title: Formation and Trapping of Azafulvene Intermediates Derived from Manganese-Mediated Oxidative Malonate Coupling.
abstract: The one-pot, three-component, coupling reaction of indoles/pyrroles, dimethyl malonate, and acetic acid was performed using Mn(III) acetate as an oxidant. In the presence of Mn(OAc)3, indole-2, and indole-3-carbonyl compounds were alkylated at the 3- and 2- positions, respectively, with subsequent oxidation and nucleophilic capture occurring at the newly formed benzylic carbon. In contrast, oxidation of 2- and 3-indole carboxylic acids afforded the corresponding 2-oxindol-3-ylidenes and 3-oxindol-2-ylidenes. The reaction conditions, scope, and mechanism are discussed herein.
authors.affiliation: Department of Chemistry, University of Michigan, 930 N. University Ave., Ann Arbor, MI 48109, USA.
authors.forename: Verner A
authors.initials: VA
authors.lastname: Lofstrand
authors.affiliation: Department of Chemistry, University of Michigan, 930 N. University Ave., Ann Arbor, MI 48109, USA.
authors.forename: Bryan S
authors.initials: BS
authors.lastname: Matsuura
authors.affiliation: Department of Chemistry, University of Michigan, 930 N. University Ave., Ann Arbor, MI 48109, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Furst
authors.affiliation: Department of Chemistry, University of Michigan, 930 N. University Ave., Ann Arbor, MI 48109, USA.
authors.forename: Jagan M R
authors.initials: JM
authors.lastname: Narayanam
authors.affiliation: Department of Chemistry, University of Michigan, 930 N. University Ave., Ann Arbor, MI 48109, USA.
authors.forename: Corey R J
authors.initials: CR
authors.lastname: Stephenson