title: Asymmetric Michael addition/intramolecular cyclization catalyzed by bifunctional tertiary amine-squaramides: construction of chiral 2-amino-4H-chromene-3-carbonitrile derivatives.
abstract: The efficient asymmetric Michael addition/intramolecular cyclization of malononitrile with dienones catalyzed by a chiral bifunctional tertiary amine-squaramide catalyst for the synthesis of chiral 2-amino-4H-chromene-3-carbonitrile derivatives was developed. The corresponding products were obtained in good to excellent yields (up to 99%) with excellent enantioselectivities (up to 98% ee) for most of the bisarylidenecyclopentanones.
authors.affiliation: School of Chemical Engineering and Environment, Beijing Institution of Technology, 5 South Zhongguancun Street, Beijing 100081 (China), Fax: (+86) 010-6891-4985.
authors.forename: Yu
authors.initials: Y
authors.lastname: Gao
authors.forename: Da-Ming
authors.initials: DM
authors.lastname: Du
mesh_terms: D000577:Amides / Q000737:chemistry*; D001578:Benzopyrans / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D009570:Nitriles / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy; D013237:Stereoisomerism
chemical_list: C572731:2-amino-4H-chromene-3-carbonitrile; D000577:Amides; D001578:Benzopyrans; D009570:Nitriles
keywords: Michael addition; asymmetric catalysis; chromenes; cyclization; squaramides