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Diazo Compounds and Phenyliodonium Ylides in Inter- and Intramolecular Cyclopropanations Catalyzed by Dirhodium(II). Synthesis and Chiral Resolution by GC versus HPLC

Ghanem, Ashraf ; Lacrampe, Fabienne ; Aboul-Enein, Hassan Y. ; Schurig, Volker

In: Monatshefte für Chemie / Chemical Monthly, 2005, vol. 136, no. 7, p. 1205-1219

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    Titel
    • Diazo Compounds and Phenyliodonium Ylides in Inter- and Intramolecular Cyclopropanations Catalyzed by Dirhodium(II). Synthesis and Chiral Resolution by GC versus HPLC
    Autor
    • Ghanem, Ashraf. Department of Organic Chemistry, University of Geneva, 1211, Geneva 4, Switzerland
    • Lacrampe, Fabienne. Natural Product Discovery, MtGravatt Research Park, 4111, Brisbane, Queensland, Australia
    • Aboul-Enein, Hassan Y.. Pharmaceutical Analysis Laboratory, Biological and Medical Research Department (MBC-03-65), King Faisal Specialist Hospital and Research Center, 11211, Riyadh, Saudi Arabia
    • Schurig, Volker. Institute of Organic Chemistry, University of Tübingen, 72076, Tübingen, Germany
    Dokumententyp
    • Postprint
    Sprache
    • Englisch
    Veröffentlicht in
    • Monatshefte für Chemie / Chemical Monthly, 2005, vol. 136, no. 7, p. 1205-1219. Springer-Verlag
    Andere elektronische Ausgabe
    OAI-PMH-ID
    • oai:doc.rero.ch:320680
    Summary
    Summary.: The dirhodium(II)-catalyzed intermolecular cyclopropanation of a set of olefins with either diazo free phenyliodonium ylides or diazo compounds afforded cyclopropanes derived from Meldrum's acid, dimethyl malonate, (silanoxyvinyl)diazoacetates, 3,3,3-trifluoro-2-diazopropionate, ethyl diazo(triethyl)- and (dimethylphenyl)silylacetate with moderate to high yield in either racemic or enantio-enriched forms. The intramolecular cyclopropanation of triethylsilyl-substituted allyl diazoacetates in the presence of the chiral rhodium(II) catalyst [Rh2(s-nttl)4] in toluene afforded the corresponding cyclopropanes with up to 37% ee. An efficient chiral separation method based on enantioselective GC and HPLC was developed. The method provides information about the chemical yields of the cyclopropane products, enantioselectivity, substrate specifity, and catalytic activity of the chiral catalysts used in the inter- and intramolecular cyclopropanation reactions and avoids time-consuming work-up procedures