Organophosphorus compounds based on phospholene oxide structural units and methods for their preparation

Abstract

This invention provides a class of organophosphorus compounds based on phosphane structural units and their preparation methods, namely phosphane phosphonium oxides represented by formula (II) and phosphane phosphonium hydrogens represented by formula (III). These organophosphorus compounds are widely used in the manufacture of optoelectronic devices. Their synthesis method avoids the use of highly polluting chlorine gas and the subsequent emissions problems caused by traditional phosphorus chemical production, making it an extremely environmentally friendly production method. Furthermore, the method disclosed in this invention features mild reaction conditions, short reaction time, simple post-processing, and high yield.

Description

Technical Field

[0001] This invention relates to the field of organophosphorus chemistry, and more specifically, to an organophosphorus oxide and an organophosphorus hydrogen based on the phosphorus fluorene structural unit, and methods for their preparation. Background Technology

[0002] Phosphafluorenes are a class of compounds in which the carbon atom at position 9 of a fluorene compound is replaced by a phosphorus atom; they are also known as dibenzophospholes. Because of the introduction of the heteroatom—phosphorus—into these phosphafluorenes, they can be used as ligands in organometallic chemistry to synthesize rare-earth metal complexes or transition metal complexes (see Non-Patent Literature 1 and 2). Furthermore, phosphafluorenes possess a tricyclic large π-conjugated structure with a rigid conjugated plane, thus maintaining the excellent photoelectric properties of fluorene compounds. In addition, the phosphorus atom can alter the electronic structure of the material through the interaction between the d-orbital and the π-conjugated system, and can be modified through oxidation reactions, thereby effectively regulating the photoelectric properties of the material. They are widely used in the fabrication of optoelectronic devices (see Non-Patent Literature 3 and 4).

[0003] Phosphine oxides and phosphine hydrogens are two representative phosphine compounds. In the prior art, 9-phosphine (structural formula: It is obtained by further quenching the lithium phosphonium salt obtained by reacting 9-phenyl-9-phosphonium with an alkali metal (see Non-Patent Literature 5 and 6); while phosphonium phosphonium oxides, such as 9-oxo-9-phosphonium (structural formula: Although the reported method also involves a similar quenching reaction, it does not provide characterization data for the product (see Non-Patent Literature 7), only the preparation method. For other phosphafenoxan oxides and phosphafenoxan hydrogens with wider applications, preparation methods are currently lacking, which significantly limits their further utilization.

[0004] As can be seen from the various preparation methods in the aforementioned literature, the reaction substrate 9-phenyl-9-phosphazene used in them is synthesized from the basic phosphorus chemical product arylphosphine dichloride (ArPCl2). Currently, the basic raw material for such compounds is prepared from white phosphorus (P4) in the phosphorus chemical industry, which requires the use of chlorine, a toxic gas that is harmful to both the environment and human health. We know that this type of process also generates a large amount of waste gas and waste acid during the reaction. Therefore, the entire production process is not only energy-intensive but also extremely polluting to the environment (see Non-Patent Literature 8).

[0005] Therefore, given the aforementioned problems, there is an urgent need to find a method that can replace the chlorine gas used and uses readily available raw materials to easily synthesize phosphonium oxides and phosphonium hydrogens to solve the current problems.

[0006] Existing technical documents

[0007] Non-patent literature

[0008] Non-patent literature 1: N. and R.Louis,J.Organomet.Chem.1994,464,149-154;

[0009] Non-patent literature 2: S. Wolfdieter, S. Michael and H. Michael, J. Organomet. Chem. 1998, 560, 257-263;

[0010] Non-patent literature 3: R.-F. Chen, R. Zhu, Q.-L. Fan, and W. Huang, Org. Lett. 2008, 10, 2913-2916;

[0011] Non-patent literature 4: P. Hibner-Kulicka, J. Joule, J. Skalika and P. RSCAdv.2017,7,9194-9236;

[0012] Non-patent literature 5: C. Thoumazet, L. Ricard, H. Grützmacherb and P. Le Floch, Chem. Commun. 2005, 1592-1594;

[0013] Non-patent literature 6: P. Eisenberger, I. Kieltsch, N. Armanino, A. Togni, Chem. Commun. 2008, 1575-1577.

[0014] Non-patent literature 7: M. Davis and FG Mann, J. Chem. Soc. 1964, 3770-3785;

[0015] Non-patent literature 8: Synthesis of Carbon-Phosphorus Bonds, 2nd edition, CRC Press, Boca Raton 2004. Summary of the Invention

[0016] The technical problem that the invention aims to solve

[0017] This invention was made in view of the above-mentioned problems, and its object is to provide a phosphonium phosphonium oxide compound based on the phosphonium structural unit, and a method for its preparation thereof, which can not only be synthesized efficiently but also greatly reduce environmental pollution caused during the production process. Another object of this invention is to provide a phosphonium phosphonium hydrogen compound based on the phosphonium structural unit and a method for its preparation thereof.

[0018] Solution for solving the problem

[0019] The technical solution of the present invention is as follows:

[0020] The first aspect of the present invention is a phosphane phosphonium oxide compound, which is a compound containing phosphane structural units as shown in formula (II), characterized in that...

[0021]

[0022] Among them, R 1 and R 2 They can be the same or different, and each 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, pyridyl, thiophene.

[0023] In a preferred manner, the R 1 and R 2 Each of these can be hydrogen, halogen, methyl, tert-butyl, trifluoromethyl, trifluoromethoxy, nitro, methoxy, ethoxy, or phenyl.

[0024] In a preferred manner, the R 1 and R 2 Each of them can be hydrogen, halogen, methyl, tert-butyl, trifluoromethyl, or trifluoromethoxy.

[0025] Another aspect of the present invention relates to a method for preparing a phosphane fluorene phosphonium oxide compound, which is a method for preparing a compound containing a phosphane fluorene structural unit as shown in formula (II).

[0026]

[0027] In equation (II), 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, pyridyl, thiophene.

[0028] In a preferred manner, the R 1 and R 2 Each of these can be hydrogen, halogen, methyl, tert-butyl, trifluoromethyl, trifluoromethoxy, nitro, methoxy, ethoxy, or phenyl.

[0029] In a preferred manner, the R 1 and R 2 Each of them can be hydrogen, halogen, methyl, tert-butyl, trifluoromethyl, or trifluoromethoxy.

[0030] The preparation method includes the following steps:

[0031] Step 1-1: Prepare compound (V) by reacting compound (IV) with an organometallic reagent at low temperature.

[0032]

[0033] In compounds of formula (IV), X can be chlorine, bromine, or iodine, with bromine and iodine being preferred.

[0034] The organometallic reagent used in step 1-1 can be an organolithium reagent, Grignard reagent, sodium reagent, potassium reagent, or calcium reagent, with organolithium reagent being preferred.

[0035] The preferred organolithium reagents are n-butyllithium and tert-butyllithium.

[0036] M can be lithium, sodium, potassium, calcium, or magnesium, with lithium being the preferred choice.

[0037] In reaction step 1-1, the low temperature is in the range of -120℃ to -60℃, preferably -90℃ to -70℃; the reaction time is 0.5 to 3 hours at the aforementioned low temperature, and then the reaction continues at room temperature for 2 to 6 hours, preferably 3 to 4 hours.

[0038] There are no particular limitations on the solvent used in the above reactions; any organic solvent that can dissolve the reactants and does not react with the organometallic reagent is acceptable. Examples include tetrahydrofuran (THF), diethyl ether (Et₂O), benzene, toluene, 1,4-dioxane, dimethyl ethylene glycol ether (DME), or tetramethylethylenediamine (TMEDA).

[0039] For the ratio of the compound of formula (IV) to the organometallic reagent, the ratio of the organometallic reagent to the compound of formula (IV) is 2 to 3 molar equivalents, preferably 2.2 to 2.5 molar equivalents.

[0040] Steps 1-2: Compound (I) is prepared by reacting compound (V) with white phosphorus (P4) at room temperature or above.

[0041]

[0042] In reaction steps 1-2, the reaction temperature is in the range of room temperature to 50°C, preferably 25°C to 40°C; the reaction time is 6 to 24 hours, preferably 10 to 20 hours.

[0043] As the solvent used in the above reaction, an organic solvent is required that can dissolve the reactants without reacting with them; the solvent is the coordination solvent of metal M in the compound of formula (I), that is, Sol is the coordination solvent, and can be tetrahydrofuran (THF), diethyl ether (Et2O), dimethyl ethylene glycol (DME) or tetramethylethylenediamine (TMEDA), preferably tetrahydrofuran (THF) or diethyl ether (Et2O), and more preferably tetrahydrofuran (THF).

[0044] n represents the number of coordinating solvents, which is a positive integer or half-integer greater than 0 and less than 3.

[0045] For the ratio of compound (V) to white phosphorus (P4), the ratio of white phosphorus (P4) to compound (V) is 1 to 1.5 molar equivalents, preferably 1.1 to 1.45 molar equivalents.

[0046] Steps 1-3: Compound (II) is prepared by reacting compound (I) with water (H2O) at room temperature or below.

[0047]

[0048] In reaction steps 1-3, the reaction temperature is within the range of 0°C to room temperature; the reaction time is 0.5 to 6 hours, preferably 1 to 5 hours.

[0049] There are no particular limitations on the solvent used in the above reaction; any organic solvent that can dissolve the reactants without reacting with the compound of formula (I) is acceptable. Examples include tetrahydrofuran (THF), diethyl ether (Et2O), benzene, toluene, 1,4-dioxane, dimethyl ethylene glycol ether (DME), or tetramethylethylenediamine (TMEDA).

[0050] For the ratio of compound (I) to water (H2O), the amount of water (H2O) used is 1 to 50 molar equivalents relative to compound (I), preferably 2 to 45 molar equivalents, and more preferably 5 to 40 molar equivalents.

[0051] The solvents used in steps 1-1, 1-2, and 1-3 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.

[0052] The second aspect of the present invention is a phosphane phosphonium compound, which is a compound containing phosphane structural units as shown in formula (III), characterized in that...

[0053]

[0054] In equation (III), R 1 and R 2 The same as formula (II), that is, it can be the same or different, and can be hydrogen, halogen, nitro, cyano, trifluoromethyl, trifluoromethoxy, C1 to C6 alkyl (including straight-chain alkyl, branched alkyl and cycloalkyl), C1 to C6 alkoxy, substituted or unsubstituted phenyl, pyridinyl, thiophene.

[0055] In a preferred manner, the R 1 and R 2 Each of these can be hydrogen, halogen, methyl, tert-butyl, trifluoromethyl, trifluoromethoxy, nitro, methoxy, ethoxy, or phenyl.

[0056] In a preferred manner, the R 1 and R 2 Each of them can be hydrogen, halogen, methyl, tert-butyl, trifluoromethyl, or trifluoromethoxy.

[0057] Another aspect of the present invention relates to a method for preparing a phosphane fluorene hydrogen compound, which is a method for preparing a compound containing a phosphane fluorene structural unit as shown in formula (III).

[0058]

[0059] In equation (III), 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, pyridyl, thiophene.

[0060] In a preferred manner, the R 1 and R 2 Each of these can be hydrogen, halogen, methyl, tert-butyl, trifluoromethyl, trifluoromethoxy, nitro, methoxy, ethoxy, or phenyl.

[0061] In a preferred manner, the R 1 and R 2 Each of them can be hydrogen, halogen, methyl, tert-butyl, trifluoromethyl, or trifluoromethoxy.

[0062] The preparation method includes the following steps:

[0063] In this preparation method, steps 2-1 and 2-2 are the same as steps 1-1 and 1-2 in the preparation method of the compound shown in formula (II), that is...

[0064] Step 2-1: Prepare compound (V) by reacting compound (IV) with an organometallic reagent at low temperature.

[0065]

[0066] In compound (IV), X can be chlorine, bromine, or iodine, preferably bromine or iodine. The organometallic reagent used in step 2-1 can be an organolithium reagent, Grignard reagent, sodium reagent, potassium reagent, or calcium reagent, preferably an organolithium reagent.

[0067] The preferred organolithium reagents are n-butyllithium and tert-butyllithium.

[0068] M can be lithium, sodium, potassium, calcium, or magnesium, with lithium being the preferred choice.

[0069] In reaction step 2-1, the low temperature is in the range of -120°C to -60°C, preferably -90°C to -70°C; the reaction time is 0.5 to 3 hours at the aforementioned low temperature, and then the reaction continues at room temperature for 2 to 6 hours, preferably 3 to 4 hours.

[0070] There are no particular limitations on the solvent used in the above reactions; any organic solvent that can dissolve the reactants and does not react with the organometallic reagent is acceptable. Examples include tetrahydrofuran (THF), diethyl ether (Et₂O), benzene, toluene, 1,4-dioxane, dimethyl ethylene glycol ether (DME), or tetramethylethylenediamine (TMEDA).

[0071] For the ratio of the compound of formula (IV) to the organometallic reagent, the ratio of the organometallic reagent to the compound of formula (IV) is 2 to 3 molar equivalents, preferably 2.2 to 2.5 molar equivalents.

[0072] Step 2-2: Prepare compound (I) by reacting compound (V) with white phosphorus (P4) at room temperature or above.

[0073]

[0074] In reaction step 2-2, the reaction temperature is in the range of room temperature to 50°C, preferably 25°C to 40°C; the reaction time is 6 to 24 hours, preferably 10 to 20 hours.

[0075] As the solvent used in the above reaction, an organic solvent is required that can dissolve the reactants without reacting with them; the solvent is the coordination solvent of metal M in the compound of formula (I), that is, Sol is the coordination solvent, and can be tetrahydrofuran (THF), diethyl ether (Et2O), dimethyl ethylene glycol (DME) or tetramethylethylenediamine (TMEDA), preferably tetrahydrofuran (THF) or diethyl ether (Et2O), and more preferably tetrahydrofuran (THF).

[0076] n represents the number of coordinating solvents, which is a positive integer or half-integer greater than 0 and less than 3.

[0077] For the ratio of compound (V) to white phosphorus (P4), the ratio of white phosphorus (P4) to compound (V) is 1 to 1.5 molar equivalents, preferably 1.1 to 1.45 molar equivalents.

[0078] Steps 2-3: Compound (III) is prepared by reacting compound (I) with triethylamine hydrochloride (Et3N·HCl) at room temperature or below.

[0079]

[0080] In reaction steps 2-3, the reaction temperature is within the range of 0°C to room temperature, and the reaction time is 6 to 24 hours. The preferred reaction time is 10 to 20 hours.

[0081] There are no particular limitations on the solvent used in the above reaction; any organic solvent that can dissolve the reactants and does not react with the compound of formula (I) is acceptable. Examples include tetrahydrofuran (THF), diethyl ether (Et2O), benzene, toluene, 1,4-dioxane, dimethyl ethylene glycol ether (DME), or tetramethylethylenediamine (TMEDA).

[0082] For the ratio of compound (I) to triethylamine hydrochloride, the amount of triethylamine hydrochloride used relative to compound (I) is 1 to 1.5 molar equivalents, preferably 1.1 to 1.45 molar equivalents, and more preferably 1.1 to 1.4 molar equivalents.

[0083] The solvents used in steps 2-1, 2-2, and 2-3 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.

[0084] In addition, the compounds represented by formula (II), namely phosphafenoxanol oxide, and the compounds represented by formula (III), namely phosphafenoxanol hydrogen, can also be used directly as organic light-emitting materials, or further derivatized and then applied to organic optoelectronic devices.

[0085] The effects of the invention

[0086] According to the present invention, phosphafenoxan oxides and phosphafenoxan hydrogens based on phosphafenoxan structural units and their preparation methods are provided. Since this reaction uses readily available and inexpensive raw materials such as common white phosphorus, water, and solvents, it eliminates the need for previously used aryl phosphorus dichloride (ArPCl2) or diaryl phosphorus dichloride (Ar2PCl), thereby overcoming the highly polluting chlorine gas used in traditional phosphorus 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 phosphafenoxan oxides and phosphafenoxan hydrogens, 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.

[0087] The phosphane phosphonium oxide and phosphane phosphonium hydrogen compounds based on the phosphane structural unit provided by this invention, or their further derivatized organophosphorus compounds, can serve as electron transport layer materials in organic light-emitting diode (OLED) devices. Furthermore, the efficiency of the electron transport layer can be further improved by adjusting the substituents. Compared with existing technologies, these compounds offer advantages such as a wide variety of substituents and simple, efficient synthesis. Detailed Implementation

[0088] 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.

[0089] The compounds containing phosphonium structural units of the present invention include phosphonium phosphonium oxides of formula (II) and phosphonium phosphonium hydrogens of formula (III).

[0090]

[0091] In the phosphane phosphonium oxide compound shown in formula (II) and the phosphane phosphonium hydrogen compound shown in formula (III), R 1 and R 2They 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, pyridyl, thiophene.

[0092] Wherein, the R 1 and R 2 Preferably, each of the following can be 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 R 2 Further preferred groups include hydrogen, methyl, methoxy, tert-butyl, trifluoromethyl, and fluorine.

[0093] Preparation of compounds

[0094] The method for preparing compounds containing phosphane structural units of the present invention is a method for preparing phosphane phosphonium oxide compounds represented by formula (II), which includes the following steps:

[0095] Step 1-1: Prepare compound (V) by reacting compound (IV) with an organometallic reagent at low temperature.

[0096]

[0097] In compounds of formula (IV), X can be chlorine, bromine, or iodine, with bromine and iodine being preferred.

[0098] The organometallic reagent used in step 1-1 can be an organolithium reagent, Grignard reagent, sodium reagent, potassium reagent, or calcium reagent, with organolithium reagent being preferred.

[0099] The preferred organolithium reagents are n-butyllithium and tert-butyllithium.

[0100] M can be lithium, sodium, potassium, calcium, or magnesium, with lithium being the preferred choice.

[0101] In reaction step 1-1, the low temperature is in the range of -120℃ to -60℃, preferably -90℃ to -70℃; the reaction time is 0.5 to 3 hours at the aforementioned low temperature, and then the reaction continues at room temperature for 2 to 6 hours, preferably 3 to 4 hours.

[0102] There are no particular limitations on the solvent used in the above reactions; any organic solvent that can dissolve the reactants and does not react with the organometallic reagent is acceptable. Examples include tetrahydrofuran (THF), diethyl ether (Et₂O), benzene, toluene, 1,4-dioxane, dimethyl ethylene glycol ether (DME), or tetramethylethylenediamine (TMEDA).

[0103] For the ratio of the compound of formula (IV) to the organometallic reagent, the ratio of the organometallic reagent to the compound of formula (IV) is 2 to 3 molar equivalents, preferably 2.2 to 2.5 molar equivalents.

[0104] Steps 1-2: Compound (I) is prepared by reacting compound (V) with white phosphorus (P4) at room temperature or above.

[0105]

[0106] In reaction steps 1-2, the reaction temperature is in the range of room temperature to 50°C, preferably 25°C to 40°C; the reaction time is 6 to 24 hours, preferably 10 to 20 hours.

[0107] As the solvent used in the above reaction, an organic solvent is required that can dissolve the reactants without reacting with them; the solvent is the coordination solvent of metal M in the compound of formula (I), that is, Sol is the coordination solvent, and can be tetrahydrofuran (THF), diethyl ether (Et2O), dimethyl ethylene glycol (DME) or tetramethylethylenediamine (TMEDA), preferably tetrahydrofuran (THF) or diethyl ether (Et2O), and more preferably tetrahydrofuran (THF).

[0108] n represents the number of coordinating solvents, which is a positive integer or half-integer greater than 0 and less than 3.

[0109] For the ratio of compound (V) to white phosphorus (P4), the ratio of white phosphorus (P4) to compound (V) is 1 to 1.5 molar equivalents, preferably 1.1 to 1.45 molar equivalents.

[0110] Steps 1-3: Compound (II) is prepared by reacting compound (I) with water (H2O) at room temperature or below.

[0111]

[0112] In steps 1-3 of the reaction, the reaction temperature is in the range of 0°C to room temperature, and the reaction time is 0.5 to 6 hours, preferably 1 to 5 hours.

[0113] There are no particular limitations on the solvent used in the above reaction; any organic solvent that can dissolve the reactants without reacting with the compound of formula (I) is acceptable. Examples include tetrahydrofuran (THF), diethyl ether (Et2O), benzene, toluene, 1,4-dioxane, dimethyl ethylene glycol ether (DME), or tetramethylethylenediamine (TMEDA).

[0114] For the ratio of compound (I) to water (H2O), the amount of water (H2O) used is 1 to 50 molar equivalents relative to compound (I), preferably 2 to 45 molar equivalents, and more preferably 5 to 40 molar equivalents.

[0115] The solvents used in steps 1-1, 1-2, and 1-3 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.

[0116] The method for preparing the compound containing the phosphane structural unit shown in formula (III) of the present invention is a method for preparing the phosphane phosphine hydrogen compound shown in formula (III), which includes the following steps:

[0117] In this preparation method, steps 2-1 and 2-2 are the same as steps 1-1 and 1-2 in the preparation method of the compound shown in formula (II), that is...

[0118] Step 2-1: Prepare compound (V) by reacting compound (IV) with an organometallic reagent at low temperature.

[0119]

[0120] In compounds of formula (IV), X can be chlorine, bromine, or iodine, with bromine and iodine being preferred.

[0121] The organometallic reagent used in step 2-1 can be an organolithium reagent, Grignard reagent, sodium reagent, potassium reagent, or calcium reagent, with organolithium reagent being preferred.

[0122] The preferred organolithium reagents are n-butyllithium and tert-butyllithium.

[0123] M can be lithium, sodium, potassium, calcium, or magnesium, with lithium being the preferred choice.

[0124] In reaction step 2-1, the low temperature is in the range of -120℃ to -60℃, preferably -90℃ to -70℃; the reaction time is 0.5 to 3 hours at the aforementioned low temperature, and then the reaction continues at room temperature for 2 to 6 hours, preferably 3 to 4 hours.

[0125] There are no particular limitations on the solvent used in the above reactions; any organic solvent that can dissolve the reactants and does not react with the organometallic reagent is acceptable. Examples include tetrahydrofuran (THF), diethyl ether (Et₂O), benzene, toluene, 1,4-dioxane, dimethyl ethylene glycol ether (DME), or tetramethylethylenediamine (TMEDA).

[0126] For the ratio of the compound of formula (IV) to the organometallic reagent, the ratio of the organometallic reagent to the compound of formula (IV) is 2 to 3 molar equivalents, preferably 2.2 to 2.5 molar equivalents.

[0127] Step 2-2: Prepare compound (I) by reacting compound (V) with white phosphorus (P4) at room temperature or above.

[0128]

[0129] In step 2-2 of the reaction, the reaction temperature is in the range of room temperature to 50°C, preferably 25°C to 40°C; the reaction time is 6 to 24 hours, preferably 10 to 20 hours.

[0130] As the solvent used in the above reaction, an organic solvent is required that can dissolve the reactants without reacting with them; the solvent is the coordination solvent of metal M in the compound of formula (I), that is, Sol is the coordination solvent, and can be tetrahydrofuran (THF), diethyl ether (Et2O), dimethyl ethylene glycol (DME) or tetramethylethylenediamine (TMEDA), preferably tetrahydrofuran (THF) or diethyl ether (Et2O), and more preferably tetrahydrofuran (THF).

[0131] n represents the number of coordinating solvents, which is a positive integer or half-integer greater than 0 and less than 3.

[0132] For the ratio of compound (V) to white phosphorus (P4), the ratio of white phosphorus (P4) to compound (V) is 1 to 1.5 molar equivalents, preferably 1.1 to 1.45 molar equivalents.

[0133] Steps 2-3: Compound (III) is prepared by reacting compound (I) with triethylamine hydrochloride (Et3N·HCl) at room temperature.

[0134]

[0135] In steps 2-3 of the reaction, the reaction temperature is within the range of 0°C to room temperature, and the reaction time is 6 to 24 hours. The preferred reaction time is 10 to 20 hours.

[0136] There are no particular limitations on the solvent used in the above reaction; any organic solvent that can dissolve the reactants without reacting with the compound of formula (I) is acceptable. Examples include tetrahydrofuran (THF), diethyl ether (Et2O), benzene, toluene, 1,4-dioxane, dimethyl ethylene glycol ether (DME), or tetramethylethylenediamine (TMEDA).

[0137] Regarding the ratio of compound (I) to triethylamine hydrochloride (Et3N·HCl), the amount of triethylamine hydrochloride (Et3N·HCl) used relative to compound (I) is 1 to 1.5 molar equivalents, preferably 1.1 to 1.45 molar equivalents, and more preferably 1.1 to 1.4 molar equivalents.

[0138] The solvents used in steps 1-1, 1-2, and 1-3 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.

[0139] 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.

[0140] The preparation method of the above compounds is described in detail below through examples.

[0141] Synthesis of compound (V)

[0142] Example 1: Synthesis of 2,2'-dilithium-1,1'-biphenyl

[0143]

[0144] At room temperature, 2.0 mmol of 2,2'-dibromo-1,1'-biphenyl was added to a 50 mL reaction flask and dissolved in 20 mL of diethyl ether. Then, 2.8 mL of n-butyllithium (4.4 mmol, 1.6 M) was added at -78 °C. After reacting at this low temperature for 1 hour, the reaction system became a pale yellow solution. After returning to room temperature and continuing the reaction for another 3 hours, the reaction was confirmed to be complete by GC-MS. The ether solvent was removed under reduced pressure to obtain 2,2'-dilithium-1,1'-biphenyl (white solid).

[0145] Key NMR data: 1 H NMR (400MHz, THF-d8): 6.87 (t, J = 6.9 Hz, 2H, CH), 7.12 (t, J = 7.8 Hz, 2H, CH), 7.96 (dd, J = 6.5, 1.8 Hz, 4H, CH).

[0146] Example 2: Synthesis of 4-methyl-2,2'-dilithium-1,1'-biphenyl

[0147]

[0148] At room temperature, 2.0 mmol of 4-methyl-2,2'-dibromo-1,1'-biphenyl was added to a 50 mL reaction flask and dissolved in 20 mL of diethyl ether. Then, 2.8 mL of n-butyllithium (4.4 mmol, 1.6 M) was added at -78 °C. After reacting at this low temperature for 1 hour, the reaction system became a pale yellow solution. After returning to room temperature and continuing the reaction for another 3 hours, the reaction was confirmed to be complete by GC-MS. The reaction solvent, diethyl ether, was removed under reduced pressure to obtain 4-methyl-2,2'-dilithium-1,1'-biphenyl (white solid).

[0149] Example 3: Synthesis of 4-methoxy-2,2'-dilithium-1,1'-biphenyl

[0150]

[0151] At room temperature, 2.0 mmol of 4-methoxy-2,2'-dibromo-1,1'-biphenyl was added to a 50 mL reaction flask and dissolved in 20 mL of diethyl ether. Then, 2.8 mL of n-butyllithium (4.4 mmol, 1.6 M) was added at -78 °C. After reacting at this low temperature for 1 hour, the reaction system became a pale yellow solution. After returning to room temperature and continuing the reaction for another 3 hours, the reaction was confirmed to be complete by GC-MS. The reaction solvent, diethyl ether, was removed under reduced pressure to obtain 4-methoxy-2,2'-dilithium-1,1'-biphenyl (white solid).

[0152] Example 4: Synthesis of 4,4'-di-tert-butyl-2,2'-dilithium-1,1'-biphenyl

[0153]

[0154] At room temperature, 2.0 mmol of 4,4'-di-tert-butyl-2,2'-dibromo-1,1'-biphenyl was added to a 50 mL reaction flask and dissolved in 20 mL of diethyl ether. Then, 2.8 mL of n-butyllithium (4.4 mmol, 1.6 M) was added at -78 °C. After reacting at this low temperature for 1 hour, the reaction system became a pale yellow solution. After returning to room temperature and continuing the reaction for another 3 hours, the reaction was confirmed to be complete by GC-MS. The reaction solvent, diethyl ether, was removed under reduced pressure to obtain 4,4'-di-tert-butyl-2,2'-dilithium-1,1'-biphenyl (white solid).

[0155] Key NMR data: 1 H NMR(400MHz,THF-d8):1.27(s,18H, t Bu), 7.16 (dd, J=8.4, 2.5Hz, 2H, CH), 7.91 (d, J=8.4Hz, 2H, CH), 8.09 (d, J=2.4Hz, 2H, CH).

[0156] Example 5: Synthesis of 4-trifluoromethyl-2,2'-dilithium-1,1'-biphenyl

[0157]

[0158] At room temperature, 2.0 mmol of 4-trifluoromethyl-2,2'-dibromo-1,1'-biphenyl was added to a 50 mL reaction flask and dissolved in 20 mL of diethyl ether. Then, 2.8 mL of n-butyllithium (4.4 mmol, 1.6 M) was added at -78 °C. After reacting at this low temperature for 1 hour, the reaction system became a pale yellow solution. After returning to room temperature and continuing the reaction for another 3 hours, the reaction was confirmed to be complete by GC-MS. The reaction solvent, diethyl ether, was removed under reduced pressure to obtain 4-trifluoromethyl-2,2'-dilithium-1,1'-biphenyl (white solid).

[0159] Example 6: Synthesis of 6-fluoro-2,2'-dilithium-1,1'-biphenyl

[0160]

[0161] At room temperature, 2.0 mmol of 6-fluoro-2,2'-dibromo-1,1'-biphenyl was added to a 50 mL reaction flask and dissolved in 20 mL of diethyl ether. Then, 2.8 mL of n-butyllithium (4.4 mmol, 1.6 M) was added at -78 °C. After reacting at this low temperature for 1 hour, the reaction system became a pale yellow solution. After returning to room temperature and continuing the reaction for another 3 hours, the reaction was confirmed to be complete by GC-MS. The reaction solvent, diethyl ether, was removed under reduced pressure to obtain 6-fluoro-2,2'-dilithium-1,1'-biphenyl (white solid).

[0162] Example 7: Synthesis of 4-trifluoromethoxy-2,2'-dilithium-1,1'-biphenyl

[0163]

[0164] At room temperature, 2.0 mmol of 4-trifluoromethoxy-2,2'-dibromo-1,1'-biphenyl was added to a 50 mL reaction flask and dissolved in 20 mL of diethyl ether. Then, 2.8 mL of n-butyllithium (4.4 mmol, 1.6 M) was added at -78 °C. After reacting at this low temperature for 1 hour, the reaction system became a pale yellow solution. After returning to room temperature and continuing the reaction for another 3 hours, the reaction was confirmed to be complete by GC-MS. The reaction solvent, diethyl ether, was removed under reduced pressure to obtain 4-trifluoromethoxy-2,2'-dilithium-1,1'-biphenyl (white solid).

[0165] Key NMR data: 1H NMR (400MHz, THF-d8): 6.88 (m, 3H, CH), 7.09 (m, 1H, CH), 7.82 (s, 1H, CH), 7.96 (d, J = 6.7Hz, 2H).

[0166] Synthesis of compound (I)

[0167] Example 8: Synthesis of 9-phosphaphene lithium salt

[0168]

[0169] 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, and then 1.1 mmol of white phosphorus was added. After reacting at room temperature for 12 hours, the reaction system became a dark brown solution. The tetrahydrofuran solvent was removed under reduced pressure, and the remaining solid was extracted multiple times with diethyl ether to obtain an orange solution. The diethyl ether solvent was removed again under reduced pressure to obtain 366 mg of 9-phosphaphene lithium salt (orange-yellow solid), with a separation yield of 99%.

[0170] Key NMR data: 1 H NMR(400MHz,THF-d8): δ1.76-1.79(m,8H,β-CH2,THF),3.60-3.63(m,8H,α-CH2,THF),6.79(t ,J=6.9Hz,2H,CH),6.86(t,J=7.1Hz,2H,CH),7.75-7.85(m,2H,CH),8.00(d,J=7.8Hz,2H,CH); 13 C NMR(126MHz,THF-d8): δ26.5(s,β-CH2,THF),68.4(s,α-CH2,THF),115.9(s,CH),120.5(s,C H),120.8(d,J=10.4Hz;CH),127.3(d,J=25.2Hz;quat.C),136.1(s,CH),158.3(m,quat.C); 31 P{ 1 H}NMR(202MHz,THF-d8): δ9.63(s).

[0171] Example 9: Synthesis of 2-methyl-9-phosphafluorene lithium salt

[0172]

[0173] At room temperature, 1.0 mmol of 2,2'-dilithium-4-methyl-1,1'-biphenyl was added to a 25 mL reaction flask, dissolved in 10 mL of tetrahydrofuran, and then 1.1 mmol of white phosphorus was added. After reacting at room temperature for 12 hours, the reaction system became a dark brown solution. The tetrahydrofuran solvent was removed under reduced pressure, and the remaining solid was extracted multiple times with diethyl ether to obtain an orange-yellow solution. The diethyl ether solvent was removed again under reduced pressure to obtain 387 mg of 2-methyl-9-phosphafluorene lithium salt (yellow solid), with a separation yield of 92%.

[0174] Key NMR data: 1 H NMR(400MHz,THF-d8): δ1.76-1.79(m,4H,β-CH2,THF),2.35(s,3H,CH3),3.60 -3.63(m,4H,α-CH2,THF),6.60(dd,J=8.0,1.7Hz,1H,CH),6.72(ddd,J=7.9,6 .6,1.3Hz,1H,CH),6.76-6.85(m,1H,CH),7.54-7.63(m,1H,CH),7.76(ddt,J= 7.7,4.1,1.0Hz,1H,CH),7.88(d,J=7.9Hz,1H,CH),7.93(d,J=7.7Hz,1H,CH); 13 C NMR(126MHz,THF-d8): δ22.4(s,CH3)26.5(s,β-CH2,THF),68.4(s,α-CH2,THF),115.7(s,CH),117.7(s,CH),120.1(d,J=3.6Hz),120.4(d,J=10.9Hz ),127.0(d,J=6.4Hz),127.2(d,J=6.4Hz),128.8(d,J=11.2Hz),134.2(d, J=2.5Hz), 136.2 (d, J=2.3Hz), 158.4 (d, J=37.1Hz), 159.0 (d, J=36.9Hz); 31 P{ 1 H}NMR(202MHz,THF-d8): δ7.87(s).

[0175] Example 10: Synthesis of 2-methoxy-9-phosphafluorene lithium salt

[0176]

[0177] At room temperature, 1.0 mmol of 2,2'-dilithium-4-methoxy-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 room temperature for 12 hours, the reaction system became a dark brown solution. The tetrahydrofuran solvent was removed under reduced pressure, and the remaining solid was extracted multiple times with diethyl ether to obtain an orange solution. The diethyl ether solvent was removed again under reduced pressure to obtain 410 mg of 2-methoxy-9-phosphafluorene lithium salt (orange solid), with a separation yield of 92%. Main NMR data: 1 H NMR (400MHz, THF-d8): δ1.76-1.79(m,4H,β-CH2,THF),3.60-3.63(m,4H,α-CH2,THF),3.76(s,3H,OCH3),6.44(dd,J=8. 5,2.4Hz,1H,CH),6.81-6.68(m,2H,CH),7.31(dd,J=4.4,2.4Hz,1H,CH),7.78-7.69(m,1H,CH),δ7.90-7.82(m,2H,CH); 13 C NMR(126MHz,THF-d8): δ26.5(s,β-CH2,THF),55.3(s,OCH3),68.4(s,α-CH2,THF),106.5 (s,CH),108.4(d,J=27.6Hz;CH),116.1(s,CH),119.6(s,CH),120.1(d,J=10.6Hz;quat.C ),120.9(s,CH),126.8(d,J=25.4Hz;CH),131.0(d,J=2.6Hz;CH),136.4(d,J=2.3Hz;CH), 156.3(d,J=12.2Hz; quat.C), 157.7(d,J=36.5Hz; quat.C), 160.1(d,J=37.1Hz; quat.C); 31 P{ 1 H}NMR(202MHz,THF-d8):δ9.02(s).

[0178] Example 11: Synthesis of 2,7-di-tert-butyl-9-phosphafluorene lithium salt

[0179]

[0180] At room temperature, 1.0 mmol of 2,2'-dilithium-4,4'-di-tert-butyl-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 room temperature for 12 hours, the reaction system became a dark brown solution. The tetrahydrofuran solvent was removed under reduced pressure, and the remaining solid was extracted multiple times with diethyl ether to obtain a red solution. The diethyl ether solvent was removed again under reduced pressure to obtain 405 mg of 2,7-di-tert-butyl-9-phosphafluorene lithium salt (red solid), with a separation yield of 90%.

[0181] Key NMR data: 1 H NMR(400MHz,THF-d8)δ1.37(s,18H, t Bu),1.76-1.79(m,4H,β-CH2,THF),3.60-3.63(m,4H,α-CH2,THF),6.89(dd,J= 8.3,2.0Hz,2H,CH),7.82(dd,J=5.0,1.9Hz,1H,CH),7.89(d,J=8.2Hz,1H,CH), 13 C NMR(101MHz,THF-d8)δ26.5(s,β-CH2,THF),32.7(s,CH3, t Bu), 35.3(s,quat.C, t Bu),68.4(s,α-CH2,THF),114.7(s,CH),120.0(s,CH),122.8(d,J=25.6Hz,CH),134 .4(d,J=2.0Hz,quat.C),142.3(d,J=10.5Hz,quat.C),158.1(d,J=35.2Hz,quat.C); 31 P{ 1 H}NMR(202MHz,THF-d8):δ0.87(s).

[0182] Example 12: Synthesis of 2-trifluoromethyl-9-phosphafluorene lithium salt

[0183]

[0184] At room temperature, 1.0 mmol of 2,2'-dilithium-4-trifluoromethyl-1,1'-biphenyl was added to a 25 mL reaction flask, dissolved in 10 mL of tetrahydrofuran, and then 1.1 mmol of white phosphorus was added. After reacting at room temperature for 12 hours, the reaction system became a dark brown solution. The tetrahydrofuran solvent was removed under reduced pressure, and the remaining solid was extracted multiple times with diethyl ether to obtain an orange solution. The diethyl ether solvent was removed again under reduced pressure to obtain 450 mg of 2-trifluoromethyl-9-phosphafluorene lithium salt (orange solid), with a separation yield of 95%.

[0185] Key NMR data: 1 H NMR(400MHz,THF-d8)δ1.76-1.79(m,8H,β-CH2,THF),3.60-3.63(m,8H,α-CH2,THF),6.80(ddd,J=7.9,6.6,1.2Hz,1H,CH ),6.97-6.85(m,2H,CH),7.89(ddt,J=7.9,4.2,1.0Hz,1H,CH),8.09(d,J=8.1Hz,2H,CH),8.14(dq,J=3.0,0.9Hz,1H,CH); 13 C NMR (126MHz, THF-d) 8 )δ26.5(s,β-CH2,THF),68.4(s,α-CH2,THF),110.4(s,CH),116.0(s,CH),120.2(d, J=2.1Hz,quat.C),121.0(s,CH),121.1(s,CH),121.3(s,CH),124.4(dq,J=27.2,4.4 Hz,quat.C),127.7(d,J=25.5Hz,CH),128.2(q,J=270.8Hz,CF3),134.5(d,J=4.1Hz , quat.C), 136.7 (s, CH), 157.8 (d, J = 40.6Hz, quat.C), 160.4 (d, J = 39.6Hz, quat.C); 31 P{ 1 H}NMR(202MHz,THF-d8):δ28.33(s); 19 F NMR(471MHz,THF-d8):δ-60.32(s).

[0186] Example 13: Synthesis of 4-fluoro-9-phosphafluorene lithium salt

[0187]

[0188] At room temperature, 1.0 mmol of 2,2'-dilithium-6-fluoro-1,1'-biphenyl was added to a 25 mL reaction flask, dissolved in 10 mL of tetrahydrofuran, and then 1.1 mmol of white phosphorus was added. After reacting at room temperature for 12 hours, the reaction system became a dark brown solution. The tetrahydrofuran solvent was removed under reduced pressure, and the remaining solid was extracted multiple times with diethyl ether to obtain an orange-yellow solution. The diethyl ether solvent was removed again under reduced pressure to obtain 403 mg of 4-fluoro-9-phosphafluorene lithium salt (yellow solid), with a separation yield of 95%.

[0189] Key NMR data:1 H NMR(400MHz,THF-d8)δ1.76-1.79(m,6H,β-CH2,THF),3.60-3.63(m,6H,α-CH2,THF),6.34(ddd,J=12.8,7.4,0.9Hz,1H,CH),6.78-6.68( m,2H,CH),6.86-6.79(m,1H,CH),7.57(ddt,J=7.8,4.3,1.2Hz,1H,CH),7.82(ddt,J=8.0,4.5,1.0Hz,1H,CH),8.30(d,J=8.0Hz,1H,CH); 13 C NMR(126MHz,THF-d8)δ26.5(s,β-CH2,THF),68.4(s,α-CH2,THF),99.9(d,J=21.3Hz,CH),115.8(s ,CH),119.7(dd,J=11.9,8.0Hz,CH),120.1(d,J=11.8Hz,CH),122.9(dd,J=25.9,2.5Hz,CH),124. 9(d,J=10.7Hz,CH),126.9(d,J=25.9Hz,CH),133.1(t,J=4.4Hz,quat.C),158.8(d,J=38.7Hz,qua t.C), 161.2 (d, J=2.2Hz, quat.C), 162.8 (dd, J=40.3, 4.9Hz, quat.C), 163.2 (d, J=2.2Hz, quat.C); 31 P{ 1 H}NMR(202MHz,THF-d8): δ26.79(s); 19 F{ 1 H} NMR (471MHz, THF-d8): δ-121.69 (d, J=4.2Hz).

[0190] Synthesis of compound (II)

[0191] Example 15: Synthesis of 9-oxo-9-phosphafluorene

[0192]

[0193] At room temperature, 0.5 mmol of lithium phosphafenene was added to a 25 mL reaction flask and dissolved in 6 mL of tetrahydrofuran. 0.5 mL of water was added directly, and the mixture was stirred for 30 minutes, resulting in an orange suspension. Then, 0.4 mL of hydrochloric acid (3.0 M) was added to neutralize the mixture, resulting in a colorless suspension. The reaction mixture was extracted with dichloromethane (10 mL × 3), and the organic phases were combined and dried over anhydrous sodium sulfate. The dried reaction mixture was then subjected to a rotary evaporator to remove the solvent, yielding a crude product. Recrystallization was performed using dichloromethane as the solvent to finally obtain 85 mg of 9-oxo-9-phosphafenene (white solid), with a separation yield of 85%.

[0194] Key NMR data: 1 H NMR (400MHz, DMSO-d6): δ7.45(d,J=3.6Hz,2H,CH),7.54-7.72(m,4H,CH),7.99(d,J=4.5Hz,2H,CH). 13 C NMR (101MHz, DMSO-d6): δ121.4(d,J=11.5Hz,CH), 127.5(d,J=8.8Hz,CH), 129.2(d,J=11.4H z, CH), 131.7 (d, J = 134.6Hz, quat.C), 132.8 (d, J = 2.2Hz, CH), 139.0 (d, J = 27.1Hz, quat.C). 31 P{ 1 H₂NMR (202 MHz, DMSO-d₆): δ 34.81 (s). High-resolution mass spectrometry: ESI-HRMS: [M⁺H⁺]¹⁰ ... + ]calcd,201.04638; found,201.04608.

[0195] Example 16: Synthesis of 2-methyl-9-oxo-9-phosphafluorene

[0196]

[0197] At room temperature, 0.5 mmol of lithium 2-methyl-9-phosphafluorene was added to a 25 mL reaction flask and dissolved in 6 mL of tetrahydrofuran. 0.5 mL of water was added directly, and the mixture was stirred for 30 minutes, resulting in an orange suspension. Then, 0.4 mL of hydrochloric acid (3.0 M) was added to neutralize the mixture, resulting in a colorless suspension. The reaction mixture was extracted with dichloromethane (10 mL × 3), and the organic phases were combined and dried over anhydrous sodium sulfate. The dried reaction mixture was then subjected to a rotary evaporator to remove the solvent, yielding a crude product. Recrystallization was performed using dichloromethane as the solvent, ultimately yielding 90 mg of 2-methyl-9-oxo-9-phosphafluorene (white solid), with a separation yield of 84%.

[0198] Key NMR data: 1 H NMR (400MHz, DMSO-d6): δ2.39(s,3H,CH3),7.28-7.74(m,5H,CH),7.82-8.07(m,2H,CH); 13 C NMR (101MHz, DMSO-d) 6 )δ21.30(s,CH3),121.51(d,J=11.7Hz,CH),121.71(d,J=12.1Hz,CH),127.92(d,J=8. 9Hz,CH),128.37(d,J=8.7Hz,CH),129.20(d,J=11.1Hz,CH),132.73(d,J=22.7Hz,quat .C),133.18(d,J=2.5Hz,CH),133.77(d,J=2.5Hz,CH),134.69(dd,J=60.7,1.9Hz,quat .C), 136.92 (d, J = 27.0Hz, quat.C), 139.48 (s, quat.C), 139.55 (d, J = 40.1Hz, quat.C). 31 P{ 1 H NMR (202 MHz, DMSO-d6): δ 35.09 (s). High-resolution mass spectrometry: ESI-HRMS: [M+H] + ]calcd,215.06203; found,215.06159.

[0199] Example 17: Synthesis of 4-Fluoro-9-oxo-9-phosphafluorene

[0200]

[0201] At room temperature, 0.5 mmol of lithium 4-fluoro-9-phosphafluorene was added to a 25 mL reaction flask and dissolved in 6 mL of tetrahydrofuran. 0.5 mL of water was added directly, and the mixture was stirred for 30 minutes, resulting in an orange suspension. Then, 0.4 mL of hydrochloric acid (3.0 M) was added to neutralize the mixture, resulting in a colorless suspension. The reaction mixture was extracted with dichloromethane (10 mL × 3), and the organic phases were combined and dried over anhydrous sodium sulfate. The dried reaction mixture was then subjected to a rotary evaporator to remove the solvent, yielding a crude product. Recrystallization was performed using dichloromethane as the solvent, ultimately yielding 81 mg of 4-fluoro-9-oxo-9-phosphafluorene (white solid), with a separation yield of 74%.

[0202] Key NMR data: 1H NMR (400MHz, DMSO-d6): δ7.43-7.59(m,4H,CH),7.59-7.79(m,2H,CH),7.97(dd,J=7.8,3.5Hz,1H,CH). 13 C NMR (101MHz, DMSO-d6) δ120.4(dd,J=21.5,2.0Hz),123.8(dd,J=8.2,3.4Hz),125.4-124.9(m),127.8(d,J=8.7Hz),129.5(d,J=11.7Hz),131.7(d d,J=13.4,7.3Hz), 131.9(d,J=135.5Hz), 133.2(d,J=1.7Hz), 135.4(d,J=3.4Hz), 135.8(d,J=1.3Hz), 157.5(d,J=17.1Hz), 160.0(d,J=16.9Hz). 31 P{ 1 H}NMR (202MHz, DMSO-d6): δ33.23 (d, J=7.0Hz). 19 F{ 1 ¹H NMR (471 MHz, DMSO-d⁶): δ -116.48 (d, J = 6.7 Hz). High-resolution mass spectrometry: ESI-HRMS: [M+H] + ]calcd,219.03696; found,219.03676.

[0203] Synthesis of compound (III)

[0204] Example 18: Synthesis of 2-methyl-9-phosphafluorene

[0205]

[0206] At room temperature, 0.2 mmol of lithium 2-methyl-9-phosphafluorene was added to a 25 mL reaction flask and dissolved in 6 mL of tetrahydrofuran. A THF solution of 0.2 mmol of triethylamine hydrochloride was then added dropwise to the reaction flask, and the mixture was reacted at room temperature for 12 hours, resulting in a dark brown solution. The remaining solid was extracted multiple times with n-pentane to obtain a colorless solution. The solvent n-pentane was then removed again under reduced pressure to give 2-methyl-9-phosphafluorene (a white solid).

[0207] Key NMR data: 1H NMR (400MHz, THF-d8): δ5.18(d,J=196.9Hz,1H,PH),7.29(t,J=8.8Hz,2H,CH),7.43(t,J=7.5Hz ,1H,CH),7.62(d,J=5.2Hz,1H,CH),7.77(t,J=6.4Hz,1H,CH),7.92(dd,J=25.5,7.9Hz,2H,CH). 31 P{ 1 H}NMR(202MHz,THF-d8):δ-68.61(s).

[0208] Example 19: Synthesis of 4-Fluoro-9-phosphaphene

[0209]

[0210] At room temperature, 0.2 mmol of lithium 4-fluoro9-phosphafluorene was added to a 25 mL reaction flask and dissolved in 6 mL of tetrahydrofuran. A THF solution of 0.2 mmol of triethylamine hydrochloride was then added dropwise to the reaction flask, and the mixture was reacted at room temperature for 12 hours, resulting in a dark brown solution. The remaining solid was extracted multiple times with n-pentane to obtain a colorless solution. The solvent n-pentane was then removed again under reduced pressure to obtain 4-fluoro9-phosphafluorene (a white solid).

[0211] Key NMR data: 1 H NMR (400MHz, THF-d8): δ5.33 (d, J=199.6Hz, 1H, PH), 7.22 (dd, J=11.7, 8.2Hz, 1H, CH), 7.43-7.30 (m, 2H, CH), 7.50(t,J=7.6Hz,1H,CH),7.63(t,J=6.2Hz,1H,CH),7.85(h,J=6.8,5.9Hz,1H,CH),8.23(d,J=7.9Hz,1H,CH), 31 P{ 1 H}NMR(202MHz,THF-d8):δ-64.74(s).

[0212] Industry availability

[0213] The organophosphorus compounds based on the phosphane fluorene structural unit of the present invention have broad application prospects in organic light-emitting materials or organic optoelectronic devices, either directly or through derivatization.

Claims

1. A method for preparing a phosphonium fluoride compound, comprising a method for preparing a phosphonium compound as shown in formula (II). In equation (II), R 1 and R 2 They may be the same or different, and each of them is hydrogen, halogen, trifluoromethyl, C1-C6 alkyl, or C1-C6 alkoxy. The preparation method includes the following steps: Step 1-1: Prepare compound (V) by reacting compound (IV) with an organometallic reagent at low temperature; In compounds of formula (IV), R 1 and R 2 Similar to formula (II), X is chlorine or bromine; in formula (V), R 1 and R 2 Same as in formula (II), M is lithium; The organometallic reagent used in step 1-1 is an organolithium reagent, which is n-butyllithium or tert-butyllithium, and the low temperature is in the range of -120°C to -60°C. The organometallic reagent used is in a ratio of 2 to 3 molar equivalents to the compound of formula (IV); Steps 1-2: Compound (I) is prepared by reacting compound (V) with white phosphorus at room temperature or above. The white phosphorus used is in a ratio of 1 to 1.5 molar equivalents relative to the compound of formula (V); In equation (I), R 1 and R 2 Same as formula (II), M is lithium; Sol represents the coordination solvent, which is tetrahydrofuran or diethyl ether; n represents the number of coordination solvents, which is a positive integer or half-integer greater than 2 and less than 3, and the reaction temperature above room temperature is room temperature to 50°C; Steps 1-3: Compound (II) is prepared by reacting compound (I) with water at room temperature or below. For the ratio of compound (I) to water, the amount of water used is 1 to 50 molar equivalents relative to compound (I), and the reaction temperature is below room temperature in the range of 0°C to room temperature.

2. The method for preparing phosphazenephosphosilicates according to claim 1, characterized in that, In step 1-1, the reaction is carried out at the low temperature range for 0.5 to 3 hours, and then the reaction is continued at room temperature for 2 to 6 hours. In steps 1-2, the reaction time is 6 to 24 hours; In steps 1-3, the reaction time is 0.5 to 6 hours.

3. A method for preparing a phosphonium fluoride compound, comprising the method for preparing a phosphonium compound as shown in formula (III). In equation (III), R 1 and R 2 They may be the same or different, and each of them is hydrogen, halogen, trifluoromethyl, C1-C6 alkyl, or C1-C6 alkoxy. The preparation method includes the following steps: Step 2-1: Prepare compound (V) by reacting compound (IV) with an organometallic reagent at low temperature; In compounds of formula (IV), R 1 and R 2 Similar to formula (III), X is chlorine or bromine; in formula (V), R 1 and R 2 Same as in equation (III), M is lithium; The organometallic reagent used in step 2-1 is an organolithium reagent, which is n-butyllithium or tert-butyllithium, and the low temperature is in the range of -120°C to -60°C. The organometallic reagent used is in a ratio of 2 to 3 molar equivalents to the compound of formula (IV); Step 2-2: Compound (I) is prepared by reacting compound (V) with white phosphorus at room temperature or above. The white phosphorus used is in a ratio of 1 to 1.5 molar equivalents relative to the compound of formula (V); In equation (I), R 1 and R 2 Same as formula (III), M is lithium; Sol represents the coordination solvent, which is tetrahydrofuran or diethyl ether; n represents the number of coordination solvents, which is a positive integer or half-integer greater than 2 and less than 3, and the reaction temperature above room temperature is room temperature to 50°C. Steps 2-3: Compound (III) is prepared by reacting compound (I) with triethylamine hydrochloride at room temperature or below. For the ratio of compound (I) to triethylamine hydrochloride, the amount of triethylamine hydrochloride used is 1 to 1.5 times the equivalent of compound (I), and the reaction temperature is in the range of 0°C to room temperature.

4. The method for preparing the phosphazenephosphonium hydrogen compound according to claim 3, characterized in that, In step 2-1, the reaction is carried out in the low temperature range for 0.5 to 3 hours, and then the reaction is continued at room temperature for 2 to 6 hours. In step 2-2, the reaction time is 6 to 24 hours; In steps 2-3, the reaction time is 6 to 24 hours.

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