1881results about "Asymmetric syntheses" patented technology

Disclosed is a process to produce a purified carboxylic acid slurry. The process comprises removing impurities from a crystallized product in a solid liquid displacement zone to form the purified carboxylic acid slurry. The process produces purified carboxylic acid slurry having good color and low impurity levels without the use of purification steps like hydrogenation or an impurity removal process.

The present invention relates to methods for use in producing epothilones and analogs and derivatives thereof. A general method according to the present invention broadly comprises performing an aldol condensation of a first compound with a second compound thereby to form a third compound selected from the formulas:

and stereoisomers thereof, and performing a macrolactonization of the third compound. The present invention also provides chemical compounds, and methods for producing such chemical compounds, that are useful in producing epothilones and analogs and derivatives thereof.

A method of solvating metal ions in an aromatic organic liquid. The method includes adding an ammonium salt having an organic acid reagent to the aromatic organic liquid. The organic acid reagent comprises a carboxylate having eight (8) or less carbon atoms. Thereafter, an aqueous solution comprising a metal salt is added to the aromatic organic liquid comprising the ammonium salt and the organic acid reagent. As a result, at least 10% by weight of metal ions is solvated in the aromatic organic liquid.

The invention relates to a chiral spiro aminophosphine ligand compound and a synthesis method as well as an application thereof. The chiral spiro aminophosphine compound contains a compound with a structure shown in I, or a racemic body or an optical isomer thereof, or a catalyzed acceptable salt thereof, wherein the main structure characteristic is with a chiral spirobiindane matrix. The chiral spiro aminophosphine compound can be synthesized by taking 7-diaryl/phosphito-7'-carboxy-1, 1'-spirobiindane or substituted 7-diaryl/phosphito-7'-carboxy-1, 1'-spirobiindane as chiral starting materials, which has optical activity and spiro matrix. The chiral spiro aminophosphine compound can be used as a chiral ligand for an asymmetrically catalyzed hydrogenation of an iridium catalyzed carboxy compound and achieves high yield and enantioselectivity (97%ee). The reactive activity is also high and the consumption of the catalyst can be reduced to 0.01% molar.

This invention provides a method of making (S)-(+)-3-(aminomethyl)-5-methylhexanoic acid (pregabalin) or a salt thereof via an asymmetric hydrogenation synthesis. Pregabalin is useful for the treatment and prevention of seizure disorders, pain, and psychotic disorders. The invention also provides intermediates useful in the production of pregabalin.

To provide a chiral reagent or a salt thereof. The chiral reagent has following chemical formula (I). In the formula (I), G¹ and G² are independently a hydrogen atom, a nitro group (—NO₂), a halogen atom, a cyano group (—CN), a group of formula (II) or (III), or both G¹ and G² taken together to form a group of formula (IV).

The present invention relates to new chiral salen catalysts and methods for the preparation of chiral compounds from racemic epoxides by using new catalyst. More particularly, the present invention is to provide novel chiral salen catalysts and their uses for producing chiral compounds having high optical purity to be used as raw materials for preparing chiral medicines or food additives in a large scale economically, wherein the chirl salen catalyst having a particular molecules structure can be reused continuously without any activating process of used catalysts and cause no or little racemization after the reaction is completed because it maintains its catalytic activity after the reaction process.

The present invention relates to a ruthenium carbonyl complex that is represented by the following Formula (1):

RuXY(CO)(L)  (1)

• • (in the Formula (1), X and Y, which may be the same or different from each other, represent an anionic ligand and L represents a tridentate aminodiphosphine ligand which has two phosphino groups and a —NH— group), its production method, and a method for production of alcohols by hydrogenation-reduction of ketones, esters, and lactones using the complex as a catalyst.

The ruthenium carbonyl complex of the invention has a high catalytic activity and it can be easily prepared and handled.

The invention relates to a platinum/carbon nanotube catalyst suitable for multiphase asymmetric hydrogenation reaction. Platinum is loaded on a carbon nanotube carrier. A preparation method comprises the following steps of: heating a purified carbon nanotube in nitric acid, washing, filtering, washing by using water until the pH value of filtrate is neutral, drying to obtain the carbon nanotube carrier, soaking in aqueous solution of chloroplatinic acid, and performing ultrasonic treatment at room temperature; and stirring and impregnating a mixture of the carbon nanotube and the aqueous solution of chloroplatinic acid, raising the temperature to 110 DEG C from room temperature, drying at the temperature of 110 DEG C, grinding into fine powder, reducing by using aqueous solution of sodiumformate with heating, filtering, washing by using deionized water and drying. The invention also provides the preparation method of the catalyst and application of the catalyst to the multiphase asymmetric hydrogenation reaction.

A process for preparing a fluoride from its corresponding alcohol comprises the steps of (a) forming a mixture comprising (i) at least one fluorinated, saturated aliphatic or alicyclic sulfonyl fluoride (for example, perfluorobutanesulfonyl fluoride) and (ii) at least one primary or secondary alcohol; and (b) adding a molar excess of at least one strong, aprotic, non-nucleophilic, hindered, double bond-containing, organic base (for example, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)) to the mixture.

The invention provides a novel method for preparing optically pure substituted [(pyridyl methylene) sulfinyl]-1H-benzimidazole sulphoxide compound by enantioselective synthesis. The method requiring protection is to directly and asymmetrically oxidize prochiral thioether into a corresponding optically pure sulphoxide compound or a sulphoxide compound rich in single enantiomer by a mild and cheap oxidizing agent in the presence of a complex compound catalyst formed by an accessible and stable (+)- or (-)- tartaric acid diamide ligand shown in a general formula and titanium. Therefore, optically pure omeprazole, lansoprazole and pantoprazole can be obtained, wherein R8, R9, R10 and R11 are the same or different, and are selected from hydrogen, alkyl, aralkyl, aryl, organic polymers or a silica loading body.

The invention relates to a process for obtaining anhydrous or substantially anhydrous formic acid, in which firstly aqueous formic acid is prepared by hydrolysis of methyl formate and is freed from water in the subsequent work-up. The process has the special feature that steam, which is employed for the hydrolysis of methyl formate and for heating a distillation column serving for work-up, is also used as stripping steam for waste-water stripping. The stripped waste water is produced during work-up.

A hydrodeoxygenation catalyst comprises a metal catalyst, an acid promoter, and a support. The metal catalyst is selected from platinum, palladium, ruthenium, rhenium rhodium, osmium, iridium, nickel, cobalt, molybdenum, copper, tin, or mixtures thereof. The support is a promoted-zirconium material including texture promoters and acid promoters. The hydrodeoxygenation catalyst may be used for hydrodeoxygenation (HDO) of sugar or sugar alcohol in an aqueous solution. In one embodiment the HDO catalyst may be used for HDO of fatty acids such as fatty acid methyl esters (FAME), triglycerols (in plant oil and animal fat), pyrolysis oil, or lignin. The hydrodeoxygenation catalyst for fatty acid process does not require the use of an acid promoter, it is optional.

Low melting point organic liquid compounds with high boiling points are prepared by a preferred process having the J^+xQ_y(R—COO⁻)_x-y where x is 1 to 8, preferably 1-3, y is 0 to x−1, where R—COO⁻ is an anion selected from the group consisting of 2-ethyl hexanoate, pivalate, neodecanoate, and mixtures thereof, Q is another anion or mixture of other anions, and J^+x is a cation selected from cations of Groups IA, IIA, IB, IIB, IIIB, IVB, VB, VIB, VIIB, VIII and lanthanide metals, cations selected from cations of B, Si, Ge, As, Sb, Te and Po metalloids, an ammonium cation derived from ammonia or an organic amine, an organic phosphonium cation, and mixtures thereof the organic liquid compounds being substantially free of volatile organic compounds. These compounds, as liquids, are useful as low volatile organic solvents, e.g., solvents in which a variety of chemical reactions may be carried out.