title: Transition-metal-catalyzed ring expansion of diazocarbonylated cyclic N-hydroxylamines: a new approach to cyclic ketonitrones.
abstract: Novel C-ethoxycarbonyl cyclic ketonitrones are synthesized from the Ag- or Cu-catalyzed ring expansion of β-diazo cyclic hydroxylamines. The latter are themselves easily obtained by the addition of lithiated ethyl diazoacetate onto cyclic nitrones. The regioselective metal-catalyzed rearrangement of β-diazo cyclic hydroxylamines proved highly efficient and resulted in a synthetically useful ring expansion to produce 6- or 7-membered ring functionalized nitrones. The outcome of the two steps, i.e. nucleophilic addition of α-diazoesters to nitrones and ring expansion, is a formal nitrone homologation.
authors.affiliation: Univ. Grenoble Alpes , DCM, F-38000 Grenoble, France.
authors.forename: Evelyn
authors.initials: E
authors.lastname: Lieou Kui
authors.forename: Alice
authors.initials: A
authors.lastname: Kanazawa
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Poisson
authors.forename: Sandrine
authors.initials: S
authors.lastname: Py