title: Highly enantioselective synthesis of 1,2,3-substituted cyclopropanes by using α-Iodo- and α-chloromethylzinc carbenoids.
abstract: Herein, we report the enantio- and diastereoselective formation of trans-iodo- and trans-chlorocyclopropanes from α-iodo- and α-chlorozinc carbenoids by using a dioxaborolane-derived chiral ligand. The synthetically useful iodocyclopropane building blocks were derivatized by an electrophilic trapping of the corresponding cyclopropyl lithium species or a Negishi coupling to give access to a variety of enantioenriched 1,2,3-substituted cyclopropanes. The synthetic utility of this method was demonstrated by the formal synthesis of an HIV-1 protease inhibitor. In addition, the related stereoselective bromocyclopropanation was also investigated. New insights about the relative electrophilicity of haloiodomethylzinc carbenoids are also presented.
authors.affiliation: Centre in Green Chemistry and Catalysis, Department of Chemistry, Université de Montréal, Station Downtown, Canada.
authors.forename: Louis-Philippe B
authors.initials: LP
authors.lastname: Beaulieu
authors.forename: Lucie E
authors.initials: LE
authors.lastname: Zimmer
authors.forename: Alexandre
authors.initials: A
authors.lastname: Gagnon
authors.forename: André B
authors.initials: AB
authors.lastname: Charette
mesh_terms: D002384:Catalysis; D003521:Cyclopropanes / Q000138:chemical synthesis* / Q000737:chemistry; D006219:Halogens / Q000737:chemistry*; D008024:Ligands; D008094:Lithium / Q000737:chemistry*; D013237:Stereoisomerism; D015032:Zinc / Q000737:chemistry*
chemical_list: D003521:Cyclopropanes; D006219:Halogens; D008024:Ligands; D008094:Lithium; D015032:Zinc