Patents by Inventor Donald Herman Valentine, Jr.

Donald Herman Valentine, Jr. has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Metal phosphine complex
    Patent number: 4120870
    Abstract: 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.
    Type: Grant
    Filed: July 18, 1977
    Date of Patent: October 17, 1978
    Assignee: Hoffmann-La Roche Inc.
    Inventors: John Melvin Townsend, Donald Herman Valentine, Jr.
  • Asymmetric hydrogenation catalyzed by rhodium complexes of chiral tertiary phosphines
    Patent number: 4115417
    Abstract: 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.
    Type: Grant
    Filed: August 10, 1977
    Date of Patent: September 19, 1978
    Assignee: Hoffmann-La Roche Inc.
    Inventor: Donald Herman Valentine, Jr.
  • Process for the preparation of aldehydes
    Patent number: 4016212
    Abstract: 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.
    Type: Grant
    Filed: February 15, 1974
    Date of Patent: April 5, 1977
    Assignee: Hoffmann-La Roche Inc.
    Inventors: Willy Leimgruber, Donald Herman Valentine, Jr.
  • Preparation of triaryl phosphines
    Patent number: 4008282
    Abstract: 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.
    Type: Grant
    Filed: October 29, 1974
    Date of Patent: February 15, 1977
    Assignee: Hoffmann-La Roche Inc.
    Inventors: John Melvin Townsend, Donald Herman Valentine, Jr.