Hoffmann-la Roche Inc.

Donald H Valentine, Jr

Willy Leimgruber

Andrew D Batcho

John William Scott

Urs Oskar Hengartner

John M Townsend

Novel substituted diphenyl tertiary phosphines of a pyrrolidine carboxylic acid derivative and their use as catalysts in the enantioselective hydrogenation of .alpha.-keto-.beta.,.beta.-dimethyl-.gamma.-butyrolactone.

Chiral phosphines

The preparation of racemic and optically pure tryptophans is described. The D-enantiomers of the 6-substituted compounds possess a potent sweetening capability. Novel intermediates are also disclosed.

Pyrroles and pyrrolidines

Novel syntheses of tryptophans

Novel Group IB and IIB metal phosphine complexes are disclosed. These complexes are reacted with rhodium complex precursors to form useful enantioselective hydrogenation catalysts. Also disclosed is a method of preparing useful compounds having optical activity such as natural products and compounds useful as flavors and fragrances.

Metal phosphine complex

Lower alkyl esters of 2-formamido-3(4,5,6 or 7-methyl substituted-3-indolyl)-2-carbalkoxy propionic acid which are useful as intermediates for tryptophane sweetners.

Lower alkyl esters of .alpha.-formamido,.alpha.-carbalkoxy tryptophans

A multi-step process for the preparation of alpha,beta-unsaturated aliphatic aldehydes such as citral by first reacting an allylic alcohol with a butadienyl ether, or a corresponding acrolein derivative or its acetal, including novel intermediates in this process.

Process for the preparation of aldehydes

A method for the homogeneous catalytic enantioselective hydrogenation of alkyl and alkenyl substituted acrylic acids wherein these acids are selectively hydrogenated at the double bond alpha,beta to the acid function, said hydrogenations are catalyzed by rhodium complexes of chiral tertiary phosphines. This method provides a route to chiral dihydrogeranic acid and other intermediates useful in the synthesis of chiral vitamin E, citronellal, and menthol. Novel chiral tertiary phosphines are also disclosed.

Chiral tertiary phosphines

Group IB and IIB metal phosphine complexes are disclosed. These complexes are reacted with rhodium complex precursors to form useful enantioselective hydrogenation catalysts. Also disclosed is a method of preparing useful compounds having optical activity such as natural products and compounds useful as flavors and fragrances.

A method for the homogeneous catalytic enantioselective hydrogenation of alkyl and alkenyl substituted acrylic acids wherein these acids are selectively hydrogenated at the double bond alpha, beta to the acid function, said hydrogenations are catalyzed by rhodium complexes of chiral tertiary phosphines. This method provides a route to chiral dihydrogeranic acid and other intermediates useful in the synthesis of chiral vitamin E, citronellal, and menthol. Novel chiral tertiary phosphines are also disclosed.

Asymmetric hydrogenation catalyzed by rhodium complexes of chiral

Synthesis of tryptophans

The conversion of triaryl phosphine oxide to the corresponding phosphine by reduction with hydrogen utilizing sulfur or selenium as the catalyst wherein said reduction is carried out in the presence of silicon tetrahalide.

Growing community of inventors

Westfield, NJ, United States of America

Donald H Valentine, Jr