title: Efficient cu-catalyzed asymmetric conjugate additions of alkylzincs to trisubstituted cyclic enones.
abstract: The first examples of efficient catalytic asymmetric conjugate addition (ACA) of alkylzincs to trisubstituted cyclic enones is disclosed. These Cu-catalyzed reactions proceed efficiently with five- and seven-membered ring substrates to afford the desired products in >/=95% ee. Intermediate enolates can be trapped with alkyl halides to generate a quaternary stereogenic center. The requisite chiral ligand is prepared from commercially available materials and can be used in situ without further purification in the presence of commercial grade (CuOTf)2.PhMe.
authors.affiliation: Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, USA.
authors.forename: Sylvia J
authors.initials: SJ
authors.lastname: Degrado
authors.forename: Hirotake
authors.initials: H
authors.lastname: Mizutani
authors.forename: Amir H
authors.initials: AH
authors.lastname: Hoveyda
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D004151:Dipeptides / Q000737:chemistry; D006844:Hydrocarbons, Cyclic / Q000138:chemical synthesis*; D007659:Ketones / Q000138:chemical synthesis*; D009942:Organometallic Compounds / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D004151:Dipeptides; D006844:Hydrocarbons, Cyclic; D007659:Ketones; D009942:Organometallic Compounds; D003300:Copper; C454811:diethylzinc