Patents by Inventor Tae-Lim Choi

Tae-Lim Choi 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).

  • Publication number: 20030236367
    Abstract: This invention relates generally synthetic procedures that include the step of ring-opening metathesis of cyclic olefins and reaction with an acyclic diene co-reactant to produce olefin macrocycles by ring expansion, or alternatively. The ring expansion of the cyclic olefin is provided by three types of sequential olefin metathesis (ring-opening, cross, and ring-closing olefin metathesis). More particularly, the invention pertains to synthesis of olefin macrocycles via olefin metathesis reactions using a Group 8 transition metal complex as the metathesis catalyst. Macrocycles provided herein have a variety of uses in the pharmaceutical, biomedical, organic synthesis and chemical industries, such as the production of crown ethers that are useful as metal complexing species.
    Type: Application
    Filed: February 19, 2003
    Publication date: December 25, 2003
    Inventors: Tae-Lim Choi, Choon Woo Lee, Hyunjin M. Kim, Robert H. Grubbs
  • Publication number: 20030100776
    Abstract: The invention pertains to the use of Group 8 transition metal carbene complexes as catalysts for olefin cross-metathesis reactions. In particular, ruthenium and osmium alkylidene complexes substituted with an N-heterocyclic carbene ligand are used to catalyze cross-metathesis reactions to provide a variety of substituted and functionalized olefins, including phosphonate-substituted olefins, directly halogenated olefins, 1,1,2-trisubstituted olefins, and quaternary allylic olefins. The invention further provides a method for creating functional diversity using the aforementioned complexes to catalyze cross-metathesis reactions of a first olefinic reactant, which may or may not be substituted with a functional group, with each of a plurality of different olefinic reactants, which may or may not be substituted with functional groups, to give a plurality of structurally distinct olefinic products.
    Type: Application
    Filed: April 1, 2002
    Publication date: May 29, 2003
    Inventors: Robert H. Grubbs, Arnab K. Chatterjee, Tae-Lim Choi, Steven D. Goldberg, Jennifer A. Love, John P. Morgan, Daniel P. Sanders, Matthias Scholl, F. Dean Toste, Tina M. Trnka
  • Publication number: 20020198426
    Abstract: A catalytic method is provided for a ring-opening cross-metathesis reaction between a cycloolefinic substrate and a second olefinic reactant, wherein the catalyst used is a transition metal alkylidene complex substituted with an N-heterocyclic carbene ligand. The substrates are selected so that the rate of the cross-metathesis reaction of the second olefinic reactant, kCM, is greater than or equal to the rate of the ring-opening metathesis reaction, kRO. In this way, the predominant ROCM product is a monomer, dimer, and/or oligomer, but not a polymer. The invention additionally provides for selective production of an end-differentiated olefinic product, using trisubstituted cycloolefins as substrates and/or a subsequent cross-metathesis reaction following an initial ROCM step. The cycloolefinic substrates include low-strain olefins such as cyclohexene as well as higher strain olefins such as cyclooctene.
    Type: Application
    Filed: April 1, 2002
    Publication date: December 26, 2002
    Inventors: John P. Morgan, Christie Morrill, Robert H. Grubbs, Tae-Lim Choi
  • Publication number: 20020137978
    Abstract: The invention is directed to the cross-metathesis and ring-closing metathesis reactions between geminal disubstituted olefins and terminal olefins, wherein the reaction employs a Ruthenium or Osmium metal carbene complex. Specifically, the invention relates to the synthesis of &agr;-functionalized or unfunctionalized olefins via intermolecular cross-metathesis and intramolecular ring-closing metathesis using a ruthenium alkylidene complex.
    Type: Application
    Filed: June 25, 2001
    Publication date: September 26, 2002
    Inventors: Robert H. Grubbs, Arnab K. Chatterjee, John P. Morgan, Matthias Scholl, Tae-Lim Choi