A method for synthesizing organic peroxides by visible light-catalyzed decarboxylation of carboxylic acids.

Abstract

This invention discloses a method for synthesizing organic peroxides from carboxylic acids using visible light catalysis, belonging to the field of organic synthesis technology. The method includes: mixing carboxylic acid with an organic photocatalyst, tert-butyl hydroperoxide, an organic base, and a solvent; applying visible light; and conducting a carboxylic acid decarboxylation and peroxidation reaction under visible light excitation to obtain the organic peroxide. In this method, the organic photocatalyst becomes excited under light irradiation; the inexpensive and readily available carboxylic acid is converted to a carboxylate under the action of the organic base; the carboxylate is then oxidized and decarboxylated by the excited-state photocatalyst to generate a free radical, which couples with a peroxide free radical to obtain the organic peroxide product. This method uses the more inexpensive and readily available carboxylic acid as the reactant, and tert-butyl hydroperoxide simultaneously serves as both the oxidant and the peroxide source, resulting in high atom economy; the preparation process uses green and clean energy, visible light, and is simple to operate; the product yield is high and it is easy to separate and purify, making it highly valuable in organic synthesis.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and in particular to a method for synthesizing organic peroxides by visible light-catalyzed decarboxylation of carboxylic acids. Background Technology

[0002] Organic peroxides are a special and important class of compounds with wide applications in synthetic chemistry, biochemistry, medicinal chemistry, and materials chemistry. Currently, the types of reactions in which organic peroxides are used in synthetic chemistry are very limited, and their application in the synthesis of complex organic molecules is even less common. This is mainly due to the limitations of the synthetic methods for organic peroxides. Currently, established efficient methods for synthesizing organic peroxides include: 1) metal-catalyzed CH bond peroxidation; 2) acid or base-catalyzed substitution reactions of hydroperoxides with various electrophiles; and 3) olefin-involved bifunctionalization peroxidation reactions. However, these methods all suffer from drawbacks to varying degrees, such as harsh reaction conditions, poor selectivity, long reaction times, low efficiency, and high cost. Therefore, designing and developing efficient and highly selective methods for synthesizing peroxides under mild conditions is of great significance. Summary of the Invention

[0003] The purpose of this invention is to provide a method for synthesizing organic peroxides by visible light-catalyzed decarboxylation of carboxylic acids, thereby addressing the problems existing in the prior art. In this method, the organic photocatalyst becomes excited under light irradiation. The inexpensive and readily available carboxylic acid is converted into a carboxylate under the action of an organic base. The carboxylate is then oxidized and decarboxylated by the excited-state organic photocatalyst to generate a free radical, which couples with a peroxide free radical to yield the organic peroxide product. This method uses the more inexpensive and readily available carboxylic acid as the reactant and tert-butyl hydroperoxide as both the oxidant and peroxide source, resulting in high atom economy. The preparation process utilizes green and clean energy, visible light, and is simple to operate. The product yield is high and easily separated and purified, making it highly valuable in organic synthesis.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] One of the technical solutions of the present invention is a method for synthesizing organic peroxides by decarboxylation of carboxylic acids under visible light catalysis, wherein carboxylic acids and tert-butyl hydrogen peroxide (t-BuOOH) undergo a carboxylation peroxidation reaction under the catalysis of an organic photocatalyst to obtain organic peroxides.

[0006] Furthermore, the carboxylic acid decarboxylation peroxidation reaction with tert-butyl hydroperoxide under the catalysis of an organic photocatalyst comprises: mixing the carboxylic acid with an organic photocatalyst, tert-butyl hydroperoxide, an organic base, and a solvent; applying visible light; and performing the carboxylation peroxidation reaction under visible light excitation to obtain an organic peroxide compound; the structural formula of the carboxylic acid is as follows: The structural formula of the organic peroxide compound is as follows: Among them, R 1 R is an unsubstituted aromatic group, an N-substituted aromatic group, an unsubstituted heteroaryl group, or an N-substituted heteroaryl group, where N is 1 or 2; 2 R is an unsubstituted aromatic group, an N-substituted aromatic group, an unsubstituted heteroaryl group, an N-substituted heteroaryl group, an alkyl group, or a hydrogen atom, where N is 1 or 2; 3 R is an alkyl group or a hydrogen atom; 1 With R 2 They can exist alone or be connected in a ring.

[0007] Furthermore, the substituents on the N substituted aromatic groups include: -Ph, -Me, -OMe, -F, Cl, Br, -NO2; when N is 2, the two substituents on the aromatic groups can be the same or different.

[0008] Furthermore, R 1 and R 2 They can be the same or different, R 1 and R 2 Optional unsubstituted aromatic groups include: The N substituted aromatic groups that can be selected include: Selectable heteroaryl groups include: R 2 and R 3 Selectable alkyl groups include: -Me, -Et, -Pr, -Bu. When R 2 and R 3 When both are alkyl or hydrogen atoms, R 2 and R 3 They can be the same or different.

[0009] The process of applying visible light and performing carboxylic acid decarboxylation peroxidation under visible light excitation includes: the organic photocatalyst becoming excited under visible light excitation; the carboxylic acid being converted into a carboxylate under the action of an organic base; the carboxylate being oxidized and decarboxylated by the excited-state organic photocatalyst to generate free radicals; and the free radicals being coupled with peroxy free radicals generated by tert-butyl hydrogen peroxide to obtain an organic peroxy compound.

[0010] Furthermore, the organic photocatalyst is 10-methyl-9-trimethylyl acridine perchlorate (structural formula Mes-AcrClO4, which can also be represented as Acr). + -Mes); the organic base is 2,6-dimethylpyridine (2,6-Lutidine); the solvent is dichloromethane (DCM). The general formula (overall reaction process) for the decarboxylation peroxidation reaction of the carboxylic acid with tert-butyl hydroperoxide under the catalysis of an organic photocatalyst is:

[0011]

[0012] The specific reaction process is as follows:

[0013]

[0014] Furthermore, the visible light is blue light with a wavelength of 456 nm.

[0015] Furthermore, the power of the visible light is 20W.

[0016] Furthermore, the ratio of carboxylic acid, organic photocatalyst, tert-butyl hydroperoxide, 2,6-dimethylpyridine, and dichloromethane is 0.2 mmol:0.01 mmol:0.6 mmol:0.2 mmol:1.0 mL.

[0017] Furthermore, the carboxylic acid decarboxylation peroxidation reaction is carried out at room temperature for 3 hours.

[0018] The room temperature mentioned in this invention can also be referred to as normal temperature or general temperature (generally 15-30℃), which means that the carboxylic acid decarboxylation peroxidation reaction of this invention does not require additional heating with a heat source.

[0019] The second technical solution of the present invention: an organic peroxide compound prepared according to the above preparation method.

[0020] Furthermore, the organic peroxide compound is (1-phenylethyl) tert-butyl peroxide ether, (diphenylmethyl) tert-butyl peroxide ether, 1-(tert-butylperoxy)-1,2,3,4-tetrahydronaphthalene, (1-biphenylmethyl) tert-butyl peroxide ether, (1-p-fluorophenylmethyl) tert-butyl peroxide ether, (1-naphthylmethyl) tert-butyl peroxide ether, 5-((tert-butylperoxy)methyl)benzo[d][1,3]dioxotrope, (1-thienylmethyl) tert-butyl peroxide ether, or 2-((tert-butylperoxy)methyl)dibenzo[b,e]oxazolomide-11(6H)-one.

[0021] The third technical solution of the present invention: the application of the above-mentioned organic peroxide compounds as intermediates in the preparation of ketones, alcohols or indole compounds.

[0022] Furthermore, in addition to serving as intermediates in the chemical synthesis of ketones, alcohols, or indole compounds, the aforementioned organic peroxides can also be used as initiators for monomer polymerization, curing agents for thermosetting resins, crosslinking agents for elastomers, and oxidizing agents in organic synthesis.

[0023] The present invention discloses the following technical effects:

[0024] (1) This invention provides a method for synthesizing organic peroxides by decarboxylation of carboxylic acids under visible light catalysis. It uses carboxylic acids, which are cheaper and more readily available, as the reaction raw materials, and tert-butyl hydrogen peroxide as both the oxidant and the peroxide source. It has high atom economy. The preparation process uses green and clean energy, visible light, and is easy to operate. The product yield is high and it is easy to separate and purify. It has high value in synthesis.

[0025] (2) The organic peroxides prepared by the method of the present invention can be used as intermediates in chemical synthesis to prepare ketones, alcohols or indole compounds. The preparation method and products of the present invention have high potential application value in the fields of synthesis, medicine, and materials. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 The 1H NMR spectrum of (1-phenylethyl) tert-butyl peroxide ether prepared in Example 1 of this invention;

[0028] Figure 2 The carbon NMR spectrum of (1-phenylethyl) tert-butyl peroxide ether prepared in Example 1 of this invention;

[0029] Figure 3 The 1H NMR spectrum of (diphenylmethyl) tert-butyl peroxide ether prepared in Example 2 of this invention;

[0030] Figure 4 The carbon NMR spectrum of (diphenylmethyl) tert-butyl peroxide ether prepared in Example 2 of this invention;

[0031] Figure 5 The 1H NMR spectrum of 1-(tert-butylperoxy)-1,2,3,4-tetrahydronaphthalene prepared in Example 3 of this invention;

[0032] Figure 6 The carbon NMR spectrum of 1-(tert-butylperoxy)-1,2,3,4-tetrahydronaphthalene prepared in Example 3 of this invention;

[0033] Figure 7 The 1H NMR spectrum of 2-((tert-butylperoxy)methyl)dibenzo[b,e]oxazolidin-11(6H)-one prepared in Example 4 of this invention;

[0034] Figure 8The carbon NMR spectrum of 2-((tert-butylperoxy)methyl)dibenzo[b,e]oxazo-11(6H)-one prepared in Example 4 of the present invention;

[0035] Figure 9 The 1H NMR spectrum of (1-biphenylmethyl) tert-butyl peroxide ether prepared in Example 5 of this invention;

[0036] Figure 10 The carbon NMR spectrum of (1-biphenylmethyl) tert-butyl peroxide ether prepared in Example 5 of this invention;

[0037] Figure 11 The 1H NMR spectrum of (1-p-fluorophenylmethyl) tert-butyl peroxide ether prepared in Example 6 of this invention;

[0038] Figure 12 The carbon NMR spectrum of (1-p-fluorophenylmethyl) tert-butyl peroxide ether prepared in Example 6 of this invention;

[0039] Figure 13 The 1H NMR spectrum of (1-naphthylmethyl)tert-butyl peroxide ether prepared in Example 7 of this invention;

[0040] Figure 14 The carbon NMR spectrum of (1-naphthylmethyl)tert-butyl peroxide ether prepared in Example 7 of this invention;

[0041] Figure 15 The 1H NMR spectrum of 5-((tert-butylperoxy)methyl)benzo[d][1,3]dioxotrope prepared in Example 8 of this invention;

[0042] Figure 16 The carbon NMR spectrum of 5-((tert-butylperoxy)methyl)benzo[d][1,3]dioxotrope prepared in Example 8 of this invention;

[0043] Figure 17 The 1H NMR spectrum of (1-thienylmethyl)tert-butyl peroxide ether prepared in Example 9 of this invention;

[0044] Figure 18 The carbon NMR spectrum of (1-thienylmethyl)tert-butyl peroxide ether prepared in Example 9 of this invention. Detailed Implementation

[0045] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0046] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0047] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0048] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0049] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0050] The structural formulas of the raw materials used in the following embodiments and application examples are as follows:

[0051] Mes-AcrClO4: tert-butyl hydroperoxide:

[0052] 2-Phenylacetic acid: Diphenylacetic acid:

[0053] 1,2,3,4-Tetrahydro-1-naphthoic acid: Isosorbide:

[0054] 4-Phenylacetic acid: 4-Fluorophenylacetic acid:

[0055] 2-Naphthaleneacetic acid: Piperacetic acid:

[0056] 2-Thiopheneacetic acid: 1,8-Dazabicycloundec-7-ene (DBU):

[0057] 3-Methylindole:

[0058] Example 1

[0059] Preparation of (1-phenylethyl) tert-butyl peroxide ether

[0060] Under nitrogen atmosphere, 2-phenylacetic acid (0.2 mmol), Mes-AcrClO4 (0.01 mmol), 2,6-dimethylpyridine (0.2 mmol), tert-butyl hydroperoxide (0.6 mmol), and dichloromethane (1.0 mL) were added sequentially to the reaction tube. The reaction was carried out at room temperature under 20 W and 456 nm blue light irradiation for 3 hours. After the reaction was completed, the mixture was rotary evaporated and separated by column chromatography to obtain (1-phenylethyl) tert-butyl peroxide ether. The yield of (1-phenylethyl) tert-butyl peroxide ether was 30 mg, with a yield of 76%.

[0061] Figure 1 2 are the 1H NMR spectrum and 1C NMR spectrum of the (1-phenylethyl) tert-butyl peroxide ether prepared in this embodiment, respectively, and are characterized as follows:

[0062] 1 H NMR (600MHz, CDCl3) δ7.36-7.32(m,4H),7.29-7.26(m,1H),4.99(q,J=6.6Hz,1H),1.47(d,J=6.6Hz,3H),1.22(s,9H); 13 CNMR(150MHz,CDCl3,ppm)δ142.1,128.2,127.6,126.7,81.6,80.1,26.4,20.4; HRMS(ESI)m / z:[M+Na] + Calcd for C 12 H 18 O2Na 217.1199; Found:217.1203.

[0063] The (1-phenylethyl) tert-butyl peroxide ether prepared in this embodiment can be used as an intermediate to prepare acetophenone, 2-phenylethanol and 1,1-di(3-methylindole)methane, as detailed in Application Examples 1-3.

[0064] Example 2

[0065] Preparation of (diphenylmethyl) tert-butyl peroxide ether

[0066] Under nitrogen atmosphere, diphenylacetic acid (0.2 mmol), Mes-AcrClO4 (0.01 mmol), 2,6-dimethylpyridine (0.2 mmol), tert-butyl hydroperoxide (0.6 mmol), and dichloromethane (1.0 mL) were added sequentially to a reaction tube. The reaction was carried out at room temperature under 20 W and 456 nm blue light irradiation for 3 hours. After the reaction was completed, the mixture was rotary evaporated, and the product was separated by column chromatography to obtain (diphenylmethyl)-tert-butyl peroxide ether. The yield of (diphenylmethyl)-tert-butyl peroxide ether was 46 mg, with a yield of 90%.

[0067] Figure 3 4 are the 1H and 1C NMR spectra of the (diphenylmethyl) tert-butyl peroxide ether prepared in this embodiment, respectively, and are characterized as follows:

[0068] 1 H NMR (600MHz, CDCl3) δ7.33-7.24(m,10H),5.97(s,1H),1.26(s,9H); 13 C NMR (150MHz, CDCl3, ppm) δ140.4, 128.2, 127.6, 87.3, 80.5, 26.6; HRMS (ESI) m / z: [M+Na] + Calcdfor C 17 H 20 O2Na 279.1356; Found:279.1355.

[0069] The (diphenylmethyl) tert-butyl peroxide ether prepared in this embodiment can be used as an intermediate in the preparation of benzophenone. The preparation method is the same as in Application Example 1) and diphenylethanol ( The preparation method is the same as in application example 2).

[0070] Example 3

[0071] Preparation of 1-(tert-butylperoxy)-1,2,3,4-tetrahydronaphthalene

[0072] Under nitrogen atmosphere, 1,2,3,4-tetrahydro-1-naphthoic acid (0.2 mmol), Mes-AcrClO4 (0.01 mmol), 2,6-dimethylpyridine (0.2 mmol), tert-butyl hydroperoxide (0.6 mmol), and dichloromethane (1.0 mL) were added sequentially to a reaction tube. The reaction was carried out at room temperature under 20 W and 456 nm blue light irradiation for 3 hours. After the reaction was completed, the mixture was rotary evaporated, and 1-(tert-butylperoxy)-1,2,3,4-tetrahydronaphthalene was obtained by column chromatography. The yield of 1-(tert-butylperoxy)-1,2,3,4-tetrahydronaphthalene was 29 mg, with a yield of 65%.

[0073] Figure 5 6 are the 1H and 1C NMR spectra of 1-(tert-butylperoxy)-1,2,3,4-tetrahydronaphthalene prepared in this embodiment, respectively, and are characterized as follows:

[0074] 1 H NMR (600MHz, CDCl3) δ7.43(d,J=8.0Hz,1H),7.21(td,J=7.4,1.6Hz,1H),7.17(t,J=7.6Hz,1H),7.10(d,J=7.6Hz,1H),4.99( t,J=3.8Hz,1H),2.83-2.79(m,1H),2.72-2.66(m,1H),2.39-2.36(m,1H),2.01-1.93(m,2H),1.81-1.71(m,2H),1.29(s,9H); 13 C NMR(150MHz, CDCl3)δ138.8,133.4,130.9,129.0,128.1,125.6,80.0,78.8,29.3,27.1,26.6,18.1; HRMS(ESI)m / z:[M+Na] + Calcd for C 14 H 20 O2Na 243.1356; Found:243.1353.

[0075] The 1-(tert-butylperoxy)-1,2,3,4-tetrahydronaphthalene prepared in this embodiment can be used as an intermediate to prepare 1,2,3,4-tetrahydro-1-naphthol. The preparation method is the same as in application example 2).

[0076] Example 4

[0077] Preparation of 2-((tert-butylperoxy)methyl)dibenzo[b,e]oxacon-11(6H)-one

[0078] Under nitrogen atmosphere, isosorbide (0.2 mmol), Mes-AcrClO4 (0.01 mmol), 2,6-dimethylpyridine (0.2 mmol), tert-butylhydrogen peroxide (0.6 mmol), and dichloromethane (1.0 mL) were added sequentially to the reaction tube. The reaction was carried out at room temperature under 20 W and 456 nm blue light irradiation for 3 hours. After the reaction was completed, the mixture was rotary evaporated and separated by column chromatography to obtain 2-((tert-butylperoxy)methyl)dibenzo[b,e]oxazo-11(6H)-one. The yield of 2-((tert-butylperoxy)methyl)dibenzo[b,e]oxazo-11(6H)-one was 31 mg, with a yield of 50%.

[0079] Figure 7Figures 8 and 9 are the 1H and 1C NMR spectra of 2-((tert-butylperoxy)methyl)dibenzo[b,e]oxazo-11(6H)-one prepared in this embodiment, respectively, and are characterized as follows:

[0080] 1 H NMR(600MHz, CDCl3)δ8.22(d,J=2.2Hz,1H),7.88(dd,J=7.6,1.0Hz,1H),7.57-7.52(m,2H),7.46(td,J=7.8, 1.2Hz,1H),7.35(d,J=7.4Hz,1H),7.04(d,J=8.4Hz,1H),5.19(s,2H),4.94(s,2H),1.25(s,9H),1.21(s,9H); 13 C NMR (150MHz, CDCl3) δ190.8,161.2,140.5,136.3,135.4,132.7,132.6,130.0,1 29.4,129.3,127.8,125.0,120.9,80.6,76.4,73.6,26.3; HRMS(ESI)m / z:[M+Na] + Calcd for C 19 H 20 O4Na 335.1254; Found:335.1247.

[0081] The 2-((tert-butylperoxy)methyl)dibenzo[b,e]oxazo-11(6H)-one prepared in this embodiment can be used as an intermediate to prepare 2-(hydroxymethyl)dibenzo[b,e]oxazo-11-one. The preparation method is the same as in application example 1).

[0082] Example 5

[0083] Preparation of (1-Biphenylmethyl)tert-butylperoxy ether

[0084] Under nitrogen atmosphere, 0.2 mmol of 4-phenylphenylacetic acid, 0.01 mmol of Mes-AcrClO4, 0.2 mmol of 2,6-dimethylpyridine, 0.6 mmol of tert-butyl hydroperoxide, and 1.0 mL of dichloromethane were added sequentially to the reaction tube. The reaction was carried out at room temperature under 20 W and 456 nm blue light irradiation for 3 hours. After the reaction was completed, the mixture was rotary evaporated and separated by column chromatography to obtain (1-biphenylmethyl)-tert-butyl peroxide ether. The yield of (1-biphenylmethyl)-tert-butyl peroxide ether was 40 mg, with a yield of 78%.

[0085] Figure 910 and 10 are the 1H and 1C NMR spectra of (1-biphenylmethyl) tert-butyl peroxide ether prepared in this embodiment, respectively, and are characterized as follows:

[0086] 1 H NMR (600MHz, CDCl3) δ7.59-7.57(m,4H),7.45-7.41(m,4H),7.35-7.32(m,1H),4.98(s,2H),1.27(s,9H); 13 C NMR(150MHz, CDCl3)δ141.1,140.8,135.0,129.5,128.7,127.3,127.1,80.5,77.1,26.4; HRMS(ESI)m / z:[M+Na] + Calcd for C 17 H 20 O2Na 279.1355; Found:279.1354.

[0087] The (1-biphenylmethyl) tert-butyl peroxide ether prepared in this embodiment can be used as an intermediate in the preparation of 1,1'-biphenyl-4-methanol. The preparation method is the same as in application example 2).

[0088] Example 6

[0089] Preparation of (1-p-fluorophenylmethyl)tert-butyl peroxide ether

[0090] Under nitrogen atmosphere, 4-fluorophenylacetic acid (0.2 mmol), Mes-AcrClO4 (0.01 mmol), 2,6-dimethylpyridine (0.2 mmol), tert-butyl hydroperoxide (0.6 mmol), and dichloromethane (1.0 mL) were added sequentially to the reaction tube. The reaction was carried out at room temperature under 20 W and 456 nm blue light irradiation for 3 hours. After the reaction was completed, the mixture was rotary evaporated and separated by column chromatography to obtain (1-p-fluorophenylmethyl)-tert-butyl peroxide ether. The yield of (1-p-fluorophenylmethyl)-tert-butyl peroxide ether was 27 mg, with a yield of 68%.

[0091] Figure 11 12 are the 1H and 1C NMR spectra of (1-p-fluorophenylmethyl) tert-butyl peroxide ether prepared in this embodiment, respectively, and are characterized as follows:

[0092] 1 H NMR (600MHz, CDCl3) δ7.35-7.33 (m, 2H), 7.04 (t, J = 8.4Hz, 2H), 4.89 (s, 2H), 1.23 (s, 9H); 13 CNMR (150MHz, CDCl3) δ 162.7 (d, JC-F =247.4Hz), 131.9(d,J C-F =4.8Hz), 130.9(d,J C-F =9.6Hz), 115.2(d,J C-F =21.4Hz), 80.5, 76.5, 26.3; 19 FNMR(564MHz, CDCl3)δ-113.9(s,1F); HRMS(ESI)m / z:[M+Na] + Calcd for C 11 H 15 FO2Na 221.0948; Found:221.0946.

[0093] The (1-(p-fluorophenylmethyl)tert-butyl peroxide ether) prepared in this embodiment can be used as an intermediate in the preparation of (4-fluorophenyl)methanol. The preparation method is the same as in application example 2).

[0094] Example 7

[0095] Preparation of (1-naphthylmethyl)tert-butylperoxy ether

[0096] Under nitrogen atmosphere, 2-naphthylacetic acid (0.2 mmol), Mes-AcrClO4 (0.01 mmol), 2,6-dimethylpyridine (0.2 mmol), tert-butyl hydroperoxide (0.6 mmol), and dichloromethane (1.0 mL) were added sequentially to the reaction tube. The reaction was carried out at room temperature under 20 W and 456 nm blue light irradiation for 3 hours. After the reaction was completed, the mixture was rotary evaporated and separated by column chromatography to obtain (1-naphthylmethyl)-tert-butyl peroxide ether. The yield of (1-naphthylmethyl)-tert-butyl peroxide ether was 34 mg, with a yield of 73%.

[0097] Figure 13 14 are the 1H and 1C NMR spectra of (1-naphthylmethyl)tert-butyl peroxide ether prepared in this embodiment, respectively, and are characterized as follows:

[0098] 1 H NMR (600MHz, CDCl3) δ7.85-7.82(m,4H),7.51-7.47(m,3H),5.10(s,2H),1.27(s,9H); 13 CNMR(150MHz, CDCl3)δ133.6,133.2,133.1,128.1,128.0,127.9,127.7,126.8,126.1,126.0,80.6,77.5,26.4; HRMS(ESI)m / z:[M+Na] +Calcd for C 25 H 28 O3Na 399.1931; Found:399.1930.

[0099] The (1-naphthylmethyl) tert-butyl peroxide ether prepared in this embodiment can be used as an intermediate in the preparation of naphthalene-2-methanol ( The preparation method is the same as in application example 2).

[0100] Example 8

[0101] Preparation of 5-((tert-butylperoxy)methyl)benzo[d][1,3]dioxotrope

[0102] Under nitrogen atmosphere, piperoacetic acid (0.2 mmol), Mes-AcrClO4 (0.01 mmol), 2,6-dimethylpyridine (0.2 mmol), tert-butylhydrogen peroxide (0.6 mmol), and dichloromethane (1.0 mL) were added sequentially to the reaction tube. The reaction was carried out at room temperature under 20 W and 456 nm blue light irradiation for 3 hours. After the reaction was completed, the mixture was rotary evaporated and separated by column chromatography to obtain 5-((tert-butylperoxy)methyl)benzo[d][1,3]dioxone. The yield of 5-((tert-butylperoxy)methyl)benzo[d][1,3]dioxone was 33 mg, with a yield of 74%.

[0103] Figure 15 16 are the 1H and 1C NMR spectra of 5-((tert-butylperoxy)methyl)benzo[d][1,3]dioxotrope prepared in this embodiment, respectively, and are characterized as follows:

[0104] 1 H NMR (600MHz, CDCl3) δ6.87(d,J=1.6Hz,1H),6.83(dd,J=8.0,1.8Hz,1H),6.77(d,J=8.0Hz,1H),5.95(s,2H),4.83(s,2H),1.24(s,9H); 13 C NMR(150MHz, CDCl3)δ147.6,147.5,129.8,123.0,109.7,108.1,101.0,80.5,77.2,26.3; HRMS(ESI)m / z:[M+Na] + Calcdfor C 12 H 16 O4Na 247.0941; Found:247.0935.

[0105] The 5-((tert-butylperoxy)methyl)benzo[d][1,3]dioxacol prepared in this embodiment can be used as an intermediate for the preparation of benzo[d][1,3]dioxacol-5-methanol. The preparation method is the same as in application example 2).

[0106] Example 9

[0107] Preparation of (1-thienylmethyl)tert-butyl peroxide ether

[0108] Under nitrogen atmosphere, 2-thienenoic acid (0.2 mmol), Mes-AcrClO4 (0.01 mmol), 2,6-dimethylpyridine (0.2 mmol), tert-butyl hydroperoxide (0.6 mmol), and dichloromethane (1.0 mL) were added sequentially to the reaction tube. The reaction was carried out at room temperature under 20 W and 456 nm blue light irradiation for 3 hours. After the reaction was completed, the mixture was rotary evaporated and separated by column chromatography to obtain (1-thienylmethyl)tert-butyl peroxide ether. The yield of (1-thienylmethyl)tert-butyl peroxide ether was 17 mg, with a yield of 47%.

[0109] Figure 17 18 are the 1H and 1C NMR spectra of (1-thienylmethyl)tert-butyl peroxide ether prepared in this embodiment, respectively, and are characterized as follows:

[0110] 1 H NMR (600MHz, CDCl3) δ7.31-7.30 (dd, J=5.2, 1.2Hz, 1H), 7.06 (d, J=3.4Hz, 1H), 6.99-6.98 (m, 1H), 5.07 (s, 2H), 1.24 (s, 9H); 13 C NMR (150MHz, CDCl3) δ138.1, 128.0, 126.7, 126.6, 80.6, 71.0, 26.3; HRMS (ESI) m / z: [M+Na] + Calcd for C9H 14 O2SNa 209.0607; Found:209.0606.

[0111] The (1-thienylmethyl) tert-butyl peroxide ether prepared in this embodiment can be used as an intermediate in the preparation of thien-2-methanol ( The preparation method is the same as in application example 2).

[0112] The structural formulas of the products obtained in Examples 1-9 are shown in Table 1:

[0113] Table 1

[0114]

[0115]

[0116] Application Example 1

[0117] (1-Phenylacetyl)tert-butylperoxide ether was used as an intermediate in the preparation of acetophenone.

[0118] The reaction process is as follows:

[0119] The specific steps are as follows: (1-Phenylacetyl)-tert-butylperoxy ether (0.1 mmol) and 1,8-diazabicycloundec-7-ene (0.15 mmol) were dissolved in 1.0 mL of acetonitrile (MeCN), and reacted at 50 °C for 1 h. After the reaction was complete, acetophenone was obtained by column chromatography (yield 11.2 mg, yield 93%). Characterization was as follows: 1 H NMR (600MHz, CDCl3) δ7.96-7.95(m,2H),7.57-7.54(m,1H),7.47-7.45(m,2H),2.60(s,3H).

[0120] Application Example 2

[0121] (1-Phenylacetyl)tert-butylperoxide ether was used as an intermediate in the preparation of 2-phenylethanol.

[0122] The reaction process is as follows:

[0123] The specific steps are as follows: (1-Phenylacetyl)-tert-butylperoxy ether (0.1 mmol), palladium on carbon (Pd / C, 0.1 mmol), and ammonium formate (0.2 mmol) are dissolved in 1.0 mL of methanol, and reacted at 75 °C for 3 h. After the reaction is complete, 2-phenylethanol is obtained by column chromatography (yield 10.0 mg, yield 82%). Characterization is as follows: 1 H NMR (600MHz, CDCl3) δ7.30-7.29(m,4H),7.26-7.19(m,1H),4.78(q,J=6.4Hz,1H),1.41(d,J=6.8Hz,3H).

[0124] Application Example 3

[0125] (1-Phenylacetyl)tert-butylperoxide ether was used as an intermediate in the preparation of 1,1-di(3-methylindole)methane.

[0126] The reaction process is as follows: That is, (1-phenylethyl) tert-butyl peroxide ether undergoes Hock rearrangement under acidic conditions.

[0127] The specific steps were as follows: (1-Phenylacetyl)-tert-butylperoxy ether (0.1 mmol), 3-methylindole (0.5 mmol), and trifluoroacetic acid (TFOH, 0.15 mmol) were dissolved in 1.0 mL of acetonitrile and reacted at 25 °C for 24 h. After the reaction was complete, 1,1-bis(3-methylindole)methane was obtained by column chromatography (yield: 22.9 mg, yield: 62%). Characterization was as follows: 1 H NMR (600MHz, CDCl3) δ7.71 (s, 2H), 7.52 (d, J = 7.8Hz, 2H), 7.25-7.23 (m, 2H), 7.15-7.09(m,4H),4.72(q,J=7.4Hz,1H),2.25(s,6H),1.74(d,J=7.4Hz,3H).

[0128] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for synthesizing organic peroxides by visible light-catalyzed decarboxylation of carboxylic acids, characterized in that, A carboxylic acid is mixed with an organic photocatalyst, tert-butyl hydrogen peroxide, an organic base, and a solvent. Visible light is applied, and the carboxylic acid undergoes a decarboxylation peroxidation reaction under visible light excitation to obtain an organic peroxide compound. The structural formula of the carboxylic acid is [insert structural formula here]. The structural formula of the organic peroxide compound is as follows: The organic photocatalyst is 10-methyl-9-trimethylmethylacridine perchlorate; the organic base is 2,6-dimethylpyridine; and the solvent is dichloromethane. The visible light is blue light with a wavelength of 456 nm.

2. The method for synthesizing organic peroxides by visible light-catalyzed decarboxylation of carboxylic acids as described in claim 1, characterized in that, The ratio of carboxylic acid, organic photocatalyst, tert-butyl hydroperoxide, 2,6-dimethylpyridine, and dichloromethane was 0.2 mmol:0.01 mmol:0.6 mmol:0.2 mmol:1.0 mL.

3. The method for synthesizing organic peroxides by visible light-catalyzed decarboxylation of carboxylic acids as described in claim 1, characterized in that, The carboxylic acid decarboxylation peroxidation reaction was carried out at room temperature for 3 hours.

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