A triarylphosphine compound based on a phospholene structure and a preparation method thereof

Abstract

The application provides a kind of triarylphosphine compound based on phospholene structure and a preparation method thereof, which is a triarylphosphine compound shown in the following formula (I), and the compound can be used as an organic monophosphine ligand in organic synthesis methodology.The synthesis method avoids the use of highly polluting chlorine gas in traditional phosphorus chemical production and the subsequent emission problems, and is an extremely environmentally friendly production method.In addition, the method disclosed in the application has mild reaction conditions, short reaction time, simple post-treatment and high yield.

Description

Technical Field

[0001] This invention relates to the field of organophosphorus chemistry and chemical engineering, and more specifically, to a triarylphosphine compound based on the phosphane fluorene structural unit and its preparation method. Background Technology

[0002] Triarylphosphine compounds are among the most common trivalent organophosphine compounds, widely used in organic chemistry research, including organic synthetic chemistry, organometallic chemistry, and coordination chemistry. Triphenylphosphine is a typical example. As a good σ-electron donor and π-electron acceptor, triphenylphosphine can effectively alter the electronic effects of the metal center, thereby affecting the activity and selectivity of catalytic reactions. Currently, most triarylphosphine compounds are modified with triphenylphosphine as the basic structure, resulting in diverse structures and a wide variety of types. Among them, triarylphosphine compounds with polyfluorophenyl groups on the phosphorus atom (structural formula: [structural formula missing]) are particularly noteworthy. Typically, this process involves adding lithium metal to diphenylphosphine chloride (Ph₂PCl) to obtain lithium diphenylphosphine, reacting it with trimethylaluminosilicate (Me₃SiCl) to obtain diphenyltrimethylsilylphosphine, and finally reacting it with pentafluorobenzene to obtain a triarylphosphine compound with a tetrafluorophenyl group (see Non-Patent Literature 1). In contrast, triarylphosphine compounds that link the two aryl groups on the phosphorus atom, i.e., triarylphosphine compounds based on the phosphorus fluorene structure (structural formula: [structural formula missing]), offer a more efficient alternative. There have been no reports yet, mainly due to the lack of effective synthesis methods.

[0003] As can be seen, in the existing technology, the starting material diphenylphosphine chloride is a basic phosphorus chemical product. Industrially, it is prepared from white phosphorus (P4) as the starting material. In this process, chlorine gas, which is toxic to both the environment and human health, is required. The process also generates a large amount of waste gas and waste acid during the reaction. The entire production process is not only energy-intensive, but also extremely polluting to the environment (refer to non-patent literature 2).

[0004] Therefore, in view of the above-mentioned problems, there is an urgent need to find a readily available raw material that can replace chlorine to easily synthesize triarylphosphine compounds. The present invention solves the above-mentioned problems based on a previously unreported method for synthesizing triarylphosphine compounds based on the phosphonium structure.

[0005] Existing technical literature Non-patent literature:

[0006] Non-patent literature 1: J. Fluerine Chem. 2014, 164, 58–69.

[0007] Non-patent literature 2: Acc. Chem. Res. 2014, 47, 77–87. Summary of the Invention The technical problem that the invention aims to solve

[0008] The present invention was made in view of the above-mentioned problems, and its purpose is to provide a triarylphosphine compound based on the phosphonium structure and its preparation method, which can not only be synthesized efficiently, but also greatly reduce the environmental pollution caused during the production process.

[0009] Solution for solving the problem The technical solution of the present invention is as follows:

[0010] One aspect of the present invention is a triarylphosphine compound, which is a compound containing a phosphaphene structural unit as shown in formula (I), characterized in that...

[0011] Among them, R 1 and R 2 They can be the same or different, each independently being hydrogen, halogen, nitro, cyano, trifluoromethyl, trifluoromethoxy, C1-C6 alkyl (including straight-chain alkyl, branched alkyl and cycloalkyl), C1-C6 alkoxy, substituted or unsubstituted phenyl, pyridyl, thiophene.

[0012] In a preferred manner, the R 1 and R 2 Each can be independently hydrogen, halogen, methyl, tert-butyl, trifluoromethyl, trifluoromethoxy, nitro, methoxy, ethoxy, or phenyl.

[0013] In a preferred manner, the R 1 and R 2 Each can be independently hydrogen, halogen, methyl, tert-butyl, trifluoromethyl, or trifluoromethoxy.

[0014] R 3 It is selected from any one of hydrogen, halogen, nitro, cyano, trifluoromethyl, trifluoromethoxy, C1-C6 alkyl (including straight-chain alkyl, branched alkyl and cycloalkyl), C1-C6 alkoxy, substituted or unsubstituted phenyl, pyridyl, thiophene.

[0015] In a preferred manner, the R 3 Selected from hydrogen, halogen, trifluoromethyl, and trifluoromethoxy.

[0016] Another aspect of the present invention relates to a method for preparing a triarylphosphine compound, which is a method for preparing a compound containing a phosphaphene structural unit as shown in formula (I).

[0017] In equation (I), R 1and R 2 They can be the same or different, and can be hydrogen, halogen, nitro, cyano, trifluoromethyl, trifluoromethoxy, C1~C6 alkyl (including straight-chain alkyl, branched alkyl and cycloalkyl), C1~C6 alkoxy, substituted or unsubstituted phenyl, pyridinyl, thiophene.

[0018] In a preferred manner, the R 1 and R 2 Each can be independently hydrogen, halogen, methyl, tert-butyl, trifluoromethyl, or trifluoromethoxy.

[0019] R 3 It is selected from any one of hydrogen, halogen, nitro, cyano, trifluoromethyl, trifluoromethoxy, C1-C6 alkyl (including straight-chain alkyl, branched alkyl and cycloalkyl), C1-C6 alkoxy, substituted or unsubstituted phenyl, pyridyl, thiophene.

[0020] In a preferred manner, the R 3 Selected from hydrogen, halogen, trifluoromethyl, and trifluoromethoxy.

[0021] The reaction formula for the preparation method is as follows:

[0022] The preparation method includes the following steps:

[0023] Step 1-1: Dissolve compound (II) in a solvent, then add white phosphorus and react at room temperature or above.

[0024] In the compound of formula (II), M can be an alkali metal or an alkaline earth metal, wherein the alkali metal is lithium, sodium, or potassium, and the alkaline earth metal is calcium or magnesium, preferably lithium.

[0025] In reaction step 1-1, the reaction temperature is in the range of room temperature to 50°C, preferably 25°C to 40°C; more preferably 28°C to 35°C; the reaction time is 6 to 24 hours, preferably 10 to 20 hours.

[0026] The solvent used in the above reaction is not particularly limited, as long as it is an organic solvent that can dissolve the reactants without reacting with them. Examples include tetrahydrofuran (THF), diethyl ether (Et2O), benzene, toluene, 1,4-dioxane, dimethyl ethylene glycol (DME), or tetramethylethylenediamine (TMEDA). Tetrahydrofuran (THF) and diethyl ether (Et2O) are preferred, and tetrahydrofuran (THF) is more preferred.

[0027] Regarding the ratio of compound (II) to white phosphorus (P4), the ratio of white phosphorus (P4) to compound (II) is 1 to 1.5 molar equivalents, preferably 1.1 to 1.45 molar equivalents, and more preferably 1.2 to 1.4 molar equivalents.

[0028] Step 1-2: Add compound (III) to the reaction mixture obtained in step 1-1 and react at room temperature to obtain compound (I).

[0029] In compound (III), R 3 It is selected from any one of hydrogen, halogen, nitro, cyano, trifluoromethyl, trifluoromethoxy, C1-C6 alkyl (including straight-chain alkyl, branched alkyl and cycloalkyl), C1-C6 alkoxy, substituted or unsubstituted phenyl, pyridyl, thiophene.

[0030] Wherein, the R 3 It is selected from any one of hydrogen, halogen, trifluoromethyl, and trifluoromethoxy.

[0031] In reaction steps 1-2, the reaction temperature is in the range of 0 °C to room temperature; the reaction time is 0.5 to 6 hours, preferably 1 to 5 hours, and more preferably 2 to 4 hours.

[0032] The solvent used in the above reaction is not particularly limited, as long as it is an organic solvent that can dissolve the reactants without reacting with them. Examples include tetrahydrofuran (THF), diethyl ether (Et2O), benzene, toluene, 1,4-dioxane, dimethyl ethylene glycol ether (DME), or tetramethylethylenediamine (TMEDA). Tetrahydrofuran (THF) and diethyl ether (Et2O) are preferred, and tetrahydrofuran (THF) is more preferred.

[0033] For the ratio of compound (III) to compound (II), the ratio of compound (III) to compound (II) is 1 to 1.3 molar equivalents, preferably 1.1 to 1.2 molar equivalents.

[0034] The solvents used in steps 1-1 and 1-2 above can be the same or different. For ease of operation and post-processing, it is preferred that the solvents in each step be the same; however, for optimal yield and effect, it is also preferred that the solvents in each step be different.

[0035] Furthermore, the compounds represented by formula (I) of this invention, namely triarylphosphine compounds containing a phosphafluorene structure, can also be directly used as organic monophosphine ligands for further application in organic synthesis methodology research. Effects of the Invention

[0036] According to the present invention, a triarylphosphine compound containing a phosphorus fluorene structure and its preparation method are provided. Since this reaction uses readily available and inexpensive raw materials such as white phosphorus, polyfluorobenzene, and solvents for synthesis, this method not only eliminates the need for the previously used diphenylphosphine chloride (Ph₂PCl) raw material, but also overcomes the highly polluting chlorine gas used in traditional phosphate chemical production and the resulting subsequent emission problems, making it a more environmentally friendly production method. This invention also pioneers a novel synthetic method for triarylphosphine compounds, and this synthetic method features mild reaction conditions, short reaction time, simple post-processing, and high yield, making it a simple, effective, economical, and practical synthetic method.

[0037] The triarylphosphine compound based on the phosphafluorene structure provided by this invention can be used as an organic monophosphine ligand in organic synthesis methodologies, and its catalytic effect can be further improved by adjusting the substituents. Compared with existing technologies, it has the advantages of diverse substituent types, simple synthesis, and high efficiency. Detailed Implementation

[0038] The following specific embodiments further illustrate the above-described contents of the present invention in detail, but should not be construed as limiting the scope of protection of the present invention in any way. All technical solutions implemented based on the above-described contents of the present invention fall within the scope of the present invention. The present invention provides a general and / or specific description of the materials and test methods used in the experiments. Those skilled in the art will understand that, unless otherwise specified, the room temperature mentioned in the following text has a technically known meaning in the art, generally referring to 20~25°C; all chemicals mentioned are commercially available.

[0039] The triarylphosphine compound of the present invention is a compound containing a phosphorus fluorene structure as shown in formula (I).

[0040]

[0041] In the triarylphosphine compound shown in formula (I) above, R 1 and R 2 They can be the same or different, and can be hydrogen, halogen, nitro, cyano, trifluoromethyl, trifluoromethoxy, C1~C6 alkyl (including straight-chain alkyl, branched alkyl and cycloalkyl), C1~C6 alkoxy, substituted or unsubstituted phenyl, pyridinyl, thiophene.

[0042] Wherein, the R 1 and R 2 Preferably, each of the following can be independently hydrogen, halogen, trifluoromethyl, trifluoromethoxy, C1-C6 alkyl, or C1-C6 alkoxy. Alkyl groups are preferably methyl, ethyl, or tert-butyl; alkoxy groups are preferably methoxy or ethoxy; R 1 and R2 Further preferred groups include hydrogen, methyl, methoxy, tert-butyl, trifluoromethyl, and fluorine.

[0043] R 3 It is selected from any one of hydrogen, halogen, nitro, cyano, trifluoromethyl, trifluoromethoxy, C1-C6 alkyl (including straight-chain alkyl, branched alkyl and cycloalkyl), C1-C6 alkoxy, substituted or unsubstituted phenyl, pyridyl, thiophene.

[0044] Wherein, the R 3 Hydrogen, halogen, trifluoromethyl, and trifluoromethoxy are preferred.

[0045] Preparation of compounds

[0046] The method for preparing the triarylphosphine compound of the present invention is a method for preparing the compound containing the phosphaphene structure shown in formula (I), and the preparation reaction formula is as follows:

[0047] The reaction includes the following steps:

[0048] Step 1-1: Dissolve compound (II) in a solvent, then add white phosphorus and react at room temperature or above.

[0049] In the compound of formula (II), M can be an alkali metal or an alkaline earth metal. The alkali metal is lithium, sodium, or potassium, and the alkaline earth metal is calcium or magnesium, with lithium being preferred.

[0050] In reaction step 1-1, the reaction temperature is in the range of room temperature to 50°C, preferably 25°C to 40°C; more preferably 28°C to 35°C, and the reaction time is 6 to 24 hours, preferably 10 to 20 hours, and more preferably 11 to 18 hours.

[0051] The solvent used in the above reaction is not particularly limited, as long as it is an organic solvent that can dissolve the reactants without reacting with them. Examples include tetrahydrofuran (THF), diethyl ether (Et2O), benzene, toluene, 1,4-dioxane, dimethyl ethylene glycol (DME), or tetramethylethylenediamine (TMEDA). Tetrahydrofuran (THF) and diethyl ether (Et2O) are preferred, and tetrahydrofuran (THF) is more preferred.

[0052] Regarding the ratio of compound (II) to white phosphorus (P4), the ratio of white phosphorus (P4) to compound (II) is 1 to 1.5 molar equivalents, preferably 1.1 to 1.45 molar equivalents, and more preferably 1.2 to 1.4 molar equivalents.

[0053] Step 1-2: Add compound (III) to the reaction mixture obtained in step 1-1 and continue the reaction below room temperature.

[0054] In compound (III), R 3 It is selected from any one of hydrogen, halogen, nitro, cyano, trifluoromethyl, trifluoromethoxy, C1-C6 alkyl (including straight-chain alkyl, branched alkyl and cycloalkyl), C1-C6 alkoxy, substituted or unsubstituted phenyl, pyridyl, thiophene.

[0055] The R 3 Preferably selected from hydrogen, halogen, trifluoromethyl, and trifluoromethoxy.

[0056] In reaction steps 1-2, the reaction temperature is in the range of 0 °C to room temperature; the reaction time is 0.5 to 6 hours, preferably 1 to 5 hours, and more preferably 2 to 4 hours.

[0057] The solvent used in the above reaction is not particularly limited, as long as it is an organic solvent that can dissolve the reactants without reacting with them. Examples include tetrahydrofuran (THF), diethyl ether (Et2O), benzene, toluene, 1,4-dioxane, dimethyl ethylene glycol ether (DME), or tetramethylethylenediamine (TMEDA). Tetrahydrofuran (THF) and diethyl ether (Et2O) are preferred, and tetrahydrofuran (THF) is more preferred.

[0058] For the ratio of compound (III) to compound (II), the ratio of compound (III) to compound (II) is 1 to 1.3 molar equivalents, preferably 1.1 to 1.2 molar equivalents.

[0059] The solvents used in steps 1-1 and 1-2 above can be the same or different. For ease of operation and post-processing, it is preferred that the solvents in each step be the same; however, for optimal yield and effect, it is also preferred that the solvents in each step be different.

[0060] As can be seen from the above preparation method, the reactants are easy to obtain, the reaction conditions are very mild, and the reaction time is relatively short. In addition, as can be seen from the reaction operation of the examples described later, the post-processing operation is also simple, and a high yield can be obtained, which is also economically advantageous.

[0061] The preparation method of the above compounds is described in detail below through examples.

[0062] Synthesis of compound (I)

[0063] Example 1: Synthesis of 9-Tetrafluorophenyl-9-phosphafluorene

[0064] At room temperature, 1.0 mmol of 2,2'-dilithium-1,1'-biphenyl was added to a 25 mL reaction flask, dissolved in 10 mL of tetrahydrofuran, followed by the addition of 1.1 mmol of white phosphorus. After reacting at 30 °C for 15 hours, the reaction system became a dark brown solution. Then, 1.1 mmol of pentafluorobenzene was added, and the reaction was continued at 20 °C for 5 hours. After the reaction was complete, the flocculent matter was removed by filtration. The reaction solvent was concentrated and separated by column chromatography using a petroleum ether / ethyl acetate mixture. The solvent was removed by rotary evaporation, yielding 266 mg of 9-tetrafluorophenyl-9-phosphafluorene (white solid), with a separation yield of 80%.

[0065] Key NMR data: 1 H NMR (400 MHz, CDCl3): δ 7.73 (ddd, J = 16.7, 9.3, 7.4Hz, 1H), 7.31-7.41 (m, 2H), 7.53 (t, J = 7.5 Hz, 2H), 7.71-7.79 (m, 2H), 7.98(d, J = 7.8 Hz,2H); 13 C NMR (126 MHz, CDCl3) δ 108.1 (t, J = 22.6 Hz), 121.7,127.9 (d, J = 7.4 Hz), 129.5, 130.5 (d, J = 23.0 Hz), 138.6 (q, J = 2.7 Hz),144.7 (d, J = 7.3 Hz), 144.7-145.0 (m), 146.4-147.3 (m), 148.8-149.2 (m);DEPT 135 (126 MHz, CDCl3) δ 108.1 (t, J = 22.6 Hz), 121.7, 127.9 (d, J = 7.4Hz), 129.5, 130.5 (d, J = 23.0 Hz); 31 P{ 1 H} NMR (202 MHz, CDCl3) δ -38.72 (t,J = 33.9 Hz); 19 F NMR (471 MHz, CDCl3) δ -137.88 (dd, J = 22.6, 13.3 Hz, 2F), -130.73– -130.41 (m, 2F). Example 2: Synthesis of 9-perfluorotoluene-9-phosphafluorene

[0066] At room temperature, 1.0 mmol of 2,2'-dilithium-1,1'-biphenyl was added to a 25 mL reaction flask, dissolved in 10 mL of diethyl ether, followed by the addition of 1.2 mmol of white phosphorus. After reacting at 40 °C for 12 hours, the reaction system became a dark brown solution. Then, 1.2 mmol of octafluorotoluene was added, and the reaction was continued at 15 °C for 6 hours. After the reaction was complete, the flocculent matter was removed by filtration. The reaction solvent was concentrated and separated by column chromatography using a petroleum ether / ethyl acetate mixture. The solvent was removed by rotary evaporation to obtain 340 mg of 9-perfluorotoluyl-9-phosphafluorene (white solid), with a separation yield of 85%.

[0067] Key NMR data: 1 H NMR (400 MHz, CDCl3): δ 7.38 (td, J = 7.5, 3.3 Hz, 2H), 7.55 (t, J = 7.5 Hz, 2H), 7.72-7.78 (m, 2H), 7.98 (d, J = 7.8 Hz, 2H). 13 C NMR (126 MHz, CDCl3) δ 121.8, 128.2 (d, J = 7.5 Hz), 130.0, 130.7 (d, J =23.1 Hz), 134.9 (d, J = 2.3 Hz), 137.3 (d, J = 2.6 Hz), 144.9 (d, J = 4.2Hz); DEPT 135 (126 MHz, CDCl3) δ 121.8, 128.2 (d, J = 7.5 Hz), 130.0, 130.7(d, J = 23.1 Hz); 31 P{ 1 H} NMR (202 MHz, CDCl3) δ -37.53 (t, J = 31.6 Hz); 19 FNMR (471 MHz, CDCl3) δ -139.84– -139.52 (m, 2F), -128.55– -128.02 (m, 2F), -56.63 (t, J = 21.7 Hz, 3F).

[0068] Example 3: Synthesis of 9-tetrafluorophenyl-9-dibenzophosphonium

[0069] At room temperature, 1.0 mmol of 2,2'-dilithium-1,1'-binaphthylene was added to a 25 mL reaction flask, dissolved in 10 mL of diethyl ether, followed by the addition of 1.2 mmol of white phosphorus. After reacting at 35 °C for 20 hours, the reaction mixture became a dark brown solution. Then, 1.1 mmol of pentafluorobenzene was added, and the reaction was continued at 20 °C for 5 hours. After the reaction was complete, the flocculent matter was removed by filtration. The reaction solvent was concentrated and then separated by column chromatography using a petroleum ether / ethyl acetate mixture. The solvent was removed by rotary evaporation to obtain 324 mg of 9-tetrafluorophenyl-9-dibenzophosphonium fluorene (white solid), with a separation yield of 75%.

[0070] Key NMR data: 1 H NMR (400 MHz, CDCl3): δ 7.04 (ddd, J = 16.7, 9.3, 7.4Hz, 1H), 7.52 (td, J = 7.6, 6.8, 1.3 Hz, 2H), 7.59 (t, J = 7.1 Hz, 2H), 7.81-7.88 (m, 2H), 7.92 (dd, J = 8.2, 3.1 Hz, 2H), 7.99 (d, J = 7.9 Hz, 2H), 8.45(d, J = 8.5 Hz, 2H); 13 C NMR (126 MHz, CDCl3) δ 108.8 (t, J = 23.0 Hz), 125.9,127.0, 127.2, 128.4, 129.1, 129.5, 130.8, 136.0, 138.8, 146.1 (ddd, J = DEPT 135 (126 MHz, CDCl3) δ108.8 (t, J = 23.0 Hz), 125.9, 127.0, 127.2, 128.4, 129.1, 129.5; 31 P{ 1 H} NMR(202 MHz, CDCl3) δ -34.66 (t, J = 32.3 Hz); 19 F NMR (471 MHz, CDCl3) δ -137.70– -137.51 (m, 2F), -130.24– -137.51 (m, 2F).

[0071] Example 4: Synthesis of 9-perfluorotolyl-9-dibenzophosphonium

[0072] At room temperature, 1.0 mmol of 2,2'-dilithium-1,1'-biphenyl was added to a 25 mL reaction flask, dissolved in 10 mL of tetrahydrofuran, followed by the addition of 1.1 mmol of white phosphorus. After reacting at 30 °C for 18 hours, the reaction system became a dark brown solution. Then, 1.2 mmol of octafluorotoluene was added, and the reaction was continued at 20 °C for 3 hours. After the reaction was complete, the flocculent matter was removed by filtration. The reaction solvent was concentrated and separated by column chromatography using a petroleum ether / ethyl acetate mixture. The solvent was removed by rotary evaporation to obtain 410 mg of 9-perfluorotoluyl-9-dibenzophosphonium fluorene (white solid), with a separation yield of 82%.

[0073] Key NMR data: 1 H NMR (400 MHz, CDCl3): δ 7.53 (td, J = 7.6, 6.8, 1.3Hz, 2H), 7.61 (t, J = 7.2 Hz, 2H), 7.80-7.89 (m, 2H), 7.95 (dd, J = 8.2, 3.2Hz, 2H), 8.00 (d, J = 8.0 Hz, 2H), 8.44 (d, J = 8.5 Hz, 2H); 13 C NMR (126 MHz, CDCl3) δ 111.2 (qt, J = 34.8, 12.7 Hz), 119.7-120.5 (m), 120.7 (q, J = 274.8Hz), 125.3, 126.4, 126.7, 127.6, 128.7, DEPT 135 (126 MHz, CDCl3) δ 121.8, 128.2 (d, J = 7.5 Hz),130.0, 130.7 (d, J = 23.1 Hz); 125.3, 126.4, 126.7, 127.6, 128.7, 129.0; 31 P{ 1H} NMR (202 MHz, CDCl3) δ -33.67 (t, J = 29.2 Hz); 19 F NMR (471 MHz, CDCl3) δ-139.72– -139.10 (m, 2F), -128.12– -127.45 (m, 2F), -56.63 (t, J = 22.1 Hz, 3F). Industry availability

[0074] The triarylphosphine compounds based on the phosphonium structure of the present invention have promising applications as organic monophosphine ligands in organic synthesis methodologies.

Claims

1. A method for preparing a triarylphosphine compound, which is a method for preparing a compound containing a phosphorus fluorene structure as shown in formula (I) below. In equation (I), R 1 and R 2 They may be the same or different, and each can independently be hydrogen, halogen, nitro, cyano, trifluoromethyl, trifluoromethoxy, C1-C6 alkyl, C1-C6 alkoxy, substituted or unsubstituted phenyl, pyridyl, thiophene; R 3 It is selected from any one of hydrogen, halogen, nitro, cyano, trifluoromethyl, trifluoromethoxy, C1-C6 alkyl, C1-C6 alkoxy, substituted or unsubstituted phenyl, pyridyl, and thiophene. The preparation method includes the following steps: Step 1-1: Dissolve compound (II) in a solvent, then add white phosphorus and react at room temperature or above. In compound (II), M is an alkali metal lithium, and R... 1 and R 2 Same as equation (I); The compound of formula (II) used is in a ratio of 1 to 1.5 molar equivalents to white phosphorus; Step 1-2: Add compound (III) to the reaction mixture obtained in step 1-1, and react at room temperature to obtain the compound shown in formula (I), where R in formula (III) is a compound of formula (I). 3 Same as equation (I); The ratio of the compound of formula (III) to the compound of formula (II) is 1 to 1.2 molar equivalents.

2. The method for preparing the triarylphosphine compound according to claim 1, characterized in that, In step 1-1, the reaction temperature is from room temperature to 50°C, and the reaction time is 6 to 24 hours. In steps 1-2, the reaction temperature is within the range of 0 ℃ to room temperature, and the reaction time is 0.5 ~ 6 hours.

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