Stable anti-aromatic fused ring isoporphyrin and preparation method thereof

Abstract

According to the stable anti-aromatic fused ring isoporphyrin and the preparation method thereof, on one hand, the number of meso-carbon atoms is increased by introducing an olefinic bond to obtain meso-expanded pentaporphyrin, and on the other hand, the stability of a macrocycle is improved and the oxidation potential of the macrocycle is reduced through meso-electron-withdrawing pentafluorophenyl, so that the stable anti-aromatic fused ring isoporphyrin is obtained. The expanded pentaporphyrin can be subjected to multiple intramolecular oxidation parallel connection, so that stable anti-aromatic fused ring isoporphyrin is obtained; furthermore, through selective reduction and dipolar cycloaddition, the regulation and control on properties such as the structure, the anti-aromaticity and the spectrum of the anti-aromaticity condensed ring isoporphyrin are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of extended porphyrin and antiaromatic molecular chemistry, in particular to a stable antiaromatic fused-ring isoporphyrin and a preparation method thereof. Background Art

[0002] Antiaromatic molecules hold significant theoretical and applied value in chemistry and materials science (Nat. Chem. 2015, 7, 418–422; Angew. Chem. Int. Ed. 2018, 57, 9728–9733). The synthesis and study of antiaromatic molecules have not only advanced quantum chemistry and molecular orbital theory but also provided new insights into the design of novel functional materials. Antiaromatic molecules play a crucial role in organic semiconductors, molecular switches, and catalysis (J. Am. Chem. Soc. 2023, 145, 2840–2851; Angew. Chem. Int. Ed. 2014, 53, 3096–3101). However, due to their 4n π electrons and fully filled antibonding orbitals, antiaromatic molecules often exhibit high reactivity and thermodynamic instability, limiting their further applications. Therefore, synthesizing highly stable antiaromatic molecules is a prerequisite for developing functional applications.

[0003] Porphyrins, a class of nitrogen-containing conjugated macrocyclic compounds that are widely found in nature, have outstanding optoelectronic properties and have gradually become an effective platform for constructing stable antiaromatic molecules (Chem. Rev. 2017, 117, 2839–2909). Extended porphyrins (J. Am. Chem. Soc. 2001, 123, 29, 7190–7191) obtained by increasing the number of pyrrole and methine bridges have many advantages over conventional porphyrins, such as: extended porphyrins have rich molecular conformations and can achieve Hückel (anti) aromaticity. Extended porphyrins possess unique properties such as (anti)aromaticity; multiple coordination sites, enabling multi-(non-)metal coordination; rich electronic properties, with the number of conjugated electrons tunable through oxidation or reduction; increased overall molecular conjugation, and a red-shifted absorption wavelength into the infrared region. Due to these unique properties, extended porphyrins are widely used in near-infrared materials, photoacoustic imaging materials, and other fields, and are gradually becoming an effective platform for constructing antiaromatic molecules. However, the synthesis of antiaromatic extended porphyrins is still in its infancy. The synthesized antiaromatic extended porphyrins involve multi-step synthesis, resulting in low yields, strict control of reaction conditions leading to cross-selectivity, and unstable products that hinder their application. Summary of the Invention

[0004] The object of the present invention is to provide a stable antiaromatic fused-ring isoporphyrin and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present application provides the following technical solutions: a stable anti-aromatic fused ring isoporphyrin, which comprises an extended porphyrin I, an oxidized fused ring product II, and oxidized fused ring product structural derivatives III, IV and V;

[0006] The structural formula of the extended porphyrin I is as follows:

[0007]

[0008] The structural formula of the oxidized fused ring product II is as follows:

[0009]

[0010] The structural formula of the oxidized fused ring product structural derivative III is as follows:

[0011]

[0012] The structural formula of the oxidized fused ring product structural derivative IV is as follows:

[0013]

[0014] The structural formula of the oxidized fused ring product structural derivative V is as follows:

[0015]

[0016] The present application also provides a preparation method of the anti-aromatic fused ring isoporphyrin, which specifically comprises the following steps:

[0017] S1, preparing the extended porphyrin;

[0018] S2, preparing the anti-aromatic fused ring isoporphyrin II;

[0019] S3, preparing the anti-aromatic fused ring isoporphyrin III;

[0020] S4, preparing the anti-aromatic fused ring isoporphyrin IV;

[0021] S5, preparing the anti-aromatic fused ring isoporphyrin V.

[0022] Preferably, the step S1 specifically comprises the following steps:

[0023] a1, stirring the diacylated tripyrralidine I-1 in a dichloromethane / methanol mixed solvent at room temperature, slowly adding NaBH4 for reduction, and then washing, drying and purifying after the reaction is completed to obtain the tripyrralidine diol I-2, which is directly used in the next step;

[0024] a2, the obtained intermediate I-2 and Z / E isomer mixed diphenyl dipyrromethene I-3 is dissolved in dichloromethane, trifluoroacetic acid catalytic condensation, followed by the addition of 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone DDQ oxidation, after the reaction, in turn washed, dried, purified, obtained orange solid meso expanded porphyrin I.

[0025] Preferably, the structure of the tripyrrolidine I-1, tripyrrolidine diol I-2 and diphenyl dipyrromethene I-3 are respectively:

[0026]

[0027] Preferably, the obtained porphyrin I in step a2 is dissolved in dichloromethane, DDQ is added for oxidation, and after the reaction is completed, it is washed, dried and purified to obtain the purple solid anti-aromatic fused ring isoporphyrin II. The equivalent ratio of porphyrin I to oxidant DDQ is 1:2, the reaction time is 3-4 hours, and the reaction temperature is 35°C.

[0028] Preferably, the obtained anti-aromatic product II is dissolved in a mixed solution of dichloromethane and methanol, and anhydrous stannous chloride is added for reaction, and after the reaction is completed, it is washed, dried and purified to obtain the orange solid anti-aromatic fused ring isoporphyrin III. The equivalent ratio of anti-aromatic isoporphyrin II to reducing agent SnCl2 is 1:30, the volume ratio of mixed solvents dichloromethane and methanol is 4:1, and the reaction time is 2-3 hours.

[0029] Preferably, the obtained anti-aromatic product II is dissolved in tetrahydrofuran, and paraformaldehyde and sarcosine are added for reaction, and after the reaction is completed, it is washed, dried and purified to obtain the orange solid, which is the 1, 3-dipolar cycloaddition product of II, anti-aromatic fused ring isoporphyrin IV. The equivalent ratio of anti-aromatic II to sarcosine and paraformaldehyde is 1:10:10, the reaction temperature is 40-50°C, and the reaction time is 6-8 hours.

[0030] Preferably, the obtained isoporphyrin IV is dissolved in acetonitrile, and DDQ is added for oxidation, and after the reaction is completed, it is washed, dried and purified to obtain the purple solid, which is anti-aromatic fused ring isoporphyrin V. The equivalent ratio of isoporphyrin IV to oxidant DDQ is 1:2, the reaction temperature is 60°C, and the reaction time is 5 hours.

[0031] Preferably, in step a1, the amount ratio of NaBH4 to bisacylated substrate is 20:1, and the volume ratio of mixed solvents dichloromethane and methanol is 4:1; in step a2, the equivalent ratio of intermediate I-2 to dipyrromethene I-3 is 1:1, the equivalent ratio of intermediate I-2 to trifluoroacetic acid is 1:0.2-0.6, the acid catalytic condensation reaction time is 0.5 hours, the equivalent ratio of intermediate I-2 to oxidant DDQ is 1:2, and the reaction time is 2-4 hours.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention provides a stable antiaromatic fused-ring isoporphyrin and a preparation method thereof. On the one hand, the number of carbon atoms at the middle position is increased by introducing an olefinic bond to obtain a meso-extended pentaporphyrin. On the other hand, the stability of the macrocycle is increased by using a meso-electron-withdrawing pentafluorophenyl group, and its oxidation potential is reduced, so that the extended pentaporphyrin can undergo multiple intramolecular oxidative linkages to obtain a stable antiaromatic fused-ring isoporphyrin. Furthermore, selective reduction and dipolar cycloaddition are used to achieve the regulation of the structure, antiaromaticity, spectrum and other properties of the antiaromatic fused-ring isoporphyrin. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The synthetic route of the meso-extended pentaporphyrin and its antiaromatic fused ring product of the present invention is as follows;

[0035] Figure 2 The absorption spectrum of the meso-extended pentaporphyrin and its antiaromatic fused ring product of the present invention;

[0036] Figure 3 This is the H NMR spectrum (298K) of the meso-extended pentaporphyrin I in Example 2 of the present invention;

[0037] Figure 4 1H NMR spectrum (298K) of the antiaromatic isoporphyrin II in Example 3 of the present invention;

[0038] Figure 5 This is the H NMR spectrum (298K) of the antiaromatic isoporphyrin III in Example 4 of the present invention;

[0039] Figure 6 This is the H NMR spectrum (298K) of the antiaromatic isoporphyrin IV in Example 4 of the present invention;

[0040] Figure 7 : is the H NMR spectrum (298K) of the antiaromatic isoporphyrin V in Example 4 of the present invention;

[0041] Figure 8 Schematic diagram of the single crystal structure of meso-extended pentaporphyrin II in Example 3 of the present invention;

[0042] Figure 9 Schematic diagram of the single crystal structure of antiaromatic porphyrin III in Example 4 of the present invention;

[0043] Figure 10 Schematic diagram of the single crystal structure of antiaromatic porphyrin IV in Example 4 of the present invention;

[0044] Figure 11A schematic diagram of a single crystal structure of the anti-aromatic isochromophyll V in the embodiment 4 of the present application. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0046] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0047] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "setting" should be understood in a broad sense, for example, can be fixedly connected, set, or can be detachably connected, set, or integrally connected, set. For a person of ordinary skill in the art, the specific meaning of the above terms in the present patent can be understood according to the specific circumstances.

[0048] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "several" is two or more, unless otherwise explicitly specified and limited.

[0049] Embodiment 1

[0050] The present application provides the following scheme: a stable anti-aromatic fused ring isochromophyll, the anti-aromatic fused ring isochromophyll includes extended porphyrin I, oxidized fused ring product II and oxidized fused ring product structural derivative III, IV and V;

[0051] The structural formula of the extended porphyrin I is:

[0052]

[0053] The structural formula of the oxidized fused ring product II is:

[0054]

[0055] The structural formula of the oxidized fused ring product structural derivative III is:

[0056]

[0057] The structural formula of the oxidized fused ring product structural derivative IV is:

[0058]

[0059] The structural formula of the oxidized fused ring product structural derivative V is:

[0060]

[0061] Example 2

[0062] The present application provides a method for preparing expanded porphyrin:

[0063] A single-necked flask was charged with diacylated tripyrridine I-1 (1.22 g, 1.29 mmol), dissolved in a mixed solution of THF / MeOH (15 mL, v / v = 4 / 1), and stirred at room temperature. NaBH4 (980 mg, 25.8 mmol) was added in portions, and the reaction was monitored by TLC until completion. Saturated aqueous NH4Cl solution was added to quench the reaction, and CH2Cl2 (3 x 10 mL) was used to extract the mixture. The organic phase was combined and dried over anhydrous Na2SO4. The solvent was removed by rotary evaporation to obtain a yellow oily product I-2, which was directly used in the next step.

[0064] Another clean single-necked flask was charged with the above-mentioned raw material I-2 and diphenyl dipyrrin ethylene I-3 (400 mg, 1.29 mmol), dissolved in CH2Cl2 (80 mL), and stirred at room temperature. TFA (48 μL, 0.64 mmol) was slowly added, and the reaction was allowed to proceed for 2 h. CH2Cl2 (200 mL) was added to dilute the reaction mixture, and a CH2Cl2 (100 mL) solution of DDQ (878 mg, 3.87 mmol) was slowly added dropwise while stirring at room temperature. The reaction was allowed to proceed for 3 h, and neutral alumina column was used to remove large polar and insoluble impurities. The solvent was removed by rotary evaporation. The residue was separated by column chromatography (dichloromethane / petroleum ether = 1 / 1) to obtain orange solid I (383 mg, 24%).

[0065] Obtained data: I: 1H NMR (400 MHz, CD2Cl2, ppm): δ = 9.85 (s, 2H, NH), 7.56 (s, 1H, NH), 7.05 (d, J = 4.4 Hz, 2H), 7.01 - 6.92 (m, 6H), 6.90 (d, J = 4.4 Hz, 2H), 6.82 (dd, J = 4.1, 1.3 Hz, 2H), 6.75 - 6.71 (m, 6H), 5.91 (s, 2H). 13 C NMR (151 MHz, CD2Cl 2， ppm): δ = 159.50, 150.60, 148.03, 146.21, 140.03, 134.99, 132.85, 131.49, 130.74, 129.80, 128.37, 128.32, 127.71, 127.69, 126.64, 124.95, 123.73, 122.59, 120.12, 116.49, 101.27, 98.10. (* indicates C-F coupling signals, less accurate). HR-ESI-MS: m / z; [M+H] + : calcd for C 62 H 24 F 20 N5: 1218.1712 found: 1218.1687. UV / Vis [(CH2Cl2): λ max (nm) (ε / 10 5 mol -1 dm 3 cm -1 ): 391 (0.48), 514 (0.98), 767 (0.33). m.p. > 300 °C (decomp.).

[0066] Example 3

[0067] The present application provides a solution for the preparation of the anti-aromatic fused-ring isoporphyrin II, comprising the following steps:

[0068] A 50 mL single-necked flask was charged with I (48.0 mg, 0.0394 mmol), dissolved in CH2Cl2(20 mL), and a solution of DDQ (26.8 mg, 0.118 mmol) in CH2Cl2(5 mL) was added dropwise with stirring at room temperature. After refluxing for 3 h, the reaction was allowed to cool to room temperature, and insoluble and highly polar impurities were removed by passing the solution through a column of neutral alumina. The solvent was removed by rotary evaporation. The residue was separated by column chromatography (dichloromethane / petroleum ether = 4 / 1 - 1 / 1) to give II as a purple solid (22 mg, 47%).

[0069] Data obtained: II: 1H NMR (400 MHz, CDC13, ppm): δ = 6.89 (dd, J = 5.4, 1.8 Hz, 3H), 6.70 (t, J = 7.4 Hz, 1H), 6.52 (t, J = 7.7 Hz, 2H), 6.31 (dd, J = 6.8, 2.7 Hz, 3H), 5.98 (d, J = 7.8 Hz, 3H), 4.97 - 4.91 (m, 1H), 3.87 (s, 1H), 3.63 (d, J = 5.6 Hz, 1H), 3.13 (d, J = 5.2 Hz, 1H), 2.82 (d, J = 4.8 Hz, 1H). HR-ESI-MS: m / z; [M+H] + : calcd for C 62 H 16 F 20 N5: 1210.1086 found: 1210.1061. UV / Vis [(CH2Cl2): λ max (nm) (ε / 10 5 mol -1 dm 3 cm -1 ): 555 (0.46), 714 (0.06). m.p. >300 °C (decomp.). The structure of II was further characterized by

[0070] single crystal structure Figure 8 characterization, indicating the correct structure of the compound.

[0071] Example 4

[0072] The present application provides the following scheme: the preparation method of anti-aromatic fused ring isoporphyrin III, IV and V includes the following steps:

[0073] In a single-necked flask, II (30.0 mg, 0.0248 mmol) was dissolved in a mixed solution of CH2Cl2 / MeOH (5 mL), and SnCl2(94 mg, 0.50 mmol) was added under stirring at room temperature. After 6 h of reaction, water was added for quenching, and CH2Cl2(3 x 5 mL) was used for extraction. The combined organic phase was dried over anhydrous Na2SO4, and the solvent was removed by rotary evaporation. The residue was separated by column chromatography (dichloromethane / petroleum ether = 3 / 2) to obtain III (25 mg, 83%) as an orange solid.

[0074] Data obtained: III: 1H NMR (400 MHz, CD2CI2, ppm): δ = 7.27 - 7.23 (m, 3H), 7.07 (q, J = 7.2 Hz, 7H), 6.87 (s, 1H, NH), 5.45 - 5.49 (m, 2H), 3.07 - 3.01 (m, 2H), 2.93 (d, J = 5.9 Hz, 2H). HR-ESI-MS: m / z;

[0075] [M+H] + : calcd for C 62 H 18 F 20 N5: 1212.1243 found: 1212.1232. UV / Vis [(CH2CI2):

[0076] λ max (nm) (ε / 10 5 mol -1 dm 3 cm -1 ): 485 (0.70), 509 (0.89), 557 (0.14), 614 (0.13), 644 (0.14). m.p. > 300 °C (decomp.). The structure of III was further characterized by single crystal structure Figure 8 determination, indicating the correct structure of the compound.

[0077] A 100 mL Schlenk tube was charged with II (40.0 mg, 0.0331 mmol), sarcosine (44.5 mg, 0.496 mmol mL), paraformaldehyde (HCHO) n (40 mg), THF (10 mL) as solvent, and the reaction was refluxed for 3 h. After cooling to room temperature, the reaction was quenched with water and extracted with CH2CI2(3 x 5 mL),

[0078] The organic phases were combined and dried over anhydrous Na2S04. The solvent was removed by rotary evaporation. The residue was separated by column chromatography (dichloromethane / petroleum ether = 3 / 2) to give IV as an orange solid (28.6 mg, 68%).

[0079] Data obtained: IV: 1 H NMR (400 MHz, acetone-d6, ppm): δ = δ 9.76 (s, 1H), 7.24 - 7.27 (m, 3H), 7.12 - 6.98 (m, 7H), 5.67 (d, J = 4.8 Hz, 1H), 5.38 (d, J = 4.0 Hz, 1H), 3.96 - 3.91 (m, 1H), 3.87 (dt, J

[0080] = 7.6, 3.8 Hz, 1H), 2.66 (d, J = 9.6 Hz, 1H), 2.55 (d, J = 9.6 Hz, 1H), 2.31 (t, J = 8.4 Hz, 1H), 2.20 (t, J = 8.8 Hz, 1H), 2.12 (s, 3H). HR-ESI-MS: m / z; [M+H] + : calcd for C 65 H 23 F 20 N6: 1267.1665 found: 1267.1648. UV / Vis

[0081] [(CH2Cl2): λ max (nm) (ε / 10 5 mol -1 dm 3 cm -1 ): 310 (0.73), 487 (0.75), 509 (0.94), 560 (0.11), 611 (0.13), 644 (0.14). m.p. >300 °C (decomp.). The structure of IV was further characterized by single crystal structure Figure 8 determination, indicating the compound structure was correct.

[0082] 25 mL Schlenk tube was charged with IV (20 mg, 0.0158 mmol), dissolved in MeCN (5 mL), then DDQ (14.5 mg, 0.0631 mmol) was added, the reaction was heated at 70 °C for 2 hours, then cooled to room temperature, passed through a neutral alumina column to remove insoluble and highly polar impurities, the solvent was removed by rotary evaporation. The residue was separated by column chromatography (dichloromethane / petroleum ether = 1 / 1) to give purple solid V (15.4 mg, 77%).

[0083] Obtained data: V: 1 H NMR (400 MHz, CDC13, ppm): δ = 7.13-7.08 (m, 3H), 6.99-6.78 (m, 7H), 6.31 (s, 1H), 5.95 (s, 1H), 3.30 (s, 3H). HR-ESI-MS: m / z; [M+H] + : calcd for C 65 H 18 ClF 20 N6: 1297.0962 found: 1297.0946. UV / Vis max (nm) (ε / 10 5 mol -1 dm 3 cm -1)]: 340 (0.60), 511 (0.53), 572 (0.51), 664 (0.12). m.p. >300 °C (decomp.) The structure of V was further confirmed by single crystal structure Figure 8 The compound was characterized and shown to have the correct structure.

[0084] Figure 2 The UV-Vis-NIR absorption spectra of the meso-expanded pentaphyrin and its intramolecularly fused product prepared in this example were shown in Figure 6. The Soret and Q-like bands of I were red-shifted to 514 nm and 769 nm, respectively, due to the introduction of vinyl groups. The Soret band of II was slightly red-shifted to 550 nm, and especially, its Q-like band was disappeared and replaced by a long and weak absorption tail extending to about 1780 nm, which was in accordance with its antiaromatic character. The reduced and cycloaddition products III and IV showed very similar absorption spectra, and their Soret bands were blue-shifted to about 505 nm due to the breaking of conjugation, and their Q-like bands were at 648 nm. Both of them also showed long and weak absorption tails blue-shifted to about 1100 nm due to the local antiaromaticity. Compound V showed overall antiaromaticity due to the oxidative conjugation, and its Q-like band was disappeared, and its Soret band was red-shifted and split to 514 nm and 574 nm compared to IV. The absorption tail extended to about 1400 nm, which indicated the antiaromaticity of V but was slightly weaker than II, which might be due to the extra pyrrole ring on the double bond that interfered with the overall conjugation.

[0085] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above examples, and the above examples and descriptions in the specification are only preferred examples of the present application, and are not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A stable antiaromatic fused-ring porphyrin, characterized in that: The antiaromatic fused ring isoporphyrin comprises an extended pentaporphyrin I, an oxidized fused ring product II, and structural derivatives III, IV, and V of the oxidized fused ring product; The structural formula of the extended pentaporphyrin I is: The structural formula of the oxidized fused ring product II is: The structural formula of the oxidized fused ring product structural derivative III is: The structural formula of the oxidized fused ring product structural derivative IV is: The structural formula of the oxidized fused ring product structural derivative V is:

2. The method for preparing an antiaromatic fused-ring porphyrin according to claim 1, wherein: The preparation method specifically comprises the following steps: S1. Preparation of extended pentaporphyrin; S2, preparing antiaromatic fused-ring isoporphyrin II; S3, preparing antiaromatic fused-ring porphyrin III; S4, preparing antiaromatic fused-ring porphyrin IV; S5. Prepare antiaromatic fused-ring porphyrin V.

3. The method for preparing an antiaromatic fused-ring porphyrin according to claim 2, wherein: The step S1 specifically includes the following steps: a1. Stir the bis-acylated tripyrrolidine I-1 in a dichloromethane / methanol mixture at room temperature, slowly add NaBH4 for reduction, and wash, dry, and purify the resulting tripyrrolidinediol I-2, which is then used directly in the next step. a2. The intermediate Ⅰ-2 and the mixed diphenyldipyrroethylene I-3 of Z / E isomers are dissolved in dichloromethane, trifluoroacetic acid is added to catalyze condensation, and then 2,3-dichloro-5,6-dicyano-1,4-benzoquinone DDQ is added for oxidation. After the reaction is completed, the mixture is washed with water, dried, and purified to obtain an orange solid meso-extended pentaporphyrin I.

4. The method for preparing an antiaromatic fused-ring porphyrin according to claim 3, wherein: The structural formulas of the tripyrrolidine I-1, tripyrrolidinediol I-2 and diphenyldipyrrolethylene I-3 are respectively:

5. The method for preparing an antiaromatic fused-ring porphyrin according to claim 3, wherein: The pentaporphyrin I obtained in step a2 is dissolved in dichloromethane, DDQ is added for oxidation, and the reaction is heated. After completion, the reaction is washed, dried, and purified to obtain a purple solid anti-aromatic fused-ring isoporphyrin II. The equivalent ratio of pentaporphyrin I to the oxidant DDQ is 1:

2. The reaction time is 3 to 4 hours and the reaction temperature is 35°C.

6. The method for preparing an antiaromatic fused-ring porphyrin according to claim 5, wherein: The obtained antiaromatic product II is dissolved in a mixed solution of dichloromethane and methanol, and anhydrous stannous chloride is added to react. After the reaction is completed, it is washed, dried, and purified to obtain an orange solid antiaromatic fused-ring porphyrin III. The equivalent ratio of antiaromatic porphyrin II to reducing agent SnCl2 is 1:30, the volume ratio of mixed solvent dichloromethane and methanol is 4:1, and the reaction time is 2 to 3 hours.

7. The method for preparing an antiaromatic fused-ring porphyrin according to claim 5, wherein: The obtained antiaromatic product II is dissolved in tetrahydrofuran, and paraformaldehyde and sarcosine are added, and the reaction is heated. After the reaction is completed, it is washed, dried, and purified to obtain an orange solid, which is the 1,3-dipolar cycloaddition product of II - antiaromatic fused-ring isoporphyrin IV. The equivalent ratio of antiaromatic II to sarcosine and paraformaldehyde is 1:10:10, the reaction temperature is 40-50°C, and the reaction time is 6-8 hours.

8. The method for preparing an antiaromatic fused-ring porphyrin according to claim 7, wherein: The obtained porphyrin IV was dissolved in acetonitrile, DDQ was added for oxidation, and the reaction was continued. After completion, the reaction was washed, dried, and purified to obtain a purple solid, which was an anti-aromatic fused-ring porphyrin V. The equivalent ratio of porphyrin IV to the oxidant DDQ was 1:2, the reaction temperature was 60°C, and the reaction time was 5 hours.

9. The method for preparing an antiaromatic fused-ring porphyrin according to claim 3, wherein: In the step a1, the amount ratio of NaBH4 and the bis-acylated substrate is 20:1, and the volume ratio of the mixed solvent dichloromethane and methanol is 4:1; in the step a2, the equivalent ratio of the intermediate I-2 and dipyrroldiphenylethylene I-3 is 1:1, the equivalent ratio of the intermediate I-2 to trifluoroacetic acid is 1:0.2~0.6, the acid-catalyzed condensation reaction time is 0.5 hour, the equivalent ratio of the intermediate I-2 to the oxidant DDQ is 1:2, and the reaction time is 2~4 hours.

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