV obtained in this example were characterized as follows:

[0135] (1) NMR characterization

[0136] Compound III was used as a sample for experimental analysis, and its H NMR spectrum (223K) was as follows Figure 9 As shown:

[0137] 1 H NMR (400MHz, CDCl3) δ11.82(s,2H),8.07(d,J=7.8Hz,2H),7.82(s,2H),7.77(d, J=7.8Hz,2H),7.68(d,J=8.0Hz,2H),7.25(s,2H),6.91(s,2H),6.86(s,2H),6.6 9(s,2H),6.51(d,J=8.0Hz,2H),6.34(s,2H),2.84–2.53(m,24H),2.47(s,6H),2 .08(s,2H),2.04(s,6H),1.27–1.15(m,30H),1.10(s,6H),0.99(t,J=7.4Hz,6H).

[0138] Compound III was used as a sample for experimental analysis, and its H NMR spectrum (373K) was as follows Figure 9 As shown:

[0139] 1H NMR(400MHz,TETRACHLOROETHAN)δ11.99(s,2H),7.96(s,4H),7.55(s,4H),7.20(s,4H),6.97(s,4H),6.78(s,2H),6.43( s,2H),2.86–2.67(m,24H),2.59(s,6H),2.14(s,6H),1.44(s,2H),1.37–1.29(m,24H),1.21(s,6H),1.18–1.09(m,12H).

[0140] Compound IV was used as a sample for experimental analysis, and its H NMR spectrum (293K) was as follows Figure 10 As shown:

[0141] 1 H NMR (600MHz, CDCl3) δ12.28(s,1H),11.82(s,1H),8.25(d,J=8.1Hz,1H),8.11(d,J=7.7Hz,1H),7.96(d,J=8.0Hz,1H),7.86–7.80(m,2H),7.72(d ,J=7.7Hz,1H),7.64(s,1H),7.59(s,1H),7.41(s,1H),7.19(s,1H),7.0 2(s,1H),6.91(s,1H),6.89–6.85(m,3H),6.84(s,1H),6.70(d,J=2.0Hz, 1H),6.62(d,J=8.0Hz,1H),6.51(d,J=8.2Hz,1H),6.35(s,1H),2.94–2. 52(m,22H),2.48(s,3H),2.43(s,3H),2.38–2.32(m,1H),2.30(s,3H),2. 18–2.12(m,1H),2.06(s,3H),2.04(s,3H),1.35(q,J=7.6Hz,6H),1.29– 1.17(m,24H),1.11(s,3H),0.86(t,J=7.3Hz,3H),0.53(t,J=7.5Hz,3H).

[0142] (2) Mass spectrometry characterization

[0143] The HRMS spectra of compound III and compound IV are as follows Figure 11 shown.

[0144] Compound III (m / z): [M+H] + Calcd.for C 96 H 103N6O2 1372.8193; found 1372.8140.

[0145] Compound IV (m / z): [M+H] + Calcd.for C 97 H 102 N7O2 1397.8121; Found 1397.8213.

[0146] The experimental results are consistent with the theoretical values, verifying the accuracy of the structure.

[0147] (3) Single crystal structure analysis

[0148] The single crystal structures of compounds III and IV are shown in the figure below. Figure 12 For the sake of clarity, the outer ethyl group and some outer hydrogen atoms are omitted, where white represents hydrogen atoms, yellow represents carbon atoms, blue represents nitrogen atoms, and red represents oxygen atoms.

[0149] The above characterization indicates that compound III is a cis-10-membered ring-expanded porphyrin modified with 9-mesityl-9-hydroxy-fluorene, and its formation mechanism can be attributed to the hydrolysis of the methoxy group in the fluorene unit under acidic conditions. Compound IV, on the other hand, exhibits a more complex structure, in which one fluorene unit maintains the 9-mesityl-9-hydroxy-fluorene structure, while the other fluorene unit undergoes a skeletal rearrangement under the influence of the cyano group in the reaction system, ultimately forming a cyano-substituted oxygen-containing six-membered ring structure.

[0150] Further conformational studies revealed that compound III exhibited a highly distorted "8"-shaped conformation in the solid state, while in solution it exhibited a dynamic conformational equilibrium. 1 H NMR quantitative analysis, this paper obtained for the first time the thermodynamic parameters of the mutual transformation between the "8" shape and the rectangular conformation (ΔH=23.2(3)kJ·mol -1 , ΔS=87.0(6.7)J·mol -1 ·K -1 ), indicating that the process is an entropy-driven conformational transition. In contrast, compound IV maintains a stable distorted figure-8 conformation both in the solid state and in solution, and its (S,P,P)- and (R,M,M)-enantiomers can be resolved by chiral HPLC.

[0151] (4) Chiral optical properties

[0152] Figure 13 The circular dichroism (CD) spectrum of compound IV is shown in Figure 1. The results show that compound IV exhibits significant chiral optical response in the wavelength range of 550-590nm and 680-750nm, and its maximum absorption asymmetry factor (|g abs|) can reach 0.032 (at 697 nm), which is relatively high among macrocyclic compounds with similar structures and has certain application potential in the field of chiral optical devices.

[0153] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A fluorene-modified ring-expanded porphyrin compound, characterized in that: A chemical structure having the following general structural formula, or a tautomer or configurational isomer of the structure shown in the following general formula: Wherein, Et is ethyl; R 1 and R 2 are independently selected from hydrogen, C 1-10 alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted aralkyl, and OR 1 With R 2 Not the same.

2. A fluorene-modified ring-expanded porphyrin compound according to claim 1, characterized in that: The fluorene-modified ring-expanded porphyrin compound includes the following structural formula: Wherein, structural formula I and structural formula II are cis-trans isomers; In the formula, Et is ethyl, MeO is methoxy, and Mes is mesityl.

3. A method for preparing the fluorene-modified ring-expanded porphyrin compound according to claim 1, characterized in that: The following steps are involved: S1: Compound 1 and R 2 -MgBr is dispersed in an organic solvent to react and generate compound 2; S2: Compound 2, sodium hydride and R 1 -I is mixed with an organic solvent and reacted to obtain compound 3; S3: Compound 3, compound 4, palladium acetate, triphenylphosphine, and potassium carbonate are heated under reflux in a mixed solvent to obtain compound 5; S4: heating and mixing compound 5, sodium hydroxide, and an organic solvent, and then subjecting the mixture to a reflux reaction to obtain compound 6; S5: Compound 6, Compound 7, an acid catalyst, and an organic solvent are mixed and reacted under an inert gas atmosphere; 2,3-dichloro-5,6-dicyanobenzoquinone is then added, and the mixture is reacted in air to finally obtain a fluorene-modified ring-expanded porphyrin compound; In step S5, the molar ratio of compound 6, compound 7, acid catalyst and 2,3-dichloro-5,6-dicyanobenzoquinone is 1:1:(5-15):(2-4); The above steps S1 to S4 are all carried out under an inert gas atmosphere; The structural formulas of compounds 1 to 7 are as follows, wherein Et is an ethyl group and Bpin is a pinacol boron group:

4. The method for preparing a fluorene-modified ring-expanded porphyrin compound according to claim 3, wherein: In step S1, the compound 1 and R 2 -MgBr molar ratio is 1:(1.5-2.5); The reaction time is 1.5-2.5 hours, and the reaction temperature is room temperature.

5. The method for preparing a fluorene-modified ring-expanded porphyrin compound according to claim 3, wherein: In step S2, the compound 2, sodium hydride and R 1 -I has a molar ratio of 1:(3.5-4.5):(2.5-3.5); The reaction time is 5-6 hours, and the reaction temperature is room temperature.

6. The method for preparing a fluorene-modified ring-expanded porphyrin compound according to claim 3, wherein: In step S3, the molar ratio of compound 3, compound 4, palladium acetate, triphenylphosphine and potassium carbonate is 1:(1.5-2.5):(0.05-0.1):(0.05-0.15):(2.5-3.5); The reaction time is 14-18 hours, and the reaction temperature is 85-95°C; The mixed solvent is composed of water and dioxane in a volume ratio of 1:(4-6).

7. The method for preparing a fluorene-modified ring-expanded porphyrin compound according to claim 3, wherein: In step S4, the molar ratio of compound 5 to sodium hydroxide is 1:(12-18); The reaction time is 1-3 hours, and the reaction temperature is 180-200°C.

8. The method for preparing a fluorene-modified ring-expanded porphyrin compound according to claim 3, wherein: In step S5, the reaction time is 2-4 hours, the reaction time after adding 2,3-dichloro-5,6-dicyanobenzoquinone is 0.5-1.5 hours, and the reaction temperature is room temperature; The acid catalyst includes any one of methanesulfonic acid, trifluoroacetic acid, p-toluenesulfonic acid, hydroiodic acid, and boron trifluoride etherate.

9. Use of the fluorene-modified ring-expanded porphyrin compound according to claim 1, characterized in that: The fluorene-modified ring-expanded porphyrin compound is used for preparing chiral optical materials.

10. A fluorene-modified ring-expanded porphyrin compound derivative, characterized in that: Including the following structural formula: The derivative corresponding to the structural formula III is prepared by reacting the fluorene-modified ring-expanded porphyrin compound according to claim 1 under acidic conditions through OR 1 Obtained by hydrolysis; The derivative corresponding to the structure IV is obtained by rearrangement of the fluorene-modified ring-expanded porphyrin compound according to claim 1 under acidic conditions and with the participation of a cyano group; The fluorene-modified ring-expanded porphyrin compound derivative is used for preparing chiral optical materials.

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