149 results about "Asymmetric carbon" patented technology

The compound of the formula

wherein the * indicates an asymmetric carbon, is specific to alpha_2B adrenergic receptors in preference over alpha_2A and alpha_2C adrenergic receptors, and as such has no or only minimal cardivascular and/or sedatory activity. The compound is useful as medicament in mammals, including humans, for treatment of diseases and or alleviations of conditions which are responsive to treatment by agonists of alpha_2B adrenergic receptors.

The present invention is directed to a compound in the R configuration about the asymmetric carbon in the following formula: ##STR1## pharmaceutical compositions containing same and the use thereof in treating CNS disorders in animals.

The present invention provides a method for manufacturing polycarbonate, which has a high conversion rate of a propylene oxide material into a polymer and can control stereoregularity of the macromolecular structure, and a catalytic compound for the manufacturing method.

The manufacturing method of the present invention is a method for manufacturing a polycarbonate copolymer by copolymerizing an epoxide compound as a monomer with carbon dioxide in the presence of a planar tetracoordinate-type cobalt-Schiff base complex, wherein a ligand of the Schiff base is N,N′-bis(2-hydroxybenzylidene)ethylenediamine, N,N′-bis(2-hydroxybenzylidene)phenylenediamine, or a derivative thereof, and a methyl group substituted with an amino group having an asymmetrical carbon atom or an asymmetrical axis is introduced to the 3- and/or 3′-position of the benzene ring derived from the salicyl group. In addition, the catalytic compound of the present invention is a cobalt-Schiff base complex, wherein a methyl group substituted with an amino group having an asymmetrical carbon atom or an asymmetrical axis is introduced to the 3- and/or 3′-position of the salicyl group.

A method of treating corticosteroid-induced cognitive impairment comprises administering an effective amount of at least one compound of formula I, or pharmaceutically acceptable salts thereof, to a subject in need of such treatment. Formula I is:

There is provided a process for producing an α-substituted ester by reaction of a fluorosulfuric acid ester of α-hydroxyester with a Grignard reagent in the presence of a zinc catalyst. It is newly found that the reaction for production of α-substituted esters, in which the raw reaction substrate is limited to expensive trifluoromethanesulfonic acid esters, can proceed favorably with the use of fluorosulfuric acid esters suitable for mass-production uses. By the use of the fluorosulfuric acid ester high in optical purity, it is possible to obtain the α-substituted ester with high optical purity upon inversion of the asymmetric carbon configuration. The process of the present invention can solve all of the prior art problems and can be applied for industrial uses.

It is an objective to produce intermediates of optically active beta-3 adrenaline receptor agonists from readily available raw materials in a safe, efficient and industrially advantageous manner. A substituted acetylpyridine derivative represented by the general formula (9) is reduced by enantioselective reduction to produce an optically active hydroxyethyl derivative represented by the general formula (10) (wherein * represents an asymmetric carbon atom), and it is further derivatized to an intermediate of an optically active beta-3 adrenaline receptor agonist, such as an optically active dihydroxyethylpyridine derivative represented by the general formula (14) or an optically active oxirane derivative represented by the general formula (16).

The present invention provides a water-soluble transition metal-diamine complex which can be easily separated from reaction products through liquid separation, etc. and is recycleable; an optically active diamine compound constituting the ligand of the complex; and a catalyst for asymmetric synthesis which comprises these. The present invention relates to a water-soluble optically active transition metal-diamine complex represented by the formula (2):

[wherein R¹ and R² each represents hydrogen, a hydrocarbon group, —SO₂R¹³ (wherein R¹³ is a hydrocarbon group, substituted amino, etc.), etc.; R³ to R¹² each represents hydrogen, a hydrocarbon group, alkoxy, substituted amino, etc.; M represents a transition metal; X represents halogen; L represents a ligand; and * indicates an asymmetric carbon atom; provided that at least one of R³ to R⁷ and R⁸ to R¹² is substituted amino], a catalyst for asymmetric synthesis containing the complex, and a process for producing an optically active alcohol, which comprises using the catalyst to asymmetrically reduce a ketone.

The present invention describes new chiral stationary phases and optically active compounds therein contained. The optically active compounds contained in the stationary phases are represented by the formula of structure (I), containing at least one asymmetric carbon atom, and a substituent acting as a spacer. The stationary phases of the present invention are useful in the preparation of chromatographic columns useful for the separation of enantiomers.

A process for producing a compound of the formula (II):(wherein R1, R2, R3 and R4 are each independently hydrogen, alkyl, alkoxy or the like, R5 is alkyl or alkoxyalkyl, A is O or S, Ar is aryl or the like, * represents the position of an asymmetric carbon atom and that the compound is the (R) or (S) isomer and Q is an optical resolution reagent)comprising isolating the compound as crystals from a solution or suspension containing the compound of the formula (II) (wherein * represents that the compound is the (R) or (S) isomer or a mixture thereof and the other symbols are the same as the above).

A process for producing optically active cysteine derivatives with high optical purity and good quality which is economically advantageous and is high in productivity even on a commercial scale is provided.A process for producing an optically active cysteine derivative which comprises synthesizing a D-form or L-form optically active cysteine derivative of the general formula (2) shown below (R1 represents an amino-protecting group of the urethane or acyl type, R0 represents a hydrogen atom or, taken together with R1, an amino-protecting group, R2 represents an alkyl, aryl or aralkyl group, R3 represents a univalent organic group and * represents the position of an asymmetric carbon) by reacting the corresponding D-form or L-form optically active amino acid derivative of the general formula (1) shown below with an alcohol of the general formula (3) shown below and a strong acid and/or a thionyl halide and recovering the above cysteine derivative (2) from the reaction mixture, the procedural series from reaction to recovery being carried out under conditions such that the medium contacting the above optically active cysteine derivative (2) is within the range from acidic to weakly basic to thereby recover the above cysteine derivative (2) from the reaction mixture while suppressing the decomposition and racemization thereof.

Process for preparing optically active beta-amino alcohols represented by a general formula (2): Ra-C*H(OH)-C*H(Rb)-Rc wherein Ra and Rc are each independently hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl, Rb is one member selected from among groups represented by the following general formulae; (3) R1CO(R2)N-, and (4) R1CO(R1'CO)N-, and C* is an asymmetric carbon atom, characterized by reacting a racemic alpha-aminocarbonyl compound represented by the general formula (1): Ra-CO-CH(Rb)-Rc, with hydrogen in the presence of an optically active transition metal compound represented by a general formula (7): MaXY(Px)m(Nx)n wherein Ma represents a metal atom belonging to VIII-group of the periodic law, X and Y represent each independently hydrogen, halogeno, Px represents a phosphine ligand, Nx represents an amine ligand, at least one of Px and Nx is optically active, and m and n each independently represent 0 or an integer of 1 through 4 and a base.

The invention provides a method for selectively recycling noble metal ions of gold and silver. The method comprises the following steps: 1, a carbon tube undergoes reflux treatment in a nitric acid solution to form a carboxylation carbon tube; 2, a carbon tube film is prepared by macroscopic interface recombination of a carboxylation carbon nano tube; 3, a macroscopic carbon tube thin film is tightly pressed to form a transferable self-supporting carbon tube thin film; 4, the carbon tube thin film is transferred to the surface of a dopamine aqueous solution so as to form an asymmetric carbon tube composite thin film; 5, the asymmetric carbon tube composite thin film is transferred to the surface of an aqueous solution, and residual impurities are cleaned and removed to obtain a macroscopic carbon tube interface reactor; 6, the carbon tube composite thin film is transferred to the surface of noble metal waste liquid; 7, the carbon tube composite thin film is transferred to the surface of the noble metal waste liquid to form a carbon tube and noble metal nanoparticle composite thin film material; and 8, the noble metal nanoparticle material is recycled and utilized. The method is simple to operate and high in selectivity.

A method for producing an optically active 1-substituted 2-propanol of the following formula 1, which comprises reacting a hydroxy aromatic compound of the following formula 2 with an optically active propylene oxide in the presence of a catalyst:wherein A is a univalent aromatic group, and C* is an asymmetric carbon atom.

The present invention provides an asymmetric reduction catalyst effective in preparing optically-active alcohol compounds having various functional groups, and a process for preparing optically-active alcohol compounds using said asymmetric reduction catalyst.

The organic metal compound of the present invention is represented by the following general formula (1):

wherein R¹ and R² may be mutually identical or different, and are an alkyl group, a phenyl group, a naphthyl group, a cycloalkyl group, or an alicyclic ring formed by binding R¹ and R², which may have a substituent; R³ is a hydrogen atom or an alkyl group; Cp is a cyclopentadienyl group, which may have a substituent, bound to M¹ via a π bond; X¹ is a halogen atom or a hydrido group; M¹ is rhodium or iridium; and * denotes asymmetric carbon.

Provided are 1,25-dihydroxy-2-methylvitamin D3 derivatives expressed by the general formula (I),

[wherein each of R₁ and R₂ is independently a hydrogen atom or a tri(C₁ to C₇ alkyl)silyl group; herein configurations of asymmetric carbons at the 1-, 2- and 3-positions are each independently α-configuration or β-configuration] and their production methods.

The compound is useful as a treating agent for osteoporosis, rickets, hyperthyroidism, etc.

An optically active 4-phenylthiazole derivative having a thrombopoietin receptor agonist activity and a pharmaceutical composition containing the present compound as an active ingredient are created, and a platelet production regulating agent which can be orally administered is provided.

Disclosed is a pharmaceutical composition containing, as an active ingredient, an optically active compound represented by the formula:

wherein, R¹ is a halogen atom or C1-C3 alkyloxy; R² is C1-C8 alkyl; R³ is C1-C8 alkyl; R⁴ and R⁵ are each independently a fluorine atom or chlorine atom; R⁶ is C1-C3 alkyl or C1-C3 alkyloxy; * indicates that a carbon atom marked with an asterisk is an asymmetric carbon,

a pharmaceutically acceptable salt thereof, or a solvate thereof.

A cooling agent composition includes a methyl menthol derivative represented by the following general formula (1). In the formula (1), a symbol * indicates an asymmetric carbon atom, X represents a hydrogen atom or a substituent, and Y represents an aryl group having 6 to 20 carbon atoms which may have a substituent.

A chiral ionic compound comprising an alkyl substituted imidazolium or pyridinium cationic core having an alkyl ester side chain (-alkyl-C(O)O—) directly linked to the core and an associated counter anion, characterized in that the —O— atom of the ester side chain is linked to an alpha, a beta or a gamma hydroxycarboxylic acid functionality via the alpha, beta or gamma hydroxy of the acid functionality and the hydroxycarboxylic acid functionality has at least one asymmetric carbon, or characterized in that an —N═ atom of the alkyl substituted imidazolium or pyridinium cationic core is substituted with an alpha, a beta or a gamma hydroxy group of a alpha, a beta or a gamma hydroxycarboxylic acid functionality and the hydroxycarboxylic acid functionality has at least one asymmetric carbon. The chiral ionic liquids (CILs) may be used as novel solvents, in particular for organic synthesis. The CILs have the potential to induce asymmetry into substrates or catalysts in a variety of organic transformations. A number of the compounds have low antimicrobial and low antifungal toxicities and are also biodegradable CILs.