Asymmetric hydrogenation of aromatic-substituted olefins using organorhenium catalyst
AssigneeEthyl Corporation
InventorsW. Dirk Klobucar, Charles H. Kolich, Thanikavelu Manimaran
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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.
Claims14
A process for preparing optically active .alpha.-aryl aliphatic carboxylic acids which comprises catalytically, asymmetrically hydrogenating a carboxylic acid of the formula ##STR4## 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 catalytically effective amount of a mixture of (i) a rhenium-containing compound selected from the group consisting of halide, a mixed halide-chelate complex and a chelate complex 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 ##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 rhenium compound selected from the group consisting of halide, a mixed halide-chelate complex and a chelate complex and (ii) an optically active ligand where the ligand is ##STR6## where R' is hydrogen, alkyl, haloalkyl, aryl or substituted aryl.
An asymmetric hydrogenation catalyst composition comprising a mixture of BINAP and ReCl.sub.5 and optionally an organic amine and hydrogen.
A process for preparing S-ibuprofen which comprises catalytically, asymmetrically hydrogenating 2-(4-isobutylphenyl)acrylic acid by utilizing a mixture of rhenium(V) chloride and an optically active BINAP where BINAP is ##STR7##
Dependencies are inferred from the claim text.