Process for producing zero-valent platinum complex having alkene ligand
The method of reacting an alkene ligand and a base with a divalent platinum complex and potassium formate in the presence of a 18-crown-6 catalyst addresses the inefficiencies of existing synthesis methods for zero-valent platinum complexes, achieving safer and more efficient production.
Patent Information
- Application Number
- JP2020200287
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2020-12-02
- Publication Date
- 2025-06-20
- Estimated Expiration
- 2040-12-02
AI Technical Summary
Existing synthesis methods for zero-valent platinum complexes with alkene ligands face challenges such as low yields, use of flammable lithium, and long reaction times, making them inefficient and unsafe.
A method involving the reaction of an alkene ligand and a base with a divalent platinum complex and potassium formate in the presence of a 18-crown-6 catalyst, which significantly shortens the reaction time and eliminates the use of flammable lithium.
This method allows for the safe and efficient production of zero-valent platinum complexes with alkene ligands, achieving higher yields and reducing the reaction time compared to conventional methods.
Smart Images
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Abstract
Description
[Technical field]
[0001] The present invention relates to a method for preparing zero-valent platinum complexes having alkene ligands. [Background technology]
[0002] Platinum complexes are used in a wide range of fields, including as organic synthesis catalysts, anticancer drugs, and nanoparticle materials. Platinum-0-alkene complexes, which have an alkene ligand that is easy to exchange and a metal center with a low oxidation number that is easy to oxidize, and bis(1,5-cyclooctadiene)platinum, which has the cyclic diene 1,5-cyclooctadiene as a ligand, have been frequently used as raw materials for these platinum complexes. However, while similar alkene complexes of nickel and palladium, which are group 10 metals related to platinum, are commercially available at relatively low prices, platinum-0-alkene complexes, such as bis(1,5-cyclooctadiene)platinum, are not commercially available from general reagent companies. This is because the synthesis methods for platinum-0-alkene complexes known to date have the following problems:
[0003] Non-Patent Document 1 discloses a method for synthesizing bis(1,5-cyclooctadiene)platinum, and describes that the yield of bis(1,5-cyclooctadiene)platinum was 31%. The synthesis method described in Non-Patent Document 1 uses lithium, and the use of flammable lithium has been problematic.
[0004] Non-Patent Document 2 describes that bis(1,5-cyclooctadiene)platinum was obtained by reacting dichloro(1,5-cyclooctadiene)platinum with 1,5-cyclooctadiene and potassium formate in the presence of a catalytic amount of 18-crown-6 in diethyl ether. Problems with this synthesis method include the generation of by-products such as HCl and formic acid, and the long reaction time of 24 hours. It describes that the yield of this synthesis method was 40%. [Prior art documents] [Non-patent literature]
[0005]
Non-Patent Document 1
Non-Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0006] The present invention provides a method for producing a zero-valent platinum complex having an alkene ligand, which is simpler than conventional synthesis methods.
Means for Solving the Problems
[0007] As a result of intensive studies to solve the above problems, the present inventors have found that a zero-valent platinum complex having an alkene ligand can be produced by reacting an alkene ligand and a base with a divalent platinum complex and potassium formate in the presence of a catalyst. The present invention has been completed based on this finding and includes the following aspects: That is, one aspect of the present invention is 〔1〕A method for producing a zero-valent platinum complex having an alkene ligand represented by the following formula (1) or (1)’,
Chemical Formula
[0008] Here, the manufacturing method of the present invention, in one embodiment [2] The manufacturing method according to [1] above, wherein the alkene (L 1 ) is an alkene selected from the group consisting of cyclodienes, norbornenes, or 1,3 - divinyldisiloxanes. Also, the manufacturing method of the present invention, in one embodiment [3] The manufacturing method according to [3] above, wherein the alkene (L 1 ) is 1,5 - cyclooctadiene, norbornene, or 1,3 - divinyltetramethyldisiloxane. Also, the manufacturing method of the present invention, in one embodiment [4] The manufacturing method according to any one of [1] to [3] above, wherein the base is potassium carbonate. Also, the manufacturing method of the present invention, in one embodiment [5] The manufacturing method according to any one of [1] to [4] above, wherein L 2 in the formula (2) is 1,5 - cyclooctadiene. Also, the manufacturing method of the present invention, in one embodiment [6] The manufacturing method according to any one of [1] to [5] above, wherein X is F, Cl, Br, I, or trifluoromethanesulfonate. [Advantages of the Invention]
[0009] According to the method for producing a zero-valent platinum complex having an alkene ligand of the present invention, a zero-valent platinum complex having an alkene ligand can be produced safely and efficiently as compared with the conventional synthesis method.
Embodiments for Carrying Out the Invention
[0010] One aspect of the present invention provides a method for producing a zero-valent platinum complex having an alkene ligand. The production method is a method for producing a zero-valent platinum complex having an alkene ligand represented by the following formula (1) or (1)’,
Chemical formula
Chemical formula
[0011] The following formula shows one embodiment of the reaction in the method for producing a zero-valent platinum complex having an alkene ligand of the present invention.
Chemical formula
[0012] In the above reaction formula, the alkene (L 1 ) used to react the divalent platinum complex having an alkene ligand with potassium formate is not particularly limited as long as it can provide the π electrons of the carbon-carbon double bond as a ligand to Pt and form a coordination bond. Preferably, they are cyclodienes, norbornenes, 1,3-divinyldisiloxanes, and more preferably 1,5-cyclooctadiene, norbornene, 1,3-divinyltetramethyldisiloxane. The alkene (L 1 ) provides a ligand to Pt through the reaction process and forms a coordination bond with Pt. As a result, a zerovalent platinum complex having an alkene ligand represented by formula (1) is produced. Therefore, L 1 in formula (1) is derived from the alkene (L 1 ) added in the reaction process.
[0013] The produced zerovalent platinum complex may form a bidentate chelate coordination in addition to the monodentate bridging coordination by the alkene (L 1 ) used for the reaction. For example, when 1,3-divinyltetramethyldisiloxane is reacted as the alkene (L 1 ), a bidentate chelate coordination as shown below may be formed.
Chemical formula
[0014] Cyclodienes can be represented by the following formula, and reference is made to the description of JP-T-2017-523144.
Chemical formula
[0015] Examples of the alkyl in R1 to R8, R3', R4', R7' and R8' in formula (3) include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, sec-butyl group, iso-butyl group, tert-butyl group, n-pentyl group, iso-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-docosyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, etc.
[0016] Examples of the aryl group in R1 to R8, R3', R4', R7' and R8' in formula (3) include phenyl group, 1-naphthyl group, 2-naphthyl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 1-triphenylenyl group, 2-triphenylenyl group, etc.
[0017] Examples of the alkoxy groups in R1 to R8, R3', R4', R7' and R8' in formula (3) include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a neopentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-heptadecyl group, an n-octadecyl group, an n-nonadecyl group, an n-docosyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-phenanthryl group, a 2-phenanthryl group, a 3-phenanthryl group, a 4-phenanthryl group, a 9-phenanthryl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-pyrenyl group, a 2-pyrenyl group, a 4-pyrenyl group, a 1-triphenylenyl group, a 2-triphenylenyl group, etc., which are alkoxy groups substituted with an oxygen atom.
[0018] Examples of the halogen substituents in R1 to R8, R3', R4', R7' and R8' in formula (3) include a fluoro group, a chloro group, a bromo group, and an iodo group.
[0019] When R5 to R6 in formula (3) combine together to form a ring structure, it is an aliphatic hydrocarbon group having 1 to 20 carbon atoms, such as a methylene group, an ethylene group, a tetramethylethylene group, an n-propylene group (trimethylene group), a 1-methylpropylene group, a 1,1-dimethylpropylene group, a 2-methylpropylene group, a 1,2-dimethylpropylene group, a 2,2-dimethylpropylene group, a 1,1,2-trimethylpropylene group, a 1,1,3-trimethylpropylene group, an n-butylene group (tetramethylene group), a 2-methyl-1,4-butylene group, a 3-methyl-1,4-butylene group, a 2,2-dimethyl-1,4-butylene group, a 2,3-dimethyl-1,4-butylene group, a 2,2,3-trimethyl-1,4-butylene group, an n-pentylene group (pentamethylene group), an n-hexanylene group (hexamethylene group), etc., which are chain hydrocarbon groups.
[0020] Examples of norbornenes include, but are not limited to, 5-methyl-bicyclo[2.2.1]-hept-2-ene, 5,5-dimethyl-bicyclo[2.2.1]-hept-2-ene, 5-ethyl-bicyclo[2.2.1]-hept-2-ene, 5-butyl-bicyclo[2.2.1]-hept-2-ene, 5-hexyl-bicyclo[2.2.1]-hept-2-ene, 5-octyl-bicyclo[2.2.1]-hept-2-ene, 5-octadecyl-bicyclo[2.2.1]-hept-2-ene, 5-ethylidene-bicyclo[2.2.1]-hept-2-ene, 5-methylidene-bicyclo[2.2.1]-hept-2-ene, 5-vinyl-bicyclo[2.2.1]-hept-2-ene, 5-propenyl-bicyclo[2.2.1]-hept-2-ene; 5-methoxycarbonyl-bicyclo[2.2.1]-hept-2-ene, 5-cyano-bicyclo[2.2.1]-hept-2-ene, 5-methyl-5-methoxycarbonyl-bicyclo[2.2.1]-hept-2-ene, 5-ethoxycarbonyl-bicyclo[2.2.1]-hept-2-ene, 5-methyl-5-ethoxycarbonyl-bicyclo[2.2.1]-hept-2-ene, bicyclo[2.2.1]-hept-5-enyl-2-methylpropionate, bicyclo[2.2.1]-hept-5-enyl-2-methyloctanoate, bicyclo[2.2.1]-hept-2-ene-5,6-dicarboxylic anhydride, 5-hydroxymethyl-bicyclo[2.2.1]-hept-2-ene, 5,6-di(hydroxymethyl)-bicyclo[2.2.1]-hept-2-ene, 5-hydroxy-i-propyl-bicyclo[2.2.1]-hept-2-ene, 5,6-dicarboxy-bicyclo[2.2.1]-hept-2-ene, bicyclo[2.2.1]-hept-2-ene-5,6-dicarboximide, 5-cyclopentyl-bicyclo[2.2.1]-hept-2-ene, 5-cyclohexyl-bicyclo[2.2.1]-hept-2-ene, 5-cyclohexenyl-bicyclo[2.2.1]-hept-2-ene, 5-phenyl-bicyclo[2.2.1]-hept-2-ene, tricyclo[4.3.0.12,5]-deca-3,7-diene, tricyclo[4.3.0.12,5]-deca-3-ene, tricyclo[4.4.0.12,5]-undeca-3,7-diene or tricyclo[4.Examples include 4.0.12,5]-undeca-3,8-diene, tricyclo[4.4.0.12,5]-undec-3-ene, etc.
[0021] Examples of 1,3-divinyldisiloxanes include compounds represented by the following formula. [Chemical formula] (In formula (4), R represents an alkyl group, aryl group, or alkoxy group having 1 to 50 carbon atoms.)
[0022] Examples of the alkyl group in formula (4) include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, sec-butyl group, iso-butyl group, tert-butyl group, n-pentyl group, iso-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-docosyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, etc.
[0023] Examples of the aryl group in formula (4) include phenyl group, 1-naphthyl group, 2-naphthyl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 1-triphenylenyl group, 2-triphenylenyl group, etc.
[0024] Examples of the alkoxy group in formula (4) include an alkoxy in which a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a neopentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-heptadecyl group, an n-octadecyl group, an n-nonadecyl group, an n-docosyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-phenanthryl group, a 2-phenanthryl group, a 3-phenanthryl group, a 4-phenanthryl group, a 9-phenanthryl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-pyrenyl group, a 2-pyrenyl group, a 4-pyrenyl group, a 1-triphenylenyl group, a 2-triphenylenyl group, etc. are substituted for an oxygen atom.
[0025] L in formula (2) 2 is an alkene that provides a ligand to Pt in the same manner as L 1 in formula (1), and the alkene is the same as the above definition. L in formula (2) 2 may be the same as or different from L 1 in formula (1). L in formula (2) 2 is preferably 1,5-cyclooctadiene. X in formula (2) represents a halogen atom or a pseudohalogen which is an anionic ligand. Although not particularly limited, it is preferably F, Cl, Br, I, or trifluoromethanesulfonate, and more preferably Cl.
[0026] The amount (charged amount) of the divalent platinum complex having an alkene ligand used in the reaction is not particularly limited, but from the viewpoint of the yield of the zero-valent platinum complex, it is preferably a concentration of 0.001 mol / L or more and 10.0 mol / L or less in the solvent, and more preferably a concentration of 0.01 mol / L or more and 1.0 mol / L or less. 18-Crown-6 (1,4,7,10,13,16-hexaoxacyclooctadecane) can be used as a catalyst. The amount of the 18-crown-6 catalyst used in the reaction is preferably 2 times or more, more preferably 5 times or more the amount of the divalent platinum complex having an alkene ligand. As the base, an inorganic base or an organic base can be used. Specifically, although not limited to the following, preferably potassium carbonate, sodium hydrogen carbonate, lithium hydroxide, calcium hydroxide, etc. can be mentioned, and more preferably potassium carbonate. The amount of the base used in the reaction is not limited, but it is preferably 7.5 times the amount of the divalent platinum complex having an alkene ligand. The amount of potassium formate used in the reaction is preferably 3.35 times the amount of the divalent platinum complex having an alkene ligand. As the solvent used in the reaction, various organic solvents can be used. Specifically, although not limited to the following, 1,5-cyclooctadiene, diethyl ether, etc. can be mentioned. The temperature condition of the reaction can be, for example, 0 to 50 °C, and preferably 35 °C. The reaction time can be, for example, 1 to 24 hours, and preferably 4 to 24 hours.
[0027] The present invention will be described more specifically with reference to the following examples, but it can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.
Examples
[0028] (Examples 1 to 16) To diethyl ether containing potassium carbonate and 18-crown-6 catalyst, dichloro(1,5-cyclooctadiene)platinum (PtCl2(cod)), 1,5-cyclooctadiene, and potassium formate were added, and after stirring for a certain period of time under temperature conditions of 25 °C or 35 °C, filtration through a membrane filter was carried out to obtain bis(1,5-cyclooctadiene)platinum (Pt(cod)2). Each example changed the amounts of each compound used in the reaction, the reaction time, and the reaction temperature (Examples 1 to 15). Also, bis(1,5-cyclooctadiene)platinum (Pt(cod)2) was obtained under the same conditions as in Example 15 except that 1,5-cyclooctadiene was used as the solvent (Example 16). [Chemical formula]
[0029] The confirmation of the compound was carried out by the analysis of various spectroscopic analyses. Specifically, it was carried out by the analysis of proton nuclear magnetic resonance spectrum (1H-NMR). Mesitylene was used as an internal standard in the nuclear magnetic resonance spectrum. Also, the amounts of each compound used in the reaction, the reaction time, the reaction temperature, and the yields of bis(1,5-cyclooctadiene)platinum in each example are shown in Table 1 below.
[0030] [Table 1]
[0031] As shown in Table 1, in Examples 1 to 15, it was possible to produce a zero-valent platinum complex with a short reaction time of 3 to 5 hours. Also, Example 16 shows that even when 1,5-cyclooctadiene was used as the solvent, it was possible to produce a zero-valent platinum complex with a high yield.
[0032] (Examples 17 to 28) Bis(1,5-cyclooctadiene)platinum was produced using the same raw materials, catalyst, and solvent as in Example 1, except that the bases described in the following table were used. Specifically, in 3.0 ml of diethyl ether, dichloro(1,5-cyclooctadiene)platinum, 1,5-cyclooctadiene, potassium formate, a base, and a 18-crown-6 catalyst were added so that the final concentrations were 0.2 mmol, 2.0 mmol, 0.67 mmol, 1.5 mmol, and 0.068 mmol, respectively. After reacting with stirring for 5 hours under the condition of 35 °C, it was filtered through a membrane filter.
Chemical formula
[0033] The yields of the bases used in the reaction and bis(1,5-cyclooctadiene)platinum are shown in Table 2 below.
Table 2
[0034] As shown in Table 2, any of the bases used in Examples 17 to 28 can be used in the method for producing the zero-valent platinum complex of the present invention, and the zero-valent platinum complex can be produced in a short reaction time of 5 hours.
Claims
1. A method for producing a zero-valent platinum complex having an alkene ligand represented by the following formula (1) or (1)': 【Chemical Formula 1】 (In formula (1) and (1)', L １ represents an alkene selected from the group consisting of cyclodienes, norbornenes, or 1,3-divinyldisiloxanes. n, m, and l are the numbers of L １ bonded to Pt, and represent integers from 1 to 4.) In the presence of a 18-crown-6 catalyst and a base (excluding potassium formate), reacting a divalent platinum complex having an alkene ligand represented by the following formula (2) with an alkene (L １ ) and potassium formate 【Chemical Formula 2】 (In formula (2), L ２ represents an alkene selected from the group consisting of cyclodienes, norbornenes, or 1,3-divinyldisiloxanes, m is the number of L ２ bonded to Pt, represents an integer from 1 to 3, and X represents a halogen atom or a pseudohalogen) A production method comprising the above.
2. The production method according to claim 1, wherein the alkene (L １ ) is 1,5-cyclooctadiene, norbornene, or 1,3-divinyltetramethyldisiloxane.
3. The production method according to claim 1 or 2, wherein the base is potassium carbonate.
4. The production method according to any one of claims 1 to 3, wherein L ２ in the formula (2) is 1,5-cyclooctadiene.
5. The production method according to any one of claims 1 to 4, wherein The production method wherein X is F, Cl, Br, I, or trifluoromethanesulfonate.
6. The production method according to any one of Claims 1 to 5, The production method wherein the solvent used in the step of causing the reaction is diethyl ether.