Patents by Inventor Yongzhen Zhang

Yongzhen Zhang 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).

  • Patent number: 12202792
    Abstract: A preparation method for optically active citronellal, which can obviously enhance the catalytic stability of an optically active transition metal catalyst for asymmetric hydrogenation of homogeneous catalysis and thereby achieve higher turnover numbers. In the preparation method for optically active citronellal, a substrate is subjected to an asymmetric hydrogenation reaction in the presence of the transition metal catalyst to generate the optically active citronellal, wherein the transition metal catalyst is obtained by reacting a transition metal compound with an optically active ligand containing two phosphorus atoms, and the raw material of the substrate is one of neral and geranial or a combination thereof to control the hydroxyl value to be less than or equal to 6 mgKOH/g and/or the iron content to be less than or equal to 50 ppm in the raw material of the substrate for the asymmetric hydrogenation reaction.
    Type: Grant
    Filed: December 9, 2019
    Date of Patent: January 21, 2025
    Assignee: WANHUA CHEMICAL GROUP CO., LTD.
    Inventors: Jing Dong, Lei Yu, Yongzhen Zhang, Yuan Li
  • Publication number: 20230043867
    Abstract: A preparation method for optically active citronellal, which can obviously enhance the catalytic stability of an optically active transition metal catalyst for asymmetric hydrogenation of homogeneous catalysis and thereby achieve higher turnover numbers. In the preparation method for optically active citronellal, a substrate is subjected to an asymmetric hydrogenation reaction in the presence of the transition metal catalyst to generate the optically active citronellal, wherein the transition metal catalyst is obtained by reacting a transition metal compound with an optically active ligand containing two phosphorus atoms, and the raw material of the substrate is one of neral and geranial or a combination thereof to control the hydroxyl value to be less than or equal to 6 mgKOH/g and/or the iron content to be less than or equal to 50 ppm in the raw material of the substrate for the asymmetric hydrogenation reaction.
    Type: Application
    Filed: December 9, 2019
    Publication date: February 9, 2023
    Inventors: Jing Dong, Lei Yu, Yongzhen Zhang, Yuan Li