title: Oxazaborolidinium ion-catalyzed cyclopropanation of α-substituted acroleins: enantioselective synthesis of cyclopropanes bearing two chiral quaternary centers.
abstract: A catalytic synthetic route to highly functionalized chiral cyclopropane derivatives was developed by Michael-initiated cyclopropanation of α-substituted acroleins with aryl- and alkyl diazoacetates. In the presence of chiral (S)-oxazaborolidinium cation 1b as a catalyst, the reaction proceeded in high yield (up to 93%) with high to excellent diastereoselectivity (up to 98% de) and enantioselectivity (up to 95% ee).
authors: Department of Chemistry, Sungkyunkwan University, Suwon 440-746, Korea.
authors: Lizhu
authors: L
authors: Gao
authors: Geum-Sook
authors: GS
authors: Hwang
authors: Do Hyun
authors: DH
authors: Ryu
mesh_terms: D000085:Acetates / Q000138:chemical synthesis / Q000737:chemistry; D000171:Acrolein / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D003521:Cyclopropanes / Q000138:chemical synthesis* / Q000737:chemistry; D003979:Diazonium Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000085:Acetates; D003521:Cyclopropanes; D003979:Diazonium Compounds; D000171:Acrolein