title: Brønsted acid-catalyzed, highly enantioselective addition of enamides to in situ-generated ortho-quinone methides: a domino approach to complex acetamidotetrahydroxanthenes.
abstract: The highly enantioselective conjugate addition of enamides and enecarbamates to in situ-generated ortho-quinone methides, upon subsequent N,O-acetalization, gives rise to acetamido-substituted tetrahydroxanthenes with generally excellent enantio- and diastereoselectivities. A chiral BINOL-based phosphoric acid catalyst controls the enantioselectivity of the carbon-carbon bond-forming event. The products are readily converted into other xanthene-based heterocycles.
authors.affiliation: Institut für Organische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig (Germany).
authors.forename: Satyajit
authors.initials: S
authors.lastname: Saha
authors.forename: Christoph
authors.initials: C
authors.lastname: Schneider
mesh_terms: D000577:Amides / Q000737:chemistry*; D002384:Catalysis; D018360:Crystallography, X-Ray; D006571:Heterocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D045563:Indolequinones / Q000737:chemistry*; D008968:Molecular Conformation; D009284:Naphthols / Q000737:chemistry; D010756:Phosphoric Acids / Q000737:chemistry*; D013237:Stereoisomerism; D014966:Xanthenes / Q000737:chemistry*
chemical_list: D000577:Amides; C406944:BINOL, naphthol; D006571:Heterocyclic Compounds; D045563:Indolequinones; D009284:Naphthols; D010756:Phosphoric Acids; D014966:Xanthenes; C068040:quinone methide; C030242:phosphoric acid
keywords: Brønsted acids; asymmetric catalysis; domino reactions; organocatalysis; xanthenes