Monsanto Company

William S Knowles

Milton J Sabacky

Billy D Vineyard

William C Christopfel

The invention is a new family of phosphine compounds which can be used to make optically active metal coordination complex catalysts which combine high efficiency with a capability of performing rapidly (high efficiency and rapidly being established from Tables I, II and III as being greater than 75% efficiency and in times of not more than a few hours, preferably less than one hour) in water and thus avoiding solvent recovery and loss problems. The catalysts can be used in some alcoholic mediums as well as in some aqueous mediums. These catalysts are useful in catalytic asymmetric hydrogenation of some olefinic compounds. The new phosphine compounds are made from novel phosphine oxides.

Coordination complexes of optically active phosphine compounds

Optically active phosphine compounds

Process for the homogeneous catalytic hydrogenation of .beta.-substituted-.alpha.-acylamido-acrylic acids which yields, after hydrogenation, an optically active mixture. The process comprises the hydrogenation of .beta.-substituted-.alpha.-acylamido-acrylic acids in the presence of an optically active coordinated metal complex hydrogenation catalyst, in which the metal is selected from the group consisting of rhodium, iridium, ruthenium, osmium, palladium and platinum. This process is a generalized process for any asymmetric hydrogenation of .beta.-substituted-.alpha.-acylamido-acrylic acids in which one .alpha.-amino acid enantiomorph is the desired end-product. It is especially useful for the preparation of .alpha.-amino acids found in nature which possess optical activity and which have a hydrogen attached to the asymmetric center. This invention also relates to new optically active coordinated metal complex hydrogenation catalysts.

Methylcyclohexyl-O-anisylphosphine

Process for the homogeneous catalytic hydrogenation of .alpha.-substituted-.alpha.-acylamido-acrylic acids which yields, after hydrogenation, an optically active mixture. The process comprises the hydrogenation of .beta.-substituted-.beta.-acylamido-acrylic acids in the presence of an optically active coordinated metal complex hydrogenation catalyst, in which the metal is selected from the group consisting of rhodium, iridium, ruthenium, osmium, palladium and platinum. This process is a generalized process for any asymmetric hydrogenation of .beta.-substituted-.alpha.-acylamido-acrylic acids in which one .alpha.-amino acid enantiomorph is the desired end-product. It is especially useful for the preparation of .alpha.-amino acids found in nature which possess optical activity and which have a hydrogen attached to the asymmetric center. This invention also relates to new optically active coordinated metal complex hydrogenation catalysts.

Catalytic asymmetric hydrogenation

Process for the homogeneous catalytic hydrogenation of .beta.-substituted-.alpha.-acylamido-acrylic acids which yields, after hydrogenation, an optically active mixture. The process comprises the hydrogenation of .beta.-substituted-.alpha.-acylamidoacrylic acids in the presence of an optically active coordinated metal complex hydrogenation catalyst, in which the metal is selected from the group consisting of rhodium, iridium, ruthenium, osmium, palladium and platinum. This process is a generalized process for any asymmetric hydrogenation of .beta.-substituted-.alpha.-acylamido-acrylic acids in which one .alpha.-amino acid enantiomorph is the desired end-product. It is especially useful for the preparation of .alpha.-amino acids found in nature which possess optical activity and which have a hydrogen attached to the asymmetric center. This invention also relates to new optically active coordinated metal complex hydrogenation catalysts.

New optically active bis phosphine compounds which are usful in optically active catalysts. Such catalysts are particularly useful in catalytic asymmetric hydrogenation.

Asymmetric catalysis

New optically active bis phosphine compounds which are useful in optically active catalysts. Such catalysts are particularly useful in catalytic asymmetric hydrogenation.

Metal coordination complexes containing optically active phosphine or

Process for the homogeneous catalytic hydrogenation of olefins, capable of existing as enantiomorphs upon hydrogenation of the olefinic bond, which yields on hydrogenation an optically active mixture. The process comprises the hydrogenation of the olefin in the presence of an optically active coordinated metal hydrogenation catalyst, in which the metal is selected from the group consisting of rhodium, iridium, ruthenium, osmium, palladium and platinum. This process is a generalized process for any asymmetric hydrogenation of olefins in which one optical enantiomorph is desired. It is also a generalized process for the selective hydrogenation of olefins in the presence of other reactive groups which are easily hydrogenated. It is especially useful for the preparation of natural products which possess optical activity, such as amino acids, and for products such as flavors, fragrances which may require optical activity for their utilitization. This invention also relates to new optically active coordinated hydrogenation catalysts.

A process for the preparation of 3-(3,4-dihydroxyphenyl)-L-alanine (L-DOPA) wherein .alpha.-acetamido-4-hydroxy-3-alkoxy-cinnamic acid acetate is subjected to catalytic asymmetric hydrogenation to yield an optically active mixture N-acetyl-3-(4-hydroxy-3-alkoxyphenyl)-alanine acetate, with the L enantiomorph being present in a major amount and the D enantiomorph being present in a minor amount, from which N-acetyl-3-(4-hydroxy-3-alkoxyphenyl)-L-alanine acetate can be easily recovered and is then converted to L-DOPA. Novel precursors for L-DOPA are prepared in the process of this invention.

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St. Louis, MO, United States of America

William S Knowles