Asymmetric fully-substituted pyrrole compound and preparation method thereof

Abstract

The invention relates to the technical field of organic chemical synthesis, in particular to an asymmetric fully-substituted pyrrole compound and a preparation method thereof. According to the present invention, the [2 + 1 + 2] cyclization reaction of the visible light induced Carbayer reagent and the olefin in the nitrile solvent is achieved for the first time, the asymmetric fully-substituted pyrrole compound is constructed, and the blank in the prior art is filled; the method provided by the invention has the advantages of mild process conditions, short flow, simple steps and wide substrate applicability, meets industrial production requirements, and overcomes the problem that a large amount of asymmetric fully-substituted pyrrole compounds are not easy to prepare in the prior art. According to the preparation method provided by the invention, the asymmetric fully-substituted pyrrole compound is obtained through the [2 + 1 + 2] cyclization reaction of the visible light induced Kabie reagent and the olefin in the nitrile solvent, the product yield is high, the research finds that the product yield can be up to 82%, and the generated fully-substituted pyrrole compound is widely applied to medicines, and is visible, and has good application prospects. The method has an important application value.

Description

Technical Field

[0001] The invention relates to the technical field of organic chemical synthesis, in particular to an asymmetric fully substituted pyrrole compound and a preparation method thereof. Background Art

[0002] Pyrroles are among the most valuable five-membered heterocycles and are present in a large number of natural products, drug molecules, and functional materials, and they are valuable and practical synthetic building blocks for the synthesis of complex molecules. Therefore, many synthetic strategies have been developed to synthesize this important class of compounds. Traditional methods, including Knorr, Hantzsch, and Paal-Knorr reactions, construct multi-substituted pyrroles through the condensation of carbonyl compounds with amines. In these examples, high temperatures and the use of strong acids to accommodate the condensation process often limit the scope of use and the applicability of the functional groups.

[0003] Recently, a number of methods, including multicomponent reactions and transition metal-catalyzed couplings, have enabled the generation of pyrroles under relatively mild conditions and with improved regioselectivity. Despite these advances, the availability of highly functionalized starting materials (e.g., iminoalkenes, alkynylaziridines, or azides) limits the applicability of the products. Furthermore, many existing methods require the use of amino-protected substrates that are further removed after the synthesis of the pyrrole ring, which greatly reduces the efficiency of the synthesis. It would be of great benefit if a complementary strategy could be developed to obtain unprotected pyrroles under mild synthetic conditions from readily available raw materials.

[0004] However, to date, there has been no report on the use of carbyne reagents and olefins in nitrile solvents to generate asymmetric fully substituted pyrrole compounds under mild synthetic conditions starting from readily available raw materials. Summary of the invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide an asymmetric fully substituted pyrrole compound and a preparation method thereof. The preparation method provided by the present invention can prepare an asymmetric fully substituted pyrrole compound by a photocatalytic [2+1+2] cyclization reaction using a carbyne reagent, an olefin and a nitrile solvent as raw materials. The reaction conditions are mild, the process is simple, and the product yield is high.

[0006] The present invention provides an asymmetric fully substituted pyrrole compound of the structure shown in formula I, which is obtained by reacting a carbyne reagent, an olefin and a nitrile solvent;

[0007]

[0008] The R2 of the present 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-C 18aromatic group, substituted or unsubstituted C1-C6 alkoxy group, substituted or unsubstituted C1-C6 alkyl ester group, substituted or unsubstituted C1-C6 alkanoyl group, substituted or unsubstituted C1-C6 18 Aroyl, C1-C6 alkyl substituted sulfonyl, C1-C6 alkoxy substituted sulfonyl, C6-C 18 Aromatically substituted sulfonyl, C1-C6 alkyl-substituted phosphoryl, C1-C6 alkoxy-substituted phosphoryl, C6-C 18 Aromatically substituted phosphoryl, C1-C6 alkyl-substituted amide, C6-C 18 One of the aromatic substituted amide groups;

[0009] The 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 alkynyl, substituted or unsubstituted C6 to C 18 Aromatic, substituted or unsubstituted C6~C 18 A type of heteroaromatic group.

[0010] In the R2 to R5 of the present invention, the substituted group refers to a group substituted by a substituted group, wherein the specific substituted group is not limited to the group, the specific substituted group includes but is not limited to C1 to C6 alkyl, C1 to C6 alkoxy, C6 to C 12 aromatic group, benzyloxy group, nitro group, halogen group, cyano group, ester group, aldehyde group or trifluoromethyl group.

[0011] Preferably, R2 of the present invention is selected from cyano, halogen-substituted C1-C3 alkyl, unsubstituted C1-C3 alkyl, C6-C 12 Aromatically substituted C1-C3 alkyl ester groups, unsubstituted C1-C3 alkyl ester groups, unsubstituted C1-C3 alkanoyl groups, unsubstituted C6-C 12 Aroyl, C1-C3 alkyl substituted sulfonyl, C1-C3 alkoxy substituted sulfonyl, C6-C 12 Aromatically substituted sulfonyl, C1-C3 alkoxy-substituted phosphoryl, C6-C 12 The halogen is selected from F, Cl or Br. The R3 and R4 are independently selected from unsubstituted C1-C4 alkyl, unsubstituted C1-C4 deuterated alkyl, unsubstituted C6-C 12 Aromatic, halogen-substituted C6~C 12 Aromatic, cyano-substituted C6~C 12 Aromatic, nitro-substituted C6~C 12 Aromatic, C1~C4 alkyl substituted C6~C 12 Aromatic, C1-C4 halogen alkyl substituted C6-C 12Aromatic, benzoyl-substituted C6~C 12 Aromatic, C1-C4 alkyl ester substituted C6-C 12 Aromatic, C1-C4 halogen alkoxy substituted C6-C 12 Aromatic, benzoyl and halogen disubstituted C6~C 12 Aromatic, substituted or unsubstituted C6~C 12 The halogen is selected from F, Cl or Br. The R5 is selected from unsubstituted C1-C4 alkyl, cyano-substituted C1-C4 alkyl, and unsubstituted C1-C4 alkyl ester.

[0012] More preferably, R2 of the present invention is selected from cyano, trifluoromethyl, methyl, carbomethoxy, carboethoxy, carbomethoxy substituted by phenyl, formyl, benzoyl, dimethoxyphosphoryl, ethoxy substituted sulfonyl, methyl substituted sulfonyl, phenyl substituted sulfonyl, diphenylphosphoryl. R3 and R4 are independently selected from methyl, deuterated methyl, ethyl, phenyl, naphthyl, biphenyl, fluorine substituted phenyl, bromine substituted phenyl, chlorine substituted phenyl, cyano substituted phenyl, nitro substituted phenyl, butyl substituted phenyl, trifluoromethyl substituted phenyl, benzoyl substituted phenyl, carbomethoxy substituted phenyl, trifluoromethoxy substituted phenyl, benzoyl and fluorine disubstituted phenyl, substituted or unsubstituted C -6 R5 is selected from one of methyl, propyl, butyl, C1-C2 alkyl substituted with cyano, and unsubstituted C1-C2 alkyl ester.

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

[0014]

[0015] The present 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] Under the action of a photocatalyst and an optional proton supply additive, a carbyne reagent having a structure of Formula 1, an olefin having a structure of Formula 2, and a nitrile solvent having a structure of Formula 3 are reacted under light to obtain an asymmetric fully substituted pyrrole compound;

[0017]

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

[0019] The carbyne reagent of the present invention has a 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 is also called a hypervalent iodine group, which is a special group formed by organic molecules containing iodine elements, and the iodine atoms in the molecules have more than the traditional structure of eight electrons. The R2 is the same as above and will not be repeated.

[0020] Preferably, the carbyne reagent is a compound having a structure of formula 1-a; or, the carbyne reagent is a substituted or unsubstituted C6-C 12 Aromatic sulfonium groups;

[0021]

[0022] Wherein, the R6 is selected from substituted or unsubstituted C6~C 12 Aromatic, substituted or unsubstituted C6~C 12 Preferably, R6 is selected from phenyl. R7 is selected from one of halogen-substituted C1-C3 alkanesulfonate, halogen-substituted C1-C3 alkylthio, and halogen-substituted C1-C3 alkanesulfonyl; Preferably, R7 is selected from one of trihalomethanesulfonate, trihalomethanethio, and trihalomethanesulfonyl; or, R6 and R7 and the I in which they are located form a substituted or unsubstituted C6-C 12 The halogen in the present invention is selected from F, Cl or Br. The R2 is the same as above and will not be described in detail.

[0023] In certain embodiments of the present invention, the carbyne reagent is selected from one of the compounds represented by the following structural formulas:

[0024]

[0025] The olefin of the present invention has a structure of Formula 2, wherein R3 and R4 are the same as those described above and are not described in detail. In certain embodiments of the present invention, the olefin is selected from one of the compounds represented by the following structural formulas:

[0026]

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

[0028]

[0029] The photocatalyst of the present invention 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 supply additive of the present invention can be added selectively or not, and its function is to provide protons, neutralize the acid generated during the reaction, and prevent the strong acid condition from decomposing the product; if the proton supply additive is not added, the corresponding product can be obtained at half the yield. The proton supply additive of the present invention is selected from one or more of KH2PO4, K2HPO4, NaHCO3, KHCO3, CH3COOH, PhOH, and PhCOOH, preferably selected from KH2PO4.

[0031] The inventors of the present application creatively discovered that, with carbyne reagent and olefin as raw materials, in the presence of a photocatalyst and a proton supply additive, after irradiation in a nitrile solvent, the carbyne reagent, olefin and nitrile solvent can react to obtain the asymmetric fully substituted pyrrole compound of the present invention, 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 invention 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 side reaction of producing acid in the reaction process of the present invention mentioned above is as follows:

[0034]

[0035] Specifically, the present invention mixes a carbyne reagent having a structure of Formula 1, an olefin having a structure of Formula 2, a nitrile solvent having a structure of Formula 3, a photocatalyst and a proton supply additive, and reacts the mixed material under light to obtain an asymmetric fully substituted pyrrole compound having a structure shown in the aforementioned Formula I. In certain embodiments of the present invention, a carbyne reagent having a structure of Formula 1 and an olefin having a structure of Formula 2 are dissolved in a nitrile solvent having a structure of Formula 3 and mixed, and the mixed material is reacted under light to obtain an asymmetric fully substituted pyrrole compound having a structure shown in the aforementioned Formula I.

[0036] The molar ratio of the carbyne reagent and the olefin of the present invention 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; the equivalent ratio of the proton supply additive and the carbyne reagent is (1.8-2.2):1.5.

[0037] The present invention reacts the mixed materials under light, so that the mixed materials can undergo a [2+1+2] cyclization reaction, and the reaction temperature is -40°C to 80°C, and the reaction time is 2h to 24h. The reaction of the present invention is carried out under visible light with a light source power of 20W to 90W, preferably under visible light with a light source power of 40W; the visible light includes white light or blue light, preferably blue light. In certain embodiments of the present invention, the light source of the light reaction of the present invention includes a white LED lamp or a blue LED lamp.

[0038] The present invention provides an asymmetric fully substituted pyrrole compound and a preparation method thereof. The present invention realizes for the first time a visible light-induced [2+1+2] cyclization reaction between a carbyne reagent and an olefin in a nitrile solvent, constructs an asymmetric fully substituted pyrrole compound, and fills the gap in the prior art; the method of the present invention has mild process conditions, a short process, simple steps, and wide substrate applicability, meets industrial production requirements, and overcomes the problem that the prior art is not easy to prepare asymmetric fully substituted pyrrole compounds in large quantities. The preparation method provided by the present invention obtains an asymmetric fully substituted pyrrole compound by a visible light-induced [2+1+2] cyclization reaction between a carbyne reagent and an olefin in a nitrile solvent, and the product yield is high. It is found through research that the product yield can be as high as 82%, and the generated fully substituted pyrrole compound is widely used in medicine. It can be seen that the present invention has important application value. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0040] Figure 2 The product is 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester 13 CNMR spectrum;

[0041] Figure 3 The product is 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-carboxylic acid ethyl ester 1 HNMR spectrum;

[0042] Figure 4 The product is 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-carboxylic acid ethyl ester13 CNMR spectrum;

[0043] Figure 5 The product is 2-methyl-4,5-diphenyl-1H-pyrrole-3-carboxylic acid ethyl ester 1 HNMR spectrum;

[0044] Figure 6 The product is 2-methyl-4,5-diphenyl-1H-pyrrole-3-carboxylic acid ethyl ester 13 CNMR spectrum;

[0045] Figure 7 The product is 2-methyl-4-phenyl-5-propyl-1H-pyrrole-3-carboxylic acid ethyl ester 1 HNMR spectrum;

[0046] Figure 8 The product is 2-methyl-4-phenyl-5-propyl-1H-pyrrole-3-carboxylic acid ethyl ester 13 CNMR spectrum;

[0047] Fig. 9 The product is 2-cyclopropyl-5-methyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester 1 HNMR spectrum;

[0048] Fig.10 The product is 2-cyclopropyl-5-methyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester 13 CNMR spectrum;

[0049] Fig.11 The product is 2-cyclopropyl-5-methyl-4-phenyl-3-(trifluoromethyl)-1H-pyrrole 1 HNMR spectrum;

[0050] Fig.12 The product is 2-cyclopropyl-5-methyl-4-phenyl-3-(trifluoromethyl)-1H-pyrrole 13 CNMR spectrum;

[0051] Fig.13 The product is 2,5-dimethyl-3-phenyl-4-(trifluoromethyl)-1H-pyrrole 1 HNMR spectrum;

[0052] Fig.14 The product is 2,5-dimethyl-3-phenyl-4-(trifluoromethyl)-1H-pyrrole 13 CNMR spectrum;

[0053] Fig.15 The product is (2,5-dimethyl-4-phenyl-1H-pyrrol-3-yl)phosphonic acid dimethyl ester1 HNMR spectrum;

[0054] Fig.16 The product is (2,5-dimethyl-4-phenyl-1H-pyrrol-3-yl)phosphonic acid dimethyl ester 13 CNMR spectrum;

[0055] Fig.17 The product is 2,5-dimethyl-4-(naphthalen-2-yl)-1H-pyrrole-3-carboxylic acid ethyl ester 1 HNMR spectrum;

[0056] Fig.18 The product is 2,5-dimethyl-4-(naphthalen-2-yl)-1H-pyrrole-3-carboxylic acid ethyl ester 13 CNMR spectrum. DETAILED DESCRIPTION

[0057] The present invention discloses an asymmetric fully substituted pyrrole compound and a method for preparing the same. Those skilled in the art can refer to the contents of this article and appropriately improve the process parameters to achieve the above. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in the present invention. The methods and applications of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications of this article without departing from the content, spirit and scope of the present invention to achieve and apply the technology of the present invention.

[0058] The present invention will be further described below in conjunction with embodiments:

[0059] Example 1

[0060] Synthesis and separation and purification of ethyl 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylate:

[0061] In a 20 mL dry transparent glass reaction bottle in a glove box, ethyl 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-13-iodoformyl)acetate (carbyne 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%), additive KH2PO4 (2.0 eq), 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 anhydrous and oxygen-free treatment were added, mixed and taken out of the glove box, and the reaction was illuminated overnight at room temperature for 12 h using a 40 W blue LED lamp (the reaction bottle was 1.5 cm away from the light source). The progress of the reaction was monitored by thin layer chromatography (TLC). After the reaction was completed, a crude product was obtained by rotary evaporation under reduced pressure. The crude product was separated and purified by a silica gel chromatography column (the eluent system used for silica gel chromatography was petroleum ether / ethyl acetate = 10 / 1) to obtain the final product: 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester, with a yield of 65%.

[0062] like Figure 1 and Figure 2 As shown, Figure 1 The product is 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester 1 HNMR spectrum; Figure 2 The product is 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester 13 CNMR spectrum; Figure 1 and Figure 2 The graph information is as follows:

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

[0064] 13 C NMR (101MHz, 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 separation and purification of ethyl 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-carboxylate:

[0067] In a 20 mL dry transparent glass reaction bottle in a glove box, ethyl 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-13-iodoformyl)acetate (carbyne 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%), additive KH2PO4 (2.0 eq), acetonitrile (nitrile solvent, structural formula see Table 1; 12 mL) and 1-fluoro-4-(prop-1-en-2-yl)benzene (olefin, structural formula see Table 1; 0.3 mmol, 1.0 eq.) after anhydrous and oxygen-free treatment were added, mixed and taken out of the glove box, and the reaction was illuminated overnight at -40°C for 12 h using a 40 W blue LED lamp (the reaction bottle was 3.5 cm away from the light source). The progress of the reaction was monitored by thin layer chromatography (TLC). After the reaction was completed, a crude product was obtained by rotary evaporation under reduced pressure. The crude product was separated and purified by a silica gel chromatography column (the eluent system used for silica gel chromatography was petroleum ether / ethyl acetate = 10 / 1) to obtain the final product: 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-carboxylic acid ethyl ester, with a yield of 60%.

[0068] like Figure 3 and Figure 4 As shown, Figure 3 The product is 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-carboxylic acid ethyl ester 1 HNMR spectrum; Figure 4 The product is 4-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-carboxylic acid ethyl ester 13 CNMR spectrum; Figure 3 and Figure 4 The graph information is as follows:

[0069] 1 H NMR (500MHz, CDCl3) δ = 8.37 (s, 1H), 7.19 (dd, J = 8.5, 5.7, 1H), 7.00 (t, J = 8 .8,1H),4.09(q,J=7.1,1H),2.48(s,1H),2.05(s,1H),1.09(t,J=7.1,1H).

[0070] 13 C NMR(126MHz, 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, separation and purification of ethyl 2-methyl-4,5-diphenyl-1H-pyrrole-3-carboxylate:

[0073] In a 20 mL dry transparent glass reaction bottle in a glove box, ethyl 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-13-iodoformyl)acetate (carbyne 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%), additive KH2PO4 (2.0 eq), acetonitrile (nitrile solvent, structural formula see Table 1; 12 mL) and ethylene-1,1-diphenyl (olefin, structural formula see Table 1; 0.3 mmol, 1.0 eq.) after anhydrous and oxygen-free treatment were added, mixed and taken out of the glove box, and the reaction was illuminated overnight at -40°C for 12 h using a 40 W blue LED lamp (the reaction bottle was 3.5 cm away from the light source). The progress of the reaction was monitored by thin layer chromatography (TLC). After the reaction was completed, a crude product was obtained by rotary evaporation under reduced pressure. The crude product was separated and purified by a silica gel chromatography column (the eluent system used for silica gel chromatography was petroleum ether / ethyl acetate = 10 / 1) to obtain the final product: 2-methyl-4,5-diphenyl-1H-pyrrole-3-carboxylic acid ethyl ester, with a yield of 38%.

[0074] like Figure 5 and Figure 6 As shown, Figure 5 The product is 2-methyl-4,5-diphenyl-1H-pyrrole-3-carboxylic acid ethyl ester 1 HNMR spectrum; Figure 6 The product is 2-methyl-4,5-diphenyl-1H-pyrrole-3-carboxylic acid ethyl ester 13 CNMR spectrum; Figure 5 and Figure 6 The graph information is as follows:

[0075] 1 H NMR (400MHz, CDCl3) δ = 8.37 (s, 1H), 7.27-7.21 (m, 5H), 7.20-7.16 (m, 2H), 7.16-7. 13(m,1H),7.12-7.08(m,2H),4.07(q,J=7.1,2H),2.60(s,3H),1.03(t,J=7.1,3H).

[0076] 13C NMR(101MHz, 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, separation and purification of ethyl 2-methyl-4-phenyl-5-propyl-1H-pyrrole-3-carboxylate:

[0079] In a 20 mL dry transparent glass reaction bottle in a glove box, ethyl 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-13-iodoformyl)acetate (carbyne 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%), additive KH2PO4 (2.0 eq), anhydrous and oxygen-free treated 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.) were added, mixed well, and then taken out of the glove box, and the reaction was illuminated overnight at -40°C for 12 h using a 40 W blue LED lamp (the reaction bottle was 3.5 cm away from the light source). The progress of the reaction 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 for silica gel chromatography was petroleum ether / ethyl acetate = 10 / 1) to obtain the final product: 2-methyl-4-phenyl-5-propyl-1H-pyrrole-3-carboxylic acid ethyl ester with a yield of 60%.

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

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

[0082] 13 C NMR (126MHz, 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, separation and purification of ethyl 2-cyclopropyl-5-methyl-4-phenyl-1H-pyrrole-3-carboxylate:

[0085] In a 20 mL dry transparent glass reaction bottle in a glove box, ethyl 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-13-iodoformyl)acetate (carbyne 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%), additive KH2PO4 (2.0 eq), cyclopropanenitrile (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 anhydrous and oxygen-free treatment were added, mixed and taken out of the glove box, and the reaction was illuminated overnight at -40°C for 12 h using a 40 W blue LED lamp (the reaction bottle was 3.5 cm away from the light source). The progress of the reaction 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 for silica gel chromatography was petroleum ether / ethyl acetate = 10 / 1) to obtain the final product: 2-cyclopropyl-5-methyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester with a yield of 55%.

[0086] like Fig. 9 and Fig.10 As shown, Fig. 9 The product is 2-cyclopropyl-5-methyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester 1 HNMR spectrum; Fig.10 The product is 2-cyclopropyl-5-methyl-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester13 CNMR spectrum; Fig. 9 and Fig.10 The graph information is as follows:

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

[0088] 13 C NMR (126MHz, 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, separation and purification of 2-cyclopropyl-5-methyl-4-phenyl-3-(trifluoromethyl)-1H-pyrrole:

[0091] In a 20 mL dry transparent glass reaction bottle in a glove box, (1-diazo-2,2,2-trifluoroethyl)(phenyl)-l3-iodoformyl trifluoromethanesulfonate (carbyne 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%), additive KH2PO4 (2.0 eq), cyclopropanenitrile (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 anhydrous and oxygen-free treatment were added, mixed and taken out of the glove box, and the reaction was illuminated overnight at -40°C for 12 h using a 40 W blue LED lamp (the reaction bottle was 3.5 cm away from the light source). The progress of the reaction 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 for silica gel chromatography was petroleum ether / ethyl acetate = 10 / 1) to obtain the final product: 2-cyclopropyl-5-methyl-4-phenyl-3-(trifluoromethyl)-1H-pyrrole, with a yield of 69%.

[0092] like Fig.11 and Fig.12 As shown, Fig.11The product is 2-cyclopropyl-5-methyl-4-phenyl-3-(trifluoromethyl)-1H-pyrrole 1 HNMR spectrum; Fig.12 The product is 2-cyclopropyl-5-methyl-4-phenyl-3-(trifluoromethyl)-1H-pyrrole 13 CNMR spectrum; Fig.11 and Fig.12 The graph information is as follows:

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

[0094] 13 C NMR (126MHz, CDCl3) δ = 134.73, 131.76 (d, J = 3.9), 130.18, 127.84, 126.47, 124.8 2(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, separation and purification of 2,5-dimethyl-3-phenyl-4-(trifluoromethyl)-1H-pyrrole:

[0097] In a 20 mL dry transparent glass reaction bottle in a glove box, (1-diazo-2,2,2-trifluoroethyl)(phenyl)-l3-iodoformyl trifluoromethanesulfonate (carbyne 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%), additive KH2PO4 (2.0 eq), 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 anhydrous and oxygen-free treatment were added, mixed and taken out of the glove box, and the reaction was illuminated overnight at -40°C for 12 h using a 40 W blue LED lamp (the reaction bottle was 3.5 cm away from the light source). The progress of the reaction was monitored by thin layer chromatography (TLC). After the reaction was completed, a crude product was obtained by rotary evaporation under reduced pressure. The crude product was separated and purified by a silica gel chromatography column (the eluent system used for 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 Fig.13 and Fig.14 As shown, Fig.13 The product is 2,5-dimethyl-3-phenyl-4-(trifluoromethyl)-1H-pyrrole 1 HNMR spectrum; Fig.14 The product is 2,5-dimethyl-3-phenyl-4-(trifluoromethyl)-1H-pyrrole 13 CNMR spectrum; Fig.13 and Fig.14 The graph information is as follows:

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

[0100] 13 C NMR (126MHz, 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 20 mL dry transparent glass reaction bottle in a glove box, add (diazo(dimethoxyphosphoryl)methyl)(phenyl)-13-iodotrifluoromethanesulfonate (carbyne 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%), additive KH2PO4 (2.0 eq), add 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 anhydrous and oxygen-free treatment, mix well, take out the glove box, and illuminate the reaction overnight at -40°C for 12 h using a 40 W blue LED lamp (the reaction bottle is 3.5 cm away from the light source). The progress of the reaction was monitored by thin layer chromatography (TLC). After the reaction was completed, a crude product was obtained by rotary evaporation under reduced pressure. The crude product was separated and purified by a silica gel chromatography column (the eluent system used for 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 70%.

[0104] like Fig.15 and Fig.16 As shown, Fig.15 The product is (2,5-dimethyl-4-phenyl-1H-pyrrol-3-yl)phosphonic acid dimethyl ester 1 HNMR spectrum; Fig.16 The product is (2,5-dimethyl-4-phenyl-1H-pyrrol-3-yl)phosphonic acid dimethyl ester 13 CNMR spectrum; Fig.15 and Fig.16 The graph information is as follows:

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

[0106] 13 C NMR (126MHz, 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 separation and purification of ethyl 2,5-dimethyl-4-(naphthalen-2-yl)-1H-pyrrole-3-carboxylate:

[0109] In a 20 mL dry transparent glass reaction bottle in a glove box, ethyl 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-13-iodoformyl)acetate (carbyne 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%), additive KH2PO4 (2.0 eq), acetonitrile (nitrile solvent, structural formula see Table 1; 12 mL) and 2-(prop-1-en-2-yl)naphthalene (olefin, structural formula see Table 1; 0.3 mmol, 1.0 eq.) after anhydrous and oxygen-free treatment were added, mixed and taken out of the glove box, and the reaction was illuminated overnight at -40°C for 12 h using a 40 W blue LED lamp (the reaction bottle was 3.5 cm away from the light source). The progress of the reaction was monitored by thin layer chromatography (TLC). After the reaction was completed, a crude product was obtained by rotary evaporation under reduced pressure. The crude product was separated and purified by a silica gel chromatography column (the eluent system used for silica gel chromatography was petroleum ether / ethyl acetate = 10 / 1) to obtain the final product: 2,5-dimethyl-4-(naphthalene-2-yl)-1H-pyrrole-3-carboxylic acid ethyl ester with a yield of 41%.

[0110] like Fig.17 and Fig.18 As shown, Fig.17 The product is 2,5-dimethyl-4-(naphthalen-2-yl)-1H-pyrrole-3-carboxylic acid ethyl ester 1 HNMR spectrum; Fig.18 The product is 2,5-dimethyl-4-(naphthalen-2-yl)-1H-pyrrole-3-carboxylic acid ethyl ester 13 CNMR spectrum; Fig.17 and Fig.18 The graph information is as follows:

[0111] 1 H NMR (500MHz, CDCl3) δ = 8.11 (s, 1H), 7.86–7.76 (m, 3H), 7.66 (s, 1H), 7.48–7. 39(m,3H),4.06(q,J=7.1,2H),2.52(s,3H),2.12(s,3H),0.99(t,J=7.1,3H).

[0112] 13C NMR(126MHz, 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 structural formulas of the carbyne reagents, photocatalysts, olefins, nitrile solvents and products of Examples 1 to 9, as well as their yields are shown in Table 1.

[0114] Table 1

[0115]

[0116]

[0117] Example 2

[0118] Exploration of factors affecting the synthesis of asymmetric fully substituted pyrrole compounds by photocatalytic [2+1+2] cyclization reaction:

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

[0120] Compared with Example 1, the main difference is that the dosage (reaction concentration) of the nitrile solvent of Formula 3 (structural formula see Table 1) is different, that is, the reaction concentrations are 0.20 mmol / mL, 0.10 mmol / mL, 0.05 mmol / mL, and 0.025 mmol / mL, respectively.

[0121] The specific operations are as follows:

[0122] In a 20 mL dry transparent glass reaction bottle in a glove box, add ethyl 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-13-iodoformyl)acetate (carbyne 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%), additive KH2PO4 (2.0 eq), add 1.5 mL, 3 mL, 6 mL, 12 mL of acetonitrile (nitrile solvent, structural formula see Table 1) and prop-1-ene-2-benzene (olefin, structural formula see Table 1; 0.3 mmol, 1.0 eq.) after anhydrous and oxygen-free treatment, respectively, mix well, take out of the glove box, and react overnight at room temperature with a 40 W blue LED lamp (the reaction bottle is 1.5 cm away from the light source) for 12 hours. The yields are 44%, 50%, 58%, and 65%, respectively. The experimental results showed that the yield was optimal when the reaction concentration was 0.025mmol / mL.

[0123] (2) Effect of additives on the synthesis of ethyl 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylate

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

[0125] The specific operations are as follows:

[0126] In a 20 mL dry transparent glass reaction bottle in a glove box, add ethyl 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-13-iodoformyl)acetate (carbyne 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%), respectively add additives NaHCO3, CH3COOH, CF3COOH, PhCOOH, KH2PO4 (2.0 ee), add 12 mL of acetonitrile (nitrile solvent, structural formula see Table 1) and prop-1-ene-2-benzene (olefin, structural formula see Table 1; 0.3 mmol, 1.0 eq.), mix well, take out the glove box, and react overnight at room temperature for 12 hours using a 40 W blue LED lamp (the reaction bottle is 1.5 cm away from the light source). The yields are 24%, 34%, 13%, 34%, and 65%, respectively. The experimental results show that the yield of the additive type KH2PO4 is the best.

[0127] (3) Effect of carbyne reagent type on the synthesis of ethyl 2,5-dimethyl-4-phenyl-1H-pyrrole-3-carboxylate

[0128] Compared with Example 1, the main difference is that the type of carbyne reagent is changed, that is, the type of carbyne reagent is a compound with a structure shown in Formula a to Formula d:

[0129]

[0130] The specific operations are as follows:

[0131] In a 20mL dry transparent glass reaction bottle in a glove box, add carbyne reagent (structural formula as shown in formula a to formula d; 0.45mmol, 1.5eq.), Ru(bpy)3(PF6)2 (photocatalyst, structural formula see Table 1; 1mol%), add additive KH2PO4 (2.0eq), add 12mL of acetonitrile (nitrile solvent, structural formula see Table 1) and prop-1-ene-2-benzene (olefin, structural formula see Table 1; 0.3mmol, 1.0eq.) after anhydrous and oxygen-free treatment, mix well, take out the glove box, and react overnight at room temperature with a 40W blue LED lamp (the reaction bottle is 1.5cm away from the light source) for 12h. The yields are 40%, 24%, 19%, and 65%, respectively. The experimental results show that the yield of ethyl 2-diazo-2-(phenyl((trifluoromethyl)sulfonyl)oxy)-13-iodoformyl)acetate is the best.

[0132] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An asymmetric fully substituted pyrrole compound having a structure shown in formula I, characterized in that: It is obtained by the reaction of carbyne reagent, olefin and nitrile solvent; The R2 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-C 18 aromatic group, substituted or unsubstituted C1-C6 alkoxy group, substituted or unsubstituted C1-C6 alkyl ester group, substituted or unsubstituted C1-C6 alkanoyl group, substituted or unsubstituted C1-C6 18 Aroyl, C1-C6 alkyl substituted sulfonyl, C1-C6 alkoxy substituted sulfonyl, C6-C 18 Aromatically substituted sulfonyl, C1-C6 alkyl-substituted phosphoryl, C1-C6 alkoxy-substituted phosphoryl, C6-C 18 Aromatically substituted phosphoryl, C1-C6 alkyl-substituted amide, C6-C 18 One of the aromatic substituted amide groups; The R3 to R5 are independently selected from substituted or unsubstituted C1 to C6 alkyl, substituted or unsubstituted C -1 ~C6 alkenyl, substituted or unsubstituted C1~C6 alkynyl, substituted or unsubstituted C6~C 18 Aromatic, substituted or unsubstituted C6~C 18 A type of heteroaromatic group.

2. The asymmetric fully substituted pyrrole compound according to claim 1, characterized in that: The R2 is selected from cyano, halogen-substituted C1-C3 alkyl, unsubstituted C1-C3 alkyl, C6-C 12 Aromatically substituted C1-C3 alkyl ester groups, unsubstituted C1-C3 alkyl ester groups, unsubstituted C1-C3 alkanoyl groups, unsubstituted C6-C 12 Aroyl, C1-C3 alkyl substituted sulfonyl, C1-C3 alkoxy substituted sulfonyl, C6-C 12 Aromatically substituted sulfonyl, C1-C3 alkoxy-substituted phosphoryl, C6-C 12 One of the aromatic substituted phosphoryl groups; The R3 and R4 are independently selected from unsubstituted C1-C4 alkyl, unsubstituted C1-C4 deuterated alkyl, unsubstituted C6-C 12 Aromatic, halogen-substituted C6~C 12 Aromatic, cyano-substituted C6~C 12 Aromatic, nitro-substituted C6~C 12 Aromatic, C1~C4 alkyl substituted C6~C 12 Aromatic, C1-C4 halogen alkyl substituted C6-C 12 Aromatic, benzoyl-substituted C6~C 12 Aromatic, C1-C4 alkyl ester substituted C6-C 12 Aromatic, C1-C4 halogen alkoxy substituted C6-C 12 Aromatic, benzoyl and halogen disubstituted C6~C 12 Aromatic, substituted or unsubstituted C6~C 12 A heteroaromatic group; The R5 is selected from one of an unsubstituted C1-C4 alkyl group, a cyano-substituted C1-C4 alkyl group, and an unsubstituted C1-C4 alkyl ester group.

3. The asymmetric fully substituted pyrrole compound according to claim 1, characterized in that: The asymmetric fully substituted pyrrole compound is selected from any one of the compounds represented by the following structural formulas:

4. The method for preparing an asymmetric fully substituted pyrrole compound according to any one of claims 1 to 3, characterized in that: The following steps are involved: Under the action of a photocatalyst and an optional proton supply additive, a carbyne reagent having a structure of Formula 1, an olefin having a structure of Formula 2, and a nitrile solvent having a structure of Formula 3 are reacted under light to obtain an asymmetric fully substituted pyrrole compound; Wherein, the R1 is selected from a halogen group, a sulfonium group, a pyridinium group, a quaternary ammonium cation group or a high-valent iodine group.

5. The method for preparing an asymmetric fully substituted pyrrole compound according to claim 4, characterized in that: The carbyne reagent is a compound having a structure of formula 1-a; or, the carbyne reagent is a substituted or unsubstituted C6-C 12 Aromatic sulfonium groups; Wherein, the R6 is selected from substituted or unsubstituted C6~C 12 Aromatic, substituted or unsubstituted C6~C 12 wherein R7 is selected from a halogen-substituted C1-C3 alkanesulfonate group, a halogen-substituted C1-C3 alkylthio group, and a halogen-substituted C1-C3 alkanesulfonyl group; or, R6 and R7 and the I where they are located form a substituted or unsubstituted C6-C 12 Heteroaromatic ring.

6. The method for preparing an asymmetric fully substituted pyrrole compound according to claim 5, characterized in that: The carbyne reagent is selected from one of the compounds shown in the following structural formula: The olefin is selected from one of the compounds shown in the following structural formula: The nitrile solvent is selected from one of the compounds shown in the following structural formula:

7. The method for preparing an asymmetric fully substituted pyrrole compound according to claim 4, 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 supply additive is selected from one or more of KH2PO4, K2HPO4, NaHCO3, KHCO3, CH3COOH, PhOH, and PhCOOH.

8. The method for preparing an asymmetric fully substituted pyrrole compound according to claim 4, 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% to 5 mol% of the molar amount of the olefin; The equivalent ratio of the proton donating additive to the carbyne reagent is (1.8-2.2):1.

5.

9. The method for preparing an asymmetric fully substituted pyrrole compound according to claim 4, characterized in that: The reaction is carried out under visible light with a light source power of 20W to 90W.

10. The method for preparing an asymmetric fully substituted pyrrole compound according to claim 4, characterized in that: The reaction temperature is -40°C to 80°C, and the reaction time is 2h to 24h.

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