ORGN 784 |
| Chromium (II) mediated formation of a carbon-carbon bond is a reaction that holds significant potential if thoroughly explored. However, a major problem of the Nozaki-Hiyama-Kishi reactions is the lack of an efficient and general enantioselective version. The relatively weak chromium-oxygen and chromium-nitrogen bonds, found in traditional ligands, diminish the stereocontrol. We are currently investigating new multidentate ligands that would form strong bonds to chromium. The proline derived amino alcohol 1 showed good enantioselectivity (er= 90:10) in asymmetric Nozaki-Hiyama allylayions. The results suggest that efficient catalysts for chromium (II) mediated reactions may be designed using ligands including, sp3 hybridized arrays of heteroatoms. Our current efforts are focused on novel carbene derived ligands as exemplified by 2.
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Asymmetric Reactions, Molecular Recognition, Self Assembly, Bioorganic Chemistry, Process R&D
8:00 PM-10:00 PM, Wednesday, 16 March 2005 Convention Center -- Hall D, Poster
Division of Organic Chemistry |
