High-allene phosphine oxide as well as preparation method and application thereof

Abstract

The invention provides a high-allene phosphine oxide as well as a preparation method and application thereof. The preparation method of the high-allene phosphine oxide comprises the following steps: in a solvent A, under the promotion of alkali, an eneyne ketone compound II and a phosphine oxide compound III are subjected to a conjugated phosphine hydrogenation reaction, and the high-allene phosphine oxide I is obtained. According to the method, the high-allene phosphine oxide is prepared by starting from simple and easily available starting raw materials and adopting an alkali-promoted conjugated phosphine hydrogenation reaction, the atom utilization rate is 100%, and the method is a reaction meeting atom economy and green chemistry, and is mild in condition, easy to implement, simple and convenient to operate, easy in product separation and purification and high in yield. The high-allene phosphine oxide synthesized by the method is excellent in diastereoselectivity and novel in structure, has various active functional groups, and has potential synthesis application value. The high-allene phosphine oxide disclosed by the invention can be used as a catalyst and is applied to a reaction for catalyzing dehydration between carboxyl groups to generate anhydride.

Description

Technical Field

[0001] The present invention relates to a highly allenylphosphine oxide, a preparation method thereof and an application thereof, belonging to the technical field of organic synthesis. Background Art

[0002] The phosphine oxide structure is a very important skeleton in organic compounds and is a key component in various bioactive molecules, pharmaceutical compounds, functional materials and organic synthesis, and has wide applications in the fields of medicine, biochemistry and material chemistry. The conjugate phosphine hydrogenation reaction of unsaturated bonds provides a direct and efficient method for preparing organophosphine oxides.

[0003] As a heavyweight carbon-carbon double bond skeleton containing axial chirality, the synthesis method of allene has also been widely studied. There are many methods for the synthesis of polysubstituted allenes, one of which is through the 1,4-difunctionalization reaction of 1,3-enynes, but this type of reaction has been very little studied at present, and it is very difficult to control the diastereoselectivity of the reaction.

[0004] Chinese Patent Document CN116082401A discloses an α-carbon chiral phosphine compound and a preparation method thereof, which involves the preparation of a compound containing a phosphine oxide and an allene structure, using alkynol and R 1 2PCl as raw materials, and obtaining the product through a reaction in tetrahydrofuran under the action of triethylamine. However, the yield of the target product needs to be further improved, and the reaction conditions are harsh, specifically reflected in the use of the phosphine reagent R 1 2PCl, which is extremely sensitive to air and needs to be added dropwise to the reaction at a temperature of -78 °C. After the dropwise addition is completed, the reaction is then raised to room temperature, and some substituents need to be heated to 60 °C, which makes the reaction operation complicated.

[0005] Therefore, it is of great significance to develop a simple, efficient and high-yield method for synthesizing highly allenylphosphine oxides and explore their applications. For this reason, the present invention is proposed. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the present invention provides a highly allenylphosphine oxide, a preparation method thereof and an application thereof. Starting from simple and easily available starting materials, the present invention uses a base-promoted conjugate phosphine hydrogenation reaction to prepare highly allenylphosphine oxides, with an atomic utilization rate of 100%, which is a reaction that conforms to atom economy and green chemistry, has mild conditions, is easy to implement, has a simple operation, the product is easy to separate and purify, and has a high yield. The highly allenylphosphine oxide synthesized by the present invention has excellent diastereoselectivity, a novel structure, has a variety of active functional groups, and has potential synthetic application value. The highly allenylphosphine oxide of the present invention can be used as a catalyst in the reaction of catalyzing the dehydration between carboxyl groups to form acid anhydrides.

[0007] The technical solution of the present invention is as follows:

[0008] A highly allenyl phosphine oxide has a structure shown in the following formula I:

[0009]

[0010] Wherein, R1, R2, and R3 are each independently selected from C1-C5 alkyl groups, naphthyl groups, or substituted phenyl groups, and the substituents of the substituted phenyl groups are H, C1-C3 alkyl groups, alkoxy groups, halogens, or -NO2; R4 is a naphthyl group or a substituted phenyl group, and the substituents of the substituted phenyl groups are C1-C3 alkyl groups, alkoxy groups, or halogens.

[0011] Preferably according to the present invention, R1 is a substituted phenyl group, and the substituents of the substituted phenyl group are H, an alkoxy group, or a halogen; R2 is a substituted phenyl group, and the substituents of the substituted phenyl group are H; R3 is a substituted phenyl group, and the substituents of the substituted phenyl group are H, C1-C3 alkyl groups, alkoxy groups, or halogens; R4 is a substituted phenyl group, and the substituents of the substituted phenyl group are H or C1-C3 alkyl groups.

[0012] Preferably according to the present invention, the highly allenyl phosphine oxide is selected from one of the following compounds:

[0013]

[0014] The preparation method of the above-mentioned highly allenyl phosphine oxide includes the steps of:

[0015] In solvent A, under the promotion of a base, an enynone compound II and a phosphine oxide compound III undergo a conjugate phosphine hydroboration reaction to obtain a highly allenyl phosphine oxide I;

[0016]

[0017] Among them, in the structural formula of the enynone compound II, the substituents R1, R2, and R3 are the same as R1, R2, and R3 in the compound of formula I; in the structural formula of the phosphine oxide compound III, the substituent R4 is the same as R4 in the compound of formula I.

[0018] Preferably according to the present invention, the enynone compound II is selected from one of the following compounds:

[0019]

[0020] Preferably according to the present invention, the phosphine oxide compound III is selected from one of the following compounds:

[0021]

[0022] Preferably according to the present invention, the solvent A is tetrahydrofuran or dichloromethane, preferably dichloromethane; the volume ratio of the solvent A to the molar amount of the enynone compound II is 2.5-10 mL:1 mmol, preferably 8-10 mL:1 mmol.

[0023] Preferably according to the present invention, the base is one or a combination of two or more of triethylamine, diisopropylamine, N,N-diisopropylethylamine (DIPEA), 1,8-diazabicycloundec-7-ene (DBU), potassium carbonate, cesium carbonate, lithium tert-butoxide, sodium tert-butoxide or potassium tert-butoxide, preferably potassium carbonate; the molar ratio of the base to the enynone compound II is 1.2-4:1, preferably 4:1.

[0024] Preferably according to the present invention, the molar ratio of the phosphine oxide compound III to the enynone compound II is 1.2-4:1, preferably 4:1.

[0025] Preferably according to the present invention, the temperature of the conjugate hydrophosphination reaction is from zero degree to room temperature, the reaction time is 12-48 h, and the reaction is carried out under stirring conditions.

[0026] Preferably according to the present invention, the conjugate hydrophosphination reaction is carried out under a nitrogen or argon atmosphere.

[0027] Preferably according to the present invention, after the enynone compound II and the phosphine oxide compound III are subjected to the conjugate hydrophosphination reaction, the product can be separated and characterized by a conventional separation and purification method. Preferably, the post-treatment steps of the reaction solution obtained by the conjugate hydrophosphination reaction of the enynone compound II and the phosphine oxide compound III are as follows: filtering the reaction solution with diatomaceous earth, removing the solvent from the filtrate, and separating the residue by silica gel column chromatography to obtain the highly allenyl phosphine oxide I; the eluent of the silica gel column chromatography is a mixed solvent of ethyl acetate and solvent B, and the solvent B is petroleum ether and / or n-hexane; more preferably, the eluent is a mixed solution of ethyl acetate and petroleum ether, and the volume ratio of ethyl acetate to petroleum ether in the mixed solution is 1:10-1:1.

[0028] Preferably according to the present invention, the preparation method of the highly allenyl phosphine oxide includes the steps of: adding a base, an enynone compound II and a phosphine oxide compound III into a solvent A, and reacting to obtain the highly allenyl phosphine oxide I.

[0029] The above application of the highly allenyl phosphine oxide is used as a catalyst in the reaction of dehydrating carboxyl compounds to form acid anhydrides.

[0030] Preferably according to the present invention, the carboxyl compound is p-methylbenzoic acid.

[0031] Preferably according to the present invention, the method for dehydrating carboxyl compounds to form acid anhydrides includes the steps of:

[0032] Mix the catalyst, anhydrous acetonitrile, oxalyl chloride, carboxyl compound and triethylamine, and stir the reaction at room temperature for 10 - 20 hours; after the reaction is completed, the obtained reaction solution is filtered, the solvent in the filtrate is evaporated, and separated by silica gel column chromatography to obtain the anhydride.

[0033] Preferably, the molar ratio of the catalyst, oxalyl chloride, carboxyl compound and triethylamine is 0.5 - 2:1 - 1.5:1:0.5 - 1.5; the molar amount of the carboxyl compound and the volume ratio of anhydrous acetonitrile is 0.1 - 1 mol / L.

[0034] The preparation route of the highly allenylphosphine oxide of the present invention is as follows:

[0035]

[0036] Among them, R1, R2, and R3 are each independently selected from C1 - C5 alkyl, naphthyl or substituted phenyl, and the substituent of the substituted phenyl is H, C1 - C3 alkyl, alkoxy, halogen or -NO2; R4 is naphthyl or substituted phenyl, and the substituent of the substituted phenyl is C1 - C3 alkyl, alkoxy or halogen.

[0037] The technical features and beneficial effects of the present invention are as follows:

[0038] 1. The present invention uses enynone compounds to undergo 1,4 - conjugate phosphine hydrogenation reaction. Under the promotion of a base, the nucleophilicity of the phosphine oxide compound is enhanced, attacking the electron - deficient double bond of the enynone compound. At the same time, the base is used to regulate the diastereoselectivity of the conjugate phosphine hydrogenation reaction to obtain highly allenylphosphine oxide. The product has a novel structure, is easy to separate and purify, contains multiple active functional groups such as polysubstituted allene, carbonyl and phosphine oxide structures, has significant activity, and has potential synthetic application value.

[0039] 2. The method of the present invention conforms to atom economy and green chemistry, with an atom utilization rate of 100%. The raw materials and reagents are easily available, the preparation steps are simple, and highly allenylphosphine oxide can be prepared in one step. The reaction conditions are mild, easy to achieve and efficient, the reaction yield is relatively high, and the diastereoselectivity is excellent. Therefore, the research of the present invention is of great significance. The highly allenylphosphine oxide of the present invention can be used as a catalyst in the reaction of dehydrating carboxyl groups to form anhydrides. Specific Embodiments

[0040] The following further describes the present invention with specific examples, but the content of the present invention is not limited thereto.

[0041] The methods described in the examples are all conventional methods unless otherwise specified; the reagents used are all commercially available or can be prepared according to the existing technology unless otherwise specified.

[0042] The yield described in the examples is the molar yield.

[0043] Example 1

[0044] A highly allenylphosphine oxide has the structures shown in Formulas I-1 and I-2 as follows, and the reaction route is as follows:

[0045]

[0046] The specific preparation method is as follows:

[0047] Under a nitrogen atmosphere, 61.0 mg (0.2 mmol) of compound II-1, 178.00 mg (0.8 mmol) of compound III-1, and 110.0 mg (0.8 mmol) of potassium carbonate were added to a 10 mL reaction tube. Finally, 2 mL of dry dichloromethane was added. The resulting mixture was stirred at room temperature for 26 hours. After the reaction was completed, the resulting reaction mixture was filtered through diatomaceous earth, and the solvent was evaporated from the filtrate to obtain a crude product. The crude product was separated by silica gel column chromatography, and the eluent was a mixed solution of ethyl acetate and petroleum ether. The volume ratio of ethyl acetate to petroleum ether in the mixed solution was 1:10 to 1:1. A pair of diastereoisomers were obtained respectively, namely 78.8 mg of compound I-1 and 9.8 mg of pure product of I-2, with an overall yield of 87% and 88 / 12 d.r.

[0048] The characterization data of highly allenylphosphine oxide I-1 are as follows:

[0049] I-1: Colorless oil, 78.8 mg, yield 77%.

[0050] 1 H NMR (500 MHz, CDCl3) δ (ppm) 8.02 - 7.94 (m, 2H), 7.64 - 7.52 (m, 4H), 7.40 - 7.34 (m, 5H), 7.33 (d, J = 7.4 Hz, 1H), 7.32 - 7.24 (m, 8H), 7.22 - 7.15 (m, 3H), 7.08 (t, J = 7.6 Hz, 2H), 6.53 (d, J = 5.8 Hz, 1H), 5.37 (d, J = 7.8 Hz, 1H);

[0051] 1313C NMR(126MHz,CDCl3)δ(ppm)217.73(d,J=6.3Hz),193.23(d,J=5.04Hz),137.22,135.36(d,J=5.04Hz),132.19(dd,J=32.13,99.54Hz),132.20,131.78(d,J=2.52Hz),130.98(dd,J=8.82,47.88Hz),131.39(d,J=2.52Hz),130.38(d,J=6.3Hz),128.68,128.58(d,J=12.6Hz),128.29,128.23,128.21,128.01(d,J=27.72Hz),127.63,127.28,107.77(d,J=3.78Hz),101.61(d,J=2.52Hz),44.33(d,J=68.04Hz);

[0052] 31 31P NMR(202MHz,CDCl3)δ(ppm)29.43;

[0053] HRMS(ESI,m / z)calcd for C 35 H 27 O2P[M+H] + 511.1821,found 511.1828.

[0054] The characterization data of the allenylphosphine oxide I-2 are as follows:

[0055] I-2: Colorless oil, 9.8 mg, yield 10%.

[0056] 1 1H NMR(500MHz,CDCl3)δ(ppm)8.01-7.92(m,2H),7.68-7.57(m,4H),7.44-7.40(m,3H),7.35(d,J=7.6Hz,3H),7.32-7.27(m,3H),7.19-7.11(m,8H),6.96-6.90(m,2H),6.64(d,J=5.5Hz,1H),5.35(d,J=7.8Hz,1H);

[0057] 1313C NMR(126MHz,CDCl3)δ(ppm)218.74(d,J=7.56Hz),192.79(d,J=3.78Hz),137.31,135.82(d,J=3.78Hz),132.40(dd,J=7.56,98.28Hz),132.15,131.62(dd,J=2.52,32.76Hz),131.34(d,J=2.52Hz),131.08(d,J=8.82Hz),130.23(d,J=6.30Hz),128.62(d,J=5.04Hz),128.52(d,J=11.34Hz),128.43,128.27(d,J=11.34Hz),128.00,127.64(d,J=12.60Hz),127.29,108.64(d,J=3.78Hz),101.93(d,J=2.52Hz),43.94(d,J=69.30Hz);

[0058] 31 31P NMR(202MHz,CDCl3)δ(ppm)30.02;

[0059] HRMS(ESI,m / z)calcd for C 35 H 27 O2P[M+H] + 511.1821,found 511.1824.

[0060] Example 2

[0061] A highly allenylphosphine oxide has the structures shown in the following formulas I-3 and I-4, and the reaction route is as follows:

[0062]

[0063] The specific preparation method is as follows:

[0064] Under N2 atmosphere, 78.0 mg (0.2 mmol) of compound Ⅱ-2, 178.0 mg (0.8 mmol) of compound Ⅲ-1, 110.0 mg (0.8 mmol) of potassium carbonate were added to a 10 mL reaction tube, and finally 2 mL of dry dichloromethane was added. The resulting mixture was stirred at room temperature for 26 hours. After the reaction was completed, the resulting reaction mixture was filtered through diatomaceous earth, and the solvent was evaporated from the filtrate to obtain a crude product. The crude product was separated by silica gel column chromatography, and the eluent was a mixed solution of ethyl acetate and petroleum ether. The volume ratio of ethyl acetate to petroleum ether in the mixed solution was 1:10 to 1:1. A pair of diastereoisomers, namely compound Ⅰ-3 and Ⅰ-4, were obtained with a total yield of 99% and a d.r. of 88 / 12. 94.0 mg of pure compound Ⅰ-3 was obtained.

[0065] The characterization data of the highly allenylphosphine oxide Ⅰ-3 are as follows:

[0066] Ⅰ-3: Yellow oil, yield 88%.

[0067] 1 H NMR (500 MHz, CDCl3) δ (ppm) 7.94 - 7.87 (m, 2H), 7.55 - 7.46 (m, 4H), 7.31 - 7.26 (m, 5H), 7.24 (dd, J = 7.4, 1.5 Hz, 1H), 7.21 - 7.14 (m, 5H), 7.09 - 7.06 (m, 3H), 7.00 (t, J = 7.8 Hz, 2H), 6.77 (d, J = 8.7 Hz, 2H), 6.40 (d, J = 6.0 Hz, 1H), 5.31 (d, J = 7.8 Hz, 1H), 3.74 (s, 3H);

[0068] 1313C NMR (126 MHz, CDCl3) δ (ppm) 216.77 (d, J = 6.3 Hz), 192.23 (d, J = 5.04 Hz), 158.47, 124.75 (dd, J = 15.12, 2919.42 Hz), 134.47 (d, J = 5.04 Hz), 131.63 (d, J = 23.94 Hz), 131.05, 130.08 (dd, J = 56.70, 221.76 Hz), 130.52 (dd, J = 2.52, 49.14 Hz), 130.24 (dd, J = 8.82, 61.74 Hz), 128.11 (d, J = 119.70 Hz), 127.22 (d, J = 153.72 Hz), 127.51 (d, J = 11.34 Hz), 126.89 (d, J = 69.30 Hz), 127.07, 126.19, 123.00 (d, J = 1.26 Hz), 113.17 (d, J = 16.38 Hz), 106.65 (d, J = 37.80 Hz), 100.05 (d, J = 2.52 Hz), 54.29, 43.24 (d, J = 68.04 Hz);

[0069] 31 31P NMR (202 MHz, CDCl3) δ (ppm) 29.44;

[0070] HRMS (ESI, m / z) calcd for C 36 H 29 O3P [M+H] + 541.1927, found 541.1928.

[0071] Example 3

[0072] A highly allenylphosphine oxide has the structures shown in Formulas II-5 and I-6 as follows, and the reaction route is as follows:

[0073]

[0074] The specific preparation method is as follows:

[0075] Under N2 atmosphere, 65.0 mg (0.2 mmol) of compound Ⅱ-3, 178.00 mg (0.8 mmol) of compound Ⅲ-1, 110.0 mg (0.8 mmol) of potassium carbonate were added to a 10 mL reaction tube, and finally 2 mL of dry dichloromethane was added. The resulting mixture was stirred at room temperature for 26 hours. After the reaction was completed, the resulting reaction mixture was filtered through diatomaceous earth, and the solvent was evaporated from the filtrate to obtain a crude product. The crude product was separated by silica gel column chromatography, and the eluent was a mixture of ethyl acetate and petroleum ether. The volume ratio of ethyl acetate to petroleum ether in the mixture was 1:10 to 1:1. A pair of diastereoisomers, namely compound Ⅰ-5 and Ⅰ-6, were obtained respectively, with a total yield of 90% and a d.r. of 87 / 13. 82.1 mg of pure compound Ⅰ-5 was obtained.

[0076] The characterization data of the highly allenylphosphine oxide Ⅰ-5 are as follows:

[0077] Ⅰ-5: yellow oil, yield 80%.

[0078] 1 H NMR (500 MHz, CDCl3) δ (ppm) 8.04 - 7.94 (m, 2H), 7.61 - 7.55 (m, 4H), 7.41 - 7.35 (m, 5H), 7.31 - 7.23 (m, 4H), 7.19 - 7.15 (m, 5H), 7.13 - 7.06 (m, 4H), 6.50 (d, J = 6.0 Hz, 1H), 5.37 (d, J = 7.9 Hz, 1H), 2.36 (s, 3H);

[0079] 13 C NMR (126 MHz, CDCl3) δ (ppm) 217.89 (d, J = 6.3 Hz), 193.29 (d, J = 5.04 Hz), 137.81, 137.30, 135.47, 132.67, (d, J = 31.50 Hz), 132.10, 131.14 (dd, J = 5.67, 221.76 Hz), 131.74, 131.28 (dd, J = 8.82, 12.74 Hz), 131.35 (d, J = 0.24 Hz), 130.39 (d, J = 6.30 Hz), 128.47 (dd, J = 10.71, 21.72 Hz), 128.44 (d, J = 5.04 Hz), 128.60, 128.19, 128.31 (d, J = 26.46 Hz), 127.23, 107.72 (d, J = 2.54 Hz), 101.46 (d, J = 1.26 Hz), 44.28 (d, J = 69.30 Hz), 21.35;

[0080] 31³¹P NMR (202 MHz, CDCl₃) δ (ppm) 29.31;

[0081] HRMS (ESI, m / z) calcd for C 36 H 29 O₂P [M + H] + 525.1978, found 525.1981.

[0082] Example 4

[0083] A highly allenylphosphine oxide has the structures shown in the following formulas I-7 and I-8, and the reaction route is as follows:

[0084]

[0085] The specific preparation method is as follows:

[0086] Under a N₂ atmosphere, 76.0 mg (0.2 mmol) of compound II-4, 178.00 mg (0.8 mmol) of compound III-1, 110.0 mg (0.8 mmol) of potassium carbonate were added to a 10 mL reaction tube, and finally 2 mL of dry dichloromethane was added. The resulting mixture was stirred at room temperature for 26 hours; after the reaction was completed, the resulting reaction mixture was filtered through diatomaceous earth, the filtrate was evaporated to remove the solvent to obtain a crude product, which was separated by silica gel column chromatography. The eluent was a mixed solution of ethyl acetate and petroleum ether, and the volume ratio of ethyl acetate to petroleum ether in the mixed solution was 1:10 to 1:1. A pair of diastereoisomers, namely compound I-7 and I-8, were obtained respectively, with a total yield of 90%, 89 / 11 d.r. 94.4 mg of pure compound I-7 was obtained.

[0087] The characterization data of highly allenylphosphine oxide I-7 are as follows:

[0088] I-7: Yellow oil, yield 81%.

[0089] 1 ¹H NMR (500 MHz, CDCl₃) δ (ppm) 8.00 - 7.93 (m, 2H), 7.61 - 7.52 (m, 4H), 7.47 - 7.38 (m, 5H), 7.35 - 7.31 (m, 4H), 7.26 (s, 2H), 7.20 - 7.15 (m, 5H), 7.11 (t, J = 7.6 Hz, 2H), 6.48 (d, J = 5.8 Hz, 1H), 5.34 (d, J = 7.7 Hz, 1H);

[0090] 1313C NMR(126MHz,CDCl3)δ(ppm)217.72(d,J=6.30Hz),192.95,137.17,135.20(d,J=5.04Hz),132.51,132.33,131.91(d,J=3.78Hz),131.85,131.19(dd,J=8.82,56.70Hz),130.28(d,J=5.04Hz),129.75,128.67(d,J=11.34Hz),128.56,128.19(d,J=12.60Hz),128.14,127.71,127.35,121.92,108.07(d,J=3.78Hz),100.68(d,J=2.52Hz),44.24(d,J=69.30Hz); 31 31P NMR(202MHz,CDCl3)δ(ppm)29.58;

[0091] HRMS(ESI,m / z)calcd for C 35 H 26 BrO2P[M+H] + 589.0927,found 589.0939.

[0092] Example 5

[0093] A highly allenyl phosphine oxide has the structures shown in the following formulas I-9 and I-10, and the reaction route is as follows:

[0094]

[0095] The specific preparation method is as follows:

[0096] Under a nitrogen atmosphere, 61.0 mg (0.2 mmol) of compound II-1, 184.2 mg (0.8 mmol) of compound III-2, and 110.0 mg (0.8 mmol) of potassium carbonate were added to a 10 mL reaction tube. Finally, 2 mL of dry dichloromethane was added. The resulting mixture was stirred at room temperature for 26 hours. After the reaction was completed, the resulting reaction mixture was filtered through diatomaceous earth, and the solvent was evaporated from the filtrate to obtain a crude product. The crude product was separated by silica gel column chromatography, and the eluent was a mixed solution of ethyl acetate and petroleum ether. The volume ratio of ethyl acetate to petroleum ether in the mixed solution was 1:10 to 1:1. A pair of diastereoisomers, namely compound I-9 and I-10, were obtained respectively, with a total yield of 84% and a d.r. of 78 / 22. 70.5 mg of pure compound I-9 was obtained.

[0097] The characterization data of the highly allenyl phosphine oxide I-9 are as follows:

[0098] Ⅰ-9: Yellow oil, yield 74%.

[0099] 1 H NMR(500MHz,CDCl3)δ(ppm)7.86 - 7.80(m,2H),7.61 - 7.53(m,2H),7.47 - 7.41(m,2H),7.38(d,J = 7.7Hz,2H),7.29 - 7.25(m,5H),7.26 - 7.22(m,1H),7.21 - 7.13(m,5H),7.10 - 7.03(m,4H),6.52(d,J = 5.7Hz,1H),5.32(d,J = 7.9Hz,1H),2.25(d,J = 4.4Hz,6H);

[0100] 13 C NMR(126MHz,CDCl3)δ(ppm)218.59(d,J = 6.30Hz),192.83(d,J = 5.04Hz),141.91(dd,J = 2.52,36.54Hz),137.38,136.15(d,J = 3.78Hz),132.09,131.46(d,J = 2.52Hz),131.19(dd,J = 10.08,32.76Hz),130.25(d,J = 6.30Hz),129.78(d,J = 6.30Hz),129.57,129.11(dd,J = 11.34,28.98Hz),128.69,128.56,128.39,127.92,127.60(d,J = 6.30Hz),127.16,108.86(d,J = 3.78Hz),101.86(d,J = 2.52Hz),44.14(d,J = 68.04Hz),21.48;

[0101] 31 P NMR(202MHz,CDCl3)δ(ppm)30.37;

[0102] HRMS(ESI,m / z)calcd for C 37 H 31 O2P[M + H] + 539.2134,found 539.2135.

[0103] Example 6

[0104] A method for preparing a highly allenyl phosphine oxide, as described in Example 1, except that: potassium carbonate is replaced with triethylamine in the same molar amount; other steps and conditions are the same as in Example 1.

[0105] In this example, the type of base was changed, and the total yield of compounds I-1 and I-2 was 68%, with a 33 / 67 d.r.

[0106] Example 7

[0107] A method for preparing a highly allenylphosphine oxide, as described in Example 1, except that: the solvent dichloromethane was replaced with the same volume of tetrahydrofuran; other steps and conditions were the same as in Example 1.

[0108] In this example, the type of solvent was changed, and the total yield of compounds I-1 and I-2 was 34%, with a 75 / 25 d.r.

[0109] Example 8

[0110] A method for preparing a highly allenylphosphine oxide, as described in Example 1, except that: the amount of phosphine oxide compound III was 0.4 mmol, and the amount of potassium carbonate was 0.8 mmol; other steps and conditions were the same as in Example 1.

[0111] The total yield of the obtained compounds I-1 and I-2 was 85%, with a 20 / 80 d.r.

[0112] Example 9

[0113] A method for preparing a highly allenylphosphine oxide, as described in Example 1, except that: the amount of phosphine oxide compound III was 0.6 mmol, and the amount of potassium carbonate was 0.6 mmol; other steps and conditions were the same as in Example 1.

[0114] The total yield of the obtained compounds I-1 and I-2 was 69%, with a 43 / 57 d.r.

[0115] Example 10

[0116] A method for preparing a highly allenylphosphine oxide, as described in Example 1, except that: the amount of phosphine oxide compound III was 0.6 mmol, and the amount of potassium carbonate was 0.8 mmol; other steps and conditions were the same as in Example 1.

[0117] The total yield of the obtained compounds I-1 and I-2 was 84%, with a 17 / 83 d.r.

[0118] Example 11

[0119] A method for preparing a highly allenylphosphine oxide, as described in Example 1, except that: the amount of phosphine oxide compound III was 0.8 mmol, and the amount of potassium carbonate was 0.4 mmol; other steps and conditions were the same as in Example 1.

[0120] The total yield of the obtained compounds I-1 and I-2 was 81%, with a 25 / 75 d.r.

[0121] Application Example 1

[0122] Using higher allenylic phosphine oxide as a catalyst, it is applied to catalyze the dehydration reaction between p-methylbenzoic acids:

[0123]

[0124] The specific preparation method is as follows:

[0125] Under an N2 atmosphere, 102.0 mg (0.2 mmol) of the pure product of compound I-1, 1 ml of anhydrous acetonitrile and 22 μl (0.26 mmol) of oxalyl chloride were added to a 10 mL reaction tube, and the mixture was stirred at room temperature for 10 minutes. Then, 27 mg (0.2 mmol) of compound IV-1 and 27 μl (0.2 mmol) of triethylamine were added successively, and the resulting mixture was stirred at room temperature for 12 hours. After the reaction was completed, the resulting reaction mixture was filtered through diatomaceous earth, the solvent of the filtrate was evaporated to obtain a crude product, which was separated by silica gel column chromatography, and the eluent was a mixed solution of ethyl acetate and petroleum ether. The volume ratio of ethyl acetate to petroleum ether in the mixed solution was 1:3 to 1:1 to obtain the product, that is, compound IV-2, with an overall yield of 57.5%. 29.2 mg of the pure product of compound IV-2 was obtained.

[0126] Application Comparative Example 1

[0127] For the dehydration reaction between p-methylbenzoic acids, as described in Application Example 1, the difference is that compound I-1 was not added, and the other steps and conditions were the same as those in Application Example 1. Compound IV-2 was not obtained finally. Since the catalyst compound I-1 was not added, the reaction could not proceed.

Claims

1. A homoalkenyl phosphine oxide, characterized in that: It has the structure shown in the following formula I: Wherein, R1, R2, R3 are each independently selected from C1-C5 alkyl, naphthyl or substituted phenyl, the substituent of the substituted phenyl is H, C1-C3 alkyl, alkoxy, halogen or -NO2; R4 is naphthyl or substituted phenyl, the substituent of the substituted phenyl is C1-C3 alkyl, alkoxy or halogen.

2. The homoalkenyl phosphine oxide according to claim 1, characterized in that: The R1 is a substituted phenyl group, the substituent of the substituted phenyl group is H, alkoxy or halogen; the R2 is a substituted phenyl group, the substituent of the substituted phenyl group is H; the R3 is a substituted phenyl group, the substituent of the substituted phenyl group is H, C1-C3 alkyl, alkoxy or halogen; the R4 is a substituted phenyl group, the substituent of the substituted phenyl group is H or C1-C3 alkyl.

3. The homoalkenyl phosphine oxide according to claim 1, characterized in that: The homoalkenyl phosphine oxide is selected from one of the following compounds:

4. The method for preparing the homoalkenyl phosphine oxide according to any one of claims 1 to 3, comprising the steps of: In solvent A, under the promotion of a base, enynone compound II and phosphine oxide compound III undergo conjugated phosphine hydrogenation reaction to obtain high-alkenyl phosphine oxide I; in, In the structural formula of the enynone compound II, the substituents R1, R2, and R3 are the same as R1, R2, and R3 in the compound of formula I; in the structural formula of the phosphine oxide compound III, the substituent R4 is the same as R4 in the compound of formula I.

5. The method for preparing a homoalkenyl phosphine oxide according to claim 4, characterized in that: The enynyl ketone compound II is selected from one of the following compounds:

6. The method for preparing a homoalkenyl phosphine oxide according to claim 4, characterized in that: The phosphine oxide compound III is selected from one of the following compounds:

7. The method for preparing a homoalkenyl phosphine oxide according to claim 4, characterized in that: Includes one or more of the following conditions: i. The solvent A is tetrahydrofuran or dichloromethane, preferably dichloromethane; the ratio of the volume of the solvent A to the molar number of the enynyl ketone compound II is 2.5-10 mL:1 mmol, preferably 8-10 mL:1 mmol; ii. The temperature of the conjugated phosphine hydrogenation reaction is zero degrees to room temperature, the reaction time is 12 to 48 hours, and the reaction is carried out under stirring conditions; iii. The conjugated phosphine hydrogenation reaction is carried out under a nitrogen or argon atmosphere.

8. The method for preparing a homoalkenyl phosphine oxide according to claim 4, characterized in that: The base is one or a combination of two or more of triethylamine, diisopropylamine, N,N-diisopropylethylamine (DIPEA), 1,8-diazabicycloundec-7-ene (DBU), potassium carbonate, cesium carbonate, lithium tert-butoxide, sodium tert-butoxide or potassium tert-butoxide, preferably potassium carbonate; the molar ratio of the base to the enynone compound II is 1.2 to 4:1, preferably 4:

1.

9. The method for preparing a homoalkenyl phosphine oxide according to claim 4, characterized in that: The molar ratio of the phosphine oxide compound III to the enynone compound II is 1.2 to 4:1, preferably 4:

1.

10. The use of the homoalkenyl phosphine oxide according to any one of claims 1 to 3, characterized in that: It is used as a catalyst to catalyze the dehydration reaction between carboxyl compounds to generate acid anhydrides; preferably, the carboxyl compound is p-toluic acid.

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