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DOI: 10.1055/s-2008-1042681
TRISPHAT-N Anion Provides Bench-Stable Ruthenium Catalyst
Contributor(s):Hisashi Yamamoto, Joshua N. PayetteUniversity of Geneva, Switzerland
Air- and Microwave-Stable (C6H5)Ru Catalysts for Improved Regio- and Enantioselective Carroll Rearrangements
Angew. Chem. Int. Ed. 2007, 46: 8979-8982
Publication History
Publication Date:
21 February 2008 (online)
Key words
ruthenium - Carroll rearrangement - TRISPHAT-N
Significance
Asymmetric ruthenium catalysis is useful for the preparation of chiral allylic compounds through nucleophilic attack at the more substituted position of an allyl-ruthenium fragment. However, these reactions require large amounts (10 mol%) of Cp*Ru type catalysts which are difficult to recover owing to their sensitivity to oxygen and moisture. The present study reports that air- and moisture-stable Cp*Ru complexes are achievable through the use of the anionic monodentate ligand TRISPHAT-N.
Comment
The authors compared the catalytic activity of conventional air-/moisture-sensitive Ru catalyst 2 to that of chromatographically stable Ru catalyst 3 in the Carroll rearrangement. Gratifyingly, 3 outperformed 2 to give 6 in excellent yield and b/l ratio. Chiral dinuclear zwitterionic complex 4 was then synthesized and applied to the rearrangement of 5 to give 6 in high yield and ee. Investigations into the ability of TRISPHAT-N to stabilize metal complexes as well as future applications in synthesis are anticipated.