摘要:
The present invention provides a ligand for a novel catalyst superior in such characteristics as selectivity (chemoselectivity and enantioselectivity) and catalytic activity in asymmetric synthesis reactions and a ligand for a novel catalyst effective in an asymmetric hydrogenation reaction in particular. The ligand is an optically active diphosphine compound represented by the following formula: ##STR1## where Ph is a phenyl group, X is a chlorine or bromine atom, and R.sup.1 and R.sup.2 are each an alkyl group having 1 to 3 carbon atoms.
摘要:
A novel chiral unsymmetric diphosphine compound of formula (I): ##STR1## wherein Ar.sup.1 and Ar.sup.2, which are different from each other, each represent a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a pyridyl group, a quinolyl group, an isoquinolyl group, a furfuryl group, a benzofurfuryl group, a thienyl group, or a benzothienyl group, and a transition metal complex containing the diphosphine compound as a ligand. The complex catalyzes various asymmetric synthesis reactions, e.g., asymmetric hydrogenation or asymmetric hydrosilylation, exhibiting excellent performance in selectivity, conversion and catalytic activity, to provide a product of desired absolute configuration at high optical purity and in high yield.
摘要:
A process for the production of an optically active carboxylic acid (I), which comprises subjecting an olefinic carboxylic acid (II) to asymmetric hydrogenation using a complex as a catalyst consisting of an optically active phosphine (III) and a ruthenium compound.Complex of ##STR1## with a ruthenium compound ##STR2## According to the process of the present invention, optically active carboxylic acids can be produced with high yield.
摘要:
A phosphine compound represented by one of the formulas: ##STR1## wherein R.sup.1 and R.sup.2, which may be the same or different, each represent a phenyl group or a phenyl group substituted with a halogen atom or a lower alkyl group or taken together form a divalent hydrocarbon group; and R.sup.3 and R.sup.4, which may be the same or different, each represent a lower alkyl group, a phenyl group or a phenyl group substituted with a halogen atom, a lower alkyl group or a lower alkoxy group or taken together form a divalent hydrocarbon group, and wherein R.sup.6 and R.sup.6' which may be the same or different, each represent a hydrogen atom, a lower alkyl group or a lower alkoxy group; R.sup.5, R.sup.5', R.sup.11 and R.sup.11' which may be the same or different, each represent a hydrogen atom, a lower alkyl group, a lower alkoxy group or a halogen atom; or a pair of R.sup.5 and R.sup.6 or a pair of R.sup.5' and R.sup.6' may form a ring; R.sup.7 and R.sup.8, which may be the same or different, each represent a phenyl group or a phenyl group substituted with a lower alkyl group, a halogen atom or a lower alkoxy group; and R.sup.9 and R.sup.10, which may be the same or different, each represent a phenyl group or a phenyl group substituted with a lower alkyl group, a lower alkoxy group or a halogen atom; or R.sup.9 and R.sup.10 may be taken together to form a divalent hydrocarbon group.
摘要:
Disclosed herein is a process for producing a (2S,5S)-2,5-diamino-1,6-diphenyl-3-hexanone derivative represented by the formula (1): ##STR1## wherein R.sup.1 means a lower alkylcarbonyl group, a halogen-substituted lower alkylcarbonyl group, an arylcarbonyl group or a lower alkoxycarbonyl group, and R.sup.2 and R.sup.3 are identical with or different from each other and denote individually an aryl group or an alkoxy-substituted aryl group, which comprises subjecting a (2S)-2,5-diamino-1,6-diphenyl-4-hexen-3-one derivative represented by the formula (2): ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 have the same meaning as defined above, to a hydrogenation reaction in the presence of a transition metal-containing catalyst.
摘要:
A process for for producing a (2R,3S)-cyclohexylnorstatine or a salt thereof is disclosed, which comprises the steps of: enantioselectively hydrogenating a 4-cyclohexyl-2-halogeno-3-oxobutyric acid ester in the presence of a ruthenium-phosphine complex to produce a 4-cyclohexyl-2-halogeno-(3R)-hydroxybutyric acid ester (2); epoxidizing the compound (2) in the presence of a base to produce a 4-cyclohexyl-(2S,3R)-epoxybutyric acid ester (3); reacting the compound (3) with a lower trialkylsilyl azide in the presence of a Lewis acid to produce a (3S)-azide-4-cyclohexyl-(2S)-substituted butyric acid ester (4); subjecting the compound (4) to hydrogenolysis to produce a (2S,3S)-cyclohexylnorstatine derivative (5); and inverting the configuration at the 2-position of the compound (5).
摘要:
A process for producing an optically active alcohol represented by formula (I): ##STR1## wherein R.sub.1 is an alkyl group having from 2 to 11 carbon atoms, an alkenyl group having from 3 to 11 carbon atoms, an alkadienyl group having from 6 to 11 carbon atoms, a cyclohexyl group, an cyclohexylmethyl group, or a cyclohexylethyl group, provided that the olefin in the alkenyl group or alkadienyl group is not conjugated to the olefin at the 2-position thereof; and * means an asymmetric carbon atom,is disclosed, comprising subjecting an olefinic alcohol represented by formula (II): ##STR2## wherein R.sub.1 is the same as defined above to asymmetric hydrogenation in the presence of, as a catalyst, a ruthenium-optically active phosphine complex.According to the process of the invention, the desired optically active alcohols which are useful not only as intermediates for the manufacture of perfumes and vitamin E but also as liquid crystal materials can be produced with high optical purities.
摘要:
A ruthenium-phosphine complex represented by formula (I): ##STR1## wherein R represents a hydrogen atom, a methyl group, or a methoxy group; S represents a tertiary amine; when y is 0, then x is 2, z is 4, and p is 1; and when y is 1, then x is 1, z is 1, and p is 0. The complex is inexpensive and exhibits excellent performance as a catalyst for various organic syntheses, and particularly asymmetric hydrogenation.
摘要:
Disclosed herein is a process for producing a (2S,5S)-2,5-diamino-1,6-diphenyl-3-hexanone derivative represented by the formula (1): ##STR1## wherein R.sup.1 means a lower alkylcarbonyl group, a halogen-substituted lower alkylcarbonyl group, an arylcarbonyl group or a lower alkoxycarbonyl group, and R.sup.2 and R.sup.3 are identical with or different from each other and denote individually an aryl group or an alkoxy-substituted aryl group, which comprises subjecting a (2S)-2,5-diamino-1,6-diphenyl-4-hexen-3-one derivative represented by the formula (2): ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 have the same meaning as defined above, to a hydrogenation reaction in the presence of a transition metal-containing catalyst.
摘要:
A process for for producing a (2R,3S)-cyclohexylnorstatine or a salt thereof is disclosed, which comprises the steps of: enantioselectively hydrogenating a 4-cyclohexyl-2-halogeno-3-oxobutyric acid ester in the presence of a ruthenium-phosphine complex to produce a 4-cyclohexyl-2-halogeno-(3R)-hydroxybutyric acid ester (2); epoxidizing the compound (2) in the presence of a base to produce a 4-cyclohexyl-(2S,3R)-epoxybutyric acid ester (3); reacting the compound (3) with a lower trialkylsilyl azide in the presence of a Lewis acid to produce a (3S)-azide-4-cyclohexyl-(2S)-substituted butyric acid ester (4); subjecting the compound (4) to hydrogenolysis to produce a (2S,3S)-cyclohexylnorstatine derivative (5); and inverting the configuration at the 2-position of the compound (5).