Patent Grant
10112884
The present application claims priority of Chinese application number 201410468805.9, filed to Chinese Patent Office on Sep. 15, 2014, titled “Asymmetrical hydrogenation reaction of an ∂-ketonic acid compound”, the entire contents of which are hereby incorporated by reference.
The present invention relates to ligand chemistry technical field, specifically relates to the asymmetrical hydrogenation reaction of an ∂-ketonic acid compound.
Rarely disclosure about the asymmetrical hydrogenation reaction of an ∂-ketonic acid compound. In the ligand field, the disclosure of the asymmetrical hydrogenation reaction of an ∂-ketonic acid compound by directly using an metal ligand complex also basically on an vacancy stage. The reasons through analyzing can be concluded as: the carboxyl group on the ∂-ketonic acid compound can coordinate with metal, in that way it will result the catalysts to be poisoned and spoiled, so the reaction yield is lowered. What's more, the two ∂ carbonyl groups one on the ∂-ketonic acid compound and the other on the carboxylic acid are nearly in coplanar position, there will result equal opportunities for chiral ligand catalysts to attack ∂-ketonic acid compound from two sides, of course, leads to lower enantioselectivity and reaction yield.
The following structure chiral spiro-pyridylamidophosphine ligand iridium complex are developed at the earliest by Nankai university.
And it has been disclosed in Chinese application documents with the publication number CN102040625, the chiral spiro-pyridylamidophosphine ligand iridium complex used as a catalyst in the asymmetrical hydrogenation reaction of carbonyl compounds including aryl alkyl ketones, ketenes and keto esters. However, the chiral catalysts actually obtained a little bad catalytic result for keto esters compounds according to its Example 11 table 1 serial number 27.
Considering asymmetrical hydrogenation reaction technology are on an important position and are widely used in organic chemistry, it is necessary to overcome the defects of this technology in the application of ∂-ketonic acid compound. And it is also necessary to improve the asymmetrical hydrogenation reaction technology to form a new technical proposal to finally solve the problem which hardly or difficulty to catalytic ∂-ketonic acid compound.
To solve the technical problem of ∂-ketonic acid compound which are hardly or difficulty to carry out asymmetrical hydrogenation reaction technology, the present invention provides the following technical proposal:
Wherein R1 is a phenyl, a substituted phenyl, a naphthyl, a substituted naphthyl, a C1-C6 alkyl or aralkyl, the substitute is a C1-C6 alkyl, a C1-C6 alkoxy a halogen, the number of the substituents is 1-3.
Wherein, M can be the following structure chiral spiro-pyridylamidophosphine ligand iridium complex,
Wherein, R is hydrogen, 3-methyl, 4-tBu or 6-methyl.
The said base can be selected from sodium hydroxide, potassium hydroxide, sodium tert-butyl oxide, potassium tert-butyl oxide. The molar dosage ratio of the said base to the substrate A compound is (1.0˜3):1, the preferred molar ratio is (1.001˜1.5):1.
The said solvent can be selected from methanol, ethanol propanol, isopropanol, tetrahydrofuran, toluene, methyl tert-butyl ether, dioxane, DMF etc.
To be preferable, R1 represents phenyl, substituted phenyl, naphthyl, substituted naphthyl.
Preferably, the present invention takes the following technical proposal: under the protection of nitrogen atmosphere, at a hydrogen pressure of 0.5-10 MPa, with a base dosage 1.0˜3.0 molar equivalent, in the presence of organic solvent, ∂-ketonic acid compound is successfully formed into B compound in the catalytic of chiral spiro-pridylamidophosphine ligand iridium complex (M) with the molar dosage 0.00001˜0.01 molar equivalent.
To be more preferable, under the protection of nitrogen atmosphere, were added into the inner hydrogenation tube substrate A, 1.0˜3.0 molar equivalent (eq) base selected from sodium hydroxide, potassium hydroxide, sodium tert-butyl oxide or potassium tert-butyl oxide, chiral spiro-pyridylamidophosphine ligand compound (M) with the molar dosage 0.00001˜0.01 molar equivalent (eq) and the solvent. The inner reaction tube was placed into the hydrogenation reactor at a hydrogen pressure of 0.5-10 MPa was filled. The reaction was stirred for 1-30 hours at a temperature of 10˜90° C. to obtain B compound.
The technical proposal of the present invention can overcome the produced strong coordination effects between carboxyl group of the substrate and central metals through changing the base dosage, and successfully realize directly asymmetrical hydrogenation reaction of ∂-ketonic acid compound.
In order to further understand the present invention, preferable embodiments of the present invention will be described by reference to the examples, but it should be appreciated that these descriptions are merely intended to further illustrate the features and advantages of the present invention, rather than limiting the claims of the invention.
HPLC analytical instrument and method
instrument model: Agilent 1200
chromatographic column: Chiracel OD-H, 4.6 mm×250 mm×5 μm
mobile phase A n-hexane
mobile phase B: isopropanol
flow velocity: 1.0 mL/min
column temperature: 35° C.
wave length: 210 nm
sample size: 5 μL
Under the protection of nitrogen atmosphere, to the inner hydrogenation tube (200 mL), were added substrate ∂-ketonic acid 2a (3 g, 20 mmol), potassium tert-butyl oxide (112 mg, 1 mmol), catalyst M (20 mg, 0.02 mmol, R=3-methyl) and solvent (50 mL). The inner reaction tube was placed into the hydrogenation reactor. After substitution by hydrogen, with hydrogen filled to a pressure of 15 atm, the reaction was stirred under the hydrogen pressure at room temperature for 24 hours. After the hydrogenation was finished, release hydrogen, and open the hydrogenation reactor. The reaction solution was filtered through a short silica gel column to remove the catalyst, and the conversion rate and yield of the reaction were analyzed by nuclear magnetic resonance (NMR). And the optical purity of the product was analyzed after derived to methyl ester compound. The results are listed as table 1.
The experimental results of Example 2-15 in the following table 1 were carried out according to or referred to the same method of the Example 1.
iPrOH
nPrOH
nBuOH
nBuOH
nBuOH
nBuOH
nBuOH
nBuOH
Wherein B/S represents the molar ratio of basic dosage and substrate ∂-ketonic acid dosage, conv. represents the conversion rate analyzed by nuclear magnetic resonance (NMR).
The experimental results of Example 16-30 in the following table 2 were carried out in the catalytic of 1c according to or referred to the same method of the Example 1.
S/C=50000 Carry out the highly conversion experiment in accordance with the same method disclosed in Example 1.
Under the protection of nitrogen atmosphere, to the inner hydrogenation tube (200 mL), were added substrate ∂-ketonic acid 2a (3 g, 20 mmol), potassium tert-butyl oxide (1.68 g, 30 mmol), catalyst 1c (20 mg, 0.02 mmol) and n-butanol (50 mL). The inner reaction tube was placed into the hydrogenation reactor. After substitution by hydrogen, with hydrogen filled to a pressure of 30 atm, the reaction was stirred under the hydrogen pressure at room temperature for 10 hours. After the hydrogenation was finished, release hydrogen and open the hydrogenation reactor. The reaction solution was filtered through a short silica gel column to remove the catalyst, and the conversion rate and yield of the reaction were analyzed by nuclear magnetic resonance (NMR). The conversion rate is 100%. And the optical purity of the product was analyzed after derived to methyl ester compound. The optical purity is 84% ee.
Under the protection of nitrogen atmosphere, to the inner hydrogenation tube (200 mL), were added substrate ∂-ketonic acid 2m (4 g, 20 mmol), potassium tert-butyl oxide (3.36 g, 30 mmol), catalyst 1b (20 mg, 0.02 mmol) and n-butanol (50 mL). The inner reaction tube was placed into the hydrogenation reactor. After substitution by hydrogen, with hydrogen filled to a pressure of 15 atm, the reaction was stirred under the hydrogen pressure at room temperature for 12 hours. After the hydrogenation was finished, release hydrogen, and open the hydrogenation reactor. The reaction solution was filtered through a short silica gel column to remove the catalyst, and the conversion rate and yield of the reaction were analyzed by nuclear magnetic resonance (NMR). The conversion rate is 100%. And the optical purity of the product was analyzed after derived to methyl ester compound. The optical purity is 95% ee.
Under the protection of nitrogen atmosphere, to the inner hydrogenation tube (200 mL), were added substrate ∂-ketonic acid 2o (2.6 g, 20 mmol) potassium tert-butyl oxide (3.36 g, 30 mmol), catalyst 1b (40 mg, 0.04 mmol) and n-butanol (50 mL). The inner reaction tube was placed into the hydrogenation reactor. After substitution by hydrogen, with hydrogen filled to a pressure of 15 atm, the reaction was stirred under the hydrogen pressure at room temperature for 24 hours. After the hydrogenation was finished, release hydrogen, and open the hydrogenation reactor. The reaction solution was filtered through a short silica gel column to remove the catalyst, and the conversion rate and yield of the reaction were analyzed by nuclear magnetic resonance (NMR). The conversion rate is 100%. And the optical purity of the product was analyzed after derived to benzyl ester compound. The optical purity is 85% ee.
Although fully description has been made for the present application in combing the specific Examples, it is apparent that modification, or appropriate change and combination can be made to achieve the present invention. In particular, it should be pointed out that all similar replacements and modifications become apparent to those skilled in the art, and they are deemed to be within the spirit, scope and contents of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014 1 0468805 | Sep 2014 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2015/077660 | 4/28/2015 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2016/041351 | 3/24/2016 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 8962839 | Zhou et al. | Feb 2015 | B2 |
| 20130225822 | Zhou | Aug 2013 | A1 |
| Number | Date | Country |
|---|---|---|
| 1112563 | Nov 1995 | CN |
| 1439643 | Sep 2003 | CN |
| 101671365 | Mar 2010 | CN |
| Entry |
|---|
| Himeda et al., “pH-Dependent Catalytic Activity and Chemoselectivity in Transfer Hydrogenation Catalyzed by Iridium Complex with 4,4′-Dihydroxy-2,2′-bipyridine,” Chem. Eur. J. 2008, 14, 11076-11081 (Year: 2008). |
| Taran et al., “High-Throughput Screening of Enantioselective Catalysts by Immunoassay,” Angew. Chem. Int. Ed. 2002, 41(1) 124-127 (Year: 2002). |
| English abstract; Chinese Application with Publication No. CN1112563A. |
| Chinese Application with Publication No. CN1439643A. |
| Chinese Application with Publication No. CN101671365A. |
| Number | Date | Country | |
|---|---|---|---|
| 20170260119 A1 | Sep 2017 | US |
