Process for the preparation of unsymmetrical per-substituted pyrrole compounds

Abstract

The present application relates to the technical field of organic chemical synthesis, in particular to an asymmetrically fully-substituted pyrrole compound and a preparation method thereof. The present application first realizes a [2+1+2] cyclization reaction of a carbene reagent and an olefin in a nitrile solvent under visible light induction to construct an asymmetrically fully-substituted pyrrole compound, filling a blank in the prior art. The method of the present application has mild process conditions, a short process flow, simple steps, wide substrate applicability, and meets the requirements of industrial production, overcoming the problem in the prior art that it is difficult to mass-produce asymmetrically fully-substituted pyrrole compounds. The preparation method provided by the present application obtains an asymmetrically fully-substituted pyrrole compound through a [2+1+2] cyclization reaction of a carbene reagent and an olefin in a nitrile solvent under visible light induction, and the yield of the product is high. Research shows that the yield of the product can be as high as 82%, and the generated fully-substituted pyrrole compound is widely used in drugs, so the present application has important application value.

Description

Technical Field

[0001] This invention relates to the field of organic chemical synthesis technology, specifically to asymmetric fully substituted pyrrole compounds and their preparation methods. Background Technology

[0002] Pyrroles are among the most valuable five-membered heterocycles and are found in a wide range of natural products, pharmaceutical molecules, and functional materials. They serve as valuable and practical synthetic modules for synthesizing complex molecules. Therefore, many synthetic strategies for synthesizing this important class of compounds have been developed. Traditional methods, including the Knorr, Hantzsch, and Paal-Knorr reactions, construct polysubstituted pyrroles through the condensation of carbonyl compounds with amines. In these examples, the high temperatures and the use of strong acids to adapt the condensation process often limit their applicability and the suitability of the functional groups.

[0003] Recently, numerous methods, including multicomponent reactions and transition metal-catalyzed coupling, have enabled the synthesis of pyrrole under relatively mild conditions and with better regioselectivity. Despite these advances, the applicability of highly functionalized starting materials (e.g., iminoenes, alkynylaziridines, or azides) limits the range of products. Furthermore, many existing methods require the use of amino-protected substrates, which are subsequently removed after pyrrole ring synthesis, significantly reducing synthetic efficiency. Developing a complementary strategy that allows for the synthesis of unprotected pyrrole under mild conditions from readily available starting materials would be highly beneficial.

[0004] However, to date, there have been no reports of using carbain reagents to react with alkenes in nitrile solvents to generate asymmetric fully substituted pyrrole compounds that can be synthesized under mild conditions from readily available starting materials. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide asymmetric fully substituted pyrrole compounds and their preparation methods. The preparation method provided by the present invention can prepare asymmetric fully substituted pyrrole compounds from carbapenem reagent, olefins and nitrile solvents through photocatalytic [2+1+2] cyclization reaction. The reaction conditions are mild, the process is simple and the product yield is high.

[0006] This invention provides an asymmetric fully substituted pyrrole compound with the structure shown in Formula I, which is obtained by reacting a carbain reagent, an olefin, and a nitrile solvent;

[0007] Formula I;

[0008] The R2 mentioned in this invention is selected from hydrogen, cyano, nitro, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkenyl, substituted or unsubstituted C1-C6 alkynyl, substituted or unsubstituted C6-C6 alkyl. 18Aromatic group, substituted or unsubstituted C1-C6 alkoxy group, substituted or unsubstituted C1-C6 alkyl ester group, substituted or unsubstituted C1-C6 alkyl acyl group, substituted or unsubstituted C6-C 18 Aromatic acyl, C1-C6 alkyl-substituted sulfonyl, C1-C6 alkoxy-substituted sulfonyl, C6-C 18 Aromatic group-substituted sulfonyl group, C1-C6 alkyl-substituted phosphoryl group, C1-C6 alkoxy-substituted phosphoryl group, C6-C 18 Aromatic group-substituted phosphoryl group, C1~C6 alkyl-substituted amide group, C6~C 18 One of the aromatic-substituted amide groups;

[0009] R3 to R5 are independently selected from substituted or unsubstituted C1 to C6 alkyl, substituted or unsubstituted C1 to C6 alkenyl, substituted or unsubstituted C1 to C6 ynyl, substituted or unsubstituted C6 to C6 alkyl, and substituted or unsubstituted C6 to C6 alkyl. 18 Aromatic group, substituted or unsubstituted C6~C 18 One of the heteroaryl groups.

[0010] In the R2-R5 of this invention, the substituted group refers to the group that is replaced by the substituted group. Among the groups for which no specific substituted group is defined, the specific substituted group includes, but is not limited to, C1-C6 alkyl, C1-C6 alkoxy, and C6-C6 alkyl groups. 12 Aromatic group, benzyloxy group, nitro group, halogen, cyano group, ester group, aldehyde group or trifluoromethyl group.

[0011] Preferably, R2 in this invention is selected from cyano, halogen-substituted C1-C3 alkyl, unsubstituted C1-C3 alkyl, and C6-C4 alkyl groups. 12 Aromatic group-substituted C1-C3 alkyl ester group, unsubstituted C1-C3 alkyl ester group, unsubstituted C1-C3 alkyl acyl group, unsubstituted C6-C 12 Aromatic acyl, C1-C3 alkyl-substituted sulfonyl, C1-C3 alkoxy-substituted sulfonyl, C6-C 12 Aromatic group-substituted sulfonyl group, C1~C3 alkoxy-substituted phosphoryl group, C6~C 12 One of the aromatic-substituted phosphoryl groups, wherein the halogen is selected from F, Cl, or Br. R3 and R4 are independently selected from unsubstituted C1-C4 alkyl groups, unsubstituted C1-C4 deuterated alkyl groups, and unsubstituted C6-C4 deuterated alkyl groups. 12 Aromatic groups and halogen-substituted C6~C 12 Aromatic or cyano-substituted C6~C 12 Aromatic groups, nitro-substituted C6~C 12 Aromatic group, C1~C4 alkyl-substituted C6~C 12 Aromatic group, C1~C4 halogenated alkyl group, C6~C 12Aromatic, benzoyl-substituted C6~C 12 Aromatic groups, C1-C4 alkyl ester groups substituted with C6-C 12 Aromatic group, C1~C4 halogenated alkoxy group, C6~C 12 C6~C with aryl, benzoyl and halogen disubstituted groups 12 Aromatic group, substituted or unsubstituted C6~C 12 One of the heteroaryl groups, wherein the halogen is selected from F, Cl, or Br. The R5 is selected from one of unsubstituted C1-C4 alkyl, cyano-substituted C1-C4 alkyl, and unsubstituted C1-C4 alkyl ester groups.

[0012] More preferably, R2 in this invention is selected from one of cyano, trifluoromethyl, methyl, methyl ester, ethyl ester, phenyl-substituted methyl ester, formyl, benzoyl, dimethoxyphosphoryl, ethoxy-substituted sulfonyl, methyl-substituted sulfonyl, phenyl-substituted sulfonyl, and diphenylphosphoryl. R3 and R4 are independently selected from one of methyl, deuterated methyl, ethyl, phenyl, naphthyl, biphenyl, fluorinated phenyl, bromosubstituted phenyl, chlorosubstituted phenyl, cyanosubstituted phenyl, nitrosubstituted phenyl, butylsubstituted phenyl, trifluoromethyl-substituted phenyl, benzoyl-substituted phenyl, methyl ester-substituted phenyl, trifluoromethoxy-substituted phenyl, benzoyl and fluorinated disubstituted phenyl, and substituted or unsubstituted C6-C8 heteroaryl groups. R5 is selected from one of methyl, propyl, butyl, cyano-substituted C1-C2 alkyl, and unsubstituted C1-C2 alkyl ester groups.

[0013] In some embodiments of the present invention, the asymmetric fully substituted pyrrole compound is selected from any one of the compounds shown in the following structural formulas:

[0014] .

[0015] This invention also provides a method for preparing the asymmetric fully substituted pyrrole compound described in any of the above technical solutions, comprising the following steps:

[0016] In the presence of a photocatalyst and optional proton-donating additives, a carbapenem reagent having the structure of Formula 1, an olefin having the structure of Formula 2, and a nitrile solvent having the structure of Formula 3 are reacted under light to obtain an asymmetric fully substituted pyrrole compound.

[0017] Formula 1; Formula 2; Formula 3;

[0018] Wherein, R1 is selected from halogen groups, thionium groups, pyridinium groups, quaternary ammonium cation groups, or high-valent iodine groups; R2 to R5 are the same as above and will not be described again.

[0019] The carbene reagent of the present application has the structure of Formula 1, wherein R1 is a leaving group selected from a halogen group, a sulfonium group, a pyridinium group, a quaternary ammonium cation group, or a hypervalent iodine group; wherein the halogen group includes F, Cl, Br, or I; the hypervalent iodine group, also known as hyperiodine group, is a special group formed by a class of organic molecules containing iodine element, in which the iodine atom has more than eight electrons in the traditional structure. R2 is the same as described above and will not be repeated.

[0020] Preferably, the carbene reagent is a compound having the structure of Formula 1-a; or, the carbene reagent is a substituted or unsubstituted C6-C 12 aromatic sulfonium group;

[0021] Formula 1-a;

[0022] wherein R6 is selected from one of a substituted or unsubstituted C6-C 12 aromatic group, a substituted or unsubstituted C6-C 12 heteroaromatic group; preferably, R6 is selected from a phenyl group. R7 is selected from one of a halogen-substituted C1-C3 alkyl sulfonate group, a halogen-substituted C1-C3 alkyl sulfide group, a halogen-substituted C1-C3 alkyl sulfonyl group; preferably, R7 is selected from one of a trihalogenomethanesulfonate group, a trihalogenomethyl sulfide group, a trihalogenomethyl sulfonyl group; or, R6 and R7, together with I to which they are attached, form a substituted or unsubstituted C6-C 12 heteroaromatic ring; the halogen of the present application is selected from F, Cl, or Br. R2 is the same as described above and will not be repeated.

[0023] In some embodiments of the present application, the carbene reagent is selected from one of the compounds shown in the following structural formulas:

[0024] .

[0025] The olefin of the present application has the structure of Formula 2, wherein R3 and R4 are the same as described above and will not be repeated. In some embodiments of the present application, the olefin is selected from one of the compounds shown in the following structural formulas:

[0026] .

[0027] The nitrile solvent of the present application has the structure of Formula 3, wherein R5 is the same as described above and will not be repeated. In some embodiments of the present application, the nitrile solvent is selected from one of the compounds shown in the following structural formulas:

[0028] .

[0029] The photocatalyst is selected from one or more of [Ir(dF(CF3)ppy)2(dtbbpy)](PF6), Ir(ppy)3PF6, Ru(bpy)3(PF6)2, and Ru(dtbbpy)3(PF6)2. Specifically, the photocatalyst is Ru(bpy)3(PF6)2, and its structural formula is .

[0030] The proton-donating additive can be selectively added or not added, and its role is to provide protons, neutralize the acid generated in the reaction process, and prevent strong acid conditions from causing product decomposition; if the proton-donating additive is not added, the corresponding product can also be obtained at a yield of half. The proton-donating additive is selected from one or more of KH2PO4, K2HPO4, NaHCO3, KHCO3, CH3COOH, PhOH, and PhCOOH, and is preferably selected from KH2PO4.

[0031] The present inventors have found that, by using carbene reagent and olefin as raw materials, in the presence of a photocatalyst and a proton-donating additive, and after irradiation in a nitrile solvent, the carbene reagent, the olefin, and the nitrile solvent can react to obtain the asymmetrically fully substituted pyrrole compound of the present application. The reaction conditions are mild, the process is simple, and the product yield is high. The mechanism of the preparation method provided by the present application is shown in the following reaction formula (the specific compounds involved in the reaction formula are non-limiting examples):

[0032]

[0033] The reaction formula of the aforementioned side reaction of generating acid in the reaction process of the present application is as follows:

[0034]

[0035] Specifically, the carbene reagent having the structure of formula 1, the olefin having the structure of formula 2, the nitrile solvent having the structure of formula 3, the photocatalyst, and the proton-donating additive are mixed, and the mixture is subjected to a reaction under irradiation to obtain the asymmetrically fully substituted pyrrole compound having the structure of formula I. In some embodiments of the present application, the carbene reagent having the structure of formula 1 and the olefin having the structure of formula 2 are dissolved in the nitrile solvent having the structure of formula 3, and the mixture is subjected to a reaction under irradiation to obtain the asymmetrically fully substituted pyrrole compound having the structure of formula I.

[0036] The molar ratio of the carbene reagent and the olefin is (1-3): 1, preferably 1.5:1; the molar concentration of the olefin in the nitrile solvent is 0.025 mol / L-2 mol / L; the amount of the photocatalyst is 1 mol%-5 mol% of the molar amount of the olefin; and the equivalent ratio of the proton donor additive and the carbene reagent is (1.8-2.2):1.5.

[0037] The mixed material is subjected to a reaction under light irradiation, so that the mixed material can undergo a [2+1+2] cyclization reaction, the reaction temperature is-40℃-80℃, and the reaction time is 2 h-24 h.

[0038] The present application provides an asymmetrically fully substituted pyrrole compound and a preparation method thereof. The present application fills the blank of the prior art by first realizing a [2+1+2] cyclization reaction of a carbene reagent and an olefin in a nitrile solvent under visible light induction to construct an asymmetrically fully substituted pyrrole compound. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 HNMR spectrum of product 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester 1 HNMR spectrum of product 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester

[0040] Figure 2 HNMR spectrum of product 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester 13 HNMR spectrum of product 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester

[0041] Figure 3 HNMR spectrum of product 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester 1 HNMR spectrum of product 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester

[0042] Figure 4HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester 13 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester

[0043] Figure 5 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester 1 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester

[0044] Figure 6 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester 13 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester

[0045] Figure 7 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester 1 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester

[0046] Figure 8 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester 13 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester

[0047] Figure 9 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester 1 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester

[0048] Figure 10 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester 13 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester

[0049] Figure 11 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester 1 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester

[0050] Figure 12 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester 13 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester

[0051] Figure 13 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester 1 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester

[0052] Figure 14 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester 13 HNMR Spectrum for product 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3- carboxylic acid ethyl ester

[0053] Figure 15HNMR spectrum of the product (2,5-dimethyl-4-phenyl-lH-pyrrol-3-yl) dimethyl phosphonate 1 HNMR spectrum of the product (2,5-dimethyl-4-phenyl-lH-pyrrol-3-yl) dimethyl phosphonate

[0054] Figure 16 HNMR spectrum of the product (2,5-dimethyl-4-phenyl-lH-pyrrol-3-yl) dimethyl phosphonate 13 HNMR spectrum of the product (2,5-dimethyl-4-phenyl-lH-pyrrol-3-yl) dimethyl phosphonate

[0055] Figure 17 HNMR spectrum of the product (2,5-dimethyl-4-phenyl-lH-pyrrol-3-yl) dimethyl phosphonate 1 HNMR spectrum of the product (2,5-dimethyl-4-phenyl-lH-pyrrol-3-yl) dimethyl phosphonate

[0056] Figure 18 HNMR spectrum of the product (2,5-dimethyl-4-phenyl-lH-pyrrol-3-yl) dimethyl phosphonate 13 HNMR spectrum of the product (2,5-dimethyl-4-phenyl-lH-pyrrol-3-yl) dimethyl phosphonate DETAILED DESCRIPTION

[0057] The present application discloses asymmetrically fully substituted pyrrole compounds and their preparation methods. Those skilled in the art can refer to the content herein and make appropriate improvements to the process parameters. It is particularly pointed out that all similar substitutions and changes are obvious to those skilled in the art, and they are considered to be included in the present application. The methods and applications of the present application have been described by preferred embodiments, and relevant personnel can obviously make changes or appropriate changes and combinations to the methods and applications herein without departing from the content, spirit and scope of the present application, to realize and apply the present application technology.

[0058] The present application is further described below in conjunction with examples:

[0059] Example 1

[0060] Synthesis and separation and purification of 2,5-dimethyl-4-phenyl-lH-pyrrol-3-carboxylic acid ethyl ester:

[0061] In a glove box, 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-l3-iodomethyl) ethanoate (Carbyl reagent, see Table 1 for structure; 0.45 mmol, 1.5 eq.), Ru(bpy)3(PF6)2(photo catalyst, see Table 1 for structure; 1 mol%), additive KH2PO4(2.0 eq), anhydrous and oxygen-free treated acetonitrile (nitrile solvent, see Table 1 for structure; 12 mL) and prop-l-en-2-ylbenzene (alkene, see Table 1 for structure; 0.3 mmol, 1.0 eq.) were added into a 20 mL dry transparent glass reaction flask. After mixing, the flask was taken out of the glove box and irradiated with a 40 W blue LED lamp (1.5 cm distance between the light source and the flask) at room temperature overnight for 12 h. The reaction progress was monitored by thin layer chromatography (TLC). After the reaction was completed, the crude product was obtained by rotary evaporation under reduced pressure. The crude product was separated and purified by silica gel column chromatography (petroleum ether / ethyl acetate = 10 / 1 was used as the eluent for silica gel column chromatography). The final product, ethyl 2,5-dimethyl-4-phenyl-lH-pyrrole-3-carboxylate, was obtained in a yield of 65%.

[0062] As shown in Figure 1 and Figure 2 , the Figure 1 HNMR spectrum of the product, ethyl 2,5-dimethyl-4-phenyl-lH-pyrrole-3-carboxylate, is shown in 1 HNMR spectrum; Figure 2 CNMR spectrum of the product, ethyl 2,5-dimethyl-4-phenyl-lH-pyrrole-3-carboxylate, is shown in 13 CNMR spectrum; Figure 1 and Figure 2 are shown below:

[0063] 1 H NMR (400 MHz, CDCl3) δ = 8.36 (s, 1 H), 7.38 - 7.30 (m, 2 H), 7.33- 7.20 (m, 3 H), 4.11 (q, J = 7.1, 2 H), 2.50 (s, 3 H), 2.10 (s, 3 H), 1.08(t, J = 7.1, 3 H).

[0064] 13 C NMR (101 MHz, CDCl3) δ = 166.05, 136.29, 134.05, 130.43, 127.36,125.86, 123.61, 122.41, 110.46, 59.14, 14.05, 13.64, 11.17.

[0065] Example 2

[0066] Synthesis and isolation / purification of ethyl 4-(4-fluorophenyl)-2,5-dimethyl-lH- pyrrole-3-carboxylate:

[0067] In a dry clear glass reaction flask, 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-l3- iodoformyl)acetic acid ethyl ester (Carbyl reagent, see Table 1 for structure; 0.45 mmol, 1.5 eq.), Ru(bpy)3(PF6)2(photo catalyst, see Table 1 for structure; 1 mol%), additive KH2PO4(2.0 eq), anhydrous and oxygen-free treated acetonitrile (nitrile solvent, see Table 1 for structure; 12 mL) and 1-fluoro-4-(prop-l-en-2-yl)benzene (olefin, see Table 1 for structure; 0.3 mmol, 1.0 eq.) were added. After mixing, the reaction flask was taken out of the glove box and irradiated with a 40 W blue LED lamp (reaction flask distance from light source 3.5 cm) at -40 °C overnight for 12 h. The reaction progress was monitored by thin layer chromatography (TLC). After the reaction was completed, the crude product was obtained by rotary evaporation under reduced pressure. The crude product was separated and purified by silica gel column chromatography (silica gel column chromatography used eluent system petroleum ether / ethyl acetate = 10 / 1). The final product, ethyl 4-(4-fluorophenyl)-2,5-dimethyl-lH-pyrrole-3-carboxylate, was obtained with a yield of 60%.

[0068] As shown in Figure 3 and Figure 4 , the Figure 3 HNMR spectrum of the product ethyl 4-(4-fluorophenyl)-2,5-dimethyl-lH-pyrrole-3- carboxylate is as follows: 1 HNMR spectrum; Figure 4 CNMR spectrum of the product ethyl 4-(4-fluorophenyl)-2,5-dimethyl-lH-pyrrole-3- carboxylate is as follows: 13 CNMR spectrum; Figure 3 and Figure 4 The spectral information is as follows:

[0069] 1 H NMR (500 MHz, CDCl3) δ = 8.37 (s, 1 H), 7.19 (dd, J = 8.5, 5.7, 1H), 7.00 (t, J = 8.8, 1 H), 4.09 (q, J = 7.1, 1 H), 2.48 (s, 1 H), 2.05 (s, 1H), 1.09 (t, J = 7.1, 1 H).

[0070] 13C NMR (126 MHz, CDCl3) δ = 165.94, 162.44, 160.50, 134.16, 132.20,132.17, 131.90, 131.84, 123.71, 121.44, 114.25, 114.08, 110.39, 59.18, 14.09,13.70, 11.06.

[0071] Example 3

[0072] Synthesis and isolation / purification of ethyl 2-methyl-4,5-diphenyl-lH-pyrrole-3- carboxylate:

[0073] In a glove box, in a 20 mL dry transparent glass reaction bottle, add ethyl 2-diazo-2- (phenyl((trifluoromethyl)sulfonyl)oxy)-l3-iodomethyl)acetate (Carbyl reagent, see Table 1 for structure; 0.45 mmol, 1.5 eq.), Ru(bpy)3(PF6)2(photo catalyst, see Table 1 for structure; 1 mol%), additive KH2PO4(2.0 eq), add anhydrous and oxygen-free treated acetonitrile (nitrile solvent, see Table 1 for structure; 12 mL) and ethene- 1,1-diyl dibenzene (olefin, see Table 1 for structure; 0.3 mmol, 1.0 eq.), mix well, take out of the glove box, and irradiate at -40 °C with a 40 W blue LED lamp (the reaction bottle is 3.5 cm away from the light source) for 12 h overnight. The reaction progress is monitored by thin layer chromatography (TLC), and after the reaction is completed, the crude product is obtained by rotary evaporation under reduced pressure, and the crude product is separated and purified by silica gel chromatography column (the eluent system used for silica gel chromatography is petroleum ether / ethyl acetate = 10 / 1), to obtain the final product: ethyl 2-methyl-4,5-diphenyl-lH-pyrrole-3-carboxylate, with a yield of 38%.

[0074] As shown in Figure 5 and Figure 6 , the Figure 5 HNMR spectrum of the product ethyl 2-methyl-4,5-diphenyl-lH-pyrrole-3-carboxylate is as follows: 1 HNMR spectrum; Figure 6 The 13 CNMR spectrum of the product ethyl 2-methyl-4,5-diphenyl-lH-pyrrole-3-carboxylate is as follows: Figure 5 and Figure 6 spectrum information is as follows:

[0075] 1H NMR (400 MHz, CDCl3) δ = 8.37 (s, 1 H), 7.27 - 7.21 (m, 5 H), 7.20- 7.16 (m, 2 H), 7.16 - 7.13 (m, 1 H), 7.12 - 7.08 (m, 2 H), 4.07 (q, J =7.1, 2 H), 2.60 (s, 3 H), 1.03 (t, J = 7.1, 3 H).

[0076] 13 C NMR (101 MHz, CDCl3) δ = 165.65, 136.09, 135.45, 132.20, 130.79,128.49, 127.60, 127.26, 126.74, 126.55, 126.33, 123.41, 112.66, 59.23, 13.95,13.88.

[0077] Example 4

[0078] Synthesis and purification of ethyl 2-methyl-4-phenyl-5-propyl-1H-pyrrole-3-carboxylate:

[0079] In a 20 mL dry, transparent glass reaction flask in a glove box, add ethyl 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-13-iodoformyl)ethyl acetate (Carbay reagent, structural formula see Table 1; 0.45 mmol, 1.5 eq.), Ru(bpy)3(PF6)2 (photocatalyst, structural formula see Table 1; 1 mol%), KH2PO4 (2.0 eq.) as an additive, anhydrous and oxygen-free n-butyronitrile (nitrile solvent, structural formula see Table 1; 12 mL) and prop-1-ene-2-benzene (olefin, structural formula see Table 1; 0.3 mmol, 1.0 eq.), mix well, remove from the glove box, and irradiate the reaction overnight for 12 h at -40 °C using a 40 W blue LED lamp (reaction flask 3.5 cm away from the light source). The reaction process was monitored by thin-layer chromatography (TLC). After the reaction was completed, the crude product was obtained by rotary evaporation under reduced pressure. The crude product was separated and purified by silica gel chromatography (the eluent system used in silica gel chromatography was petroleum ether / ethyl acetate = 10 / 1) to obtain the final product: ethyl 2-methyl-4-phenyl-5-propyl-1H-pyrrole-3-carboxylate, with a yield of 60%.

[0080] like Figure 7 and Figure 8 As shown, Figure 7 The product is ethyl 2-methyl-4-phenyl-5-propyl-1H-pyrrole-3-carboxylic acid.1 HNMR spectrum; Figure 8 The spectral information of the product 2-methyl-4-phenyl-5-propyl-1 H- pyrrole-3-carboxylic acid ethyl ester is as follows: 13 CNMR spectrum; Figure 7 and Figure 8 The spectral information of the product 2-methyl-4-phenyl-5-propyl-1 H- pyrrole-3-carboxylic acid ethyl ester is as follows:

[0081] 1 H NMR (500 MHz, CDCl3) δ = 8.05 (s, 1 H), 7.35 - 7.28 (m, 2 H), 7.24(t, J = 7.9, 3 H), 4.06 (q, J = 7.1, 2 H), 2.52 (s, 3 H), 2.42 (t, J = 7.7, 2H), 1.51 (h, J = 7.3, 2 H), 1.02 (t, J = 7.1, 3 H), 0.85 (t, J = 7.3, 3 H).

[0082] 13 C NMR (126 MHz, CDCl3) δ = 165.86, 136.38, 133.82, 130.47, 128.17,127.31, 125.90, 122.56, 110.70, 59.03, 27.39, 23.35, 13.99, 13.78, 13.73.

[0083] Example 5

[0084] Synthesis and isolation and purification of 2-cyclopropyl-5-methyl-4-phenyl-1 H- pyrrole-3-carboxylic acid ethyl ester:

[0085] In a glove box, 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-l3-iodomethyl) ethanoate (Carbyl reagent, see Table 1 for structure; 0.45 mmol, 1.5 eq.), Ru(bpy)3(PF6)2(photo catalyst, see Table 1 for structure; 1 mol%), additive KH2PO4(2.0 eq), anhydrous and oxygen-free treated cyclopropanenitrile (nitrile solvent, see Table 1 for structure; 12 mL) and prop-l-en-2-ylbenzene (alkene, see Table 1 for structure; 0.3 mmol, 1.0 eq.) were added into a 20 mL dry clear glass reaction flask. After mixing, the reaction flask was taken out of the glove box and irradiated with a 40 W blue LED lamp (the distance between the light source and the reaction flask was 3.5 cm) at -40 °C overnight for 12 h. The reaction progress was monitored by thin layer chromatography (TLC). After the reaction was completed, the crude product was obtained by rotary evaporation under reduced pressure. The crude product was separated and purified by silica gel column chromatography (the eluent system used in silica gel column chromatography was petroleum ether / ethyl acetate = 10 / 1). The final product, 2-cyclopropyl-5-methyl-4-phenyl-lH-pyrrole-3-carboxylic acid ethyl ester, was obtained in a yield of 55%.

[0086] As shown in Figure 9 and Figure 10 , the Figure 9 HNMR spectrum of the product 2-cyclopropyl-5-methyl-4-phenyl-lH-pyrrole-3-carboxylic acid ethyl ester is shown in 1 . Figure 10 The 13 CNMR spectrum of the product 2-cyclopropyl-5-methyl-4-phenyl-lH-pyrrole-3-carboxylic acid ethyl ester is shown in Figure 9 and Figure 10 is as follows:

[0087] 1 H NMR (500 MHz, CDCl3) δ = 7.96 (s, 1 H), 7.31 (t, J = 7.8, 2 H),7.24 (d, J = 7.2, 3 H), 4.09 (q, J = 7.1, 2 H), 2.56 (ddd, J = 14.0, 8.5,5.4, 1H), 2.06 (s, 3 H), 1.05 (t, J = 7.1, 3 H), 1.01 - 0.92 (m, 2 H), 0.70(q, J = 5.6, 2 H).

[0088] 13C NMR (126 MHz, CDCl3) δ = 165.96, 138.71, 136.21, 130.37, 127.35,125.86, 123.08, 122.72, 111.68, 59.15, 14.00, 11.23, 8.75, 7.35.

[0089] Example 6

[0090] Synthesis and isolation / purification of 2-cyclopropyl-5-methyl-4-phenyl-3- (trifluoromethyl)-lH-pyrrole:

[0091] In a dry clear glass reaction flask (20 mL), (l-diazo-2,2,2-trifluoroethyl)(phenyl)- l3-iodomethanoyl trifluoromethanesulfonate (Carbyne reagent, see Table 1 for structure; 0.45 mmol, 1.5 eq.), Ru(bpy)3(PF6)2(photo catalyst, see Table 1 for structure; 1 mol%), additive KH2PO4(2.0 eq.), anhydrous and oxygen-free treated cyclopropanenitrile (nitrile solvent, see Table 1 for structure; 12 mL) and prop-l-en-2-ylbenzene (alkene, see Table 1 for structure; 0.3 mmol, 1.0 eq.) were added. After mixing, the reaction flask was taken out of the glove box and irradiated at -40 °C with a 40 W blue LED lamp (distance of the reaction flask to the light source: 3.5 cm) overnight for 12 h. The reaction progress was monitored by thin layer chromatography (TLC). After the reaction was completed, the crude product was obtained by rotary evaporation under reduced pressure. The crude product was separated and purified by silica gel column chromatography (silica gel column chromatography used eluent system: petroleum ether / ethyl acetate = 10 / 1). The final product, 2-cyclopropyl-5-methyl-4-phenyl-3-(trifluoromethyl)-lH-pyrrole, was obtained in a yield of 69%.

[0092] As shown in Figure 11 and Figure 12 , the Figure 11 spectrum of the product 2-cyclopropyl-5-methyl-4-phenyl-3-(trifluoromethyl)-lH-pyrrole is as follows: 1 HNMR spectrum; Figure 12 The 13 CNMR spectrum of the product 2-cyclopropyl-5-methyl-4-phenyl-3-(trifluoromethyl)-lH-pyrrole is as follows: Figure 11 and Figure 12 spectrum information is as follows:

[0093] 1H NMR (500 MHz, CDCl3) δ = 7.72 (s, 1 H), 7.35 (t, J = 7.7, 2 H), 7.31 - 7.21 (m, 3 H), 2.10 (s, 3 H), 2.09 - 2.00 (m, 1 H), 0.94 (q, J = 6.5,2 H), 0.74 - 0.67 (m, 2 H).

[0094] 13 C NMR (126 MHz, CDCl3) δ = 134.73, 131.76 (d, J = 3.9), 130.18,127.84, 126.47, 124.82 (q, J = 267.8), 123.12, 120.36 (d, J = 2.3), 110.52(q, J = 34.0), 11.21, 7.57, 6.24.

[0095] Example 7

[0096] Synthesis and purification of 2,5-dimethyl-3-phenyl-4-(trifluoromethyl)-1H-pyrrole:

[0097] In a 20 mL dry, transparent glass reaction flask in a glove box, add (1-diazo-2,2,2-trifluoroethyl)(phenyl)-13-iodoformyltrifluoromethanesulfonate (Carbay reagent, structural formula see Table 1; 0.45 mmol, 1.5 eq.), Ru(bpy)3(PF6)2 (photocatalyst, structural formula see Table 1; 1 mol%), KH2PO4 (2.0 eq), anhydrous and oxygen-free acetonitrile (nitrile solvent, structural formula see Table 1; 12 mL), and prop-1-ene-2-benzene (olefin, structural formula see Table 1; 0.3 mmol, 1.0 eq.). After mixing, remove from the glove box and irradiate the reaction overnight at -40°C with a 40W blue LED lamp (reaction flask 3.5 cm away from the light source) for 12 h. The reaction process was monitored by thin-layer chromatography (TLC). After the reaction was completed, the crude product was obtained by rotary evaporation under reduced pressure. The crude product was separated and purified by silica gel chromatography (the eluent system used in silica gel chromatography was petroleum ether / ethyl acetate = 10 / 1) to obtain the final product: 2,5-dimethyl-3-phenyl-4-(trifluoromethyl)-1H-pyrrole, with a yield of 60%.

[0098] like Figure 13 and Figure 14 As shown, Figure 13 The product is 2,5-dimethyl-3-phenyl-4-(trifluoromethyl)-1H-pyrrole. 1HNMR spectrum; Figure 14 The HNMR spectrum of the product 2,5-dimethyl-3-phenyl-4-(trifluoromethyl)-1H- pyrrole is as follows: 13 CNMR spectrum; Figure 13 and Figure 14 The spectrum information of the product is as follows:

[0099] 1 H NMR (400 MHz, CDCl3) δ = 7.70 (s, 1 H), 7.27 (t, J = 7.5, 2 H),7.20 (d, J = 7.5, 3 H), 2.27 (q, J = 2.1, 3 H), 2.02 (s, 3 H).

[0100] 13 C NMR (126 MHz, CDCl3) δ = 133.74, 129.13, 126.79, 125.61 (q, J =4.0), 125.41, 123.84 (q, J = 267.5), 122.70, 119.05 (q, J = 2.4), 108.15 (q,J = 33.8), 11.35, 10.05.

[0101] Example 8

[0102] Synthesis and separation and purification of dimethyl (2,5-dimethyl-4-phenyl-1H- pyrrol-3-yl)phosphonate:

[0103] In a glove box, (diazonium (dimethoxyphosphoryl) methyl) (phenyl)-l3- iodotri-fluoromethanesulfonate (CAB-R, see Table 1 for structure; 0.45 mmol, 1.5 eq.), Ru(bpy)3(PF6)2 (photocatalyst, see Table 1 for structure; 1 mol%), additive KH2PO4 (2.0 eq.), anhydrous and oxygen-free treated acetonitrile (nitrile solvent, see Table 1 for structure; 12 mL) and prop-1- ene-2-phenyl (olefin, see Table 1 for structure; 0.3 mmol, 1.0 eq.) were added into a 20 mL dry transparent glass reaction bottle. After mixing, the glove box was taken out, and the reaction was carried out under irradiation of a 40W blue LED lamp (the distance between the reaction bottle and the light source was 3.5 cm) at -40°C overnight for 12 h. The reaction progress was monitored by thin layer chromatography (TLC), and after the reaction was completed, the crude product was obtained by rotary evaporation under reduced pressure. The crude product was separated and purified by silica gel chromatography column (the eluent system used in silica gel chromatography was petroleum ether / ethyl acetate = 10 / 1), and the final product 2,5-dimethyl-3-phenyl-4-(trifluoromethyl)-1H-pyrrole was obtained with a yield of 70%.

[0104] As Figure 15 and Figure 16 shown, Figure 15 HNMR spectrum of the product (2,5-dimethyl-4-phenyl-1 H-pyrrol-3-yl) dimethyl phosphonate is shown in Figure 1 HNMR spectrum; Figure 16 CNMR spectrum of the product (2,5-dimethyl-4-phenyl-1 H-pyrrol-3-yl) dimethyl phosphonate is shown in Figure 13 CNMR spectrum; Figure 15 and Figure 16 are shown below:

[0105] 1 H NMR (500 MHz, CDCl3) δ = 9.33 (s, 1 H), 7.35 - 7.28 (m, 4 H), 7.27- 7.21 (m, 1 H), 3.49 (d, J = 11.3, 6 H), 2.49 (d, J = 2.0, 3 H), 2.10 (s, 3H).

[0106] 13 C NMR (126 MHz, CDCl3) δ = 136.68 (d, J = 24.7), 135.82, 130.29,127.52, 126.21, 124.80 (d, J = 15.4), 123.66 (d, J = 13.0), 101.47 (d, J =215.7), 51.68 (d, J = 5.3), 13.15, 11.10.

[0107] Example 9

[0108] Synthesis and isolation / purification of 2,5-dimethyl-4-(naphthalen-2-yl)-1 H-pyrrole-3- carboxylic acid ethyl ester:

[0109] In a glove box, 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-l3-iodomethyl) ethyl acetate (Carbyl reagent, see Table 1 for structure; 0.45 mmol, 1.5 eq.), Ru(bpy)3(PF6)2(photo catalyst, see Table 1 for structure; 1 mol%), additive KH2PO4(2.0 eq), anhydrous and oxygen-free treated acetonitrile (nitrile solvent, see Table 1 for structure; 12 mL) and 2-(prop-l-en-2-yl)naphthalene (olefin, see Table 1 for structure; 0.3 mmol, 1.0 eq.) were added into a 20 mL dry transparent glass reaction flask. After mixing, the reaction flask was taken out of the glove box and irradiated with a 40 W blue LED lamp (3.5 cm distance between the light source and the reaction flask) at -40 °C overnight for 12 h. The reaction progress was monitored by thin layer chromatography (TLC). After the reaction was completed, the crude product was obtained by rotary evaporation under reduced pressure. The crude product was separated and purified by silica gel column chromatography (petroleum ether / ethyl acetate = 10 / 1 was used as the eluent for silica gel column chromatography). The final product, ethyl 2,5-dimethyl-4-(naphthalen-2-yl)-lH-pyrrole-3-carboxylate, was obtained in 41% yield.

[0110] As shown in Figure 17 and Figure 18 , the Figure 17 HNMR spectrum of the product, ethyl 2,5-dimethyl-4-(naphthalen-2-yl)-lH-pyrrole-3-carboxylate, is shown in 1 HNMR spectrum of the product, ethyl 2,5-dimethyl-4-(naphthalen-2-yl)-lH-pyrrole-3-carboxylate, is shown in 13 CNMR spectrum of the product, ethyl 2,5-dimethyl-4-(naphthalen-2-yl)-lH-pyrrole-3-carboxylate, is shown in Figure 18 HNMR spectrum of the product, ethyl 2,5-dimethyl-4-(naphthalen-2-yl)-lH-pyrrole-3-carboxylate, is shown in Figure 17 and Figure 18 are shown below:

[0111] 1 HNMR (500 MHz, CDCl3) δ = 8.11 (s, 1 H), 7.86 – 7.76 (m, 3 H), 7.66(s, 1 H), 7.48 – 7.39 (m, 3 H), 4.06 (q, J = 7.1, 2 H), 2.52 (s, 3 H), 2.12(s, 3 H), 0.99 (t, J = 7.1, 3 H).

[0112] 13C NMR (126 MHz, CDCl3) δ = 165.85, 134.14, 133.96, 133.21, 132.04, 129.79, 128.22, 127.76, 127.58, 126.47, 125.58, 125.22, 123.84, 122.36, 110.72, 59.13, 14.09, 13.69, 11.28.

[0113] The structures of the carbazole reagent, photocatalyst, olefin, nitrile solvent and product of Examples 1-9, and the yield are shown in Table 1.

[0114] Table 1

[0115]

[0116]

[0117] Example 2

[0118] Exploration of influencing factors of photocatalytic [2+1+2] cyclization reaction for synthesis of unsymmetrical per-substituted pyrrole compounds:

[0119] (1) Effect of reaction concentration on synthesis of 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester

[0120] Compared with Example 1, the main difference is that the amount of nitrile solvent of formula 3 (see Table 1 for structure) is different, i.e. the reaction concentration is 0.20 mmol / mL, 0.10 mmol / mL, 0.05 mmol / mL, 0.025 mmol / mL, respectively.

[0121] The specific operation is as follows:

[0122] In a glove box, 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-l3-iodoformyl) ethyl acetate (carbyl reagent, see Table 1 for structure; 0.45 mmol, 1.5 eq.), Ru(bpy)3(PF6)2(photo-catalyst, see Table 1 for structure; 1 mol%), additive KH2PO4(2.0 eq), 1.5 mL, 3 mL, 6 mL, 12 mL anhydrous and oxygen-free treated acetonitrile (nitrile solvent, see Table 1 for structure) and prop-1-ene-2-ylbenzene (olefin, see Table 1 for structure; 0.3 mmol, 1.0 eq.) were added into a 20 mL dry transparent glass reaction bottle, respectively. After mixing, the glove box was taken out, and the reaction was carried out under room temperature with a 40W blue LED lamp (the distance between the reaction bottle and the light source was 1.5 cm) for 12 h overnight. The yields were 44%, 50%, 58%, 65%, respectively. The experimental results showed that the yield was optimal when the reaction concentration was 0.025 mmol / mL.

[0123] (2) Effect of additive on synthesis of 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester

[0124] Compared with Example 1, the main difference is that the type of additive is changed, i.e. the additive is NaHCO3, CH3COOH, CF3COOH, PhCOOH, KH2PO4.

[0125] The specific operation is as follows:

[0126] In a glove box, 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-l3-iodoformyl) ethyl acetate (carbyl reagent, see Table 1 for structure; 0.45 mmol, 1.5 eq.), Ru(bpy)3(PF6)2(photo-catalyst, see Table 1 for structure; 1 mol%), additive KH2PO4(2.0 eq), 1.5 mL, 3 mL, 6 mL, 12 mL anhydrous and oxygen-free treated acetonitrile (nitrile solvent, see Table 1 for structure) and prop-1-ene-2-ylbenzene (olefin, see Table 1 for structure; 0.3 mmol, 1.0 eq.) were added into a 20 mL dry transparent glass reaction bottle, respectively. After mixing, the glove box was taken out, and the reaction was carried out under room temperature with a 40W blue LED lamp (the distance between the reaction bottle and the light source was 1.5 cm) for 12 h overnight. The yields were 44%, 50%, 58%, 65%, respectively. The experimental results showed that the yield was optimal when the reaction concentration was 0.025 mmol / mL.

[0127] (3) Effect of carbyl reagent type on synthesis of 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester

[0128] The difference compared with Example 1 is mainly that the type of carbene reagent is changed, i.e. the carbene reagent is a compound of the structure shown in formula a~d:

[0129] Formula a; Formula b; Formula c; Formula d.

[0130] The specific operation is as follows:

[0131] In a glove box, 20 mL of dry transparent glass reaction bottle was added with carbene reagent (structure formula as shown in formula a~d; 0.45 mmol, 1.5 eq.), Ru(bpy)3(PF6)2 (photocatalyst, structure formula shown in Table 1; 1 mol%), added with additive KH2PO4 (2.0 eq.), 12 mL of anhydrous and oxygen-free treated acetonitrile (nitrile solvent, structure formula shown in Table 1) and prop-1-ene-2-phenyl (olefin, structure formula shown in Table 1; 0.3 mmol, 1.0 eq.), mixed well, taken out of the glove box, and irradiated with a 40W blue LED lamp (the distance between the reaction bottle and the light source is 1.5 cm) at room temperature overnight for 12 h. The yield is 40%, 24%, 19%, 65% respectively. The experimental results show that the yield of the carbene reagent type 2-diazo-2- (phenyl ((trifluoromethyl) sulfonyl) oxy) -l3-iodomethyl) ethyl acetate is optimal.

[0132] The above description is only the preferred specific implementation of the present application, but the protection scope of the present application is not limited to this. Any skilled person in the art, according to the technical solution and the inventive concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A method for preparing an unsymmetrical per-substituted pyrrole compound, characterized by, The method comprises the following steps: Carbyne reagent with structure of formula 1, olefin with structure of formula 2 and nitrile solvent with structure of formula 3 are reacted under the action of photocatalyst and optional proton donor additive under light to obtain asymmetrically fully substituted pyrrole compound; Formula 1 ; Formula 2; Formula 3; The R1 is selected from halogen group, sulfonium group, pyridinium group, quaternary ammonium cation group or high-valence iodine group; R2 is selected from hydrogen, cyano, nitro, unsubstituted C1-C6 alkyl, unsubstituted C1-C6 alkenyl, unsubstituted C1-C6 ynyl, and unsubstituted C6-C6 alkyl. 18 Aromatic group, unsubstituted C1-C6 alkoxy group, unsubstituted C1-C6 alkyl ester group, unsubstituted C1-C6 alkyl acyl group, unsubstituted C6-C 18 Aromatic acyl, C1-C6 alkyl-substituted sulfonyl, C1-C6 alkoxy-substituted sulfonyl, C6-C 18 Aromatic group-substituted sulfonyl group, C1-C6 alkyl-substituted phosphoryl group, C1-C6 alkoxy-substituted phosphoryl group, C6-C 18 Aromatic group-substituted phosphoryl group, C1~C6 alkyl-substituted amide group, C6~C 18 One of the aromatic-substituted amide groups; R3 to R5 are independently selected from unsubstituted C1 to C6 alkyl, unsubstituted C1 to C6 alkenyl, unsubstituted C1 to C6 ynyl, and unsubstituted C6 to C6 alkyl. 18 Aromatic group, unsubstituted C6~C 18 One of the heteroaryl groups.

2. The production method according to claim 1, characterized by, R2 is selected from cyano, halogen-substituted C1-C3 alkyl, unsubstituted C1-C3 alkyl, and C6-C4 alkyl groups. 12 Aromatic group-substituted C1-C3 alkyl ester group, unsubstituted C1-C3 alkyl ester group, unsubstituted C1-C3 alkyl acyl group, unsubstituted C6-C 12 Aromatic acyl, C1-C3 alkyl-substituted sulfonyl, C1-C3 alkoxy-substituted sulfonyl, C6-C 12 Aromatic group-substituted sulfonyl group, C1~C3 alkoxy-substituted phosphoryl group, C6~C 12 One of the aromatic group-substituted phosphoryl groups; R3 and R4 are independently selected from unsubstituted C1-C4 alkyl groups, unsubstituted C1-C4 deuterated alkyl groups, and unsubstituted C6-C4 deuterated alkyl groups. 12 Aromatic groups and halogen-substituted C6~C 12 Aromatic or cyano-substituted C6~C 12 Aromatic groups, nitro-substituted C6~C 12 Aromatic group, C1~C4 alkyl-substituted C6~C 12 Aromatic group, C1~C4 halogenated alkyl group, C6~C 12 Aromatic, benzoyl-substituted C6~C 12 Aromatic groups, C1-C4 alkyl ester groups substituted with C6-C 12 Aromatic group, C1~C4 halogenated alkoxy group, C6~C 12 C6~C with aryl, benzoyl and halogen disubstituted groups 12 Aromatic group, unsubstituted C6~C 12 One of the heteroaryl groups; The R5 is selected from one of unsubstituted C1-C4 alkyl, cyano-substituted C1-C4 alkyl and unsubstituted C1-C4 alkyl ester.

3. The preparation method according to claim 1, characterized in that, The asymmetrically fully substituted pyrrole compound is selected from any one of compounds shown in the following structural formulae: 。 4. The method for preparing the asymmetric fully substituted pyrrole compound according to claim 1, characterized in that, The carbine reagent is a compound having the structure of Formula 1-a; alternatively, the carbine reagent is an unsubstituted C6-Ci2aromatic sulfonium group. 12 aromatic sulfonium group; Equation 1-a; wherein said R6is selected from one of unsubstituted C6-C10aryl, unsubstituted C6-C10heteroaryl, and 12 unsubstituted C6-C10heteroaryl; said R7is selected from one of halogen-substituted C1-C3alkylsulfonate, halogen-substituted C1-C3alkylthio, and halogen-substituted C1-C3alkylsulfonyl; or, said R6and said R7, together with the I to which they are attached, form an unsubstituted C6-C10heteroaromatic ring. 12 unsubstituted C6-C10heteroaryl; said R7is selected from one of halogen-substituted C1-C3alkylsulfonate, halogen-substituted C1-C3alkylthio, and halogen-substituted C1-C3alkylsulfonyl; or, said R6and said R7, together with the I to which they are attached, form an unsubstituted C6-C10heteroaromatic ring. 12 unsubstituted C6-C10heteroaryl; said R7is selected from one of halogen-substituted C1-C3alkylsulfonate, halogen-substituted C1-C3 5. The method of claim 4, wherein the asymmetrically fully substituted pyrrole compound is prepared by the reaction of a compound of formula (2) with a compound of formula (3) in the presence of a base. The carbyne reagent is selected from one of compounds shown in the following structural formulae: ； The olefin is selected from one of compounds shown in the following structural formulae: ； The nitrile solvent is selected from one of compounds shown in the following structural formulae: 。 6. The method for preparing the asymmetric fully substituted pyrrole compound according to claim 1, characterized in that, The photocatalyst is selected from one or more of [Ir(dF(CF3)ppy)2(dtbbpy)](PF6), Ir(ppy)3PF6, Ru(bpy)3(PF6)2 and Ru(dtbbpy)3(PF6)2; The proton donor additive is selected from one or more of KH2PO4, K2HPO4, NaHCO3, KHCO3, CH3COOH, PhOH and PhCOOH.

7. The method for preparing the asymmetric fully substituted pyrrole compound according to claim 1, characterized in that, The molar ratio of the carbyne reagent to the olefin is (1-3):1, and the molar concentration of the olefin in the nitrile solvent is 0.025 mol / L-2 mol / L; The amount of the photocatalyst is 1 mol%-5 mol% of the molar amount of the olefin; The equivalent ratio of the proton donor additive to the carbyne reagent is (1.8-2.2):1.

5.

8. The method for preparing the asymmetric fully substituted pyrrole compound according to claim 1, characterized in that, The reaction is carried out under visible light with a light source power of 20 W-90 W.

9. The method for preparing the asymmetric fully substituted pyrrole compound according to claim 1, characterized in that, The temperature of the reaction is-40℃-80℃, and the time of the reaction is 2 h-24 h.

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