A method for synthesizing alkyl carboxylic acid compounds based on olefin hydrocarboxylation

Abstract

This invention discloses a method for synthesizing alkyl carboxylic acid compounds based on olefin hydrocarboxylation, belonging to the field of organic synthesis technology. The method mainly includes the following steps: adding an olefin compound, a photocatalyst, a base, and additives to a reaction vessel, and then... 2 A reducing agent and solvent are added under a certain atmosphere, and the reaction is stirred at 0-100°C for 0.1-100 h under light irradiation. The reaction product is then separated and purified to obtain a carboxylic acid compound. The preparation method of the present invention exhibits excellent reactivity for olefin substrates and has the advantages of convenient operation, inexpensive and readily available raw materials, mild reaction conditions, broad substrate applicability, and high product yield.

Description

A method for synthesizing alkyl carboxylic acid compounds based on olefin hydrocarboxylation Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a method for synthesizing alkyl carboxylic acid compounds based on olefin hydrogen carboxylation. Background Technology

[0002] The widespread existence of alkenes makes them very important in organic synthetic chemistry. A wide variety of compounds can be synthesized by functionalizing the double bonds of alkenes, and they are now widely used in fields such as medicinal chemistry, polymer chemistry and materials chemistry.

[0003] In recent years, thanks to the efforts of chemists, significant progress has been made in the hydrocarboxylation of activated alkenes, which has become an effective means of efficiently constructing complex compound molecules. However, due to the low reactivity of unactivated alkenes and the inherent chemical inertness of CO2, the hydrocarboxylation of unactivated alkenes still faces considerable challenges. In particular, the photocatalytic hydrocarboxylation of some commonly used industrial olefin gases (such as ethylene, propylene, butene, Fischer-Tropsch-Heptene, etc.) has not yet been successfully reported. Furthermore, the synthesis of various structurally diverse alkyl carboxylic acids of different chain lengths using this strategy is also a major challenge in this field. On the other hand, carbon dioxide, as a widely available, inexpensive, and renewable carbon-1 synthon, is widely used in various chemical syntheses. Therefore, providing a method for synthesizing carboxylic acid compounds by hydrocarboxylation of unactivated alkenes (excluding activated alkenes) using carbon dioxide is of great significance. Summary of the Invention

[0004] To address the aforementioned shortcomings, the present invention aims to provide a method for synthesizing alkyl carboxylic acid compounds based on olefin hydrocarboxylation. This method effectively fills the gap in existing research on the hydrocarboxylation reaction of non-activated olefins using visible light-catalyzed carbon dioxide. Furthermore, this method is characterized by convenient operation, readily available and inexpensive raw materials, mild reaction conditions, broad substrate applicability, and high product yield.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: to provide a method for synthesizing alkyl carboxylic acid compounds based on olefin hydrocarboxylation, the method comprising the following steps:

[0006] S1: Mix olefin compound, photocatalyst, base and additive, then add reducing agent and solvent under CO2 atmosphere to obtain reaction solution; the molar ratio of olefin compound, photocatalyst, base, reducing agent and additive is 1:0.0001~0.5:0.1~10:1~10:0.1~10;

[0007] S2: The reaction solution obtained in S1 is stirred at room temperature (0-100℃) under light irradiation for 0.1-100 h, and the reaction product is then acidified and purified to obtain alkyl carboxylic acid compounds.

[0008] The general structural formulas of olefin compounds are shown below:

[0009]

[0010] Wherein, R, R', R” and R”' are hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, ester, amide, cyano, carboxyl, carbonyl, acyloxy, alkoxy, aryloxy, siloxy, sulfonyloxy, phosphoxy, amino, substituted amino, mercapto, thioether, thioester, sulfonic acid, halogen, silyl, or boron; R, R', R” and R”' may be the same or different.

[0011] Based on the above technical solution, the present invention can be further improved as follows.

[0012] Furthermore, the olefin compound is one of the following compounds:

[0013]

[0014]

[0015] Furthermore, organic dyes or organometallic complexes.

[0016] Furthermore, the photocatalyst is a DA-type photocatalyst or an Ir-type photocatalyst.

[0017] Furthermore, the photocatalyst is at least one of 4CzIPN, 4DPAIPN, 3DPAFIPN, 3DPA2FBN, 5CzBN, 4CzPN, DPZ, 4CzPN-Ph, 4CzPN-Bu, 4CzTPN, 4CzTPN-Bu, Ir(dFCF3ppy)2(dtbbpy)PF6, fac-Ir(dF(ppy)3), fac-Ir(ppy)3 and Ir(ppy)2(dtbbpy)PF6; preferably fac-Ir(ppy)3.

[0018] Furthermore, the base is a tert-butoxide, carbonate, bicarbonate, fluoride, phosphate, hydrogen phosphate, carboxylate, or organic base.

[0019] Furthermore, tert-butoxide is a KO t Bu, NaO t Bu、LiO t Bu or Ca(O tBu)2; carbonates are Cs2CO3, K2CO3, Na2CO3 or Li2CO3; bicarbonates are CsHCO3, KHCO3 or NaHCO3; fluorides are CsF, KF, NaF or LiF; phosphates are K3PO4, Na3PO4 or Li3PO4; carboxylates are CsOAc, KOAc, NaOAc, CsOPiv, NaOPiv or KOPiv; organic bases are DBU, TBD, DABCO, TMG, DBN, TMEDA, Cy2NEt, Cy2NMe, PMP, NBu3, NMe3 or NET3.

[0020] Furthermore, the reducing agent is an organic amine compound.

[0021] Furthermore, the organic amine compounds are DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene), DABCO (N,N-dimethylethanolamine), TMG (1,1,3,3-tetramethylguanidine), DBN (1,5-diazabicyclo[4.3.0]non-5-ene), i Pr2NEt (N,N-diisopropylethylamine), TMEDA (tetramethylethylenediamine), Cy2NEt, Cy2NMe, PMP (1-phenyl-3-methyl-5-pyrazolone), NBu3, NMe3, or NEt3; preferably i Pr2NEt.

[0022] Furthermore, the additives are quaternary ammonium salt compounds.

[0023] Furthermore, the quaternary ammonium salt compound is TBAC (tetrabutylammonium chloride), TBAB (tetrabutylammonium bromide), TBAI (tetrabutylammonium iodide), TBAF (tetrabutylammonium fluoride), TBAClO4 (tetrabutylammonium perchlorate), TBAN3 (tetrabutylammonium azide), TBAAc (tetrabutylammonium acetate), TPAPF6 (tetrabutylammonium hexafluorophosphate) or TBABF4 (tetrabutylammonium tetrafluoroborate); preferably TBAC.

[0024] Furthermore, the wavelength of visible light is 300–700 nm, the power of visible light is 0.1–60 W, and the pressure of the CO2 atmosphere is 0.1–30 times atmospheric pressure.

[0025] Furthermore, the solvent is NMP, DMSO, DMF, DMAc, THF, DCM, MeOH, or MeCN; preferably NMP. The solvent concentration is 0.01-10.0M.

[0026] The reaction formula of this invention is as follows:

[0027]

[0028] Wherein, R, R, R” and R”’ are functional groups such as hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, ester, amide, cyano, carboxyl, carbonyl, acyloxy, alkoxy, aryloxy, siloxy, sulfonyloxy, phosphoxy, amino, substituted amino, mercapto, thioether, thioester, sulfonic acid, halogen, silyl or boron; R, R’, R” and R”’ can be the same or different.

[0029] The reaction mechanism of this invention is shown in Figure 1. The specific process is as follows: using Ir III Taking catalysts as an example; firstly, photoexcitation of Ir... III Catalyst generation [Ir III ] * Species, further under the action of light, reduce carbon dioxide to carbon dioxide free radical anions and Ir. IV Species, Ir IV The species is then reduced to Ir by the electron reducing agent. III The species completes catalytic cycle regeneration; the resulting carbon dioxide radical anions undergo radical addition to olefins, generating alkyl carbon radical intermediates (I); subsequently from... i Pr2NEt ·+ Hydrogen atoms are extracted from the solvent; after acidification, the target alkyl carboxylic acid derivative is obtained.

[0030] The beneficial effects of this invention are:

[0031] 1. This invention provides a method for synthesizing alkyl carboxylic acid compounds based on olefin hydrocarboxylation. Under visible light catalysis, olefin compounds are used as reaction substrates, carbon dioxide is used as the carboxylic acid source, and photocatalysts, reducing agents, bases and additives are added simultaneously to obtain carboxylic acid compounds. This method is characterized by convenient operation and inexpensive and readily available raw materials.

[0032] 2. The preparation method of the present invention exhibits excellent reactivity for olefin substrates, realizes the olefin hydrocarboxylation reaction, and has the characteristics of mild reaction conditions, broad substrate versatility, and high product yield. Attached Figure Description

[0033] Figure 1 is a reaction mechanism diagram of the present invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments.

[0035] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0036] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0037] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0038] Example 1

[0039] A method for synthesizing alkyl carboxylic acid compounds based on olefin hydrocarboxylation, the specific process of which is as follows:

[0040] After drying a 25 mL Schlenk reaction tube equipped with a stirrer under vacuum, add 0.2 mmol of olefin (if it is a solid substrate, add it at this stage; if it is a liquid substrate, add it via syringe after adding the solvent) and the photocatalyst fac-Ir(ppy)3 (1 mol%). Then place the tube in a glove box and add 3 equivalents of... t After adding 1.5 equivalents of TBAC, the tube was sealed and removed from the glove box. The tube was then subjected to three purging cycles under a double-row CO2 atmosphere. After purging, 1.5 equivalents of DIPEA (N,N-diisopropylethylamine) and 2 mL of NMP (ultra-dry solvent) were added under a CO2 stream. After adding the solvent, the tube was sealed and placed 1 cm away from 30W blue (wavelength 400–480 nm) LEDs. The mixture was stirred at 50°C for 48 h. After the reaction was complete, 2 mL of 2NHCl and 3 mL of ethyl acetate were added, and the mixture was stirred for 5 min. The mixture was then extracted six times with ethyl acetate. The combined organic phases were transferred to a separatory funnel and washed with 10 mL of water. The organic phase was then evaporated to dryness using a rotary evaporator. The solid residue was separated by silica gel column chromatography to obtain the target product, an alkyl carboxylic acid. Specific results are as follows:

[0041]

[0042]

[0043]

[0044] Note: All results above are separation results. [a] represents a reaction time of 72 h, [b] represents a 10 mmol scale, [c] represents the use of 0.5 mol% fac-Ir(ppy) 3, 2 equivalents of DIPEA, and a reaction temperature of 60 degrees Celsius. [d] represents the use of 2 equivalents of DIPEA and a reaction temperature of 60 degrees Celsius.

[0045] The experimental results above demonstrate that olefin substrates modified with different substituents, including electron-rich, electron-poor, and electron-neutral groups, are compatible, and all can yield the target hydrocarboxylated product in moderate to high yields. A variety of functional groups or substituents are compatible in this reaction system, including fluorine, methyl, methoxy, ester, phenyl, and amide groups. Furthermore, the system is also compatible with cholesterol, menthol-derived long-chain alkenes, and aryl-substituted alkenes, with excellent reaction performance.

[0046] Example 2

[0047] A method for synthesizing alkyl carboxylic acid compounds based on olefin hydrocarboxylation, the specific process of which is as follows:

[0048] After drying a 25 mL Schlenk reaction tube equipped with a stirrer under vacuum, the photocatalyst fac-Ir(ppy)3 (1 mol%, 1.3 mg) was added. The tube was then placed in a glove box and the following steps were taken: t After buOK (68mg), the tube was sealed and removed from the glove box. The tube was then subjected to three purging cycles under a CO2 atmosphere with a double-row tube. After purging, DIPEA (N,N-diisopropylethylamine, 50µL) and 2mL NMP were added under a CO2 atmosphere. After the solvent was added, a gaseous olefin at 2 atm was added. The tube was then sealed and placed 1cm away from a 30W blue LED. The mixture was stirred at 50°C for 48h. After the reaction was complete, 2mL of 2N HCl and 3mL of ethyl acetate were added, and the mixture was stirred for 5min. The target product was then detected by ESI-MS and quantitatively analyzed by GC. The specific results are as follows:

[0049]

[0050] Note: 'a' represents results obtained through low-resolution detection, and 'b' represents results obtained through GC quantification.

[0051] The experimental results above indicate that gaseous olefins can also be compatible with the formation of corresponding carboxylic acids in this system, which has certain application potential for industrial applications.

[0052] Example 3

[0053] This study used 5-([1,1'-biphenyl]-4-yl)valeric acid as a template substrate and investigated the effect of changing reaction conditions on the reaction yield. The specific process is as follows:

[0054]

[0055] Note: All yields mentioned above are separation yields.

[0056] The experimental results above show that the separation yield of the corresponding carboxylic acid is as high as 72% under the reaction conditions of this invention. A series of control experiments indicate that photocatalyst, light, and carbon dioxide are all essential; the target product cannot be obtained without any of them. NMP, t Buok and DIPEA significantly promote the reaction. The yield decreases significantly when other photocatalysts, solvents, bases, or reducing agents are used.

[0057] The product obtained by 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:

[0058] 5-([1,1'-biphenyl]-4-yl)valeric acid (1a)

[0059]

[0060] 1 H NMR(400MHz, DMSO-d6)δ7.66–7.60(m,2H),7.61–7.52(m,2H),7.51–7.40(m,2H), 7.37–7.31(m,1H),7.30–7.24(m,2H),2.62(t,J=7.3Hz,2H),2.24(t,J=7.1Hz,2H),1.69– 1.48(m,4H); 13 C NMR(101MHz,DMSO-d6)δ175.10,141.81,140.60,138.09,129.35,127.60, 127.02,126.94,34.91,34.13,30.84,24.68; HRMS(ESI-):calculated forC 17 H 17 O2 - [MH] -253.1234, found 253.1232.

[0061] 5-(4-Fluorophenyl)valerate (1b)

[0062]

[0063] 1 H NMR (400MHz, CDCl3) δ7.15–7.06(m,2H),7.00–6.90(m,2H),2.67–2.52(m,2H),2.44–2.30(m,2H),1.73–1.58(m,4H); 13 C NMR (101MHz, CDCl3) δ179.79, 162.41, 159.99, 137.52 (d, J = 3.1Hz), 129.63 (d, J = 7 .9Hz),115.02(d,J=21.0Hz),34.68,33.84,30.86,24.13; HRMS(ESI-):calculated for C 11 H 12 FO2 - [MH] - 195.0827, found 195.0834.

[0064] 5-(4-Methoxyphenyl)valerate (1c)

[0065]

[0066] 1 HNMR (400MHz, CDCl3) δ7.14–7.00(m,2H),6.86–6.74(m,2H),3.78(s,3H),2.57(t,J= 6.9Hz,2H),2.42–2.30(m,2H),1.73–1.56(m,4H); 13 C NMR(101MHz, CDCl3)δ179.7,157.8, 134.1,129.3,113.8,55.3,34.6,33.9,31.0,24.2; HRMS(ESI-):calculated forC 12 H 15 O3 - [MH] - 207.1027, found 207.1027.

[0067] 5-Phenylanic acid (1d)

[0068]

[0069] 1 1H NMR (400 MHz, CDCl3) δ 7.30–7.24 (m, 2H), 7.22–7.13 (m, 3H), 2.71–2.56 (m, 2H), 2.42 –2.33 (m, 2H), 1.74–1.61 (m, J=3.8 Hz, 4H); 13 13C NMR (101 MHz, CDCl3) δ 180.06, 141.99, 128.37, 128.33, 125.81, 35.52, 33.91, 30.77, 24.26; HRMS (ESI-): calculated for C 11 H 13 O2 - [M-H] - 177.0921, found 177.0918.

[0070] 4-Phenylbutyric acid (1e)

[0071]

[0072] 1 1H NMR (400 MHz, CDCl3) δ 7.32–7.26 (m, 2H), 7.22–7.16 (m, 3H), 2.71–2.64 (m, 2H), 2.38 (t, J=7.4 Hz, 2H), 2.02–1.92 (m, 2H). 13 13C NMR (101 MHz, CDCl3) δ 179.82, 141.20, 128.50, 128.45, 35.00, 33.32, 26.22; HRMS (ESI-): calculated for C 10 H 11 O2 - [M-H] - 163.0765, found 163.0800. All analytical data are consistent with those reported in the literature.

[11]

[0073] 7-(9H-Carbazol-9-yl)heptanoic acid (1f)

[0074]

[0075] 1 H NMR (400MHz, CDCl3) δ8.13–8.06(m,2H),7.49–7.41(m,2H),7.40–7.34(m,2H),7.26 –7.17(m,2H),4.27(t,J=7.2Hz,2H),2.30(t,J=7.4Hz,2H),1.94–1.80(m,2H),1.65–1.51(m,2H),1.41–1.30(m,4H); 13 C NMR (101MHz, CDCl3) δ179.94,140.37,125.59,122.80, 120.35,118.74,108.60,42.88,33.87,28.78,28.77,26.95,24.45; HRMS ESI(-): calculated for C 19 H 20 NO2 - [MH] - 294.1500, found: 294.1496.

[0076] 4-(1,2,3,4-tetrahydronaphth-1-yl)butyric acid (1g)

[0077]

[0078] 2.45–2.27(m,2H),1.93–1.54(m,8H); 13 C NMR (101MHz, CDCl3) δ179.88,140.87,137.10, 129.15,128.52,125.59,37.35,36.23,34.24,29.68,27.32,22.56,19.77; HRMS (ESI-): calculated for C 14 H 17 O2 - [MH] - 217.1234, found 217.1238.

[0079] 5,5-Diphenylvaleric acid (1h)

[0080]

[0081] 1H NMR (400MHz, CDCl3) δ7.30–7.19(m,8H),7.19–7.12(m,2H),3.89(t,J=7.8Hz,1H), 2.36(t,J=7.4Hz,2H),2.15–2.02(m,2H),1.65–1.54(m,2H); 13 C NMR(101MHz, CDCl3)δ 179.79,144.66,128.53,127.82,126.26,51.17,34.97,33.96,29.75,23.22; HRMS(ESI-):calculated for C 17 H 17 O2 - [MH] - 253.1234, found 253.1236.

[0082] 4-Benzamido-4-phenylbutyric acid (1i)

[0083]

[0084] MP 145-156℃;

[0085] 1 H NMR (400MHz, DMSO-d6) δ12.14 (s, 1H), 8.81 (d, J = 8.3Hz, 1H), 7.92–7.84 (m, 2H), 7.56 –7.50(m,1H),7.50–7.44(m,2H),7.41–7.37(m,2H),7.37–7.30(m,2H),7. 27–7.20(m,1H),5.09–4.98(m,1H),2.36–2.20(m,2H),2.15–1.94(m,2H); 13 C NMR(101MHz,DMSO-d6)δ 174.51,166.36,144.15,134.89,131.62,128.71,128.65,127.78,127.21,126.86,52.97,31.56, 31.44; HRMS(ESI-): calculated for C 17 H 16 NO3 - [MH] - 282.1136, found 282.1137.

[0086] 6-(2-(thiophen-2-yl)ethoxy)hexanoic acid (1j)

[0087]

[0088] R f (PE / EA = 3:1) = 0.2 - 0.3;

[0089] 1 H NMR (400MHz, CDCl3) δ7.15–7.09(m,1H),6.95–6.89(m,1H),6.86–6.80(m,1H),3.65 (t,J=6.8Hz,2H),3.46(t,J=6.5Hz,2H),3.09(td,J=6.9,0.9Hz,2H),2.35(t,J=7.5Hz,2H),1.71–1.55(m,4H),1.47–1.35(m,2H); 13 C NMR(101MHz, CDCl3)δ179.65,141.35,126.60, 125.03,123.58,71.40,70.68,33.93,30.44,29.27,25.66,24.45; HRMS(ESI-):calculated for C 12 H 17 O3S - [MH] - 241.0904, found 241.0900.

[0090] (Z)-6-(hexadecane-3-ene-1-propoxy)hexanoic acid (1k)

[0091]

[0092] R f (PE / EA = 3:1) = 0.2 - 0.3;

[0093] 1 H NMR (400MHz, CDCl3) δ5.51–5.42(m,1H),5.38–5.29(m,1H),3.49–3.34(m,4H),2.40 –2.28(m,4H),2.11–2.01(m,2H),1.72–1.54(m,4H),1.47–1.36(m,2H),0.96(t,J=7.5Hz, 3H); 13C NMR(101MHz, CDCl3)δ179.48,133.60,124.78,70.53,70.52,33.92,29.31,27.77, 25.67,24.48,20.59,14.26; HRMS(ESI-):calculated for C 12 H 21 O3 - [MH] - 213.1496, found 213.1496.

[0094] 6-(cyclohexyloxy)hexanoic acid (1l)

[0095]

[0096] 1 H NMR(400MHz, CDCl3)δ3.44(t,J=6.6Hz,2H),3.25–3.14(m,1H),2.36(t,J=7.5Hz, 2H),1.96–1.84(m,2H),1.79–1.48(m,8H),1.47–1.34(m,2H),1.30–1.17(m,4H); 13 CNMR (101MHz, CDCl3)179.58,77.60,67.52,32.33,29.80,25.85,25.77,24.55,24.27; HRMS(ESI-): calculated for C 12 H 21 O3 - [MH] - 213.1496, found 213.1496.

[0097] 7-(tert-butoxy)-6-(tert-butoxycarbonyl)-7-oxyheptanoic acid (1m)

[0098]

[0099] 1 H NMR (400MHz, CDCl3) δ3.12 (t, J = 7.5 Hz, 1H), 2.36 (t, J = 7.4 Hz, 2H), 1.88–1.78 (m, 2H), 1.72–1.60 (m, 2H), 1.46 (s, 18H), 1.42–1.33 (m, 2H); 13C NMR(101MHz, CDCl3)δ179.27,168.82,81.39,53.76,33.66,28.19,27.92,26.63,24.33; HRMS(ESI-):calculated for C 16 H 27 O6 - [MH] - 315.1813, found 315.1817.

[0100] 7-(tert-butoxy)-7-oxoheptanoic acid (1n)

[0101]

[0102] R f (PE / EA = 3:1) = 0.3 - 0.4;

[0103] 1 H NMR (400MHz, CDCl3) δ2.39–2.33(m,2H),2.27–2.18(m,2H),1.72–1.55(m,4H),1.44 (d,J=1.2Hz,9H),1.43–1.31(m,2H); 13 C NMR(101MHz, CDCl3)δ179.63,173.07,80.12, 35.29,33.78,28.41,28.07,24.66,24.30; HRMS(ESI-):calculated for C 11 H 19 O4 - [MH] - 215.1289, found 215.1295.

[0104] Methoxy-4,4-dimethyl-6-oxohexanoic acid (1o)

[0105]

[0106] 1 H NMR (400MHz, CDCl3) δ3.67(s,3H),2.45–2.32(m,2H),2.23(s,2H),1.76–1.64(m,2H), 1.03(s,6H); 13C NMR(101MHz, CDCl3)δ180.3,172.5,51.4,45.6,36.3,32.9,29.5,27.0; HRMS(ESI-):calculated for C9H 15 O4 - [MH] - 187.0976, found 187.0978.

[0107] 6-O-6-(phenylamino)hexanoic acid (1p)

[0108]

[0109] 1 H NMR (400MHz, DMSO-d6) δ12.02(s,1H),9.85(s,1H),7.69–7.47(m,2H),7.24(t,J=7.9 Hz,2H),6.98(t,J=7.4Hz,1H),2.26(t,J=7.1Hz,2H),2.20(t,J=7.1Hz,2H),1.60–1.44(m, 4H); 13 C NMR(101MHz,DMSO-d6)δ174.80,171.43,139.73,129.06,123.36,119.43,36.53, 33.86,25.09,24.58; HRMS(ESI-):calculated for C 12 H 14 NO3 - [MH] - 220.0979, found 220.0977. 3-(1-(tert-Butoxycarbonyl)piperidin-4-yl)propionic acid (1q)

[0110]

[0111] 1 H NMR (400MHz, CDCl3) δ4.09 (d, J = 13.1 Hz, 2H), 2.68 (t, J = 12.8 Hz, 2H), 2.39 (t, J = 7.6 Hz, 2H), 1.74–1.56 (m, 4H), 1.46 (m, 10H), 1.19–1.02 (m, 2H); 13C NMR(101MHz, CDCl3)δ179.2,154.9,79.4,43.7,35.4,31.7,31.2,31.1,28.4; HRMS(ESI-):calculatedfor C 13 H 22 NO4 - [MH] - 256.1554, found 256.1550.

[0112] 3-(cyclohexyl-3-en-1-yl)propionic acid (1r)

[0113]

[0114] 1 H NMR (400MHz, CDCl3) δ5.76–5.60(m,2H),2.47–2.37(m,2H),2.20–1.97(m,3H),1.83–1.50(m,5H),1.34–1.18(m,1H); 13 C NMR(101MHz, CDCl3)δ180.30, 127.05,126.09,32.99,31.67,31.43,31.24,28.51,25.05; HRMS(ESI-):calculated for C9H 13 O2 - [MH] - 153.0921, found 153.0928.

[0115] 3-Cyclohexylpropionic acid (1s)

[0116]

[0117] 1 H NMR (400MHz, CDCl3) δ2.43–2.29(m,2H),1.77–1.60(m,5H),1.60–1.47(m,2H),1.34–1.08(m,5H),0.97–0.83(m,2H); 13 C NMR(101MHz, CDCl3)δ180.40,37.07,32.89,32.01, 31.60,26.47,26.16; HRMS(ESI-):calculated for C9H 15 O2 - [MH] -155.1078, found 155.1082. Undecanoic acid (1t)

[0118]

[0119] R f (PE / EA = 3:1) = 0.4 - 0.5;

[0120] 1 H NMR (400MHz, CDCl3) δ2.35 (t, J = 7.5Hz, 2H), 1.63 (p, J = 7.4Hz, 2H), 1.39–1.19 (m, 14H), 0.93–0.85 (m, 4H); 13 C NMR(101MHz, CDCl3)δ180.25,34.06,31.86,29.53,29.41,29.28,29.22,29.03,24.64,22.66,14.1; HRMS(ESI-):calculated for C 11 H 23 O2 - [MH] - 185.1547, found 185.1557.

[0121] Nonadecanoic acid (1u)

[0122]

[0123] R f (PE / EA = 3:1) = 0.4 - 0.5;

[0124] 1 H NM-R (400MHz, CDCl3) δ2.35 (t, J = 7.5Hz, 2H), 1.63 (p, J = 7.5Hz, 2H), 1.26 (s, 30H), 0.88 (t, J = 6.8Hz, 3H); 13 C NMR (101MHz, CDCl3) δ180.11,34.03,31.91,29.69,29.65,29.63, 29.58,29.42,29.35,29.23,29.04,24.65,22.68,14.12; HRMS (ESI-): calculated for C 19 H 37 O2 - [MH] -297.2799,found 297.2796.All analytical data are consistent with those reported in the literature.

[0125] 9-Hydroxy-5,9-dimethyldecanoic acid (1v)

[0126]

[0127] R f (PE / EA = 1:1) = 0.1 - 0.2;

[0128] 1 H NMR (400MHz, CDCl3) δ2.33(t,J=7.2Hz,2H),1.73–1.52(m,2H),1.49–1.24(m,8H), 1.22(s,6H),1.19–1.06(m,2H),0.88(d,J=6.5Hz,3H); 13 C NMR(101MHz, CDCl3)δ179.37, 71.39,44.02,37.19,36.17,34.28,32.41,29.14,29.04,22.20,21.59,19.48; HRMS(ESI-):calculated for C 12 H 23 O3 - [MH] - 215.1653, found 215.1650.

[0129] 4-((1R,2R,4S)-1,7,7-trimethylbicyclo[2.2.1]heptane-2-yl)oxy)butyric acid (1w)

[0130]

[0131] 3.20–3.12(m,1H),2.45(t,J=7.3Hz,2H),1.91–1.81(m,2H),1.76–1.40(m,6H),1.04–0.91 (m,5H),0.87(s,3H),0.79(s,3H); 13C NMR (101MHz, CDCl3) δ179.69,87.27,67.78,49.25, 46.40,45.07,38.45,34.50,31.36,27.31,25.17,20.25,20.16,11.81; HRMS (ESI-): calculated for C 14 H 24 O3 - [MH] - 239.1653, found 239.1651.

[0132] 4-((3S,8S,9S,10R,13R,14S,17R)-10,13-dimethyl-17-((R)-6-methylheptane-2-yl)-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecano-1H-cyclopentane[a]phenanthrene-3-yl)oxy)butyric acid (1x)

[0133]

[0134] 1H),3.57–3.48(m,2H),3.21–3.09(m,1H),2.47(t,J=7.1Hz,2H),2.39–2.29(m,1H),2.25– 2.12(m,1H),2.07–1.75(m,7H),1.65–1.28(m,11H),1.23–0.96(m,13H),0.91(d,J=6.5Hz,3H),0.88–0.85(m,6H),0.68(s,3H); 13 C NMR (101MHz, CDCl3) δ179.18,140.75,121.64, 79.21,66.76,56.72,56.10,50.12,42.28,39.73,39.49,38.96,37.16,36.83,36.16,35.77,31.91, 31.84,31.25,28.27,28.23,28.00,25.05,24.27,23.81,22.83,22.56,21.04,19.36,18.70,11.84; HRMS(ESI-):calculated for C 31 H 51 O3 - [MH] - 471.3844, found 471.3844.

[0135] 4-((1S,2R,5S)-2-isopropyl-5-methylcyclohexyl)oxy)butyric acid (1y)

[0136]

[0137] 1H),3.10–2.96(m,1H),2.54–2.45(m,2H),2.26–2.15(m,1H),2.14–2.05(m,1H),1.96–1.85(m,2H) ,1.71–1.58(m,2H),1.43–1.29(m,1H),1.28–1.17(m,1H),1.04–0.82(m,9H),0.78(d,J=7.0Hz,3H); 13 C NMR (101MHz, CDCl3) δ179.13,79.45,67.19,48.25,40.34,34.55, 31.54,31.25,25.61,25.26,23.31,22.33,20.96,16.15; HRMS (ESI-): calculated for C 14 H 25 O3 - [MH] - 241.1809, found 241.1808.

[0138] 4-((3s,5s,7s)-adamantane-1-yl)oxy)butyric acid (1z)

[0139]

[0140] 1 H NMR (400MHz, CDCl3) δ2.33 (t, J = 7.5 Hz, 2H), 1.72–1.52 (m, 2H), 1.37–1.18 (m, 15H), 0.86 (t, J = 6.7 Hz, 3H); 13 C NMR(101MHz, CDCl3)δ178.17,72.75,59.03,41.32,36.35,31.94, 30.44,25.21; HRMS(ESI-):calculated for C 14 H 21 O3 - [MH] - 237.1496, found 237.1496.

[0141] 4-((3,7-dimethyl-6-en-1-yl)oxy)butyric acid (1aa)

[0142]

[0143] 1 H NMR (400MHz, CDCl3) δ5.15–5.05(m,1H),3.55–3.36(m,4H),2.46(t,J=7.3Hz,2H), 2.07–1.85(m,4H),1.70–1.66(m,3H),1.66–1.48(m,4H),1.42–1.28(m,2H),1.24–1.09(m,1H),0.91(d,J=6.5Hz,3H); 13 C NMR (101MHz, CDCl3) δ179.27,131.17,124.80,69.59,69.34, 37.21,36.56,31.07,29.57,25.71,25.46,24.78,19.55,17.63; HRMS (ESI-): calculated for C 14 H 25 O3 - [MH] - 241.1809, found 241.1809.

[0144] 5-([1,1'-biphenyl]-4-yl)-3-methylvaleric acid (1ab)

[0145]

[0146] 2H),7.46–7.39(m,2H),7.35–7.29(m,1H),7.28–7.22(m,2H),2.79–2.56(m,2H),2.48– 2.38(m,1H),2.28–2.19(m,1H),2.11–1.99(m,1H),1.82–1.68(m,1H),1.63–1.51(m,1H),1.06(d,J=6.6Hz,3H); 13 C NMR (101MHz, CDCl3) δ179.52,141.33,141.05,138.76,128.73, 128.70,127.11,126.99,41.45,38.40,32.92,29.93,29.72,19.62; HRMS(ESI-):calculated for C 18 H 19 O2 - [MH]- 267.1391, found 267.1389.

[0147] 3-Methyl-5-phenylpentanoic acid (1ac)

[0148]

[0149] 1 H NMR (400MHz, CDCl3) δ7.32-7.23(m, 2H), 7.21-7.13(m, 3H), 2.74–2.54(m,2H),2.46–2.35(m,1H),2.26–2.15(m,1H),2.11–1.95(m,1H),1.76–1.63(m,1H),1.61–1.47(m,1H),1.04(d,J=6.7Hz,3H); 13 C NMR(101MHz, CDCl3)δ179.39,142.23, 128.38,128.32,125.80,41.44,38.45,33.32,29.93,19.62; HRMS(ESI-):calculated for C 12 H 15 O2 - [MH] - 191.1078, found 191.1100.

[0150] 4-(4-Methoxyphenyl)-3-methylbutyric acid (1ad)

[0151]

[0152] 1 H NMR(400MHz, CDCl3)δ7.10–7.05(m,2H),6.85–6.79(m, 2H),3.78(s,3H),2.61–2.54(m,1H),2.52–2.43(m,1H),2.41–2.33(m,1H),2.26–2.11(m,2H),1.00–0.94(m,3H); 13 CNMR(101MHz, CDCl3)δ179.14,158.00,132.13,130.13,113.72, 55.25,42.02,40.63,32.27,19.55; HRMS(ESI-):calculated for C 12 H 15 O2 -[MH] - 207.1027, found 207.1031.

[0153] 3-Methyltetradecanoic acid (1ae)

[0154]

[0155] 1 H NMR (400MHz, CDCl3) δ2.39–2.31(m,1H),2.18–2.08(m,1H),2.02–1.88(m,1H),1.31 –1.21(m,20H),0.96(d,J=6.6Hz,3H),0.92–0.83(m,3H); 13 C NMR (101MHz, CDCl3) δ179.07,41.48,36.68,31.93,30.17,29.73,29.68,29.65,29.63,29.36,26.90,22.70,19.70,14.13; HRMS (ESI-): calculated for C 15 H 29 O2 - [MH] - 241.2173, found241.2169. All analytical data are consistent with those reported in the literature.

[0156] 2-Cyclododecylacetic acid (1af)

[0157]

[0158] MPa 85-86℃

[0159] 1 H NMR (400MHz, CDCl3) δ2.26 (d, J = 7.1Hz, 2H), 2.06–1.95 (m, 1H), 1.53–1.11 (m, 21H); 13 C NMR(101MHz, CDCl3)δ179.83,39.85,31.29,28.99,24.45,24.01,23.29,23.18,21.51; HRMS(ESI-):calculated for C 14 H 25 O2 - [MH]- 225.1860, found 225.1861.

[0160] Although specific embodiments of the present invention have been described in detail with reference to examples, they should not be construed as limiting the scope of protection of this patent. Various modifications and variations that can be made by those skilled in the art without inventive effort within the scope described in the claims are still within the scope of protection of this patent.

Claims

1. A method for synthesizing alkyl carboxylic acid compounds based on olefin hydrocarboxylation, characterized in that, The process includes the following steps: S1: Mixing an olefin compound, a photocatalyst, a base, and an additive, then adding a reducing agent and a solvent under a CO2 atmosphere to obtain a reaction solution; the molar ratio of the olefin compound, photocatalyst, base, reducing agent, and additive is 1:0.0001~0.5:0.1~10:1~10:0.1~10; the photocatalyst is fac-Ir(ppy)3, the base is tert-butoxide, the reducing agent is DIPEA, the additive is TBAC, and the solvent is NMP; S2: The reaction solution obtained in S1 is stirred under light irradiation at room temperature (0-100 °C) for 0.1-100 h. The reaction product is then acidified and purified to obtain alkyl carboxylic acid compounds. The olefin compound is one of the following compounds: 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 。 2. The method for synthesizing alkyl carboxylic acid compounds based on olefin hydrocarboxylation according to claim 1, characterized in that: The tert-butanol salt is KO t Bu, NaO t Bu or LiO t Bu.

3. The method for synthesizing alkyl carboxylic acid compounds based on olefin hydrocarboxylation according to claim 1, characterized in that: The wavelength of the visible light used for irradiation is 300~700 nm, the power of the visible light is 0.1~60 W, and the pressure of the CO2 atmosphere is 0.1~30 times the atmospheric pressure.

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