Asymmetric hydrogenation of aromatic-substituted olefins using cationic ruthenium(III) complexes
AssigneeEthyl Corporation
InventorsThanikavelu Manimaran, W. Dirk Klobucar, Charles H. Kolich
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Abstract
A process for the asymmetric reduction of carboxylic acids of the formula ##STR1## or the amine salts thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
Claims17
A process for preparing optically active .alpha.-aryl aliphatic carboxylic acids which comprises catalytically, asymmetrically hydrogenating a carboxylic acid of the formula ##STR5## or the amine salt thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl, or haloalkyl;
- and Ar is aryl or substituted aryl;
- by utilizing a mixture of (i) a cationic ruthenium (III) complex of the formula:
- ##STR6## where R.sub.2 and R.sub.3 are the same or different and are alkyl, haloalkyl, aryl, substituted aryl, phenylalkyl or substituted phenylalkyl;
- x is an anion;
- and (solvent) is any neutral solvent molecule capable of coordinating to the metal;
- and (ii) a chiral phosphine compound.
A process for preparing optically active .alpha.-aryl aliphatic carboxylic acids which comprises catalytically, asymmetrically hydrogenating a carboxylic acid of the formula ##STR7## or the amine salt thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl, or haloalkyl;
- and Ar is aryl or substituted aryl;
- by utilizing a mixture of (i) a cationic ruthenium (III) complex of the formula:
- ##STR8## where R.sub.2 and R.sub.3 are the same or different and are alkyl, phenylalkyl or substituted phenylalkyl;
- x is an anion;
- and (solvent) is any neutral solvent molecule capable of coordinating to the metal;
- and (ii) an optically active ligand having the structure ##STR9## where R' is hydrogen, alkyl, haloalkyl, aryl or substituted aryl.
An asymmetric hydrogenation catalyst composition comprising a mixture of (i) chiral phosphine compound, and (ii) a compound of the formula ##STR10##
A process for preparing S-ibuprofen which comprises catalytically, asymmetrically hydrogenating 2-(4-isobutylphenyl)acrylic acid by utilizing a mixture of ##STR11## and S-BINAP, where R.sub.2 and R.sub.3 are the same or different and are alkyl and BINAP is ##STR12## and where x is an anion and (solvent) is any neutral solvent molecule capable of coordinating to the metal.
Dependencies are inferred from the claim text.