Method for carboxylation reaction of photocatalytic unsaturated hydrocarbons

Abstract

The invention discloses a method for a carboxylation reaction of photocatalytic unsaturated hydrocarbons, and belongs to the technical field of carboxylation of unsaturated hydrocarbons. The method comprises the following steps: adding a sulfur-containing photocatalyst and formate into a solvent to obtain a solution A; adding an unsaturated hydrocarbon compound into the solution A to obtain a solution B; and irradiating the solution B by using a light source so that the unsaturated hydrocarbon compound and formate are subjected to carboxylation reaction to prepare the carboxylic acid compound. According to the invention, carboxylation reaction of unsaturated hydrocarbon compounds is realized through light-driven metal-doped quantum dot catalysis for the first time. The method is mild in condition and can be realized by irradiating the metal-doped quantum dot catalyst with a light source at a certain temperature and normal pressure, and harsh conditions of a high-temperature and high-pressure lamp are not needed. Meanwhile, various alkane carboxylic acids are obtained through carboxylation reaction of unsaturated hydrocarbon compounds and formate in the photocatalytic system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of unsaturated hydrocarbon carboxylation, and particularly relates to a method for photocatalytic carboxylation of unsaturated hydrocarbons. BACKGROUND

[0002] Carboxylic acid compounds are widely present in nature. Among them, alkyl carboxylic acids represented by propionic acid, succinic acid, and adipic acid play an important role in chemical production, organic synthesis industry, medicine, and lubricant manufacturing. Therefore, efficient construction of alkyl carboxylic acids has attracted widespread attention in the fields of organic chemistry, medicinal chemistry, and biochemistry.

[0003] Traditionally, propionic acid is mainly manufactured by using the Rapoport method or propionaldehyde oxidation method, but the reaction system needs to use toxic CO as a carbonyl source, and its safety faces certain problems. Succinic acid is mainly prepared by catalytic hydrogenation of maleic acid, but maleic acid is expensive. Adipic acid is mainly manufactured by using the “nitric acid oxidation method”, but the manufacturing process produces and releases nitrous oxide (N2O, commonly known as “laughing gas”), which destroys the ozone layer and causes global warming. Therefore, it is not environmentally friendly and stable. Therefore, it is of great academic significance and application value to explore the efficient synthesis of alkyl carboxylic acids.

[0004] Formate is a C1 source that is easy to obtain, non-toxic, and low in cost. The use of formate as a C1 raw material to synthesize high-value chemicals has attracted great interest. One particularly attractive and challenging transformation is the carboxylation of unsaturated hydrocarbons with formate to synthesize high-value carboxylic acids.

[0005] In order to further realize the carboxylation conversion of unsaturated hydrocarbons and formate in a green, safe, mild, and efficient manner, scientists have begun to use photocatalytic systems to realize the carboxylation conversion of olefins and formate. For example, a photocatalytic strategy for the synthesis of succinic acid by dicarboxylation of olefins using carbon dioxide and formate as a synergistic carbon source, but the substrate is limited to active olefins. There is also a strategy for promoting the hydroxylation of unactivated olefins through photochemical activation of formate, which uses formate and ethylene to construct propionic acid, but the reaction uses a homogeneous sulfenyl catalyst.

[0006] Therefore, it is very meaningful to study a heterogeneous photocatalytic system with wide substrate applicability for the carboxylation of unsaturated hydrocarbons at room temperature and pressure. SUMMARY

[0007] In order to solve the above-mentioned deficiencies existing in the prior art, the purpose of the present application is to provide a method for photocatalytic carboxylation of unsaturated hydrocarbons, which can prepare various alkyl carboxylic acids under mild conditions through carboxylation reaction of unsaturated hydrocarbons and formate under the catalysis of metal-doped quantum dots under light conditions.

[0008] The technical scheme for solving the above technical problems of the present application is as follows: a method for photocatalyzing carboxylation of unsaturated hydrocarbons is provided, comprising the following steps:

[0009] (1) adding a sulfur-containing photocatalyst and a formate into a solvent to obtain solution A;

[0010] (2) adding an unsaturated hydrocarbon compound into solution A to obtain solution B;

[0011] (3) irradiating solution B with a light source to make the unsaturated hydrocarbon compound and the formate undergo carboxylation reaction, and prepare a carboxylic compound.

[0012] Further, the mass ratio of the sulfur-containing photocatalyst and lithium formate is 5-15:20-200; the temperature during the carboxylation reaction is 30-80℃, and the reaction time is 1-60h.

[0013] Further, the sulfur-containing photocatalyst is a sulfur-containing metal-doped quantum dot, which can be Ni / CdS, Co / CdS, Fe / CdS, Cu / CdS, Ru / CdS, Ti3C2 / CdS, Ni / Ti3C2 / CdS, CdS nanosheet, or CdS nanoflower.

[0014] Further, the formate is at least one of lithium formate, sodium formate, potassium formate, cesium formate, and ammonium formate.

[0015] Further, the solvent is at least one of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), acetonitrile (MeCN), tetrahydrofuran (THF), cyclohexane, and dichloroethane (DCE).

[0016] Further, the unsaturated hydrocarbon compound is an unsaturated olefin or an unsaturated alkyne.

[0017] Further, the unsaturated olefin has the following structural formula:

[0018]

[0019] R, R', R'', and R''' are all hydrogen, C 1-20 alkyl, alkenyl or substituted alkenyl, aryl or substituted aryl, ester or substituted ester, amide or substituted amide, amine or substituted amine, halogen; R, R', R'', and R''' are the same or different.

[0020] Further, the unsaturated olefin is ethylene, propylene, butylene, 1,3-butadiene, or an unsaturated olefin having the following structural formula:

[0021]

[0022] Further, the unsaturated alkyne is wherein R 1 is hydrogen, C 1-20 alkyl; preferably R 1 is hydrogen, C 1-12 alkyl.

[0023] Further, the unsaturated alkyne is acetylene, propyne and the unsaturated alkyne of the following structure:

[0024]

[0025] Further, the light source is sunlight, LED lamp, medium pressure mercury lamp, high pressure mercury lamp or xenon lamp.

[0026] Further, under the irradiation of the light source, the reaction temperature is room temperature to 80℃, and the reaction time is 1-60h.

[0027] Further, CO2 and basic substance are added in the reaction system, and the unsaturated hydrocarbon compound is carboxylated to obtain a dicarboxylic acid compound.

[0028] Further, the basic substance is at least one of lithium methoxide, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, lithium tert-butoxide, sodium tert-butoxide, potassium tert-butoxide, sodium tert-amyl alcohol, lithium carbonate, sodium carbonate, potassium carbonate, cesium carbonate, cesium bicarbonate, cesium iodide and cesium acetate.

[0029] The present application has the following beneficial effects:

[0030] (1) The photocatalytic carboxylation reaction of the unsaturated hydrocarbon provided by the present application is that the sulfur-containing photocatalyst is excited by light to generate photo-generated electrons and holes, and the sulfur anion on the surface of the catalyst is oxidized by the photo-generated holes to generate sulfur radicals. The sulfur radicals react with formate to generate mercapto and carbon dioxide radical anion. Then, the generated carbon dioxide radical anion attacks the unsaturated hydrocarbon to obtain an alkyl radical intermediate, and the alkyl radical intermediate further undergoes hydrogen proton transfer reaction with the generated mercapto to obtain the target product and sulfur anion. In the process, the holes of the photocatalyst are generated, and the photo-generated electrons are annihilated, the photocatalyst returns to the ground state and starts a new cycle.

[0031] (2) The carboxylation reaction of the unsaturated hydrocarbon compound is realized by the light-driven metal-doped quantum dot catalyst for the first time in the present application. The present application has mild conditions, and the light source irradiates the metal-doped quantum dot catalyst at a certain temperature and under normal pressure, without the harsh conditions of high temperature and high pressure lamps. At the same time, since the photocatalytic system generates a variety of alkane carboxylic acids by the hydrogen carboxylation reaction of the unsaturated hydrocarbon compound and formate, the present application has a wide range of reactants, i.e. unsaturated alkenes, unsaturated alkynes and 1,3-butadiene compounds can all react.

[0032] (3) In the method of this invention, metal-doped quantum dots serve as heterogeneous photocatalysts, exhibiting advantages such as high stability and the ability to be recycled multiple times. The catalyst retains excellent catalytic activity even after multiple cycles of use. Detailed Implementation

[0033] The examples given below are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified, conditions in the examples are performed under standard conditions or as recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0034] The photocatalyst preparation method involved in this invention is as follows:

[0035] Ni / CdS: Add Cd(OAc)2·2H2O (2 mmol), SC(NH2)2 (6 mmol), and NiCl2·6H2O (0.3 mmol) to a Schlenk tube containing a stir bar. Loosen the cap and purge the tube with N2 three times to fill it with N2 gas. Add H2O (5 mL) and ethylenediamine (60 mL) under N2 atmosphere to seal the tube and stir at 106 °C for 8 h. After cooling to room temperature, separate the solid by filtration and wash with ethanol and water. Dry under vacuum at 60 °C for 12 h.

[0036] Co / CdS: Add Cd(OAc)2·2H2O (2 mmol), SC(NH2)2 (6 mmol), and CoCl2·6H2O (0.3 mmol) to a Schlenk tube containing a stir bar. Loosen the cap and purge the tube with N2 three times to fill it with N2 gas. Add H2O (5 mL) and ethylenediamine (60 mL) under N2 atmosphere to seal the tube and stir at 106 °C for 8 h. After cooling to room temperature, separate the solid by filtration and wash with ethanol and water. Dry under vacuum at 60 °C for 12 h.

[0037] Fe / CdS: Add Cd(OAc)2·2H2O (2 mmol), SC(NH2)2 (6 mmol), and FeCl2·6H2O (0.3 mmol) to a Schlenk tube containing a stir bar. Loosen the cap and purge the tube with N2 three times to fill it with N2 gas. Add H2O (5 mL) and ethylenediamine (60 mL) under N2 atmosphere to seal the tube and stir at 106 °C for 8 h. After cooling to room temperature, separate the solid by filtration and wash with ethanol and water. Dry under vacuum at 60 °C for 12 h.

[0038] Cu / CdS: Add Cd(OAc)2·2H2O (2 mmol), SC(NH2)2 (6 mmol), and CuCl2·2H2O (0.3 mmol) to a Schlenk tube containing a stir bar. Loosen the cap and purge the tube with N2 three times to fill it with N2 gas. Add H2O (5 mL) and ethylenediamine (60 mL) under N2 atmosphere to seal the tube and stir at 106 °C for 8 h. After cooling to room temperature, separate the solid by filtration and wash with ethanol and water. Dry under vacuum at 60 °C for 12 h.

[0039] Ru / CdS: Add Cd(OAc)2·2H2O (2 mmol), SC(NH2)2 (6 mmol), and RuCl3 (0.3 mmol) to a Schlenk tube containing a stir bar. Loosen the cap and purge the tube with N2 three times to fill it with N2 gas. Add H2O (5 mL) and ethylenediamine (60 mL) under N2 atmosphere to seal the tube and stir at 106 °C for 8 h. After cooling to room temperature, separate the solid by filtration and wash with ethanol and water. Dry under vacuum at 60 °C for 12 h.

[0040] Ti3C2 / CdS: Add Cd(OAc)2·2H2O (2mmol), SC(NH2)2 (6mmol), and Ti3C2 (30mg) to a Schlenk tube containing a stir bar. Loosen the cap and purge the tube with N2 three times to fill it with N2 gas. Add H2O (5mL) and ethylenediamine (60mL) under N2 atmosphere to seal the tube and stir at 106℃ for 8h. After cooling to room temperature, separate the solid by filtration and wash with ethanol and water. Dry under vacuum at 60℃ for 12h.

[0041] Ni / Ti3C2 / CdS: Add Cd(OAc)2·2H2O (2mmol), SC(NH2)2 (6mmol), NiCl2·6H2O (0.3mmol), and Ti3C2 (30mg) to a Schlenk tube containing a stir bar. Loosen the cap and purge the tube with N2 three times to fill it with N2 gas. Add H2O (5mL) and ethylenediamine (60mL) under N2 atmosphere to seal the tube and stir at 106℃ for 8h. After cooling to room temperature, separate the solid by filtration and wash with ethanol and water. Dry under vacuum at 60℃ for 12h.

[0042] CdS nanosheets: Add Cd(OAc)2·2H2O (2 mmol) and SC(NH2)2 (6 mmol) to a Schlenk tube containing a stir bar, loosen the cap and purge the tube with N2 three times to fill it with N2 gas; add ethylenediamine (60 mL) under N2 atmosphere to seal the tube and stir at 106 °C for 8 h, cool to room temperature, separate the solid by suction filtration and wash with ethanol and water, and dry under vacuum at 60 °C for 12 h.

[0043] CdS nanoflower: Add Cd(OAc)2·2H2O (2 mmol) and SC(NH2)2 (6 mmol) to a Schlenk tube containing a stir bar, loosen the cap and purge the tube with N2 three times to fill it with N2 gas; add H2O (5 mL) and ethylenediamine (60 mL) under N2 atmosphere to seal it and stir at 106 °C for 8 h, cool to room temperature, separate the solid by suction filtration and wash with ethanol and water, and dry under vacuum at 60 °C for 12 h.

[0044] Example 1:

[0045] A method for the carboxylation reaction of unsaturated hydrocarbons via photocatalysis, specifically the photocatalytic synthesis of propionic acid from ethylene and formate, comprising the following steps:

[0046] In a glove box under N2 atmosphere, lithium formate (1 mmol) was added to a dry Schlenk tube containing the photocatalyst Ni / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to an ethylene cylinder. The cap was loosened, and the tube was purged and purged three times to replace the ethylene gas, filling it with ethylene gas. DMSO (7 mL) was added under an ethylene atmosphere, the tube was sealed, and the mixture was stirred at 60 °C. After reacting for 3 h under 30 W 450 nm Blue LED illumination, the mixture was cooled to room temperature. The reaction mixture was quenched with trifluoroacetic acid (TFA), and mesitylene (0.2 mmol) was added as an internal standard. DMSO- d6 As a deuteration reagent, it yielded an NMR yield of 80%.

[0047] By changing the type of photocatalyst in the above preparation process, the results of different photocatalysts under the same conditions are shown in Table 1:

[0048] Table 1 Results for different catalysts under the same conditions.

[0049] Catalyst NMR yield Ni / CdS 80％ Co / CdS 74％ Cu / CdS 24％ Fe / CdS 35％ Ru / CdS 21％ CdS nanosheets 65％ CdS nanoflower 42％

[0050] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0051]

[0052] 1 H NMR (400MHz, DMSO-d6) δ11.94 (s, 1H), 2.25–2.15 (m, 2H), 0.98 (t, J = 7.6Hz, 3H). 13 C NMR(101MHz,DMSO-d6)δ175.3,27.0,9.1.

[0053] Example 2:

[0054] A method for the carboxylation reaction of unsaturated hydrocarbons via photocatalysis, specifically the photocatalytic synthesis of 1-butyric acid from propylene and formate, comprising the following steps:

[0055] In a glove box under N2 atmosphere, lithium formate (1 mmol) was added to a dry Schlenk tube containing the photocatalyst Ni / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to a propylene cylinder. The cap was loosened, and the propylene was purged and replaced three times in the double-row tube to fill it with propylene gas. DMSO (7 mL) was added under a propylene atmosphere, the tube was sealed, and the mixture was stirred at 60 °C. After reacting for 3 h under 30 W 450 nm Blue LED illumination, the mixture was cooled to room temperature. The reaction mixture was quenched with TFA, and mesitylene (0.2 mmol) was added as an internal standard. DMSO- d6 As a deuteration reagent, the NMR yield was 63%.

[0056] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0057]

[0058] 1 H NMR (400MHz, DMSO-d6) δ11.94(s,1H),2.17(t,J=7.3Hz,2H),1.50(h,J=7.3Hz,2H),0.87(t,J=7.4Hz,3H). 13 C NMR(101MHz,DMSO-d6)δ174.4,35.6,18.0,13.5.

[0059] Example 3:

[0060] A method for the photocatalytic carboxylation of unsaturated hydrocarbons, specifically the photocatalytic synthesis of 1-pentanoic acid from butene and formate, includes the following steps:

[0061] In a glove box under N2 atmosphere, lithium formate (1 mmol) was added to a dry Schlenk tube containing photocatalyst Ni / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to a butene cylinder. The cap was loosened, and the butene was replaced three times in the double-row tube to fill it with butene gas. DMSO (7 mL) was added under a butene atmosphere, the tube was sealed, and the mixture was stirred at 60 °C. After reacting for 3 h under 30 W 450 nm Blue LED illumination, the mixture was cooled to room temperature. The reaction mixture was quenched with TFA, and mesitylene (0.2 mmol) was added as an internal standard. d6 As a deuteration reagent, the NMR yield was 48%.

[0062] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0063]

[0064] 1 H NMR (400MHz, DMSO-d6) δ11.94(s,1H),2.18(t,J=7.4Hz,2H),1.47(p,J=7.4Hz,2H),1.28(dq,J=14.4,7.3Hz,1H),0.86(t,J=7.3Hz,3H). 13 C NMR (101MHz, DMSO-d6) δ174.5,33.4,26.7,21.7,13.7.

[0065] Example 4:

[0066] A method for the carboxylation reaction of unsaturated hydrocarbons via photocatalysis, specifically the photocatalytic synthesis of tridecanoic acid from dodecene and formate, comprising the following steps:

[0067] In a glove box under N2 atmosphere, lithium formate (0.5 mmol) was added to a dried Schlenk tube containing photocatalyst Ni / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to an N2 cylinder. The cap was loosened, and the tube was purged with N2 three times to fill it with N2 gas. Dodecene (0.2 mmol) and DMSO (3 mL) were added under N2 atmosphere, the tube was sealed, and stirred at 60 °C. The reaction was carried out for 12 h under 30 W 450 nm Blue LED light source. After cooling to room temperature, the reaction mixture was quenched with 2 N hydrochloric acid, followed by extraction with ethyl acetate five times. The organic phases were combined, and residual solvent was completely removed by rotary evaporation. After rotary drying, silica gel and solvent were added, the mixture was rotary dried, and the sample was loaded. Column chromatography was used for separation and purification to obtain the desired pure product. The chemical yield was calculated to be 35%.

[0068] The structural formula of the above-mentioned dodecene is as follows:

[0069]

[0070] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0071]

[0072] 1 H NMR (400MHz, Chloroform-d) δ2.35(t,J=7.5Hz,2H),1.69–1.57(m,2H),1.32–1.23(m,18H),0.88(t,J=6.7Hz,3H). 13 C NMR (101MHz, Chloroform-d) δ178.9,33.8,31.9,29.6,29.6,29.6,29.4,29.3,29.2,29.0,24.7,22.7,14.1.

[0073] Example 5:

[0074] A method for the photocatalytic carboxylation of unsaturated hydrocarbons, specifically the photocatalytic synthesis of 5-([1,1'-biphenyl]-4-yl)pentanoic acid from 4-(but-3-en-1-yl)-1,1'-biphenyl and formate, comprising the following steps:

[0075] In a glove box under N2 atmosphere, lithium formate (0.5 mmol) was added to a dry Schlenk tube containing photocatalyst Ni / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to an N2 cylinder. The cap was loosened, and the tube was purged with N2 three times to fill it with N2 gas. 4-(but-3-en-1-yl)-1,1'-biphenyl (0.2 mmol) and DMSO (3 mL) were added under N2 atmosphere. The tube was sealed and stirred at 60 °C. After reacting for 12 h under 30W 450nm Blue LED illumination, the mixture was cooled to room temperature. The reaction mixture was quenched with 2N hydrochloric acid, followed by extraction with ethyl acetate five times. The organic phases were combined, and residual solvent was completely removed by rotary evaporation. After rotary evaporation to dryness, silica gel and solvent were added, and the mixture was dried again before loading. The sample was purified by column chromatography to obtain the desired pure product, with a calculated chemical yield of 69%.

[0076] The structural formula of the above 4-(but-3-en-1-yl)-1,1'-biphenyl is as follows:

[0077]

[0078] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0079]

[0080] 1 H NMR (400MHz, DMSO-d6) δ12.03(s,1H),7.67–7.60(m,2H),7.56(d,J=8.2Hz,2H),7.44(t,J=7.6Hz,2H),7 .37–7.30(m,1H),7.27(d,J=8.2Hz,2H),2.61(t,J=7.3Hz,2H),2.25(t,J=7.1Hz,2H),1.72–1.44(m,4H). 13 C NMR (101MHz, DMSO-d6) δ174.5,141.3,140.1,137.6,128.9,127.1,126.7,126.6,126.5,34.4,33.5,30.3,24.2.

[0081] Example 6:

[0082] A method for the photocatalytic carboxylation of unsaturated hydrocarbons, specifically the photocatalytic synthesis of (4,4-difluorobut-3-en-1-yl)benzene and formate.

[0083] The synthesis of 2,2-difluoro-5-phenylpentanoic acid includes the following steps:

[0084] In a glove box under N2 atmosphere, lithium formate (0.5 mmol) was added to a dry Schlenk tube containing photocatalyst Ni / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to an N2 cylinder. The cap was loosened, and the tube was purged with N2 three times to fill it with N2 gas. (4,4-difluorobut-3-en-1-yl)benzene (0.2 mmol) and DMSO (3 mL) were added under N2 atmosphere. The tube was sealed and stirred at 60 °C. After reacting for 12 h under 30W 450nm Blue LED illumination, the mixture was cooled to room temperature. The reaction mixture was quenched with 2N hydrochloric acid, followed by extraction with ethyl acetate five times. The organic phases were combined, and residual solvent was completely removed by rotary evaporation. After rotary evaporation to dryness, silica gel and solvent were added, and the mixture was dried again before loading. The product was purified by column chromatography, yielding a chemical yield of 75%.

[0085] The structural formula of (4,4-difluorobut-3-en-1-yl)benzene is as follows:

[0086]

[0087] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0088]

[0089] 1 H NMR (400MHz, DMSO-d6) δ7.33–7.24(m,2H),7.23–7.14(m,3H),2.63(t,J=7.6Hz,2H),2.12–1.95(m,2H),1.75–1.62(m,2H). 13C NMR (101MHz, DMSO-d6) δ165.3(t,J=31.5Hz),141.2,128.4,126.0,34.2,33.2(t,J=23.1Hz),23.2(t,J=4.3Hz).19F NMR(376MHz,DMSO-d6)δ-105.0(t,J=17.3Hz).

[0090] Example 7:

[0091] A method for the photocatalytic carboxylation of unsaturated hydrocarbons, specifically the photocatalytic synthesis of 6-(9H-carbazol-9-yl)hexanoic acid from 9-(pent-4-en-1-yl)-9H-carbazole and formate, comprising the following steps:

[0092] In a glove box under N2 atmosphere, lithium formate (0.5 mmol) was added to a dry Schlenk tube containing photocatalyst Ni / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to an N2 cylinder. The cap was loosened, and the tube was purged with N2 three times to fill it with N2 gas. 9-(pent-4-en-1-yl)-9H-carbazole (0.2 mmol) and DMSO (3 mL) were added under N2 atmosphere. The tube was sealed and stirred at 60 °C. After reacting for 12 h under 30W 450nm Blue LED illumination, the mixture was cooled to room temperature. The reaction mixture was quenched with 2N hydrochloric acid, followed by extraction with ethyl acetate five times. The organic phases were combined, and residual solvent was completely removed by rotary evaporation. After rotary evaporation to dryness, silica gel and solvent were added, and the mixture was dried again before loading. The sample was purified by column chromatography to obtain the desired pure product, with a calculated chemical yield of 75%.

[0093] The structural formula of 9-(pent-4-en-1-yl)-9H-carbazole is as follows:

[0094]

[0095] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0096]

[0097] 1H NMR(400MHz, DMSO-d6)δ8.16–8.10(m,2H),7.56(d,J=8.2Hz,2H),7.48–7.39(m,2H),7.18(t,J=7.4Hz,2H),4 .34(t,J=7.1Hz,2H),2.14(t,J=7.3Hz,2H),1.75(p,J=7.2Hz,2H),1.50(p,J=7.4Hz,2H),1.33–1.20(m,2H). 13 C NMR (101MHz, DMSO-d6) δ174.5,140.1,125.8,122.1,120.4,118.8,109.3,42.2,33.7,28.4,26.2,24.4.

[0098] Example 8:

[0099] A method for the photocatalytic carboxylation of unsaturated hydrocarbons, specifically the photocatalytic synthesis of 6-methoxy-6-oxohexanoic acid from methyl pent-4-enoate and formate, includes the following steps:

[0100] In a glove box under N2 atmosphere, lithium formate (0.5 mmol) was added to a dry Schlenk tube containing photocatalyst Ni / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to an N2 cylinder. The cap was loosened, and the tube was purged with N2 three times to fill it with N2 gas. Methyl pent-4-enoate (0.2 mmol) and DMSO (3 mL) were added under N2 atmosphere, the tube was sealed, and the mixture was stirred at 60 °C. After reacting for 12 h under a 30W 450nm Blue LED light source, the mixture was cooled to room temperature. The reaction mixture was quenched with 2N hydrochloric acid, followed by extraction with ethyl acetate five times. The organic phases were combined, and residual solvent was completely removed by rotary evaporation. After rotary evaporation to dryness, silica gel and solvent were added, the mixture was rotary evaporated, and the sample was loaded. Column chromatography was used for separation and purification to obtain the desired pure product. The chemical yield was calculated to be 71%.

[0101] The structural formula of the above methyl pent-4-enoate is as follows:

[0102]

[0103] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0104]

[0105] 1 H NMR(400MHz,Chloroform-d)δ3.66(s,3H),2.43–2.30(m,4H),1.86–1.56(m,4H). 13 C NMR (101MHz, Chloroform-d) δ179.4,173.8,51.6,33.6,33.6,24.3,24.1.

[0106] Example 9:

[0107] A method for the photocatalytic carboxylation of unsaturated hydrocarbons, specifically the photocatalytic synthesis of 4-benzamidobutanoic acid from N-allylbenzamide and formate, includes the following steps:

[0108] In a glove box under N2 atmosphere, lithium formate (0.5 mmol) was added to a dry Schlenk tube containing the photocatalyst Ni / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to an N2 cylinder. The cap was loosened, and the tube was purged with N2 three times to fill it with N2 gas. Under N2 atmosphere, N-allylbenzamide (0.2 mmol) and DMSO (3 mL) were added, the tube was sealed, and the mixture was stirred at 60 °C. After reacting for 12 h under a 30 W 450 nm Blue LED light source, the mixture was cooled to room temperature. The reaction mixture was quenched with 2 N hydrochloric acid, followed by extraction with ethyl acetate five times. The organic phases were combined, and residual solvent was completely removed by rotary evaporation. After rotary evaporation to dryness, silica gel and solvent were added, the mixture was rotary evaporated, and the sample was loaded. Column chromatography was used for separation and purification to obtain the desired pure product, with a calculated chemical yield of 89%.

[0109] The structural formula of the above-mentioned N-allylbenzamide is as follows:

[0110]

[0111] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0112]

[0113] 1H NMR (400MHz, DMSO-d6) δ8.51–8.40(s,1H),7.87–7.79(m,2H),7.55–7.41(m,3H),3.28(q,J=6.6Hz,2H),2.28(t,J=7.4Hz,2H),1.75(p,J=7.2Hz,2H). 13 C NMR (101MHz, DMSO-d6) δ174.3,166.3,134.6,131.1,128.3,127.2,38.7,31.2,24.6.

[0114] Example 10:

[0115] A method for the photocatalytic carboxylation of unsaturated hydrocarbons, specifically the photocatalytic synthesis of 4-((tert-butoxycarbonyl)amino)butanoic acid from tert-butylallylcarbamate and formate, includes the following steps:

[0116] In a glove box under N2 atmosphere, lithium formate (0.5 mmol) was added to a dry Schlenk tube containing photocatalyst Ni / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to an N2 cylinder. The cap was loosened, and the tube was purged with N2 three times to fill it with N2 gas. Tert-butyl allylcarbamate (0.2 mmol) and DMSO (3 mL) were added under N2 atmosphere. The tube was sealed and stirred at 60 °C. After reacting for 12 h under a 30W 450nm Blue LED light source, the mixture was cooled to room temperature. The reaction mixture was quenched with 2N hydrochloric acid, followed by extraction with ethyl acetate five times. The organic phases were combined, and residual solvent was completely removed by rotary evaporation. After rotary drying, silica gel and solvent were added, and the mixture was loaded onto a column for purification using column chromatography. The desired pure product was obtained, with a calculated chemical yield of 73%.

[0117] The structural formula of the above tert-butyl allylcarbamate is as follows:

[0118]

[0119] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0120]

[0121] 1H NMR (400MHz, Chloroform-d) δ3.20–3.14(m,2H),2.38(t,J=7.2Hz,2H),1.81(p,J=7.0Hz,2H),1.43(s,9H). 13 C NMR(101MHz,Chloroform-d)178.3,156.2,79.5,39.8,31.3,28.4,25.1.

[0122] Example 11:

[0123] A method for the photocatalytic carboxylation of unsaturated hydrocarbons, specifically the photocatalytic synthesis of di-tert-butylbut-2-ene-1,4-diyl(E)-dicarbamate and formate.

[0124] The synthesis of 4-((tert-butoxycarbonyl)amino)-2-(((tert-butoxycarbonyl)amino)methyl)butanoic acid includes the following steps:

[0125] In a glove box under N2 atmosphere, lithium formate (0.5 mmol) was added to a dry Schlenk tube containing photocatalyst Ni / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to an N2 cylinder. The cap was loosened, and the tube was purged with N2 three times to fill it with N2 gas. Under N2 atmosphere, di-tert-butylbut-2-ene-1,4-diyl(E)-dicarbamate (0.2 mmol) and DMSO (3 mL) were added, the tube was sealed, and the mixture was stirred at 60 °C. After reacting for 12 h under a 30 W 450 nm Blue LED light source, the mixture was cooled to room temperature. The reaction mixture was quenched with 2 N hydrochloric acid, and then extracted five times with ethyl acetate. The organic phases were combined, and residual solvent was completely removed by rotary evaporation. After rotary evaporation, silica gel and solvent were added, the mixture was rotary evaporated, and the sample was loaded. The product was purified by column chromatography, and the chemical yield was calculated to be 73%.

[0126] The structural formula of the above-mentioned di-tert-butyl but-2-ene-1,4-diyl(E)-dicarbamate is as follows:

[0127]

[0128] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0129]

[0130] 1 H NMR (400MHz, DMSO-d6) δ12.19(s,1H),6.82(t,J=5.9Hz,1H),6.77(t,J=5.6Hz,1H),3.1 6–3.06(m,1H), δ3.03–2.97(m,1H),2.97–2.79(m,3H),1.59–1.48(m,2H),1.36(s,18H). 13 C NMR (101MHz, DMSO-d6) δ175.2,155.6,155.5,77.7,77.5,43.1,41.8,38.1,29.4,28.3,28.2.

[0131] Example 12:

[0132] A method for the photocatalytic carboxylation reaction of unsaturated hydrocarbons, specifically the photocatalytic synthesis of succinic acid from acetylene and formate, includes the following steps:

[0133] In a glove box under N2 atmosphere, lithium formate (1 mmol) was added to a dry Schlenk tube containing the photocatalyst Ti3C2 / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to an acetylene cylinder. The cap was loosened, and the tube was purged and purged three times to replace the acetylene gas, filling the tube with acetylene gas. DMSO (7 mL) was added under an acetylene atmosphere, the tube was sealed, and the mixture was stirred at 60°C. After reacting for 3 hours under 30W 450nm Blue LED illumination, the mixture was cooled to room temperature. The reaction mixture was quenched with TFA, and 0.2 mmol of mesitylene was added as an internal standard. d6 As a deuteration reagent, the NMR yield was 48%.

[0134] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0135]

[0136] 1 H NMR (400MHz, DMSO-d6) δ12.13(s,2H),2.41(s,4H).

[0137] 13 C NMR(101MHz,DMSO-d6)δ173.7,28.8.

[0138] Example 13:

[0139] A method for the carboxylation reaction of unsaturated hydrocarbons via photocatalysis, specifically the photocatalytic synthesis of methylsuccinic acid from propyne and formate, comprising the following steps:

[0140] In a glove box under N2 atmosphere, lithium formate (1 mmol) was added to a dry Schlenk tube containing the photocatalyst Ti3C2 / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to an N2 cylinder. The cap was loosened, and the tube was purged and purged three times to fill it with N2 gas. Propylene (1 mmol / L) and DMF (1 mL) were added under N2 atmosphere. The tube was sealed and stirred at 60°C. After reacting for 3 hours under 30W 450nm Blue LED illumination, the mixture was cooled to room temperature. The reaction mixture was quenched with TFA, and 0.2 mmol of mesitylene (DMSO) was added as an internal standard. d6 As a deuteration reagent, the NMR yield was 24%.

[0141] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0142]

[0143] 1 H NMR (400MHz, DMSO-d6) δ12.15 (s, 2H), 2.67 (m, 1H), 2.50 (m, 1H), δ2.3 (dd, J = 16.7, 5.7Hz, 1H)., 1.10 (d, J = 7.2Hz, 3H). 13 C NMR (101MHz, DMSO-d6) δ176.5,173.1,37.3,35.3,16.9.

[0144] Example 14:

[0145] A method for the carboxylation reaction of unsaturated hydrocarbons via photocatalysis, specifically the photocatalytic synthesis of dimethyl2-(2-([1,1'-biphenyl]-4-yl)ethyl)succinate from 4-(but-3-yn-1-yl)-1,1'-biphenyl and formate, comprising the following steps:

[0146] In a glove box under N2 atmosphere, lithium formate (0.6 mmol) was added to a dry Schlenk tube containing the photocatalyst Ti3C2 / CdS (10 mg) and a stir bar. The Schlenk tube was sealed and removed from the glove box and connected to a double-row tube connected to an N2 cylinder. The cap was loosened and the tube was purged with N2 three times to fill it with N2 gas. 4-(but-3-yn-1-yl)-1,1'-biphenyl (0.2 mmol) and DMSO (3 mL) were added under N2 atmosphere. The tube was sealed and stirred at 60 °C. After reacting for 12 h under 30 W 450 nm Blue LED light, 0.8 mmol MeI was added to the reaction mixture at 65 °C and stirred for 3 h. After cooling to room temperature, 2 mL of deionized water was added, and the reaction mixture was extracted five times with ethyl acetate. The organic phases were combined and the residual solvent was completely removed by rotary evaporation. After evaporation, silica gel and solvent were added for column chromatography, and the mixture was evaporated again before loading. The product was then separated and purified by column chromatography to obtain the desired pure product. The chemical yield was calculated to be 43%.

[0147] The structural formula of the above-mentioned di-tert-butyl but-2-ene-1,4-diyl(E)-dicarbamate is as follows:

[0148]

[0149] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0150]

[0151] 1 H NMR(400MHz,Chloroform-d)δ7.57(d,J=6.9Hz,2H),7.51(d,J=8.1Hz,2H),7.42(t,J=7.6Hz,2H),7.35–7.28(m,1H),7.24(d,J=7.9Hz,2H),3.72(s,3H ),3.67(s,3H),2.98–2.87(m,1H),2.78(dd,J=16.4,9.1Hz,1H),2.75–2.56 (m,2H),2.50(dd,J=16.5,5.3Hz,1H),2.10–1.96(m,1H),1.93–1.79(m,1H). 13C NMR(101MHz,Chloroform-d)δ175.3,172.4,141.1,140.3,139.2,128.9,128.8,127.3,127.2,127.1,52.0,51.9,40.9,36.0,33.6,32.9

[0152] Example 15:

[0153] A method for the photocatalytic carboxylation reaction of unsaturated hydrocarbons, specifically the photocatalytic synthesis of 2-decylsuccinic acid from dodecyne and formate, includes the following steps:

[0154] In a glove box under N2 atmosphere, lithium formate (0.6 mmol) was added to a dry Schlenk tube containing the photocatalyst Ti3C2 / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to an N2 cylinder. The cap was loosened, and the tube was purged with N2 three times to fill it with N2 gas. Dodecylene (0.2 mmol) and DMSO (3 mL) were added under N2 atmosphere, the tube was sealed, and stirred at 60 °C. The reaction was carried out for 12 h under 30 W 450 nm Blue LED light source. After cooling to room temperature, the reaction mixture was quenched with 2 N hydrochloric acid, followed by extraction with ethyl acetate five times. The organic phases were combined, and residual solvent was completely removed by rotary evaporation. After rotary drying, silica gel and solvent were added for column chromatography, and the mixture was loaded onto a dry plate. The product was purified by column chromatography to obtain the desired pure product, with a calculated chemical yield of 39%.

[0155] The structural formula of the above-mentioned dodecanyne is as follows:

[0156]

[0157] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0158]

[0159] 1 H NMR (400MHz, DMSO-d6) δ12.18(s,2H),2.64–2.40(m,2H),2.36–2.26(m,1H),1.57–1.34(m,2H),1.23(s,16H),0.85(t,J=6.8Hz,3H). 13CNMR(101MHz,DMSO-d6)δ176.1,173.2,40.7,35.7,31.3,31.3,29.0,29.0,28.9,28.9,28.7,26.4,22.1,14.0.

[0160] Example 16:

[0161] A method for the photocatalytic carboxylation of unsaturated hydrocarbons, specifically the photocatalytic synthesis of adipic acid from 1,3-butadiene and formate, includes the following steps:

[0162] In a glove box under N2 atmosphere, cesium formate (1 mmol) was added to a dry Schlenk tube containing the photocatalyst Ni / Ti3C2 / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to a 1,3-butadiene cylinder. The cap was loosened, and the double-row tube was purged and purged three times to replace the 1,3-butadiene gas, filling the tube completely. DCE (7 mL) was added under a 1,3-butadiene atmosphere, the tube was sealed, and the mixture was stirred at 60°C. After reacting for 12 h under 30W 425nm Blue LED illumination, the mixture was cooled to room temperature. The reaction mixture was quenched with TFA, and 0.2 mmol of mesitylene (DMSO) was added as an internal standard. d6 As a deuteration reagent, the NMR yield was 29%.

[0163] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0164]

[0165] 1 H NMR (400MHz, DMSO-d6) δ12.00(s,2H),2.27–2.13(m,4H),1.56–1.42(m,4H). 13 CNMR(101MHz,DMSO-d6)δ174.4,33.4,24.0.

[0166] Example 17:

[0167] A method for the carboxylation reaction of unsaturated hydrocarbons via photocatalysis, specifically the photocatalytic synthesis of succinic acid from ethylene, CO2, and formate, comprising the following steps:

[0168] In a glove box under N2 atmosphere, cesium formate (1 mmol) and cesium carbonate (2.0 mmol) were added to a dry Schlenk tube containing the photocatalyst Ti3C2 / CdS (10 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to an ethylene cylinder. The cap was loosened, and the tube was purged and purged three times to replace the ethylene gas, filling it with ethylene gas. DMSO (7 mL) was added as solvent under an ethylene atmosphere, followed by additional CO2 gas. The mixture was stirred at room temperature and reacted for 12 h under 50W 450nm Blue LED illumination. The reaction mixture was then quenched with TFA, and 0.2 mmol of mesitylene was added as an internal standard. d6 As a deuteration reagent, the NMR yield was 11%.

[0169] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0170]

[0171] 1 H NMR (400MHz, DMSO-d6) δ12.13(s,2H),2.41(s,4H).

[0172] 13 C NMR(101MHz,DMSO-d6)δ173.7,28.8.

[0173] Example 18:

[0174] A method for the carboxylation reaction of unsaturated hydrocarbons via photocatalysis, specifically the photocatalytic synthesis of 2-decylsuccinic acid from dodecene, CO2, and formate, comprising the following steps:

[0175] In a glove box under N2 atmosphere, cesium formate (0.5 mmol) and cesium carbonate (0.3 mmol) were added to a dry Schlenk tube containing the photocatalyst Ti3C2 / CdS (8 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to a CO2 cylinder. The cap was loosened, and the double-row tube was purged with CO2 three times to fill it with CO2 gas. Dodecene (0.2 mmol) and DMSO (6 mL) were added under CO2 atmosphere, the tube was sealed, and stirred at 35°C. The reaction was carried out for 48 h under a 50W 450nm Blue LED light source. After cooling to room temperature, the reaction mixture was quenched with 2N hydrochloric acid, followed by extraction with ethyl acetate five times. The organic phases were combined, and residual solvent was completely removed by rotary evaporation. After rotary drying, silica gel and solvent were added for column chromatography, and the mixture was loaded onto a dry plate. The product was purified by column chromatography to obtain the desired pure product, with a calculated chemical yield of 72%.

[0176] The structural formula of the above-mentioned dodecene is as follows:

[0177]

[0178] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0179]

[0180] 1 H NMR (400MHz, DMSO-d6) δ12.18(s,2H),2.64–2.40(m,2H),2.36–2.26(m,1H),1.57–1.34(m,2H),1.23(s,16H),0.85(t,J=6.8Hz,3H). 13 CNMR(101MHz,DMSO-d6)δ176.1,173.2,40.7,35.7,31.3,31.3,29.0,29.0,28.9,28.9,28.7,26.4,22.1,14.0.

[0181] Example 19:

[0182] A method for the photocatalytic carboxylation of unsaturated hydrocarbons, specifically involving the photocatalytic synthesis of 2-(3-(9H-carbazol-9-yl)propyl)succinic acid from 9-(pent-4-en-1-yl)-9H-carbazole, CO2, and formate, comprises the following steps:

[0183] In a glove box under N2 atmosphere, cesium formate (0.5 mmol) and cesium carbonate (0.3 mmol) were added to a dry Schlenk tube containing the photocatalyst Ti3C2 / CdS (8 mg) and a stir bar. The Schlenk tube was sealed and removed from the glove box and connected to a double-row tube connected to a CO2 cylinder. The cap was loosened and the double-row tube was purged with CO2 three times to fill the tube with CO2 gas. 9-(pent-4-en-1-yl)-9H-carbazole (0.2 mmol) and DMSO (6 mL) were added under CO2 atmosphere. The tube was sealed and stirred at 35 °C. After reacting for 48 h under 50 W 450 nm Blue LED light source, the mixture was cooled to room temperature. The reaction mixture was quenched with 2 N hydrochloric acid and then extracted five times with ethyl acetate. The organic phases were combined and the residual solvent was completely removed by rotary evaporation. After evaporation, silica gel and solvent were added for column chromatography, and the mixture was evaporated again before loading. The product was then separated and purified by column chromatography to obtain the desired pure product. The chemical yield was calculated to be 77%.

[0184] The structural formula of 9-(pent-4-en-1-yl)-9H-carbazole is as follows:

[0185]

[0186] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0187]

[0188] 1 H NMR (400MHz, DMSO-d6) δ12.27(s,2H),8.14(d,J=7.7Hz,2H),7.59(d,J=8.2Hz,2H),7.49–7.39(m,2H),7.19(t,J=7. 4Hz,2H),4.46–4.25(m,2H),2.68–2.39(m,2H),2.30(dd,J=16.7,4.9Hz,1H),1.84–1.72(m,2H),1.69–1.47(m,1H). 13 C NMR (101MHz, DMSO-d6) δ176.3,173.5,140.4,126.2,122.5,120.7,119.2,109.7,42.5,36.1,29.3,26.6.

[0189] Example 20:

[0190] A method for the photocatalytic carboxylation reaction of unsaturated hydrocarbons, specifically the photocatalytic synthesis of 2-(3-methoxy-3-oxopropyl)succinic acid from methyl pent-4-enoate, CO2, and formate, includes the following steps:

[0191] In a glove box under N2 atmosphere, cesium formate (0.5 mmol) and cesium carbonate (0.3 mmol) were added to a dry Schlenk tube containing the photocatalyst Ti3C2 / CdS (8 mg) and a stir bar. The Schlenk tube was sealed, removed from the glove box, and connected to a double-row tube connected to a CO2 cylinder. The cap was loosened, and the double-row tube was purged with CO2 three times to fill it with CO2 gas. Methyl pent-4-enoate (0.2 mmol) and DMSO (6 mL) were added under CO2 atmosphere, the tube was sealed, and the mixture was stirred at 35°C. After reacting for 48 h under a 50W 450nm Blue LED light source, the mixture was cooled to room temperature. The reaction mixture was quenched with 2N hydrochloric acid, and then extracted five times with ethyl acetate. The organic phases were combined, and residual solvent was completely removed by rotary evaporation. After rotary drying, silica gel and solvent were added, the mixture was rotary dried again, and the sample was loaded. Column chromatography was used for separation and purification to obtain the desired pure product. The chemical yield was calculated to be 76%.

[0192] The structural formula of the above methyl pent-4-enoate is as follows:

[0193]

[0194] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0195]

[0196] 1 H NMR (400MHz, DMSO-d6) δ12.26(s,2H),3.58(s,3H),2.68–2.52(m,1H),2.48–2.30(m,4H),1.85–1.64(m,2H). 13 C NMR (101MHz, DMSO-d6) δ175.5,173.0,172.8,51.4,35.5,31.0,26.4,21.1.

[0197] Example 21:

[0198] A method for the photocatalytic carboxylation of unsaturated hydrocarbons, specifically the photocatalytic synthesis of 2-(3-((2,2,3,3-tetramethylcyclopropane-1-carboxylate), CO2, and formate into 2-(3-((2,2,3,3-tetramethylcyclopropane-1-carbonyl)oxy)propyl)succinic acid, includes the following steps:

[0199] In a glove box under N2 atmosphere, cesium formate (0.5 mmol) and cesium carbonate (0.3 mmol) were added to a dry Schlenk tube containing the photocatalyst Ti3C2 / CdS (8 mg) and a stir bar. The Schlenk tube was sealed and removed from the glove box and connected to a double-row tube connected to a CO2 cylinder. The cap was loosened and the double-row tube was purged with CO2 three times to fill the tube with CO2 gas. Pent-4-en-1-yl 2,2,3,3-tetramethylcyclopropane-1-carboxylate (0.2 mmol) and DMSO (6 mL) were added under CO2 atmosphere. The tube was sealed and stirred at 35 °C. After reacting for 48 h under 50 W 450 nm Blue LED light source, the reaction mixture was cooled to room temperature and quenched with 2 N hydrochloric acid. The reaction mixture was then extracted five times with ethyl acetate. The organic phases were combined and the residual solvent was completely removed by rotary evaporation. After rotary evaporation, silica gel and solvent were added for column chromatography, and the mixture was rotary evaporated and loaded with the sample. The product was then separated and purified by column chromatography to obtain the desired pure product. The chemical yield was calculated to be 81%.

[0200] The structural formula of the above-mentioned pent-4-en-1-yl 2,2,3,3-tetramethylcyclopropane-1-carboxylate is as follows:

[0201]

[0202] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0203]

[0204] 1H NMR (400MHz, DMSO-d6) δ12.21(s,2H),3.98–3.90(m,2H),2.67–2.56(m,1H),2.48(dd,J=16.7,9. 0Hz,1H),2.34(dd,J=16.6,5.1Hz,1H),1.63–1.41(m,4H),1.22(s,1H),1.16(s,6H),1.15(s,6H). 13 C NMR (101MHz, DMSO-d6) δ175.8,173.1,171.2,63.0,35.6,34.8,29.3,27.9,25.9,23.1,16.4.

[0205] Example 22:

[0206] A method for the carboxylation reaction of unsaturated hydrocarbons via photocatalysis, specifically involving the photocatalytic synthesis of 2-(2-(2-oxobenzo[d]oxazol-3(2H)-yl)ethyl)succinic acid from 3-(but-3-en-1-yl)benzo[d]oxazol-2(3H)-one, CO2, and formate, comprising the following steps:

[0207] In a glove box under N2 atmosphere, cesium formate (0.5 mmol) and cesium carbonate (0.3 mmol) were added to a dry Schlenk tube containing the photocatalyst Ti3C2 / CdS (8 mg) and a stir bar. The Schlenk tube was sealed and removed from the glove box and connected to a double-row tube connected to a CO2 cylinder. The cap was loosened and the double-row tube was purged with CO2 three times to fill the tube with CO2 gas. 3-(but-3-en-1-yl)benzo[d]oxazol-2(3H)-one (0.2 mmol) and DMSO (6 mL) were added under CO2 atmosphere. The tube was sealed and stirred at 35 °C. After reacting for 48 h under 50 W 450 nm Blue LED light source, the mixture was cooled to room temperature. The reaction mixture was quenched with 2 N hydrochloric acid and then extracted with ethyl acetate five times. The organic phases were combined and the residual solvent was completely removed by rotary evaporation. After evaporation, silica gel and solvent were added for column chromatography, and the mixture was evaporated again before loading. The product was then separated and purified by column chromatography to obtain the desired pure product. The chemical yield was calculated to be 66%.

[0208] The above-mentioned 3-(but-3-en-1-yl)benzo[d]oxazol-2(3H)-one structural formula is as follows:

[0209]

[0210] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0211]

[0212] 1 H NMR (400MHz, DMSO-d6) δ12.34(s,2H),7.33(d,J=7.8Hz,1H),7.28(d,J=7.7Hz,1H),7.27–7.18(m,1H),7.13(td,J= 7.7,1.4Hz,1H),3.90–3.84(m,2H),2.73–2.58(m,1H),2.54(t,J=6.9Hz,2H),2.08–1.95(m,1H),1.93–1.77(m,1H). 13 C NMR (101MHz, DMSO-d6) δ175.3,173.0,153.7,142.0,130.9,123.9,122.3,109.7,109.1,39.8,38.1,35.3,28.8.

[0213] Example 23:

[0214] A method for the photocatalytic carboxylation of unsaturated hydrocarbons, specifically the photocatalytic synthesis of tert-butyl4-methylenepiperidine-1-carboxylate, CO2, and formate.

[0215] The synthesis of 1-(tert-butoxycarbonyl)-4-(carboxymethyl)piperidine-4-carboxylicacid includes the following steps:

[0216] In a glove box under N2 atmosphere, cesium formate (0.5 mmol) and cesium carbonate (0.3 mmol) were added to a dry Schlenk tube containing the photocatalyst Ti3C2 / CdS (8 mg) and a stir bar. The Schlenk tube was sealed and removed from the glove box and connected to a double-row tube connected to a CO2 cylinder. The cap was loosened and the double-row tube was purged with CO2 three times to fill the tube with CO2 gas. Under CO2 atmosphere, tert-butyl 4-methylenepiperidine-1-carboxylate (0.2 mmol) and DMSO (6 mL) were added, the tube was sealed, and the mixture was stirred at 35 °C. After reacting for 48 h under 50 W 450 nm Blue LED light source, the mixture was cooled to room temperature. The reaction mixture was quenched with 2 N hydrochloric acid and then extracted with ethyl acetate five times. The organic phases were combined and the residual solvent was completely removed by rotary evaporation. After rotary evaporation, silica gel and solvent were added for column chromatography, and the mixture was rotary evaporated and loaded with the sample. The product was then separated and purified by column chromatography to obtain the desired pure product. The chemical yield was calculated to be 69%.

[0217] The structural formula of the above tert-butyl 4-methylenepiperidine-1-carboxylate is as follows:

[0218]

[0219] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0220]

[0221] 1 H NMR (400MHz, DMSO-d6) δ12.36(s,2H),3.53–3.42(m,2H),3.23–3.10(m,2H),2.51(s,2H),1.93–1.81(m,2H),1.56–1.41(m,2H),1.38(s,9H). 13 C NMR (101MHz, DMSO-d6) δ176.3,172.1,153.9,78.7,42.1,41.7,32.4,31.3,28.1.

[0222] Example 24:

[0223] A method for the photocatalytic carboxylation of unsaturated hydrocarbons, specifically involving the photocatalytic synthesis of 2-(3-((3,7-dimethyloct-6-en-1-yl pent-4-enoate), CO2, and formate, comprises the following steps:

[0224] In a glove box under N2 atmosphere, cesium formate (0.5 mmol) and cesium carbonate (0.3 mmol) were added to a dry Schlenk tube containing the photocatalyst Ti3C2 / CdS (8 mg) and a stir bar. The Schlenk tube was sealed and removed from the glove box and connected to a double-row tube connected to a CO2 cylinder. The cap was loosened and the double-row tube was purged with CO2 three times to fill the tube with CO2 gas. 3,7-dimethyloct-6-en-1-yl pent-4-enoate (0.2 mmol) and DMSO (6 mL) were added under CO2 atmosphere. The tube was sealed and stirred at 35 °C. After reacting for 48 h under 50 W 450 nm Blue LED light source, the mixture was cooled to room temperature. The reaction mixture was quenched with 2 N hydrochloric acid and then extracted five times with ethyl acetate. The organic phases were combined and the residual solvent was completely removed by rotary evaporation. After rotary evaporation, silica gel and solvent for column chromatography were added, and the mixture was rotary evaporated and loaded with the sample. The product was then separated and purified by column chromatography to obtain the desired pure product. The chemical yield was calculated to be 82%.

[0225] The structural formula of the above 3,7-dimethyloct-6-en-1-yl pent-4-enoate is as follows:

[0226]

[0227] The product obtained in this invention was characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The NMR and MS data were consistent with the obtained product. Specific characterization data are as follows:

[0228]

[0229] 1H NMR(400MHz, DMSO-d6)δ12.30(s,2H),5.07(t,J=6.8Hz,1H),4.10–3.96(m,2H),2.68–2.56(m,1H),2.48–2.34(m,2H),2.36–2.27(m ,2H),2.03–1.87(m,2H),1.83–1.66(m,2H),1.63(s,3H),1.55(s,3H),1.51–1.24(m,4H),1.18–1.04(m,1H),0.86(d,J=6.6Hz,3H). 13 C NMR (101MHz, DMSO-d6) δ175.6,173.1,172.4,130.7,124.6,62.3,40.0,36.5,35.5,35.0,31.3,28.9,26.5,25.6,24.9,19.3,17.6.

[0230] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of photocatalyzing a carboxylation reaction of an unsaturated hydrocarbon, characterized by, The method comprises the following steps: (1) adding a sulfur-containing photocatalyst and a formate into a solvent to obtain solution A; (2) adding an unsaturated hydrocarbon compound into solution A to obtain solution B; (3) irradiating solution B with a light source to make the unsaturated hydrocarbon compound and the formate undergo a carboxylation reaction to obtain a carboxylic acid compound.

2. The method of photocatalyzing carboxylation of unsaturated hydrocarbons according to claim 1, wherein The mass ratio of the sulfur-containing photocatalyst to lithium formate is 5-15:20-200; the temperature during the carboxylation reaction is 30-80 DEG C, and the reaction time is 1-60 h; the sulfur-containing photocatalyst is a sulfur-containing metal-doped quantum dot.

3. The method of photocatalytic carboxylation of unsaturated hydrocarbons according to claim 1 or 2, characterized in that, The sulfur-containing metal-doped quantum dot is Ni / CdS, Co / CdS, Fe / CdS, Cu / CdS, Ru / CdS, Ti3C2 / CdS, Ni / Ti3C2 / CdS, CdS nanosheet or CdS nanoflower.

4. The method of photocatalyzing carboxylation of unsaturated hydrocarbons according to claim 1, wherein The formate is at least one of lithium formate, sodium formate, potassium formate, cesium formate and ammonium formate; and the solvent is at least one of N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, acetonitrile, tetrahydrofuran, cyclohexane and dichloroethane.

5. The method of photocatalyzing carboxylation of unsaturated hydrocarbons according to claim 1, wherein The unsaturated hydrocarbon compound is an unsaturated olefin or an unsaturated alkyne.

6. The method of photocatalyzing carboxylation of unsaturated hydrocarbons according to claim 5, wherein The unsaturated olefin has the following structural formula: R, R', R" and R'" are each hydrogen, C 1-20 alkyl, alkenyl or substituted alkenyl, aryl or substituted aryl, ester or substituted ester, amide or substituted amide, amine or substituted amine, halogen; R, R', R" and R'" are the same or different; Unsaturated alkyne is wherein R 1 is hydrogen, C 1-20 alkyl.

7. The method of photocatalyzing carboxylation of unsaturated hydrocarbons according to claim 6, wherein The unsaturated olefin is ethylene, propylene, butylene, 1, 3-butadiene or the unsaturated olefin having the following structural formula: The unsaturated alkyne is acetylene, propyne or the unsaturated alkyne having the following structure:

8. The method of photocatalyzing carboxylation of unsaturated hydrocarbons according to claim 1, wherein The light source is sunlight, an LED lamp, a medium-arc mercury lamp, a high-pressure mercury lamp or a xenon lamp.

9. The method of photocatalyzing carboxylation of unsaturated hydrocarbons according to claim 1, wherein In the reaction system, CO2 and a basic substance are further added, and the unsaturated hydrocarbon compound is carboxylated to obtain a dicarboxylic acid compound.

10. The method of photocatalyzing carboxylation of unsaturated hydrocarbons according to claim 9, wherein The basic substance is at least one of lithium methoxide, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, lithium tert-butylate, sodium tert-butylate, potassium tert-butylate, sodium tert-amylate, lithium carbonate, sodium carbonate, potassium carbonate, cesium carbonate, cesium bicarbonate, cesium iodide and cesium acetate.

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