Abstract: A novel process in which an optically active alcohol compound having a desired absolute configuration and a high optical purity can be obtained by asymmetrically hydrogenating a &bgr;-keto acid compound through a simple operation. An optically active alcohol represented by general formula (III) as defined is obtained by asymmetrically hydrogenating a &bgr;-keto ester compound represented by general formula (I) as defined in the presence of at least one ruthenium complex having as a ligand an optically active tertiary diphosphine compound represented by general formula (II) as defined.

Abstract: This invention provides a novel diphosphine compound which is useful as a ligand of catalysts for asymmetric synthesis reactions, particularly asymmetric hydrogenation reaction. Particularly, it provides a diphosphine compound represented by a general formula (1): wherein R1 and R2 each independently represents a cycloalkyl group, an unsubstituted or substituted phenyl group or a five-membered aromatic heterocycle residue.

Abstract: Disclosed is a ruthenium-phosphine complex usable as the catalyst giving a high enantiomer excess in an asymmetric reaction and a method for producing the complex. The ruthenium-phosphine complex is represented by formula (1): [{(RuX(L)}2(&mgr;-X)3]−[R22NH2]+  (1) wherein R2 represents hydrogen, alkyl, cycloalkyl or benzyl and L represents a diphosphine ligand represented by formula (2): wherein R1 represents an optionally substituted phenyl group and X represents a halogen atom. The method for preparing a ruthenium-phosphine complex represented by formula (1) is characterized in that a ruthenium complex represented by the formula [RuX(arene)(L)]X and an ammonium salt represented by the formula R22NH.HX are reacted with each other.

Abstract: A novel diphosphine compound of the formula (I): ##STR1## where R.sup.1 and R.sup.2 represent independently cycloalkyl, unsubstituted or substituted phenyl, or a five-membered heteroaromatic ring. The compound is useful as a ligand for an asymmetric reaction, in particular, as an asymmetric hydrogenation catalyst.

Abstract: 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.

Abstract: 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.

Abstract: The present invention provides a method for producing novel optically active diphosphine compounds ?2,2'-bis(di-substituted phosphino)-1,1'-binaphthyl compounds! having a selectivity (chemoselectivity or enantioselectivity) and catalytic activity different from those of conventional BINAP compounds. In a method of the present invention for producing an optically active diphosphine compound (i.e., 2,2-bis(di-substituted phosphino)-1,1'-binaphthyl), 2,2'-bis(trifluoromethanesulfonyloxy)-1,1'-binaphthyl is reacted, in the presence of a transition metal-phosphine complex, with a phosphineoxide compound represented by the following general formula:A.sub.