A perfluoroalkenyl-substituted cyclopentanone compound and a method for preparing the same

Abstract

The application provides a full-carbon [3+2] cycloaddition reaction, which is a conversion under mild photocatalytic conditions by taking an easily available aldehyde as a substrate and a perfluoroalkyl alkyne as a high-value C3 synthon. The method can modularly construct a series of multifunctional cyclopentanones which are important in structure and strong in synthetic practicability, and the products are provided with unique alpha-perfluoroalkenyl substituents. The reaction steps are excellent in economy and atom economy, the functional group compatibility is good, and the yield is medium. The reaction condition is mild, the operation is simple and high in efficiency, and the method shows the characteristics of wide substrate range and excellent functional group compatibility.

Description

Technical Field

[0001] This invention belongs to the field of organic compound synthesis technology, specifically relating to a perfluoroalkenyl-substituted cyclopentanone compound and its preparation method. Background Technology

[0002] Cyclopentanones (CPOs) are a class of advantageous skeletal structures widely found in various natural products, pharmaceutical active molecules (APIs), and bioactive compounds. They also serve as multifunctional building blocks for synthesizing complex mixed-origin terpenoids (Acc. Chem. Res. 2021, 54, 583-594). A key challenge in this field is developing efficient synthetic strategies to precisely introduce fluorinated structural units into the cyclopentanone skeleton, constructing multi-substituted cyclopentanone derivatives. Such modifications can enhance molecular structural complexity and diversity, meeting the research and development needs of different applications. Of particular note is the multiple physicochemical and biological advantages derived from introducing fluoroolefin fragments into the molecular side chain: improved solubility, increased lipid solubility, enhanced protein binding affinity, and optimized metabolic stability and bioavailability. This property has been widely recognized in materials science (Prog. Polym. Sci. 1999, 24, 1095-1148), pesticide chemistry (Chin. Chem. Lett. 2022, 33, 626-642), and drug development (Chem. Eur J. 2021, 27, 17273-17292). Although researchers have achieved significant results in the synthesis of monofluoroolefins and geminidifluoroolefins through various classic alkenylation reactions such as the Wittig reaction, Julia-Kocienski reaction, and Homer-Wadsworth-Emmons reaction, methods for the synthesis of perfluoroalkenyl-substituted olefins are still relatively scarce (Chem. Rec. 2023, 23, e202200270).

[0003] In recent years, there has been progress in the fluoroalkenylation modification of acyclic carbonyl compounds: using ketones, silyl enol ethers, alkenes, alkenyl borate esters, and aldehydes as substrates (Org. Lett. 2020, 22, 4261-4265; Org. Lett. 2026, 28, 3412-3417; Chem. Commun. 2016, 52, 13668-13670; Chem. Sci. 2025, 16, 17316-17324; J. Org. Chem. 2023, 88, 4325-4333; J. Org. Chem. 2021, 86, 7425-7438), carbon-fluorocarbon double bonds can be constructed at the ortho position of the carbonyl group. However, most existing methods are limited to (hetero)aromatic substrates and cannot be applied to simple carbocyclic compounds, especially cyclopentanone skeletons. Furthermore, these reactions typically require sensitive or toxic auxiliaries, specialized fluoroalkenyl precursors, and harsh reaction conditions. These multiple drawbacks collectively limit the practical value and substrate versatility of the method. A typical example is the two-step α-perfluoroalkylation of cyclohexanone reported by Bayler et al. in the presence of stoichiometric pyrrolidine and cesium carbonate. However, this method is still immature due to the difficulty in obtaining diverse perfluoroalkyl alkenes, thus making it unsuitable for constructing valuable homologue libraries of perfluoroalkenylated derivatives (Eur. J. Org. Chem. 2020, 70-81).

[0004] Against this backdrop, developing simple, efficient, and universal synthetic strategies to construct highly functionalized five-membered rings of cyclopentanones in one step using readily available raw materials, while simultaneously introducing target (per)fluoroalkenyl functional groups, has become a highly attractive research approach. For example, researchers have developed a copper-catalyzed tandem reaction: cycloketones are synthesized from alkynyl ketones via difluoroalkylation and defluorination cleavage, but this system cannot achieve perfluoroalkenylation (Chem. Commun. 2023, 59, 1821-1824). Recently, our team reported an intramolecular fluorination reaction of alkynyl-linked acyl fluorides catalyzed by thallium trifluoromethanesulfonate, but only one example of a non-aromatic substrate was given, and it is difficult to flexibly introduce various perfluoroalkenyl structural fragments, which still has obvious limitations (Org. Lett. 2025, 27, 1322-1326).

[0005] Visible light-mediated organic transformation has the outstanding advantages of being green and sustainable. Although existing studies have confirmed that simple aldehydes can stably generate acyl radicals under mild photocatalytic conditions (Nat. Commun. 2026, 17, 2518), there are still three key challenges in this design: (1) the SOMO electrophilic reactivity of perfluoroalkyl alkynes with electron-withdrawing inducible perfluoroalkyl segments has not been reported; (2) when acyl radicals undergo intermolecular addition to fluoroalkynyl groups, there are problems with the difficulty in controlling the α / β regioselectivity and chemoselectivity; (3) the tandem cyclization-defluorination reaction process is difficult to control precisely.

[0006] To address the aforementioned issues, we have developed a method for constructing perfluoroalkenyl-substituted cyclopentanone compounds via a photocatalytic defluorination [3+2] cycloaddition reaction. This reaction is characterized by mild reaction conditions, good functional group tolerance, simple post-processing, green procedures, low pollution, and high economic efficiency. Summary of the Invention

[0007] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0008] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0009] One object of the present invention is to provide a perfluoroalkenyl-substituted cyclopentanone compound.

[0010] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a perfluoroalkenyl-substituted cyclopentanone compound, the structural formula of which is shown in Formula I;

[0011]

[0012] Wherein, R is selected from one of phenyl, halogen-substituted phenyl, tert-butyl-substituted phenyl, methoxy-substituted phenyl, methyl-substituted phenyl, trifluoromethyl-substituted phenyl, and thioheterocyclic-substituted phenyl;

[0013] R 1 Selected from one of methyl, 2-(benzoyloxy)ethyl, or phenyl;

[0014] R 2 Selected from one of methyl, phenyl, or cyclopentyl;

[0015] R f Selected from one of heptafluoropropyl, undecylfluoropentyl, and pentadecylfluoroheptyl;

[0016] Another object of this invention is to provide a method for preparing the perfluoroalkenyl-substituted cyclopentanone compound as described above. This invention features mild reaction conditions, good functional group tolerance, simple post-processing, green procedures, low pollution, and high economic benefits. The specific method includes...

[0017] The polyfluoroalkyl alkyne shown in Formula II and the alkyl aldehyde compound shown in Formula III undergo a photocatalytic defluorination [3+2] cycloaddition reaction in a solvent under the promotion of a photocatalyst to obtain the target compound shown in Formula I.

[0018]

[0019] Among them, R and R in equations II and III 1 R f With Equation I, R, R 1 R f Consistent correspondence;

[0020] As a preferred embodiment of the defluorination [3+2] cycloaddition method for polyfluoroalkyl alkynes of the present invention, wherein: the polyfluoroalkyl alkynes include (perfluorohexyl-1-yn-1-yl)benzene, 1-fluoro-4-(perfluorohexyl-1-yn-1-yl)benzene, 1-tert-butyl-4-(perfluorohexyl-1-yn-1-yl)benzene, 1-methoxy-4-(perfluorohexyl-1-yn-1-yl)benzene, 1-methyl-4-(perfluorohexyl-1-yn-1-yl)benzene, etc. -1-yn-1-yl)benzene, 1-methyl-3-(perfluorohex-1-yn-1-yl)benzene, 1-methyl-2-(perfluorohex-1-yn-1-yl)benzene, 1-(perfluorohex-1-yn-1-yl)-4-(trifluoromethyl)benzene, 4,4-dimethyl-6-(perfluorohex-1-yn-1-yl)thiosperm, (perfluorohex-1-yn-1-yl)benzene, (perfluorooctyl-1-yn-1-yl)benzene.

[0021] As a preferred embodiment of the defluorination [3+2] cycloaddition method for polyfluoroalkyl alkynes of the present invention, wherein the alkyl aldehyde compound includes 3-methylbutanal, 3-methyl-5-oxopentyl benzoate, 3-phenylpropanal, 3-phenylbutanal, and 2-cyclopentylacetaldehyde.

[0022] As a preferred embodiment of the defluorination [3+2] cycloaddition method for polyfluoroalkyl alkynes of the present invention, wherein the molar ratio of the polyfluoroalkyl alkyne to the alkyl aldehyde compound is 1:1.5 to 2.5; preferably the molar ratio is 1:2.5.

[0023] As a preferred embodiment of the defluorination [3+2] cycloaddition method for polyfluoroalkyl alkynes of the present invention, the solvent includes either acetonitrile or water; the preferred solvent is acetonitrile.

[0024] As a preferred embodiment of the defluorination [3+2] cycloaddition method for polyfluoroalkyl alkynes of the present invention, wherein: the molar ratio of the polyfluoroalkyl alkynes to the photocatalyst is 1:0.01 to 0.05; preferably, the molar ratio is 1:0.05.

[0025] As a preferred embodiment of the defluorination [3+2] cycloaddition method for polyfluoroalkyl alkynes of the present invention, the photocatalyst comprises one of tetrabutylammonium decatungstate, Acid Red 87, 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile, food coloring Red 105, and ruthenium tripyridine chloride hexahydrate; the preferred photocatalyst is tetrabutylammonium decatungstate.

[0026] As a preferred embodiment of the defluorination [3+2] cycloaddition method for polyfluoroalkyl alkynes of the present invention, the defluorination [3+2] cycloaddition reaction takes 6 to 24 hours; preferably 24 hours.

[0027] In summary, the optimal reaction equation for this invention is as follows:

[0028]

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] This invention provides a defluorination [3+2] cycloaddition reaction of polyfluoroalkyl alkynes and alkyl ketone compounds under photocatalytic conditions. The reaction conditions are mild, the functional groups are well tolerated, and the reaction is characterized by simple post-processing, green steps, low pollution, and high economic benefits. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0032] Figure 1 The proton spectrum of target product a in Example 1 of this invention;

[0033] Figure 2 The fluorine spectrum of target product a in Example 1 of this invention;

[0034] Figure 3 The carbon spectrum of target product a in Example 1 of this invention;

[0035] Figure 4 The proton spectrum of target product b in Example 2 of this invention;

[0036] Figure 5 The fluorine spectrum of target product b in Example 2 of the present invention;

[0037] Figure 6 The carbon spectrum of target product b in Example 2 of this invention;

[0038] Figure 7 The proton spectrum of target product c in Example 3 of this invention;

[0039] Figure 8 The fluorine spectrum of target product c in Example 3 of this invention;

[0040] Figure 9 The carbon spectrum of target product c in Example 3 of this invention;

[0041] Figure 10 The proton spectrum of the target product d in Example 4 of this invention;

[0042] Figure 11 The fluorine spectrum of the target product d in Example 4 of this invention;

[0043] Figure 12 The carbon spectrum of the target product d in Example 4 of this invention; Detailed Implementation

[0044] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0045] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0046] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0047] The polyfluoroalkyl alkynes used in the examples were prepared according to the method reported in the reference (J. Org. Chem. 2020, 85, 8723-8731). The alkyl aldehyde compounds used in the examples were prepared according to the method reported in the reference (Angew. Chem. Int. Ed. 2021, 60, 15020-15027). Other raw materials, unless otherwise specified, were commercially available.

[0048] Example 1

[0049] (1) A solution of (perfluorohexyl-1-yn-1-yl)benzene (96.0 mg, 0.3 mmol, 1 equiv.), 3-methylbutanal (64.6 mg, 0.75 mmol, 2.5 equiv.) and tetrabutylammonium decatungstate (49.5 mg, 0.015 mmol, 0.05 equiv.) in acetonitrile (2 mL) was reacted for 24 hours at 45 °C under stirring and irradiation with a 390 nm blue LED light source.

[0050] (2) After the reaction in step (1) is completed, the reaction is quenched with saturated NH4Cl solution and extracted with ethyl acetate (20 mL × 3). The combined organic phases are washed with saturated brine (20 mL), dried with anhydrous sodium sulfate, and concentrated under vacuum to obtain crude product. The crude product is purified by silica gel column chromatography. The column chromatography separation conditions are: stationary phase is 300-400 mesh silica gel powder, mobile phase is ethyl acetate (A) and petroleum ether (B), and the mobile phase change program (A:B) is 1:150 to 1:50. Finally, 79.6 mg of target product a is obtained.

[0051] The target product a was characterized as follows: Figure 1 , 2 As shown in Figure 3, the result is: a yellow oily substance;

[0052] 1 H NMR (400MHz, CDCl3) of Z-isomer: δ 7.33-7.28(m, 2H), 7.27-7.23(m, 1H), 7.01-6.97(m, 2H), 3.89(s, 1H), 2.55-2.50(m, 1H), 2.23-2.18(m, 1H), 1.20(s, 3H), 0.80(s, 3H)ppm.

[0053] 19 F NMR (376MHz, CDCl3) of Z-isomer: δ-80.72 (t, J=8.9Hz, 3F), -113.45 (s, 1F), -115.57--118.25 (m, 2F), -127.04 (dd, J=18.4, 8.4Hz, 2F)ppm.

[0054] 13 C NMR (100MHz, CDCl3) of Z-isomer: δ 202.6, 140.9, 128.5, 128.4, 127.4 (d, J = 46.2Hz), 117.3 (d, J = 287.1Hz), 54.8 (d, J = 4.1Hz), 50.1, 38.7, 30.6, 25.2ppm, carbonscorresponding to the n C3F7 group cannot be identified due to CF coupling.

[0055] HRMS(m / z): calcd for C 17 H 15 F8O[M+H] + 387.0917, found: 387.0918.

[0056] Characterization data revealed that the obtained reaction product was (Z)-4,4-dimethyl-2-(perfluorobutylene)-3-phenylcyclopentan-1-one (purity > 98%), and the structural formula of this compound is:

[0057]

[0058] The product yield was calculated to be 69%.

[0059] Example 2

[0060] (1) A solution of 1-fluoro-4-(perfluorohex-1-yn-1-yl)benzene (101.4 mg, 0.3 mmol, 1 equiv.), 3-methylbutanal (64.6 mg, 0.75 mmol, 2.5 equiv.) and tetrabutylammonium decatungstate (49.5 mg, 0.015 mmol, 0.05 equiv.) in acetonitrile (2 mL) was reacted for 24 hours at 45 °C under stirring and irradiation with a 390 nm blue LED light source.

[0061] (2) After the reaction in step (1) is completed, the mixture is quenched with saturated NH4Cl solution and extracted with ethyl acetate (20 mL × 3). The combined organic phases are washed with saturated brine (20 mL), dried with anhydrous sodium sulfate, and concentrated under vacuum to obtain crude product. The crude product is purified by silica gel column chromatography. The column chromatography separation conditions are: stationary phase is 300-400 mesh silica gel powder, mobile phase is ethyl acetate (A) and petroleum ether (B), and the mobile phase change program (A:B) is 1:150 to 1:50. Finally, 64.0 mg of the target product b is obtained.

[0062] The target product b was characterized as follows: Figure 4 , 5 As shown in Figure 6, the result is: a yellow oily substance;

[0063] 1 H NMR (400MHz, CDCl3) of Z-isomer: δ 7.05-7.00 (m, 2H), 6.98-6.95 (m, 2H), 3.88 (s, 1H), 2.49-2.45 (m, 1H), 2.23-2.18 (m, 1H), 1.19 (s, 3H), 0.80 (s, 3H)ppm.

[0064] 19F NMR (376MHz, CDCl3) of Z-isomer: δ-80.71 (t, J=8.9Hz, 3F), -112.85 (s, 1F), -1 14.92--114.98(m, 1F), -115.56--118.40(m, 2F), -126.93--127.07(m, 2F)ppm.

[0065] 13 C NMR (100MHz, CDCl3) of Z-isomer: δ 202.3, 161.8 (d, J = 246.6Hz), 136.7, 129.1 (d, J = 8.0Hz), 128.1, 115.5 (d, J = 21.3Hz), 54.0, 49.9, 38.7, 30.5, 25.2ppm, carbons corresponding to the n C3F7 group cannot be identified due to C-Fcoupling.

[0066] HRMS(m / z): calcd for C 17 H 14 F9O[M+H] + 405.0895, found: 405.0896.

[0067] Characterization data revealed that the obtained reaction product was (Z)-3-(4-fluorophenyl)-4,4-didimethyl-2-(perfluorobutylene)cyclopentane-1-one (purity > 98%), and the structural formula of this compound is:

[0068]

[0069] The product yield was calculated to be 53%.

[0070] Example 3

[0071] (1) A solution of (perfluorohexyl-1-yn-1-yl)benzene (96.0 mg, 0.3 mmol, 1 equiv.), 3-methyl-5-oxopentyl benzoate (165.2 mg, 0.75 mmol, 2.5 equiv.), and tetrabutylammonium decatungstate (49.5 mg, 0.015 mmol, 0.05 equiv.) in acetonitrile (2 mL) was reacted for 24 hours at 45 °C under stirring and irradiation with a 390 nm blue LED light source.

[0072] (2) After the reaction in step (1) is completed, the mixture is quenched with saturated NH4Cl solution and extracted with ethyl acetate (20 mL × 3). The combined organic phases are washed with saturated brine (20 mL), dried with anhydrous sodium sulfate, and concentrated under vacuum to obtain crude product. The crude product is purified by silica gel column chromatography. The column chromatography separation conditions are: stationary phase is 300-400 mesh silica gel powder, mobile phase is ethyl acetate (A) and petroleum ether (B), and the mobile phase change program (A:B) is 1:150 to 1:50. Finally, 52.8 mg of the target product c is obtained.

[0073] The target product c was characterized as follows: Figure 7 As shown in Figures 8 and 9, the result is: a yellow solid;

[0074] 1 H NMR (400MHz, CDCl3) of Z-isomer and E-isomer: δ 8.05-8.01(m, 2H), 7.60-7.53(m, 1H), 7.47-7.44(m, 2H), 7.33-7.28(m, 3H), 7.03-6.99(m, 2H), 4.52-4.40(m, 2H), 4 .14-3.98(m, 1H), 2.73-2.59(m, 1H), 2.53-2.51(m, 1H), 2.00-1.94(m, 1H), 1.29-1.26(m, 1H), 0.85-0.83(m, 3H)ppm.

[0075] 19 F NMR (376MHz, CDCl3) of Z-isomer: δ-80.63 (t, J=9.2Hz, 3F), -112.11--112.80 (m, 1F), -115.51--118.18 (m, 2F), -126.73--127.01 (m, 2F) ppm; E-isomer: δ-80.52 (t, J=9.0Hz, 3F), -104.32--105.61 (m, 1F), -114.82--115.08 (m, 2F), -126.50--126.59 (m, 2F)ppm.

[0076] 13C NMR (100MHz, CDCl3) of Z-isomer and E-isomer: δ 201.7, 166.4, 140.1, 133.2, 129.8, 129.5, 128.9, 128.7, 128.5, 128.1, 127.8, 127.6, 12 7.4, 61.3, 55.6, 53.4, 48.9, 48.8, 40.9, 40.6, 40.0, 39.9, 37.0, 27.2, 22.3ppm, carbons corresponding to the n C3F7 group cannot be identified due to CF coupling.

[0077] HRMS(m / z): calcd for C 25 H 21 F8O3[M+H] + 521.1357, found: 521.1354.

[0078] Characterization data revealed that the obtained reaction product was 2-(1-methyl-4-oxo-3-(perfluorobutyryl)-2-phenylcyclopentyl)ethyl benzoate (purity > 98%), and the structural formula of this compound is:

[0079]

[0080] The product yield was calculated to be 34%.

[0081] Example 4

[0082] (1) A solution of (perfluorohexyl-1-yn-1-yl)benzene (96.0 mg, 0.3 mmol, 1 equiv.), 3-phenylpropanal (100.6 mg, 0.75 mmol, 2.5 equiv.) and tetrabutylammonium decatungstate (49.5 mg, 0.015 mmol, 0.05 equiv.) in acetonitrile (2 mL) was reacted for 24 hours at 45 °C under stirring and irradiation with a 390 nm blue LED light source.

[0083] (2) After the reaction in step (1) was completed, the mixture was quenched with saturated NH4Cl solution and extracted with ethyl acetate (20 mL × 3). The combined organic phases were washed with saturated brine (20 mL), dried with anhydrous sodium sulfate, and concentrated under vacuum to obtain the crude product. The crude product was purified by silica gel column chromatography. The column chromatography separation conditions were: the stationary phase was 300-400 mesh silica gel powder, the mobile phase was ethyl acetate (A) and petroleum ether (B), and the mobile phase change program (A:B) was 1:150 to 1:50. Finally, 44.7 mg of the target product d was obtained.

[0084] The target product d was characterized as follows: Figure 10 As shown in Figures 11 and 12, the result is: a yellow oily substance;

[0085] 1 H NMR (400MHz, CDCl3)0f Z-isomer and E-isomer: δ 7.39-7.35(m, 2H), 7.33-7.27(m, 2H), 7.20-7.14(m, 3H), 7.13-7.09(m, 1H), 6.83-6.79(m, 1H), 6.65-6.63(m , 1H), 4.60-4.41(m, 1H), 3.96-3.85(m, 0.5H), 3.61-3.47(m, 0.5H), 3.03-2.94(m, 1H), 2.73-2.64(m, 1H)ppm.

[0086] 19 F NMR (376MHz, CDCl3) of Z-isomer: δ-80.72 (t, J=9.0Hz, 3F), -111.59--112.64 (m, 1F), -115.62--118.12 (m, 2F), -126.88--126.96 (m, 2F) ppm; E-isomer: δ-80.51 (q, J=8.8Hz, 3F), -104.64--105.25 (m, 1F), -114.82--115.04 (m, 2F), -126.46--126.51 (m, 2F)ppm.

[0087] 13C NMR (100MHz, CDCl3) of Z-isomer and E-isomer: δ 202.1, 201.4, 143.2, 136.8, 129.1 (d, J=6.8Hz), 129.0 (d, J=3.4Hz), 128.2, 128.0, 127.3, 127.1, 126.8 (d, J=2.3Hz), 126.4 (d, J=12.5Hz), 54.3, 52.3, 49.4, 48.3 (d, J=23.1Hz), 45.9, 42.7, 40.2ppm, carbons corresponding to the n C3F7 group cannot be identified due to C-Fcoupling.

[0088] HRMS(m / z): calcd for C 21 H 15 F8O[M+H] + 435.0990, found: 435.0995.

[0089] Characterization data indicate that the obtained reaction product is 2-(perfluorobutylene)-3,4-diphenylcyclopentan-1-one.

[0090] (Purity > 98%), the structural formula of this compound is:

[0091]

[0092] The product yield was calculated to be 34%.

[0093] Example 5

[0094] Example 5 is basically the same as Example 1, except that in step (1), when the reaction time is 16 hours, the molar ratio of polyfluoroalkyl alkynes to alkyl ketone compounds is different, as shown in Table 4 below:

[0095] Table 1

[0096] Molar ratio of polyfluoroalkyl alkynes to alkyl ketones Yield (%) 1：1.5 57 1：2 60 1：2.5 69

[0097] As can be seen from Table 1, under the same reaction conditions, the reaction yield is highest when the molar ratio of polyfluoroalkyl alkynes to alkyl ketones is 1:2.5.

[0098] Example 6

[0099] Example 6 is basically the same as Example 1, except that the reaction solvent is different in step (1), as shown in Table 2 below:

[0100] Table 2

[0101]

[0102]

[0103] As can be seen from Table 2, under the same reaction conditions, the reaction yield is the highest when acetonitrile is used as the solvent.

[0104] Example 7

[0105] Example 7 is basically the same as Example 1, except that in step (1), the molar ratio of polyfluoroalkyl alkyne to the photocatalyst tetrabutylammonium decatungstate is different, as shown in Table 3 below:

[0106] Table 3

[0107]

[0108] As can be seen from Table 3, under the same reaction conditions, the reaction yield is the highest when the molar ratio of polyfluoroalkyl alkynes to photocatalyst tetrabutylammonium decatungstate is 1:0.05.

[0109] Example 8

[0110] Example 8 is basically the same as Example 1, except that the photocatalyst is different in step (1), as shown in Table 4 below:

[0111] Table 4

[0112] Photocatalyst Yield (%) Tetrabutylammonium decatungstate 69 Acid Red 87 0 2,4,5,6-Tetra(9-carbazolyl)-isophthalonitrile 0 Food coloring red 105 0 Tripyridine ruthenium chloride hexahydrate 0

[0113] As can be seen from Table 4, the reaction yield is the highest when the photocatalyst is tetrabutylammonium decatungstate under the same reaction conditions.

[0114] Example 9

[0115] Example 9 is basically the same as Example 1, except that the reaction time is different in step (1), as shown in Table 5 below:

[0116] Table 5

[0117] Time (h) Yield (%) 6 50 12 70 16 65 24 69

[0118] As can be seen from Table 5, under the same reaction conditions, the reaction yield is the highest when the reaction time is 24 hours.

[0119] Example 10

[0120] Example 10 is basically the same as Example 1, except that the polyfluoroalkyl alkyne is different in step (1). The specific target products obtained are shown in Table 6 below:

[0121] Table 6

[0122]

[0123]

[0124] Example 11

[0125] Example 11 is basically the same as Example 1, except that the alkyl aldehyde compound is different in step (1). The specific target products obtained are shown in Table 7 below:

[0126] Table 7

[0127]

[0128] This invention provides a full-carbon [3+2] cycloaddition reaction: using readily available aliphatic aldehydes as substrates and perfluoroalkyl alkynes as high-value C3 synthons, the conversion is achieved under mild photocatalytic conditions. This method can modularly construct a series of structurally important and synthetically practical multifunctionalized cyclopentanones, with products bearing unique α-perfluoroalkenyl substituents; it exhibits excellent reaction step economy and atom economy, good functional group compatibility, and moderate yield. The reaction conditions are mild, the operation is simple and efficient, demonstrating a broad substrate range and excellent functional group compatibility. It should be noted that the above embodiments are only used to illustrate the technical solution of this invention and are not intended to limit it. Although the invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this invention without departing from the spirit and scope of the invention, and all such modifications and substitutions should be covered within the scope of the claims of this invention.

Claims

1. A perfluoroalkenyl-substituted cyclopentanone compound, characterized in that its structural formula is shown in Formula I; in, R is selected from one of phenyl, halogen-substituted phenyl, tert-butyl-substituted phenyl, methoxy-substituted phenyl, methyl-substituted phenyl, trifluoromethyl-substituted phenyl, and thioheterocyclic-substituted phenyl; R 1 Selected from one of methyl, 2-(benzoyloxy)ethyl, or phenyl; R 2 Selected from one of methyl, phenyl, or cyclopentyl; R f It is selected from one of heptafluoropropyl, undecylfluoropentyl, and pentadecylfluoroheptyl.

2. The method for preparing a perfluoroalkenyl-substituted cyclopentanone compound as described in claim 1, characterized in that: include, The polyfluoroalkyl alkyne shown in Formula II and the alkyl aldehyde compound shown in Formula III were subjected to a photocatalytic defluorination [3+2] cycloaddition reaction in a solvent under the promotion of a photocatalyst to obtain the compound shown in Formula I. Among them, R and R in equations II and III f R 1 With Equation I, R, R f R 1 The correspondence is consistent.

3. The method for preparing the perfluoroalkenyl-substituted cyclopentanone compound as described in claim 2, characterized in that: The molar ratio of the polyfluoroalkyl alkyne to the alkyl aldehyde compound is 1:1.5 to 2.

5.

4. The method for preparing the perfluoroalkenyl-substituted cyclopentanone compound according to any one of claims 2 to 3, characterized in that: The solvent includes either acetonitrile or water.

5. The method for preparing the perfluoroalkenyl-substituted cyclopentanone compound according to any one of claims 2 to 4, characterized in that: The molar ratio of the polyfluoroalkyl alkyne to the photocatalyst is 1:0.01 to 0.

05.

6. The method for preparing the perfluoroalkenyl-substituted cyclopentanone compound according to claims 2-5, characterized in that: The photocatalyst includes one of tetrabutylammonium decatungstate, Acid Red 87, 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile, food coloring Red 105, and terpyridine ruthenium chloride hexahydrate.

7. The method for preparing the perfluoroalkenyl-substituted cyclopentanone compound according to any one of claims 2 to 6, characterized in that: The defluorination [3+2] cycloaddition reaction takes 6 to 24 hours.

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