Chiral ferrocene phosphines active in asymmetric catalysis

Details Chiral ferrocene phosphines active in asymmetric catalysis Chiral ferrocene phosphines active in asymmetric catalysis

1999-11-22

2001-07-10

Vollano, Jean F. (Department: 1621)

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

Organic compounds

Carboxylic acids and salts thereof

C562S496000, C562S590000, C564S301000, C564S336000

Reexamination Certificate

active

06258979

ABSTRACT:

The present invention pertains to new compounds of formula (I), chiral ferrocene phosphine derivatives, and their use in asymmetric catalysis, more specifically in asymmetric hydrogenation.
The compounds of formula (I) are defined as below:
in which R1, R2, R3, and R4 are identical or different and represent a group selected from among hydrogen, a linear or branched C
1-7
alkyl, a C
5-7
cycloalkyl possibly substituted by a C
1-4
alkyl, a trifluoromethyl, a halogen, a hydroxy or an alkoxy, a phenyl possibly substituted by a C
1-4
alkyl, a trifluoromethyl, a halogen, a hydroxy or an alkoxy.
The invention also covers all of the optically active forms of the compounds of formula (I).
The synthesis of optically active functionalized compounds such as, for example, the amino acids, the mono- or dicarboxylic acids, presently represents an important industrial activity. There is therefore a requirement for catalytic systems for the synthesis of these alcohols and amines which are increasingly competitive in terms of both cost and efficacy.
Known from the European patents “EP 612758” and “EP 646590”, published by Ciba-Geigy, are catalytic systems combining a rhodium or iridium complex of the type [Ir(1,5-cyclooctadiene)Cl]
2
, [Rh(norbornadiene)
2
Cl]
2
or [Rh(norbornadiene)
2
]BF
4
with an enantiomerically pure organic ligand such as the ferrocene phosphines, such as, for example, the ligand “JOSIPHOS”.
These catalytic systems enable the transformation of certain functionalized enamides, ketones or alkenes such as, for example, acetamidocinnamic acid (or the alkyl ester), itaconic acid (or the alkyl ester), acetyl acetic acid (or the alkyl ester) into corresponding chiral compounds.
The object of the present invention is the introduction of new ligands of the ferrocene phosphine type of formula (I), characterized by high performance in terms of activity and enantioselectivity for the synthesis of chiral compounds.
For this purpose, the ligands of formula (I) according to the invention are prepared from the compound of formula (II) according to the procedure described in the article J. Org. Chem. 1997, 62, p. 6733, by the authors O. Riant, O. Samuel, T. Flessner, S. Taudien and H. B. Kagan.
The compounds of formula (II) are defined as below:
in which R3 and R4 have the same meanings as in formula (I).
The compound of formula (II) is reduced by a hydride so as to obtain compound (III) as defined below:
in which R3 and R4 have the same meanings as in formula (I).
The compound of formula (III) then has its hydroxyl group substituted so as to produce the compounds of formula (I).
The invention also has as its object the use of derivatives of formula (I) as ligands in an enantioselective reduction process for unsaturated compounds of formula (IV). Said unsaturated compounds are more specifically enamides or compounds with a carbon-carbon double bond.
The compounds of formula (IV) are represented below:
in which R5 and R6 are different, with R5 selected from among a C
1-5
alkyl; an aryl group; an aryl group substituted by a C
1-4
alkyl, a C
1-4
alkoxy or a halogen; a heteroaryl group substituted by a C
1-4
alkyl, a C
1-4
alkoxy or a halogen; a carboxylic acid; a carboxylic ester; a C
1-4
alkyl carboxylic acid; a C
1-4
alkyl carboxylate; with R6 selected from among an amide; an aryl; an aryl substituted by a C
1-4
alkyl, a C
1-4
alkoxy or a halogen heteroaryl; a heteroaryl substituted by a C
1-4
alkyl, a C
1-4
alkoxy or a halogen; in which Z is represented by an NR7, NOR7 or C(R7)
2
group, with R7 selected from among hydrogen; a C
1-5
alkyl; an aryl group possibly substituted by a C
1-4
alkyl; a halogen or an alkoxyalkyl; a heteroaryl group possibly substituted by a C
1-4
alkyl or a halogen or an alkoxyalkyl.
In the implementation of the catalytic system, the transition metal is preferably rhodium and the complexes are of the type [Rh(formula (I))(COD)]BF
4
or [Rh(formula (I))COD]PF
6
or [Rh(formula (I))(C1)COD].
The reaction is perferably carried out in a temperature range of 20-100° C.
The catalytic quantity of the rhodium complex in relation to the quantity of formula (IV) substrate is from 1 to 50,000, preferably from 100 to 20,000, and especially preferably from 1000 to 10,000.


REFERENCES:
patent: 5563309 (1996-10-01), Togni et al.
patent: 2289855 (1995-12-01), None

Affiliated with

Also associated with

Rating

Chiral ferrocene phosphines active in asymmetric catalysis does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Chiral ferrocene phosphines active in asymmetric catalysis, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chiral ferrocene phosphines active in asymmetric catalysis will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2512717