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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
journal contribution
posted on 2023-05-17, 00:14 authored by Ghanem, A, Lacrampe, F, Aboul-Enein, HY, Schurig, VThe 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.
History
Publication title
Monatshefte für Chemie / Chemical MonthlyVolume
136Issue
7Pagination
1205-1219ISSN
0026-9247Department/School
School of Natural SciencesPublisher
Springer-Verlag WienPlace of publication
Sachsenplatz 4-6, Po Box 89, Vienna, Austria, A-12Rights statement
The original publication is available at www.springerlink.comRepository Status
- Restricted