JP2000001495A - Asymmetric platinum complex - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel asymmetric platinum complex, particularly an optically active substance, which acts as a Lewis acid catalyst and can give a practical reaction yield and an asymmetric yield in an asymmetric synthesis reaction An object of the present invention is to provide a novel asymmetric platinum complex obtained from a bisphosphine aryloxyacylplatinum (II) complex. The object of the present invention is to provide an asymmetric platinum complex obtained by treating an optically active sphosphine aryloxyacylplatinum (II) complex with a super strong acid in an oxygen atmosphere, that is, an optically active sphosphinearyloxyacylplatinum. (II) The problem is solved by an asymmetric platinum complex having an equivalent phosphorus-platinum bond obtained from the complex.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel platinum complex obtained from an optically active bisphosphine aryloxyacylplatinum (II) complex. Such a platinum complex is a useful compound that can serve as a catalyst for various asymmetric synthesis reactions.

[0002]

2. Description of the Related Art Platinum complexes have been used as catalysts in various reactions such as hydrosilylation, hydroformylation, hydrogenation, and isomerization reactions on carbon-carbon multiple bonds. However, attempts to make this platinum complex optically active and obtain optically active compounds that can be used as intermediates for medical and agricultural chemicals as reaction products have only reported practical asymmetric yields in hydroformylation reactions. (Eg, Organometallics, 10, 1
183 (1991)), and little has been reported on other reactions.

[0003] The reason is that the stability of the optically active platinum complex is high (that is, the reactivity is low).
For example, an optically active bisphosphine aryloxyacylplatinum (II) complex is a stable compound that can be synthesized in one step from commercially available potassium tetrachloroplatinate (J. Organom).
et. Chem. , 193, 397 (1980)), the reactivity is low as it is, and it is necessary to perform some activation treatment. For this reason, this complex is activated by treatment with perchloric acid under an inert gas (nitrogen) atmosphere (that is, under a non-oxygen atmosphere) (Organometal).
lics, 13, 3442 (1994)), and its application is limited to asymmetric oxidation reactions (furthermore, both the reaction yield and the asymmetric yield have not reached practical levels).

That is, since the optically active bisphosphine aryloxyacylplatinum (II) complex activated as described above can be expected to act as a Lewis acid, ketene silyl, a typical reaction using a Lewis acid catalyst, is used. I tried to apply it by taking up the reaction between acetal and aldehyde,
Although the reaction proceeded, the asymmetric induction observed in the product was very low, and development into other asymmetric synthesis reactions was practically impossible.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to a novel asymmetric platinum complex, particularly an optically active compound, which acts as a Lewis acid catalyst and can give a practical reaction yield and an asymmetric yield in an asymmetric synthesis reaction. Bisphosphine aryloxyacylplatinum (I
I) It is an object to provide a novel asymmetric platinum complex obtained from the complex.

[0006]

An object of the present invention is to provide an asymmetric platinum complex obtained by treating an optically active bisphosphine aryloxyacylplatinum (II) complex with a superstrong acid in an oxygen atmosphere, that is, an optically active bisphosphine aryloxyacylplatinum (II) complex. The problem is solved by an asymmetric platinum complex having an equivalent phosphorus-platinum bond, obtained from a phosphine aryloxyacylplatinum (II) complex.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The novel asymmetric platinum complex of the present invention comprises
Optically active bisphosphine aryloxyacylplatinum (I
I) An asymmetric platinum complex having an equivalent phosphorus-platinum bond obtained from an optically active bisphosphine aryloxyacylplatinum (II) complex obtained by treating a complex with a superacid in an oxygen atmosphere. .

The optically active bisphosphine aryloxyacylplatinum (II) complex includes a compound represented by the formula (1). This compound can be obtained, for example, by reacting potassium tetrachloroplatinate with a salicylaldehyde having a corresponding substituent and further with an optically active bidentate phosphine corresponding to L (Organo).
metallics, 13, 3442 (1994)).

[0009]

Embedded image (Wherein R ¹ , R ² , R ³ , and R ⁴ represent a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, a nitro group, a cyano group, or a dialkylamino group. And L represents an optically active bidentate phosphine, R ¹ , R ² , R ³ , and R ⁴ may be the same or different, and two adjacent groups may be bonded to form a ring. May be.)

[0010] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. The alkyl group has 1 to 20 carbon atoms, preferably 1 carbon atom.
To 12 alkyl groups (methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl,
Octyl group, nonyl group, decyl group, undecyl group, dodecyl group, etc.), and the alkenyl group has 2 carbon atoms.
And preferably 20 to 12 alkenyl groups (vinyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, etc.). And the aryl group has 6 to 20 carbon atoms, preferably 6 carbon atoms.
To 12 aryl groups (phenyl group, tolyl group, xylyl group, naphthyl group, dimethylnaphthyl group, etc.).

The alkoxy group has 1 to 1 carbon atoms.
0 alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group, etc.). As the aryloxy group, an aryloxy group having 6 to 14 carbon atoms (phenoxy group, toloxy group, xyloxy group, naphthoxy group) And the like. Examples of the dialkylamino group include a dialkylamino group having 2 to 10 carbon atoms (dimethylamino group, diethylamino group, and the like). Incidentally, these alkyl group, alkenyl group, aryl group,
An alkoxy group, an aryloxy group, and a dialkylamino group are n-, i-, s-, t-, o-, m-, p-, α
-, And various isomers such as β-.

When R ^{1 to} R ⁴ are the aforementioned alkyl group, alkenyl group, aryl group, alkoxy group, aryloxy group or dialkylamino group, adjacent groups (ie, R ¹ and R ² , R ² and R ³ or R ³ and R ⁴ ) may be linked to form a ring (such as a benzene ring or a cycloalkane ring having 4 to 8 carbon atoms such as cyclopentane and cyclohexane). At this time, a ring may be formed by containing a hetero atom such as an oxygen atom.

The optically active bidentate phosphine (L) includes, for example, those represented by formulas (2-a), (2-b) and (3-
a), (3-b), (4-a), (4-b), (5-
a) and the compounds represented by (5-b).

[0014]

Embedded image (Wherein, R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , and R ¹² represent an alkyl group, a cycloalkyl group, or an aryl group;
R ⁵ and R ⁶ are substituents on the naphthalene ring and represent a hydrogen atom, a halogen atom, an alkyl group, or an aryl group. Also,
n represents an integer of 0 to 10. R ⁵ and R ⁶ may be the same or different, and R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R
¹² may be the same or different. )

In the above optically active bidentate phosphine (L), R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹²
Examples of the alkyl group and aryl group represented by are the same groups as the alkyl group and aryl group represented by R ^{1 to} R ⁴ . The same applies to the halogen atom. R
^7, the ^{R 8, R 9, R 10} , cycloalkyl group represented by R ^11, R ^12, cycloalkyl (e.g., cyclopentyl, cyclohexyl, etc.) of 5-7 carbon atoms and the like.
When R ⁵ and R ⁶ are a halogen atom, an alkyl group, or an aryl group, R ⁵ and R ⁶ are 1 to 2 on the naphthalene ring.
Preferably, the number is

Examples of optically active bidentate phosphines (L)
Is R in formulas (2-a) and (2-b).⁷, R⁸But
In the phenyl group, R^Five, R⁶Is a hydrogen atom (BI
NAP) and formulas (2-a) and (2-b)
⁷, R⁸Is a p-tolyl group, and R ^Five, R⁶Is a hydrogen atom
Compound (Tol-BINAP), Formulas (3-a) and (3
In -b), R⁹, R^Ten, R¹¹, R¹²Is a methyl group
Certain compounds (Me-DUPHOS), formula (3-a) and
And in (3-b), R⁹, R^Ten, R¹¹, R^{1 Two}But
A compound (Et-DUPHOS) which is a compound of the formula (5-
In a) and (5-b), R⁷, R⁸Is a phenyl group
Wherein n = 0 (CHIRAPHOS);
In (5-a) and (5-b), R⁷, R⁸But pheny
And a compound in which n = 1 (BDPP).
It is.

In the optically active bisphosphine aryloxyacylplatinum (II) complex represented by the formula (1), for example, R ¹ and R ³ are t-butyl groups, and R ² and R ⁴ are hydrogen atoms. A compound in which L is BINAP (shown by the formula (A)), or R ^{1 to} R ⁴ are hydrogen atoms,
A compound wherein L is BINAP (shown by the formula (B))
And, in R ^1, R ³ is t- butyl group, (indicated by formula ^{(C)) R 2, R} 4 is a hydrogen atom, compound L is said of Tol-BINAP and, R ¹ to R ⁴ is a hydrogen atom,
A compound wherein L is Me-DUPHOS described above (formula (D)
Or a compound (shown by the formula (E)) wherein R ^{1 to} R ⁴ are hydrogen atoms and L is the above-mentioned CHIRAPHOS.

[0018]

Embedded image

The novel asymmetric platinum complex of the present invention can be obtained by treating the above optically active bisphosphine aryloxyacylplatinum (II) complex with a super strong acid in an oxygen (O ₂ ) atmosphere. . At this time, the oxygen concentration in the processing atmosphere is not more than 100% by volume and is not particularly limited as long as oxygen is present. For example, 0.01 to 100% by volume, further 1 to 100% by volume, particularly 15 to 25% by volume %
Is preferably within the range. The processing temperature is -78.
C. to 140.degree. C., more preferably 0 to 30.degree. The pressure is not particularly limited. Note that the treatment atmosphere can be an oxygen atmosphere by using pure oxygen, air, or pure oxygen diluted with an inert gas (such as nitrogen), and the treatment is usually performed in a system in which a solvent is present. .

As the super strong acid, at least one of trifluoromethanesulfonic acid, tetrafluoroboric acid, hexafluorophosphoric acid, hexafluoroantimonic acid and perchloric acid is used, and among them, trifluoromethanesulfonic acid is preferable. The super-strong acid is used in an amount of 1 to 1 equivalent of the optically active bisphosphine aryloxyacylplatinum (II) complex.
It is preferred to use up to 20 equivalents, more preferably 1 to 4 equivalents.

In the above-described treatment under an oxygen atmosphere, it is more preferable to carry out the treatment in the presence of water since the treatment speed can be increased. The amount of the water is preferably 1 to 20 equivalents, more preferably 2 to 4 equivalents, per equivalent of the optically active bisphosphine aryloxyacylplatinum (II) complex. Water may be added to the solvent when performing the above treatment, or may be contained in the solvent in advance.

Examples of the solvent include aliphatic halogenated hydrocarbons (such as dichloromethane and dichloroethane), aromatic hydrocarbons (such as benzene, toluene and xylene), ethers (such as diisopropyl ether and tetrahydrofuran), and amides (such as dimethylformamide). , Sulfoxide (dimethyl sulfoxide and the like), nitrile (acetonitrile and the like) and the like, among which aliphatic halogenated hydrocarbons are preferable. These solvents are preferably used in an amount of 10 to 1000 ml, more preferably about 50 to 500 ml, per 1 mmol of the optically active bisphosphine aryloxyacylplatinum (II) complex.

Thus, the optically active bisphosphine aryloxyacylplatinum (II) complex (non-equivalent phosphorus-
The novel asymmetric platinum complex of the present invention obtained from (having a platinum bond) is an asymmetric platinum complex having an equivalent phosphorus-platinum bond. That is, this asymmetric platinum complex is obtained from an optically active bisphosphine aryloxyacylplatinum (II) complex (having a non-equivalent phosphorus-platinum bond; showing two signals in phosphorus nuclear magnetic resonance analysis). An asymmetric platinum complex showing one signal in nuclear magnetic resonance analysis and having a unique chemical shift value (δ) and a phosphorus-platinum coupling constant (J _Pt-P ).

Such an asymmetric platinum complex having an equivalent phosphorus-platinum bond is, for example, one showing one signal in phosphorus nuclear magnetic resonance analysis, wherein L is the above-mentioned BINAP or Tol-BINAP. In a phosphorus nuclear magnetic resonance analysis obtained by treating a certain optically active bisphosphine aryloxyacylplatinum (II) complex as described above, a chemical shift value in the range of -3.0 ppm to 7.0 ppm and a chemical shift value of 3400 to 4200 Hz were obtained. Phosphorus nuclear magnetic resonance analysis obtained by treating an asymmetric platinum complex having a phosphorus-platinum coupling constant in the above range, an optically active bisphosphine aryloxyacylplatinum (II) complex in which L is CHIRAPHOS as described above, In, 40.0 ~
Chemical shift values in the range of 50.0 ppm and 2700-
An asymmetric platinum complex having a phosphorus-platinum coupling constant in the range of 3300 Hz, wherein the optically active bisphosphine aryloxyacylplatinum (II) wherein L is the above-mentioned DUPHOS
In a phosphorus nuclear magnetic resonance analysis obtained by treating the complex as described above, a chemical shift value in the range of 55.0 to 65.0 ppm and a phosphorus-shift in the range of 3200 to 3800 Hz were obtained.
An asymmetric platinum complex having a platinum coupling constant is exemplified.

The novel asymmetric platinum complex of the present invention includes, for example,
Asymmetric induction occurs at a very high rate in the reaction between ketene silyl acetal and aldehyde, and an optically active β-hydroxy ester derivative (an optically active β-hydroxy ester in which a hydroxyl group is protected by a silyl group) is obtained in a practical reaction yield. It can be synthesized at a high yield and an asymmetric yield.

[0026]

The present invention will be specifically described below with reference to examples and comparative examples. Example 1 [Synthesis of optically active bisphosphine aryloxyacylplatinum (II) complex (A)] Schlenk tube (100 ml)
), Potassium tetrachloroplatinate (1.6 mmol), sodium carbonate (4.8 mmol), 3,5-di-t-butyl-2-hydroxybenzaldehyde (1.6 mmol)
l), and dimethyl sulfoxide (25 ml)
The mixture was stirred at 140 ° C. for 40 minutes. Next, the temperature was raised to 100 ° C., and (R) -BINAP (1.6 mmol) was added. Then, the temperature was raised to 60 ° C., and dimethyl sulfoxide was distilled off under reduced pressure. From the obtained residue, an optically active bisphosphine aryloxyacylplatinum (II) complex (1.4 g) represented by the above formula (A) was obtained by methylene chloride extraction and recrystallization (solvent: ethanol). Rate 83%). The analysis data is shown below.

(1) ¹ H-NMR (400 MHz, CD
_{Cl 3) δ: 7.91-7.86 (m} , 4H), 7.5
5-6.98 (m, 22H), 6.75-6.72
(M, 4H), 6.60-6.57 (m, 4H), 1.
20 (s, 9H), 1.03 (s, 9H), (2) 31 P {1 H} -NMR (160MHz, CDC
l ₃ ) δ: 23.7 (d, J _PP = 10.7, J _Pt-P = 1)
512), 20.4 (d, J _PP = 10.7, J _{Pt -P} =
4474), (3) [α] _D ²⁵ = + 582 ° (c = 0.44, CH ₂ Cl)
₂ ), (4) Elemental analysis: theoretical value C: 67.48, H: 4.99 measured value C: 66.38, H: 4.94

[Synthesis of Asymmetric Platinum Complex] The optically active bisphosphine aryloxyacylplatinum represented by the above formula (A) obtained above was placed in an NMR sample tube in air.
I) The complex (0.025 mmol) was weighed out, and water (0.025 mmol) was weighed.
Methylene chloride containing 5 mmol) -d ₂ a (1 ml) was added as a solvent. Next, trifluoromethanesulfonic acid (0.025 mmol) was added in the air, and a treatment with a super strong acid was performed at room temperature as it was. The analysis by phosphorus nuclear magnetic resonance analysis ( ³¹ P-NMR) was performed 54 minutes after the start of the treatment, and showed one signal, and the chemical shift value (δ) was 3.3 ppm (singlet).
And the phosphorus-platinum coupling constant (J _Pt-P ) is 367
It was found that a new asymmetric platinum complex having a frequency of Hz was formed.

Example 2 [Synthesis of Asymmetric Platinum Complex] The solvent was dried methylene chloride-d ₂
(1 ml) was treated in the same manner as in Example 1 by using an optically active bisphosphine aryloxyacylplatinum (II) complex represented by the formula (A) and treated with a super strong acid. As a result, when analysis was performed in the same manner as in Example 1 21 hours after the start of the treatment, a product similar to that in Example 1 was confirmed.

Comparative Example 1 [Synthesis of Asymmetric Platinum Complex] An optically active bis-compound represented by the above formula (A) was prepared in the same manner as in Example 2 except that all operations were performed in a nitrogen atmosphere (non-oxygen atmosphere). The treatment with superacid was performed using a phosphine aryloxyacylplatinum (II) complex. As a result, no product as in Example 1 was observed.

Reference Example 1 [Asymmetric synthesis reaction] A solution treated with a super strong acid in the same manner as in Example 1 was prepared and cooled to -78 ° C, and 2,6-lutidine (0.025 mmol) was added to the solution. ) And then hydrocinnamaldehyde (0.5 mmol) and methyltrimethylsilyldimethylketene acetal (0.7
mmol) was added dropwise. Thereafter, the system was replaced with an argon atmosphere, the temperature was set to -25 ° C, and the reaction was performed for 168 hours.

After completion of the reaction, washing with water, treatment with hydrochloric acid, extraction with methylene chloride, drying, and column chromatography were carried out.
A colorless oily product (2,2-dimethyl-5-
Methyl phenyl-3-trimethylsiloxypentanoate;
145 mg) were isolated (94% yield). The analysis data is shown below.

(1) IR (neat): 2955, 17
29,1251,1132,1101,840,75
1,699 (cm ^-1 ), (2) ¹ H-NMR (270 MHz, C ₆ D ₆ ) δ: 7.
18-7.03 (m, 5H), 4.06 (dd, J =
8.1, 2.9, 1H), 3.29 (s, 3H), 2.
88-2.78 (m, 1H), 2.55-2.37
(M, 1H), 1.75-1.60 (m, 2H), 1.
20 (s, 3H), 1.06 (s, 3H), 0.13
(S, 9H), (3) ¹³ C-NMR (67.5 MHz, C ₆ D ₆ ) δ: 1
77.0, 142.5, 128.7, 128.6, 12
6.2, 77.9, 51.2, 48.4, 35.4, 3
3.9, 21.3, 20.9, 0.9, (4) Mass spectrometry (CI) m / z (relative i
ntency): 309 (MH ⁺ , 40), 219
(98), 159 (45), 117 (100), 91
(96), 73 (70)

The trimethylsilyl group of this product is deprotected with a tetrabutylammonium fluoride / tetrahydrofuran solution to obtain methyl 3-hydroxy-2,2-dimethyl-5-phenylpentanoate. Was determined by high performance liquid chromatography to find 9
5% e. e. Met. The analysis conditions are shown below.

Column: ChiralPak-AD (manufactured by Daicel), Eluent: hexane / ethanol / trifluoroacetic acid = 9
7.5 volume parts / 2.5 volume parts / 0.1 volume parts; 0.8m
1 / min, Column temperature: 30 ° C, Detection: UV (220 nm)

A solution treated with a super strong acid in the same manner as in Example 1 was prepared as follows. Schlenk tube (25
The optically active bisphosphine aryloxyacylplatinum (II) complex (0.025 mmol) obtained in Example 1 was weighed in the air (0.05 ml).
l) in methylene chloride (2.5 ml) was added as solvent. Next, trifluoromethanesulfonic acid (0.025 mmol) was added in the air, and the mixture was treated with a super strong acid for 15 minutes while stirring at room temperature. The product was the same as in Example 1 and separately confirmed by phosphorus nuclear magnetic resonance analysis.

Reference Example 2 [Asymmetric synthesis reaction] Asymmetric synthesis was performed in the same manner as in Reference Example 1, except that the reaction time was changed to 141 hours using the solution treated with the super strong acid as in Example 2. The reaction was carried out, and a colorless oily product (methyl 2,2-dimethyl-5-phenyl-3-trimethylsiloxypentanoate; 152 mg) was similarly separated (yield: 99%). The analytical data of the product was the same as in Reference Example 1. When the asymmetric yield was determined in the same manner as in Reference Example 1, 77% e. e. Met. The solution treated with the super strong acid in the same manner as in Example 2 was prepared in the same manner as in Reference Example 1, except that the solvent was changed to dry methylene chloride (2.5 ml). As the product, the same product as in Example 1 was separately confirmed by phosphorus nuclear magnetic resonance analysis.

Reference Example 3 [Asymmetric Synthesis Reaction] Asymmetric synthesis was performed in the same manner as in Reference Example 1 except that the reaction time was changed to 138 hours using a solution treated with a super strong acid as in Comparative Example 1. By carrying out the reaction, a colorless oily product (methyl 2,2-dimethyl-5-phenyl-3-trimethylsiloxypentanoate; 102 mg) was similarly separated (yield 67%). The analytical data of the product was the same as in Reference Example 1. When the asymmetric yield was determined in the same manner as in Reference Example 1, the yield was 16% e. e. Met. The liquid treated with the super strong acid in the same manner as in Comparative Example 1 was prepared in the same manner as in Reference Example except that the solvent was changed to dry methylene chloride (2.5 ml) and all operations were performed in a nitrogen atmosphere (non-oxygen atmosphere). Prepared as in Example 1. At this time, the same product as in Example 1 was not recognized by phosphorus nuclear magnetic resonance analysis.

Example 3 [Synthesis of optically active bisphosphine aryloxyacylplatinum (II) complex (B)] 3,5-di-t-butyl-2
The same procedure as in Example 1 was carried out except that salicylaldehyde (1.6 mmol) was used instead of -hydroxybenzaldehyde, to obtain the optically active bisphosphine aryloxyacylplatinum (II) complex (1) represented by the formula (B). .
35 g) was obtained (yield 90%). The analysis data is shown below.

(1) ¹ H-NMR (400 MHz, CD
_{Cl 3) δ: 8.07-7.97 (m} , 4H), 7.5
3-7.25 (m, 17H), 7.13-6.98
(M, 5H), 6.79-6.57 (m, 9H), 6.
36 (dd, J = 7.3,7.3,1H) , (2) 31 P {1 H} -NMR (160MHz, CDC
l ₃ ) δ: 24.4 (d, J _PP = 11.6, J _Pt-P = 1)
491), 19.2 (d, J _PP = 11.6, J _{Pt -P} =
4536), (3) Elemental analysis: theoretical value C: 65.31, H: 3.87 measured value C: 64.88, H: 3.96

[Synthesis of Asymmetric Platinum Complex] Example 1 was repeated except that the optically active bisphosphine aryloxyacylplatinum (II) complex (0.025 mmol) represented by the formula (B) obtained above was used. An asymmetric platinum complex was synthesized by performing the same operation as described above. As a result, a single signal was shown in the phosphorus nuclear magnetic resonance analysis, the chemical shift value (δ) was 3.25 ppm (singlet), and the phosphorus-platinum coupling constant (J _Pt-P ) was 3680 Hz. It was found that the asymmetric platinum complex was formed.

Reference Example 4 [Asymmetric synthesis reaction] Asymmetric synthesis was performed in the same manner as in Reference Example 1 except that the reaction time was changed to 170 hours using a solution treated with a super strong acid as in Example 3. The reaction was performed to separate a colorless oily product (methyl 2,2-dimethyl-5-phenyl-3-trimethylsiloxypentanoate; 148 mg) (yield: 92%). The analytical data of the product was the same as in Reference Example 1. When the asymmetric yield was determined in the same manner as in Reference Example 1, 91% e. e. Met.

The solution treated with a super strong acid in the same manner as in Example 3 was used to obtain the optically active bisphosphine aryloxyacylplatinum (II) complex (0) represented by the formula (B) obtained in Example 3. 0.025 mmol) in the same manner as in Reference Example 1 in a Schlenk tube (25 ml).
As the product, the same product as in Example 3 was separately confirmed by phosphorus nuclear magnetic resonance analysis.

Example 4 [Synthesis of optically active bisphosphine aryloxyacylplatinum (II) complex (C)] (R) -BINAP was converted to (R)
The same operation as in Example 1 was performed, except that -Tol-BINAP (1.6 mmol) was used, to obtain the optically active bisphosphine aryloxyacylplatinum (II) complex represented by the formula (C) (1.5 g). ) Was obtained (yield 85%). The analysis data is shown below.

(1) ¹ H-NMR (400 MHz, CD
_{Cl 3) δ: 7.79-7.71 (m} , 4H), 7.5
3 (d, J = 8.3, 1H), 7.47-7.17
(M, 15H), 7.09-7.00 (m, 4H),
6.71 (dd, J = 8.8, 8.8, 2H), 6.3
6 (d, J = 7.8, 4H), 2.39 (s, 3H),
2.35 (s, 3H), 1.95 (s, 3H), 1.9
4 (s, 3H), 1.20 (s, 9H), 1.01
(S, 9H), (2 ) 31 P {1 H} -NMR (160MHz, CDC
l ₃ ) δ: 21.8 (d, J _PP = 10.4, J _Pt-P = 1)
517), 18.6 (d, J _PP = 10.4, J _{Pt -P} =
4455), (3) Elemental analysis: theoretical value C: 68.40, H: 5.47 measured value C: 67.70, H: 5.35

[Synthesis of Asymmetric Platinum Complex] Example 1 was repeated except that the optically active bisphosphine aryloxyacylplatinum (II) complex (0.025 mmol) represented by the formula (C) obtained above was used. An asymmetric platinum complex was synthesized by performing the same operation as described above. As a result, a single signal was shown in the phosphorus nuclear magnetic resonance analysis, the chemical shift value (δ) was 1.93 ppm (singlet), and the phosphorus-platinum coupling constant (J _Pt-P ) was 3,682 Hz. It was found that the asymmetric platinum complex was formed.

Reference Example 5 [Asymmetric synthesis reaction] Using a solution treated with a super strong acid as in Example 4, replacing aldehyde with benzaldehyde (0.5 mmol) and changing the reaction time to 17.5 hours Otherwise, an asymmetric synthesis reaction was carried out in the same manner as in Reference Example 1 to give a colorless oily product (methyl 2,2-dimethyl-3-phenyl-3-trimethylsiloxypropanoate; 135).
mg) (97% yield). The analysis data is shown below.

(1) IR (neat): 2954, 17
40,1251,1135,1066,892,87
7,842,745,694 (cm ^-1 ), (2) ¹ H-NMR (400 MHz, C ₆ D ₆ ) δ: 7.
24-7.01 (m, 5H), 6.51 (d, J = 1
6.0, 1H), 6.22 (dd, J = 16.0, 7.0).
3,1H), 4.63 (d, J = 7.3, 1H), 3.
39 (s, 3H), 1.34 (s, 3H), 1.16
(S, 3H), 0.13 (s, 9H), (3) ¹³ C-NMR (100 MHz, C ₆ D ₆ ) δ: 17
6.5, 137.2, 132.6, 128.2, 12
8.1, 126.8, 110.6, 79.1, 51.
3, 48.7, 21.6, 20.1, 0.4, (4) Mass spectrometry (CI) m / z (relative i
tensity): 307 (MH ⁺ , 1), 205
(100), 157 (46), 73 (55)

When the asymmetric yield was determined in the same manner as in Reference Example 1, the yield was 26% e. e. Met. However, the analysis conditions are as follows. Column: ChiralPak-AD (manufactured by Daicel), Eluent: hexane / ethanol / trifluoroacetic acid = 1
00 volume parts / 10 volume parts / 0.1 volume parts; 0.7 ml /
min, Column temperature: 30 ° C, Detection: UV (220 nm)

The solution treated with a super strong acid in the same manner as in Example 4 was used to obtain the optically active bisphosphine aryloxyacylplatinum (II) complex (0) represented by the formula (C) obtained in Example 4. 0.025 mmol) in the same manner as in Reference Example 1 in a Schlenk tube (25 ml).
As the product, the same product as in Example 4 was separately confirmed by phosphorus nuclear magnetic resonance analysis.

Example 5 [Synthesis of optically active bisphosphine aryloxyacylplatinum (II) complex (D)] (R) -BINAP was synthesized with (R,
R) -Me-DUPHOS (1.6 mmol), except that the optically active bisphosphine aryloxyacylplatinum (II) complex (0) represented by the formula (D) was treated in the same manner as in Example 1. .91 g) (yield 9).
2%). The analysis data is shown below.

(1) ¹ H-NMR (400 MHz, CD
_{Cl 3) δ: 7.68-7.66 (m} , 2H), 7.5
6-7.54 (m, 2H), 7.30 (d, J = 7.
8, 1H), 7.18 (dd, J = 8.3, 7.8, 1
H), 6.91 (d, J = 8.3, 1H), 6.45.
(Dd, J = 7.8, 7.8, 1H), 3.55-3.
25 (m, 1H), 3.00-2.78 (m, 2H),
2.60-2.20 (m, 5H), 2.00-1.60
(M, 4H), 1.49 (dd, J = 19.5, 6.
8, 3H), 1.27 (dd, J = 16.6, 6.4,
3H), 0.85 (dd, J = 14.7, 7.3, 3
H), 0.84 (dd, J = 16.6, 7.3, 3)
^{H), (2) 31 P} {1 H} -NMR (160MHz, CDC
l ₃ ) δ: 66.0 (d, J _PP = 4.6, J _Pt-P = 15
30), 52.7 (d, J _PP = 4.6, J _Pt-P = 39
35), (3) Elemental analysis: theoretical value C: 48.31, H: 5.19 measured value C: 47.47, H: 5.10

[Synthesis of Asymmetric Platinum Complex] Example 1 was repeated except that the optically active bisphosphine aryloxyacylplatinum (II) complex (0.025 mmol) represented by the formula (D) obtained above was used. An asymmetric platinum complex was synthesized by performing the same operation as described above. As a result, a single signal was found in the phosphorus nuclear magnetic resonance analysis, the chemical shift value (δ) was 60.7 ppm (singlet), and the phosphorus-platinum coupling constant (J _Pt-P ) was 3488 Hz. It was found that the asymmetric platinum complex was formed.

Reference Example 6 [Asymmetric synthesis reaction] Asymmetric synthesis reaction was carried out in the same manner as in Reference Example 5 except that a solution treated with a super strong acid as in Example 5 was used, and the reaction time was changed to 20.5 hours. A colorless oily product (methyl 2,2-dimethyl-3-phenyl-3-trimethylsiloxypropanoate; 138 mg) was separated by asymmetric synthesis reaction (yield 99%). When the asymmetric yield was determined in the same manner as in Reference Example 5, the yield was 26% e. e. Met.

The solution treated with a super strong acid in the same manner as in Example 5 was used to obtain the optically active bisphosphine aryloxyacylplatinum (II) complex (0) represented by the formula (D) obtained in Example 5. 0.025 mmol) in the same manner as in Reference Example 1 in a Schlenk tube (25 ml).
As the product, the same product as in Example 5 was separately confirmed by phosphorus nuclear magnetic resonance analysis.

Example 6 [Synthesis of optically active bisphosphine aryloxyacylplatinum (II) complex (E)] (R) -BINAP was converted to (R,
R) -CHIRAPHOS (1.6 mmol), except that the optically active bisphosphine aryloxyacylplatinum (II) complex (1.12 g) represented by the formula (E) was treated in the same manner as in Example 1. (Yield 9)
5%). The analysis data is shown below.

(1) ¹ H-NMR (400 MHz, CD
_{Cl 3) δ: 7.95-7.75 (m} , 8H), 7.5
2-7.35 (m, 12H), 7.12 (d, J = 7.
8, 1H), 7.08 (dd, J = 7.8, 7.8, 1
H), 6.81 (d, J = 8.3, 1H), 6.34.
(Dd, J = 8.3, 7.8, 1H), 2.45-2.
32 (m, 1H), 2.30-2.15 (m, 1H),
1.02 (dd, J = 11.2, 6.8, 3H), 0.
97 (dd, J = 13.2,6.8,3H) , (2) 31 P {1 H} -NMR (160MHz, CDC
l ₃ ) δ: 45.7 (s, J _Pt-P = 1482), 35.
9 (s, J _Pt-P = 4162), (3) Elemental analysis: theoretical value C: 56.68, H: 4.35 measured value C: 55.79, H: 4.19

[Synthesis of Asymmetric Platinum Complex] Example 1 was repeated except that the optically active bisphosphine aryloxyacylplatinum (II) complex (0.025 mmol) represented by the formula (E) obtained above was used. An asymmetric platinum complex was synthesized by performing the same operation as described above. As a result, a single signal was shown in the phosphorus nuclear magnetic resonance analysis, the chemical shift value (δ) was 45.2 ppm (singlet), and the phosphorus-platinum coupling constant (J _Pt-P ) was 2960z. It was found that the asymmetric platinum complex was formed.

[0059]

According to the present invention, a novel asymmetric platinum complex, particularly an optically active bisphosphine aryloxyacylplatinum (II), which acts as a Lewis acid catalyst and can give a practical reaction yield and an asymmetric yield. A novel asymmetric platinum complex obtained from the complex can be provided. In particular, the novel asymmetric platinum complex of the present invention causes an asymmetric induction at a very high rate in the reaction of ketene silyl acetal with an aldehyde, and the corresponding optically active β-hydroxy ester derivative (the hydroxyl group is protected by a silyl group) Optically active β-hydroxyester) can be synthesized with a practical reaction yield and an asymmetric yield.

Claims (7)

[Claims] An asymmetric platinum complex obtained by treating an optically active bisphosphine aryloxyacylplatinum (II) complex with a super strong acid in an oxygen atmosphere. 2. An asymmetric platinum complex having an equivalent phosphorus-platinum bond, obtained from an optically active bisphosphine aryloxyacylplatinum (II) complex. 3. The asymmetric platinum complex according to claim 1, wherein the optically active bisphosphine aryloxyacylplatinum (II) complex is a compound represented by the formula (1). Embedded image (Wherein R ¹ , R ² , R ³ , and R ⁴ represent a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, a nitro group, a cyano group, or a dialkylamino group. And L represents an optically active bidentate phosphine, R ¹ , R ² , R ³ , and R ⁴ may be the same or different, and two adjacent groups may be bonded to form a ring. May be.) 4. When L is represented by the formulas (2-a), (2-b), (3)
-A), (3-b), (4-a), (4-b), (5-
The asymmetric platinum complex according to claim 3, which is an optically active bidentate phosphine represented by (a) or (5-b). Embedded image (Wherein, R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , and R ¹² represent an alkyl group, a cycloalkyl group, or an aryl group;
R ⁵ and R ⁶ are substituents on the naphthalene ring and represent a hydrogen atom, a halogen atom, an alkyl group, or an aryl group. Also,
n represents an integer of 0 to 10. R ⁵ and R ⁶ may be the same or different, and R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R
¹² may be the same or different. ) 5. An asymmetric platinum complex having an equivalent phosphorus-platinum bond shows -3.0 pp in phosphorus nuclear magnetic resonance analysis.
chemical shift values in the range of m-7.0 ppm and 3400
Asymmetric platinum complex having a phosphorus-platinum coupling constant in the range of ４4200 Hz, asymmetric platinum having a chemical shift value in the range of 40.0-50.0 ppm and a phosphorus-platinum coupling constant in the range of 2700-3300 Hz 3. A complex or an asymmetric platinum complex having a chemical shift value in the range of 55.0-65.0 ppm and a phosphorus-platinum coupling constant in the range of 3200-3800 Hz.
The asymmetric platinum complex according to the above. 6. The asymmetric platinum complex according to claim 1, wherein the super strong acid is trifluoromethanesulfonic acid, tetrafluoroboric acid, hexafluorophosphoric acid, hexafluoroantimonic acid, or perchloric acid. 7. A process for producing an asymmetric platinum complex, comprising treating an optically active bisphosphine aryloxyacylplatinum (II) complex with a super strong acid in an oxygen atmosphere in the presence of water.