JPH04124195A - New metallic fluoride complex of quaternary phosphonium fluoride, its production, fluorinating agent and desilylating agent - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I (R is alkyl or aryl; M is Li, Na, K or magnesium monohalide). EXAMPLE:Tetra-n-butylphosphonium fluoride lithium fluoride complex. USE:Fluorinating and desilylating agents for organic compounds. PREPARATION:A quaternary phosphonium bifluoride (e.g. tetra-n-butylphosphonium bifluoride) expressed by formula II is reacted with an organometallic reagent (e.g. n-butyl-lithium) expressed by the formula R<1>M in equiv. amounts in an organic solvent (e.g. benzene), preferably at -20 to +40 deg.C for 1.5-7hr.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention is a fluorinating agent for fluorinating organic compounds such as aliphatic alcohols, halides, and aromatic halides, or for removing silyl groups from silylated compounds. This invention relates to a novel fine metal fluoride of quaternary phosphonium fluoride which has a wide range of uses and excellent properties as a desilylating agent, etc., and a method for producing the same. [Prior Art] Until now, as compounds similar to the metal fluoride salt of the novel quaternary phosnium fluoride of the present invention, quaternary phosphonium fluorite or quaternary ammonium
Several fluoride hydrates and hydrogen fluoride salts are known. The outline of the manufacturing method of some such known compounds is as shown in (a) to (c) below. (a) A method for producing tetraphenylphosphonium fluoride tetrahydrate by reacting tetraphenylphosphonium bifluoride with an equivalent amount of an aqueous sodium hydrocarbon solution [Journal of Chemical Society Dalton Transactions (J, CheII)
1, p. 277 (1988)]. The reaction in this method can be expressed by the following reaction formula. NaHCO,b (○−−)7PF−HF−−+ (PF′−=IH
,0(b) A method for producing quaternary ammonium fluoride trihydrate by reacting quaternary ammonium sulfate with an aqueous solution of potassium fluoride and potassium hydroxide in a Hensen-water mixture [[Synthesis] (Synthesis
) J, p. 953 (1988)].The reaction in this method can be expressed by the following reaction formula: (However, R is n-butyl group, n-hexyl group, 0heptyl group or n-octyl group. (C) Tetraphenylphosphonium bromide was previously treated with an aqueous sodium hydroxide solution and then treated with hydrofluoric acid.
e) Quantitative conversion to tetraphenylphosphonium bifluoride by passing it through a column packed with a commercially available ion exchange resin such as IRA4]0 [Journal of Chemical Society
Chemical Communication (J, Cheffi,
Soc, Chem, Commun, ) J No. 125
6 (1983) and Japanese Patent Application Laid-Open No. 161224/1983]. The reaction in this reference method can be expressed by the following reaction formula. Furthermore, the tetraalkylphosphonium fluoride that the present inventors had previously succeeded in synthesizing was produced using the following production method (
d) or (e). (d) A method for producing tetra-butylphosphonium fluoride trihydrate by reacting an aqueous solution of tetra-n-butylphosphonium hydroxide with 1 equivalent of an aqueous solution of hydrofluoric acid (patent application filed by the present applicant) Hei 2-1.7
No. 6354; filed on July 5, 1990), the reaction in this method can be expressed by the following reaction formula. HF (n-C, H9)4POH+ (n-C,,Hg), P
F・3H20(e) Tetra-n-butylphosphonium
A method for producing tetra-n-butylphosphonium bifluoride by reacting a hydroxide aqueous solution with 2 equivalents of a hydrofluoric acid aqueous solution (see the above-mentioned Japanese Patent Application No. 176354/1999). The reaction in this method can be expressed by the following reaction formula. 8F (n-C4H9LPOH-1 → (n-C4H,), P
F(HF) However, the metal fluoride complex of the quaternary phosphonium fluoride represented by formula (1) of the present invention has not been described in conventional literature and is not known. [Problems to be Solved by the Invention] The quaternary phosphonium fluoride and quaternary ammonium fluoride described in (a) to (C) above are 3
~Although it can exist stably in the form of a tetrahydrate, in such a hydrated form, the nucleophilicity of the fluorine ion of the fluoride compound is significantly reduced due to the influence of the water molecules of the hydrate. . In addition, in order to remove the water molecules in the fluoride compounds that are inhibiting the nucleophilic force of the fluoride ions in the hydrated form of the fluoride compounds, when water is distilled off under reduced pressure by heating, these compounds It is known that it decomposes [Journal of Organic Chemistry (J, Org, Chem,) J Vol. 48, p. 2112 (
(1983)]. The reaction equation for this decomposition for quaternary ammonium fluoride hydrate is as follows. (n-C4H,)4~F'3H20←(n-C4H9)
4NF + 38202 (it-C4H9)4. NF
-'-4(r+-C, 1Hs)J'HF + (n-C
The present inventors have confirmed that 4'JiN + ell, CH3CN-CH2 and quaternary phosphonium fluoride trihydrate also decompose as shown in the reaction formula below when water is distilled off under heating and reduced pressure. R4PF・3H20→R4PF + 3H202R4P
F+H2O−+−pressure・匪+R□same ten times again. (a) above
, (b), and (d) all involve reactions in an aqueous solution, so coordination of water molecules to the produced fluoride compound cannot be avoided. On the other hand, quaternary phosphonium hydrofluorides such as quaternary phosphonium bifluoride obtained by methods (c) and (e) above are highly stable even in completely anhydrous form. In addition, the quaternary phosphonium hydrofluoride has high fluorination and desilylation powers for organic compounds. However, as the number of hydrofluoric acids coordinating to these quaternary compounds increases, the nucleophilic force of fluorine ions in the quaternary compounds decreases, as in the case of hydrates. The fluorination power and desilylation power of these polyhydrofluorides of quaternary phosphonium also decrease. Therefore, conventionally known quaternary phosphonium fluoride hydrates or hydrofluorides may not necessarily be satisfactory as fluorinating agents or desilylating agents depending on the type of substrate to be fluorinated or desilylated. do not have. Therefore, there is a demand for the development of a highly reactive compound in the fluorination and desilylation reactions of organic compounds in place of the conventionally known quaternary phosphonium fluoride compounds. Therefore, the object of the present invention is to provide a fluorinating agent for organic compounds;
The object of the present invention is to provide a metal fluoride complex of quaternary phosphonium fluoride that can be advantageously used industrially as a desilylating agent. [Means for Solving the Problems] The present inventors have made intensive efforts to solve the above-mentioned problems. As a result, we have developed a novel quaternary phosphonium fluoride metal fluoride that can be produced inexpensively, rapidly, and simply with high yield and purity by reacting a quaternary phosphonium bifluoride with an organometallic reagent in an organic solvent. I found a chemical complex. Therefore, the first gist of the present invention is the following general formula (1) % formula % (1) (wherein R represents an alkyl group or an aryl group, and M represents lithium, sodium or potassium. Show or
or magnesium monohalide) is a novel quaternary phosphonium fluoride metal fluoride complex. Further, the second gist of the present invention is that the following general formula (If) R4PF-HF (II) (wherein R
is an alkyl group or an aryl group) is mixed with the following general formula (II[)R' M
(face) (wherein R1 represents an alkyl group or an aryl group, and M represents lithium, sodium or potassium, or represents magnesium monohalide) in equivalent proportions. - A method for producing a novel metal fluoride complex of quaternary phosphonium fluoride represented by the formula % (1) (wherein R and M have the same meanings as above), characterized by: It is in. Furthermore, the third gist of the present invention is a fluorinating agent and a desorbing agent for organic compounds, characterized by comprising a metal fluoride complex of a quaternary phosphonium fluoride represented by the above general formula (1). In the silylating agent. The compound of the present invention of general formula (I) can be obtained by the following reaction scheme. In the formula, R, R" and M have the same meanings as above. R2 in the compound of formula (1) or R" in the compound of formula (III) is a linear or branched compound having 1 to 1 carbon atoms, respectively.
8 alkyl group, preferably an alkyl group having 1 to 6 carbon atoms, such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, 5ec-
It can be butyl, tert-butyl, n-pentyl, isopentyl, neopentyl and hexyl, or it can be aryl such as phenyl and tolyl. Further, M in the compound of formula 3 (1) is an alkali metal such as lithium, sodium, or potassium, or magnesium monochlorite. It can be magnesium monoiodide, magnesium monobromide, magnesium monofluoride, magnesium monoiodide, etc. These magnesium monohalides can be represented by 2MgHal (Hal represents a halogen atom of 5 chlorine, bromine, iodine or fluorine). Below, the method for producing a metal fluoride complex of quaternary phosphonium fluoride of the present invention will be explained in more detail. The quaternary phosphonium hifluorite of the formula (II), which is the starting material, is prepared by reacting hydrofluoric acid (hydrofluoride) in a proportion of 2 equivalents with a corresponding aqueous quaternary phosphonium hydroxide solution.
The resulting hydrate of quaternary phosphonium bifluoride can be easily obtained as a complete anhydride by subsequent dehydration (see Japanese Patent Application No. 2-176354). The production of quaternary phosphonium bifluoride is shown in the reference production example below. The anhydride of quaternary phosphonium bifluoride thus obtained is dissolved in an organic solvent, and an organometallic compound of formula (III) such as n-butyllithium is added to the solution for 1 hour.
Add dropwise in equivalent (stoichiometric) proportions. The organic solvents used in the reaction include ether solvents such as tetrahydrofuran, diethyl ether, and dibutyl ether, aromatic solvents such as xylene, toluene, and benzene, and hydrocarbon solvents such as n-hexane and n-hebutane. They can be mixed and used as desired. Examples of the organometallic reagent of formula (111) include n-butyllithium, 5ec-butyllithium, tert-butyllithium, phenyllithium, ethyl sodium, n-butyllithium, and n-butyllithium.
-pentyl potassium, methylmagnesium chloride,
Ethylmagnesium chloride, phenylmagnesium bromide, methylmagnesium fluoride, ethylmagnesium fluoride, phenylmagnesium fluoride, methylmagnesium bromide, ethylmagnesium bromide, phenylmagnesium bromide, methylmagnesium iodide, ethylmagnesium iodide, phenylmagnesium iodide, etc. can be used. The reaction temperature for the above reaction is -78
The temperature range is from 100°C to 100°C, preferably from -20°C to 40°C. Further, the organometallic compound of formula (III) is added dropwise for 1 to 5 hours, and after the completion of the addition, the reaction mixture is
The reaction is completed by stirring for about 1 minute to 2 hours. Through such reaction operations, the desired quaternary phosphonium of formula (1) can be obtained.
A metal fluoride complex of fluoride can be obtained quantitatively. After the reaction is completed, the reaction solution itself can be subjected to a fluorination reaction or a desilylation reaction of an organic compound without removing the target product of formula (r) from the reaction solution. At this time. If necessary, by distilling off the solvent from the reaction solution, the formula (r
The target product of formula (1) may be subjected to 'F-fi, or the target product of formula (1) may be redissolved in another solvent after distillation and subjected to the next reaction. Next, the fluorination and desilylation of organic compounds using the metal fluoride complex of the quaternary phosphonium fluoride of the present invention will be explained in more detail. an organic compound that can be fluorinated or desilylated;
An organic solvent and the metal fluoride complex of the quaternary phosphonium fluoride of the above formula (I) are placed in a reaction vessel and reacted at an arbitrary temperature with stirring. When fluorinating using a metal fluoride complex of the quaternary phosphonium fluoride of formula (1), it is usually 1 to 3 equivalents based on the atom or group that can be substituted for the fluorine atom in the organic compound to be fluorinated. The metal fluoride complex of formula (I) is used in a proportion of
It can be arbitrarily determined in consideration of reactivity and economic efficiency1.Also, in the case of desilylation, the proportion of 1 to 3 equivalents relative to the silyl ether group of the organic compound to be desilylated is also used. Can be used. Examples of organic solvents include DMSO, DMF, CH, and CN, since the metal fluoride complex of the quaternary phosphonium fluoride of formula (1) has good solubility in various solvents. aprotic polar solvents such as sulfolane, T) IF,
Nonpolar solvents such as xylene, toluene, and benzene can be used alone or in combination. Since the metal fluoride complex of the quaternary phosphonium fluoride of Formula 5 (1) itself can dissolve many organic compounds, it can also be used in the absence of an organic solvent. While conventional fluorinating agents and desilylating agents require the use of polar solvents such as DMSO and THF as reaction solvents, the quaternary phosphonium of formula (1)
In addition to these polar solvents, non-polar solvents such as xylene and toluene can also be used for the metal fluoride complex of fluoride. It has high dissolving power for organic compounds. Also, the expression (

Examples of silyl groups that can be released from the silylated organic compound by the compound [) include trialkylsilyl groups such as trimethylsilyl group and dimethyl-tert-butylsilyl group, and diphenyl-tert-butylsilyl group. Examples include diaryl-alkylsilyl groups. 〔Example〕

Examples are given below to specifically explain the production of the metal fluoride complex of formula (1) according to the present invention. Put 4.48 g (15 mmol) of anhydrous tetra-n-butylphosphonium bifluoride and 10 mQ of benzene into a 30@Q four-bottle flask equipped with a cooling tube and a stirrer under a nitrogen atmosphere to make a homogeneous solution. 5-10℃
It was cooled to Next, 9.0 mQ (15 mmol) of a 1.66 molar hexane solution of n-butyllithium was added dropwise to this solution over 1 hour while keeping the temperature at 5 to 10°C.
The reaction was completed by stirring for a minute. After the reaction was completed, the solvent was distilled off from the reaction solution using an evaporator at a temperature of 10°C or less under reduced pressure, resulting in 4.56 g of viscous liquid (yield: 99.9
The title compound represented by the following formula (%) was obtained. Example 2 4.48 g (15 mmol) of anhydrous tetra-n-butylphosphonium bifluoride and 10 wn of tetrahydrofuran were placed in a 30 m 12 four-bottle flask equipped with a cooling tube and a stirrer under a nitrogen atmosphere to make a homogeneous solution. This was cooled to 0-5°C. Next, 7.5 mQ (15 mmol) of a 2.00 molar solution of methylmagnesium chloride CO3MgCl in tetrahydrofuran was added dropwise to this solution over 1 hour while maintaining the temperature at 0 to 5°C, and the reaction was completed by stirring for 30 minutes. . After the reaction was completed, post-treatment was carried out in the same manner as in Example 1, and 5.30 g of liquid (yield: 99%) was obtained.
．． 1%), the title compound represented by the following formula % was obtained. Anhydrous tetraphenylphosphonium was added under a nitrogen atmosphere in a 50@Q four-bottle flask equipped with a viscous condenser and a stirrer.
Add 5.67 g (15 mmol) of bifluoride and 20 mQ of tetrahydrofuran to make a homogeneous solution. Cooled to 0-5°C. Next, add 8 8 mol of phenyllithium in cyclohexane-ether to this solution.
．． 3 mu (15 mmol) was added dropwise over 1 hour while maintaining the temperature from 0 to 5°C, and the reaction was completed by stirring for 30 minutes. After the reaction was completed, post-treatment was carried out in the same manner as in Example 1, and the title compound represented by the following formula % was obtained as 5.76 g (yield 99.9%) of a viscous liquid. Next, it will be specifically explained that the compound of formula (1) of the present invention is useful as a fluorinating agent for organic compounds or a desilylating agent for silylated organic compounds. Tetra-n-butylphosphonium fluoride 0.91 g (3 mmol) of lithium fluoride complex, 0.18 g (1 mmol) of P-methylbenzyl bromide, and Tf (
F1 was mixed to make a homogeneous solution. The reaction was completely completed after stirring this mixture at room temperature for 15 minutes. When the reaction solution was purified by silica gel chromatography, 0.11 g (yield 92%, purity 100%) of P-methylbenzyl fluoride was obtained. 0.76 g (2.5 mmol) of tetra-n-butylphosphonium fluoride lithium fluoride complex and 2
- 0.45 g (1 mmol) of tert-butyldiphenylsilyl ether of tetradecanol and 5 mf of THF
l! were mixed to form a homogeneous solution. Mix this mixture at room temperature for 4 hours.
The reaction was completely completed after stirring for 2 hours. The reaction solution was purified by silica gel chromatography. 0.20 g (yield 94%, purity 1.00%) of 2-tetradecanol was obtained. Cold i6 0.91 g (3 mmol) of tetra-n-butylphosphonium fluoride lithium fluoride complex and 0.21 g (1 mmol) of 1,2-epoxytetradecane were mixed under a nitrogen atmosphere, and the mixture was heated to room temperature. After stirring for 20 hours, the reaction was completely completed. When this reaction solution was purified by silica gel chromatography, it was found that ■-fluoro-2-tetradecanol (A) and 2-fluoro-1
0.1.9 g (yield: 82%) of a mixture of -tetradecanol (B) was obtained. The ratio of compound (A) and compound (13) was 97:3 according to the results of 19F-NMR analysis. In the following examples, the ratio of tetrafluoride used as a raw material for the production of the metal fluoride complex of formula (1) above is shown. An example of the preparation of alkylphosphonium bifluoride is shown in Reference Production Example 1. Consider 1] Ko J Synthesis of tetra-n~butylphosphonium bifluoride anhydride In a 500 m12 four-bottle flask equipped with a condenser and a stirrer, 345.6 g of a 40.0% concentration tetra-butylphosphonium hydroxide aqueous solution ( 0.50 mol) and phenolphthalein solution as an indicator.
Add dropwise and cool to 10-15°C. Next, a hydrofluoric acid aqueous solution with a concentration of 47.0% I (F) was added at a temperature of 10 to 15°C.
21.3 g of this HF aqueous solution (HF
The color change point was reached when O, 50 mol) was added. Furthermore, 1 equivalent ratio of hydrogen nofluoride 1213 g (l(F
0.50 mo) Li) was added and 30 molecules J1 were stirred at room temperature to react. Next, water was distilled off from the reaction solution at 40-50°C under reduced pressure using an evaporator, and the water was further dehydrated using a vacuum pump for 4-5 hours, resulting in a colorless and transparent liquid product (
Solid at room temperature) (7) 149.3g (yield 100.0
%, purity 100%) to obtain the title compound represented by the following formula. The analysis results of the obtained product are shown below. Melting point: 30-35°C H-NMRCDCI3), δ (ppm): 1.00
(t, d; 6.5Hz, 12H), 1.52(q
, d=6.5Hz. 16H), 2.10-2.40 (m, 8H), 1
3.90 (s, 1ll)'' F-NMR (CDC
I23) , δ (ppm) Co-155,6 (S) Element standing rice actual measurement value: C64,77%, 812.12%, F
12.70%. P 10.41% Calculated value (C engineering. H, 7F, P): C64,38
%, + (12,52%, F 12.73%. 1" i, 0, 37% [Effects of the Invention] The present invention provides a novel quaternary phosphonium fluoride metal fluoride with the following features. The complex can be provided industrially very easily. That is, firstly, the corresponding fluoride-metal fluoride complex can be prepared by a simple operation in which an easily available quaternary phosphonium bifluoride is reacted with an organometallic reagent in an organic solvent. It can be obtained in high yield and extremely easily.Secondly, the obtained quaternary phosphonium fluoride metal fluoride complex is of high purity and has excellent solubility in various solvents, and is highly soluble in aliphatic compounds and aromatic compounds. It has excellent properties such that it can be advantageously used as a fluorinating agent or a desilylating agent, and is also industrially useful.

Claims (1)

[Claims] 1) A quaternary compound represented by the general formula R_4PF・MF(I) (wherein R represents an alkyl group or an aryl group, and M represents lithium, sodium, potassium, or magnesium monohalide) metal fluoride complexes of grade phosphonium fluorides. 2) The following general formula (III) is added to the quaternary phosphonium bifluoride represented by the following general formula (II) R_4PF・HF(II) (wherein R represents an alkyl group or an aryl group) in an organic solvent. ) R^1M(III) (wherein R^1 represents an alkyl group or an aryl group,
General formula (I) R_4PF・MF(I) (wherein, R and M has the same meaning as above) A method for producing a metal fluoride complex of quaternary phosphonium fluoride. 3) A fluorinating agent and desilylating agent for organic compounds, characterized by comprising a metal fluoride complex of quaternary phosphonium fluoride represented by the general formula (I) according to claim 1.