title: Post-Ugi gold-catalyzed diastereoselective domino cyclization for the synthesis of diversely substituted spiroindolines.
abstract: An Ugi four-component reaction of propargylamine with 3-formylindole and various acids and isonitriles produces adducts which are subjected to a cationic gold-catalyzed diastereoselective domino cyclization to furnish diversely substituted spiroindolines. All the reactions run via an exo-dig attack in the hydroarylation step followed by an intramolecular diastereoselective trapping of the imminium ion. The whole sequence is atom economic and the application of a multicomponent reaction assures diversity.
authors.affiliation: Laboratory for Organic & Microwave-Assisted Chemistry (LOMAC), Department of Chemistry, University of Leuven (KU Leuven), Celestijnenlaan 200F, 3001, Leuven, Belgium ; Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi-110 007, India.
authors.forename: Amit
authors.initials: A
authors.lastname: Kumar
authors.forename: Dipak D
authors.initials: DD
authors.lastname: Vachhani
authors.forename: Sachin G
authors.initials: SG
authors.lastname: Modha
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Sharma
authors.forename: Virinder S
authors.initials: VS
authors.lastname: Parmar
authors.forename: Erik V
authors.initials: EV
authors.lastname: Van der Eycken
keywords: Ugi; alkynes; gold; indoles; multicomponent; spiroindolines