摘要:
A process for preparing an optically active carnitine ester represented by formula (I): wherein R represents a lower alkyl group; and X represents a halogen atom, is disclosed, comprises asymmetrically hydrogenating a &ggr;-trimethylammonium-3-oxobutanoic ester halide represented by formula (II): wherein R and X are as defined above, in the presence of a ruthenium-optically active phosphine complex as a catalyst. An optically active carnitine ester of any desired isomerism can be obtained through simple operation in high yield at high optical purity. The substrate used is easily available.
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:
2,2'-Bis[di-(m-tolyl)phosphino]-1,1'-binaphthyl represented by formula (I) is disclosed. ##STR1## The compound of formula (I) is capable of forming a complex with a metal, e.g., ruthenium, rhodium, and palladium, which is extremely important and industrially excellent as a catalyst for various asymmetric synthesis reactions.
摘要:
An iridium-optically active phosphine complex represented by formula (I):[H.sub.2 Ir(L.sup.1)(L.sup.2)]Y (I)wherein L.sup.1 represents an optically active phosphine compound represented by formula (II): ##STR1## wherein Ar represents a phenyl group or a p- and/or m-lower alkyl-substituted phenyl group, or formula (III): ##STR2## L.sup.2 represents a tertiary phosphine compound represented by formula (IV): ##STR3## wherein Z represents a lower alkoxy group or a di-lower alkylamino group; and A represents an integer of from 1 to 3; Y represents BF.sub.4, PF.sub.6, ClO.sub.4, or BPh.sub.4, wherein Ph represents a phenyl group, and a process for producing an optically active alcohol using the above complex as an enantioselective catalyst are disclosed. The complex exhibits excellent catalytic activity to give high enantioselective yields in enantioselective synthesis, particularly enantioselective hydrogenation.
摘要:
A ruthenium-phosphine complex having a 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl or its derivative as a ligand and carboxyl groups bonded to the ruthenium atom thereof is disclosed. The complex is inexpensive and exhibits excellent performances as a catalyst for various organic syntheses, and particularly for asymmetric hydrogenation.
摘要:
An iridium-optically active phosphine complex represented by formula (I):[H.sub.2 Ir(L.sup.1)(L.sup.2)]Y (I)wherein L.sup.1 represents an optically active phosphine compound represented by formula (II): ##STR1## wherein Ar represents a phenyl group or a p- and/or m-lower alkyl-substituted phenyl group, or formula (III): ##STR2## L.sup.2 represents a tertiary phosphine compound represented by formula (IV): ##STR3## wherein Z represents a lower alkoxy group or a di-lower alkylamino group; and A represents an integer of from 1 to 3; Y represents BF.sub.4, PF.sub.6, ClO.sub.4, or BPh.sub.4, wherein Ph represents a phenyl group,and a process for producing an optically active alcohol using the above complex as an enantioselective catalyst are disclosed. The complex exhibits excellent catalytic activity to give high enantioselective yields in enantioselective synthesis, particularly enantioselective hydrogenation.
摘要:
A process for preparing optically active threonine is disclosed, which comprises asymmetrically hydrogenating a 2-N-acylaminoacetoacetic ester represented by formula (I): ##STR1## wherein R.sup.1 represents a lower alkyl group, a phenyl group, a phenyl group substituted with a lower alkyl group or a lower alkoxy group, a benzyl group, or a benzyl group substituted with a lower alkyl group or a lower alkoxy group; R.sup.2 represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a phenyl group, a phenyl group substituted with a lower alkyl group or a lower alkoxy group, a benzyloxy group, or a benzyloxy group substituted with a lower alkyl group or a lower alkoxy group, in the presence of a ruthenium-optically active phosphine complex as a catalyst to obtain an optically active threonine derivative represented by formula (II): ##STR2## wherein R.sup.1 and R.sup.2 are as defined above, and then hydrolyzing the compound of formula (II). The 2-N-acylaminoacetoacetic ester intermediate can be selectively prepared in a high yield. Either natural type threonine or non-natural type threonine can be prepared selectively by selecting the absolute configuration of the ligand of the ruthenium-optically active phosphine complex.
摘要:
A ruthenium-phosphine complex represented by formula (I): ##STR1## wherein R represents a hydrogen atom, a methyl group, or a methoxy group; and X represents ClO.sub.4, BF.sub.4, or PF.sub.6. The ruthenium-phosphine complex is inexpensive and exhibits excellent performance as a catalyst for various organic syntheses, particularly for asymmetric hydrogenation.
摘要:
A ruthenium-phosphine complex represented by formula (I): ##STR1## wherein R.sup.1 represents a hydrogen atom, a methyl group, or a methoxy group; and R.sup.2 represents a lower alkyl group, a halogenated lower alkyl group, a phenyl group, or a phenyl group substituted with a lower alkyl group. The complex is inexpensive and exhibits excellent performance as a catalyst for various organic syntheses, particularly for asymmetric hydrogenation.
摘要翻译:由式(I)表示的钌膦络合物:其中R 1表示氢原子,甲基或甲氧基; R 2表示低级烷基,卤代低级烷基,苯基或被低级烷基取代的苯基。 该复合物是便宜的,并且作为各种有机合成的催化剂表现出优异的性能,特别是用于不对称氢化。
摘要:
A process as described for preparing hydroxycitronellal by isomerizing certain 7-hydroxygeranylamine compound or 7-hydroxynerylamine compounds using a catalyst comprising a divalent palladium compound and a phosphine compound.