Asymmetric phosphine ligand

Details Asymmetric phosphine ligand Asymmetric phosphine ligand

2002-11-12

2003-09-23

Vollano, Jean F. (Department: 1621)

Organic compounds -- part of the class 532-570 series

Organic compounds

Heavy metal containing

C568S012000, C568S017000

Reexamination Certificate

active

06624320

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to a novel phosphine-phosphorane compound, a production intermediate thereof, a transition metal complex containing the phosphine-phosphorane compound as a ligand, and a catalyst useful as a catalyst for various asymmetric syntheses, and a catalytic asymmetric synthetic technology using the same. Furthermore, the invention relates to a novel optically active phosphine-phosphorane compound, a production intermediate thereof, a transition metal complex containing the optically active phosphine-phosphorane compound as a ligand, and a catalyst useful as a catalyst for various asymmetric syntheses, and a catalytic asymmetric synthetic technology using the same.
BACKGROUND OF THE INVENTION
Hitherto, many reports have been made on the transition metal complex catalysts capable of being utilized in catalytic asymmetric syntheses such as asymmetric hydrogenation, asymmetric transfer hydrogenation, asymmetric hydrosilylation, asymmetric hydroboration, asymmetric hydroformylation, asymmetric isomerization of olefins, and asymmetric Heck reaction. Particularly, it is reported that complexes of transition metals such as ruthenium, iridium, rhodium, palladium, and nickel containing various optically active phosphines as ligands exhibit excellent performance as catalysts for asymmetric syntheses, and some of the catalysts are industrially employed (Asymmetric Catalysis in Organic Synthesis, Ed., R Noyori, Wiley & Sons, New York (1994)). Among the ligands, phosphorane-type ligands are disclosed and transition metal complexes containing the ligands are reported to be useful as the catalysts for catalytic asymmetric syntheses such as asymmetric hydrogenation ((1) H. Burunner, R. Sievi, J. Organometal. Chem., 1987, 328, 71; (2) WO 91/17998 (BPE); (3) WO 93/01199 (DuPHOS); (4) J. Org. Chem., 1998, 63, 8031 (RoPHOS); (5) WO 00/11008; (6) WO 99/59721 (PennPhos); (7) WO 00/26220; and so forth).
However, all the phosphorane-type ligands shown in (1) to (6) contain two optically active phosphorane rings per one molecule, so that their preparation requires a large amount of expensive optically active 1,3- or 1,4-diols. Moreover, in the synthesis of the diphosphine shown in (7), it is necessary to introduce an optically active center onto a phosphorus atom, which is difficult to synthesize. Thus, there is an inconvenience that these ligands are not suitable for practical use.
SUMMARY OF THE INVENTION
Thus, it is an object of the invention to provide a novel phosphine compound which can be synthesized from a small amount of an optically active compound and has excellent properties (chemical selectivity, enantioselectivity, catalytic activity) as a catalyst for asymmetric syntheses, especially asymmetric hydrogenation.
As a result of intensive studies for solving the above problem, the present inventors have found that a transition metal complex of an optically active phosphine-phosphorane having a specific structure is effective for asymmetric hydrogenation.
Moreover, they have found that the transition metal complex exhibits excellent catalytic activity and enantio- or diastereo-selectivity in asymmetric hydrogenation of olefins such as enamides and &bgr;-monosubstituted dehydroamino acid derivatives, and accomplished the invention.
Incidentally, a ligand containing one optically active phosphorane ring per one molecule has been reported in “Tetrahedron; Asymmetry 2001, 12, 1159”, which discloses the compound and process for producing the same but does not describe the preparation of an complex from a transition metal and the compound and the process of asymmetric hydrogenation of a substrate in the presence of the complex, still less the compound having a substituent other than phenyl group on the phosphine and the process for producing the same.
DETAILED DESCRIPTION OF THE INVENTION
The following will explain the invention in detail.
The phosphine-phosphorane compound of the invention is represented by the general formula (1).
(wherein R
1
represents hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms and a represents an integer of 1 to 4; R
2
, R
3
, R
4
, and R
5
are the same or different, and each represents hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, and each of R
2
and R
3
, R
3
and R
4
, and R
4
and R5 may be together combined to form a ring which may contain one or more (preferably 1 to 2) oxygen atoms; and R
6
and R
7
are the same or different, and each represents a linear or branched alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 7 carbon atoms, a perfluoroalkyl group, a phenyl group, a phenyl group having one or more (preferably 1 to 5) substituents (an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 6 carbon atoms which is substituted by one or more (preferably 1 to 7) halogen atoms, an alkoxy group having 1 to 6 carbon atoms, or a halogen atom), an aralkyl group having 7 to 12 carbon atoms, or a ring-substituted aralkyl group).
The alkyl group having 1 to 4 carbon atoms for the above R
1
is selected from the group consisting of methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, and tert-butyl group, and the alkoxy group having 1 to 6 carbon atoms includes methoxy group, ethoxy group, n-propyloxy group, iso-propyloxy group, n-butoxy group, iso-butoxy group, sec-butoxy group, tert-butoxy group, n-pentyloxy group, iso-pentyloxy group, neo-pentyloxy group, tert-pentyloxy group, 2-methylpentyloxy group, n-hexyloxy group, and iso-hexyloxy group.
The alkyl group having 1 to 6 carbon atoms for R
2
, R
3
, R
4
, or R
5
is selected from the group consisting of methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, iso-pentyl group, neo-pentyl group, tert-pentyl group, 2-methylpentyl group, n-hexyl group, and iso-hexyl group, and the alkoxy group having 1 to 6 carbon atoms includes methoxy group, ethoxy group, n-propyloxy group, iso-propyloxy group, n-butoxy group, iso-butoxy group, sec-butoxy group, tert-butoxy group, n-pentyloxy group, iso-pentyloxy group, neo-pentyloxy group, tert-pentyloxy group, 2-methylpentyloxy group, n-hexyloxy group, and iso-hexyloxy group.
Furthermore, each of R
2
and R
3
, R
3
and R
4
, and R
4
and R
5
may be together combined to form a ring, and the ring is preferably a ring having 5 to 7 carbon atoms, which is formed together with other carbon atoms. The ring may have one or more (preferably 1 to 5) substituents.
Specific examples thereof include rings containing methylenedioxy group, ethylenedioxy group, or propylenedioxy group, benzene, indane, tetrahydronaphthalene, indene, dihydronaphthalene, fluorene, naphthalene, anthracene, phenanthrene, and the like. The substituent for the rings includes an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 atoms, an alkyl group having 1 to 6 carbon atoms substituted by one or more (preferable 1 to 7) halogen atoms, a halogen atom, amino group, an amino group substituted by one or more (preferable 1 to 2) alkyl groups, and the like. The alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 atoms are selected from those the same as the above.
The linear or branched alkyl group having 1 to 6 carbon atoms for the above R
6
or R
7
is selected from those the same as the above. The cycloalkyl group having 3 to 7 carbon atoms is preferably cyclopropyl group, methylcyclopropyl group, cyclobutyl group, cyclopentyl group, 2-methylcyclopentyl group, 3-methylcyclopentyl group, cyclohexyl group, 2-methylcyclohexyl group, 3-methylcyclohexyl group, 4-methylcyclohexyl group, or cycloheptyl group.
The phenyl group may have one or more (preferable 1 to 5) substituents and the alkyl group having 1 to 6 carbon atoms as the substituent is selected from those the same as above. The alkyl group by which the phenyl group is substi

Affiliated with

Also associated with

Rating

Asymmetric phosphine ligand does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Asymmetric phosphine ligand, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Asymmetric phosphine ligand will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3022256