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1693 results about "Enantio selectivity" patented technology

Medical Definition of enantioselectivity. : the degree to which one enantiomer of a chiral product is preferentially produced in a chemical reaction.

Asymmetric synthesis method for botanical pesticide nicotine and anabasine

The invention relates to an asymmetric synthesis method for botanical pesticide nicotine and anabasine. The low-cost and easily acquired 2,5-dibromopyridine is taken as an initial raw material and is processed in two steps, so that the hydrogenation precursor annular imine is acquired; under the induction of the chiral catalyst, iridium-phosphine oxazoline, an important hydrogenated product intermediate is acquired through high enantioselectivity; the intermediate is processed in two steps, so that L-nicotine is acquired; the intermediate is converted into L-anabasine in one step. The asymmetric hydrogenation of the annular imine containing pyridine gene is taken as the key step of the method. According to the invention, the chiral catalyst, iridium-phosphine oxazoline, is used for catalyzing the asymmetric hydrogenation and the key intermediate with ultrahigh ee value is acquired, and then the methylation and reduction bromine-removing two-step reaction is performed for converting, so that the target products, natural nicotine and anabasine, are acquired. According to the invention, the operation is stable, the purity is high and the cost is low.
Owner:NANKAI UNIV

Simple stereoselective synthesis method of sex pheromones of hyphantria cunea

The invention discloses a simple stereoselective synthesis method of sex pheromones of hyphantria cunea, which relates to epoxypropane compounds. The sex pheromones of hyphantria cunea III[(9S,10R)-9,10-epoxy-(3Z,6Z)-3,6-heneicosenediene] and IV[(9S,10R)-9,10-epoxy-(3Z,6Z)-3,6-heneicosenetriene] are prepared from cheap and readily available 2-propargyl alcohol serving as raw materials by eight steps with high efficiency, high enantioselectivity and high yield, wherein the total yield of (9S,10R)-III is 36 percent; the total yield of (9S,10R)-IV is 33 percent; and enantiomer excess e is more than 99 percent. The method has the advantages that: the operation and separation of each step are simple; the yield is high; all the adopted reagents are common reagents which are cheap and readily available; and the production line is short. The method is suitable for industrial production.
Owner:XIAMEN UNIV

Method for preparing cis-pinane by asymmetric catalytic hydrogenation of alpha-pinene

The invention discloses a method for preparing cis-pinane by asymmetric catalytic hydrogenation of alpha-pinene, and belongs to the chemical engineering field. The method comprises the process steps: in a nitrogen atmosphere, heating RhCl3.3H2O to dissolve in an ethanol solution, and forming a solution A; dissolving newly recrystallized PPh3 in a deoxygenated ethanol, and forming a solution B; adding the solution B into the solution A, refluxing for a certain period of time, filtering under reduced pressure while being hot, washing with deoxygenated ether, carrying out vacuum drying to obtain a rhodium phosphine complex RhCl(PPh3)3; and adding the prepared rhodium phosphine complex RhCl(PPh3)3, an ionic liquid and alpha-pinene into a high-pressure reaction kettle according to a certain proportion, putting a cover and sealing, respectively replacing with nitrogen gas and hydrogen gas, carrying out pressure maintaining and leakage detection, and carrying out a reaction under certain conditions to prepare cis-pinane. The method has the advantages of mild reaction conditions, high conversion rate of alpha-pinene and high enantioselectivity of cis-pinane; the ionic liquid catalyst system is easily separated from the product and can be recycled; and the process flow is simple, and the energy consumption is low.
Owner:KUNMING UNIV OF SCI & TECH

Preparation method and application for phosphine-oxazoline ligand, and ionic metal complex, enantiomer or racemate thereof

The invention discloses a preparation method and an application for phosphine-oxazoline ligand, and ionic metal complex, enantiomer or racemate thereof. The ligand and the ionic metal complex thereof have the following structural formulas. The phosphine ligand related by the invention employs biphenyl as a skeleton, and realizes completely transmission from planar chirality to axial chirality through an asymmetric desymmerization. The synthetic method is simple and economic, omits a common and complex chiral separation process in the preparation of the chiral ligand. The obtained chiral ligand has the advantages of high reactive activity, good enantiomorphous selectivity and the like in a model reaction.
Owner:SUN YAT SEN UNIV

A chiral nitrogen nitrogen phosphine tridentate ligand based on a ferrocene skeleton and an application thereof

The invention belongs to the technical field of asymmetric catalysis and specifically relates to a chiral nitrogen nitrogen phosphine tridentate ligand based on a ferrocene skeleton and an applicationthereof. A coordination compound is obtained by the disclosed chiral nitrogen nitrogen phosphine tridentate ligand base on the ferrocene skeleton complexed with a transition metal precursor, the complex is used as a precious metal catalyst, and is successfully applied to high efficiency asymmetric hydrogenation of aromatic ketone. Compared with other tridentate ligands, the ligand is simple to synthetize, is stable to water and air, and easy to prepare on a large scale, shows high activity and high enantioselectivity on carbon and oxygen double bond, and has greater implementation value and social and economic benefits.
Owner:ZHEJIANG UNIV OF TECH

6-hydroxyl quinine quaternary ammonium salt asymmetric phase transfer catalyst, preparation method and application of 6-hydroxyl quinine quaternary ammonium salt asymmetry phase transfer catalyst

The invention discloses a 6-hydroxyl quinine quaternary ammonium salt asymmetric phase transfer catalyst, a preparation method and application of the 6-hydroxyl quinine quaternary ammonium salt asymmetry phase transfer catalyst and belongs to the field of organic synthesis. In a two-phase system of an oxidizing agent, an alkaline solution and an inert solvent, the 6-hydroxyl quinine quaternary ammonium salt asymmetric phase transfer catalyst converts a beta-dicarbonyl compound into a chiral alpha-hydroxyl-beta-dicarbonyl compound; the usage quantity of the chiral 6-hydroxyl quinine quaternary ammonium salt asymmetric phase transfer catalyst is 0.5-50 mol% of the beta-dicarbonyl compound, and under the mild condition that reaction temperature is -15 DEG C-65 DEG C, the yield of the chiral alpha-hydroxyl-beta-dicarbonyl compound is larger than or equal to 90%, and the enantioselectivity is higher than or equal to 70% ee. The method is mild in reaction condition, environmentally friendly, high in reaction efficiency and suitable for large-scale production and preparation.
Owner:DALIAN UNIV OF TECH
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