title: Electrophilic Carbonyl Activation: Competing Condensative Cyclizations of Tryptamine Derivatives.
abstract: A series of tryptamine derived bisindole substrates were subject to electrophilic activation of the functional grouping at their alpha-nitrogen in the form of iminium ions to enable cyclization onto the sterically hindered indole substructure. Our observations regarding divergent cyclization outcomes using electronically distinct bisindole substrates are described. Surprising preference for Friedel-Crafts alkylation reaction and evidence for an intriguing reversible spirocyclization are discussed.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Fan
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Movassaghi
keywords: Friedel-Crafts; cyclization; iminium ion; indole; tryptamine