title: Preparation of novel unsymmetrical bisindoles under solvent-free conditions: synthesis, crystal structures, and mechanistic aspects.
abstract: Indole aziridines and their hydroxyl derivatives have been used for the preparation of a small library of novel functionalized bisindoles. Diversification of these building blocks by solvent-free C-C-bond formation on solid support yielded annulated Hymenialdisine analogues under mild reaction conditions. Indoles as C-nucleophiles form potentially pharmacologically active bisindoles through an electrophilic aromatic substitution pathway in good to excellent yields. Further transformations of the indole aziridines with H-, N-, and O-nucleophiles demonstrate their versatility as key intermediates in diversity oriented synthesis. The hydroxyl precursor leads also to unsymmetrical bisindoles under similar reaction conditions. Important intermediates and final library compounds were confirmed by X-ray analysis. Theoretical studies on these systems show the possible cationic intermediate in the substitution pathway.
authors.affiliation: Leibniz-Institut für Katalyse e V an der Universität Rostock, Albert-Einstein-Strsse 29a, D-18059, Rostock, Germany.
authors.forename: Hanns Martin
authors.initials: HM
authors.lastname: Kaiser
authors.forename: Ivo
authors.initials: I
authors.lastname: Zenz
authors.forename: Wei Fun
authors.initials: WF
authors.lastname: Lo
authors.forename: Anke
authors.initials: A
authors.lastname: Spannenberg
authors.forename: Kristin
authors.initials: K
authors.lastname: Schröder
authors.forename: Haijun
authors.initials: H
authors.lastname: Jiao
authors.forename: Dirk
authors.initials: D
authors.lastname: Gördes
authors.forename: Matthias
authors.initials: M
authors.lastname: Beller
authors.forename: Man Kin
authors.initials: MK
authors.lastname: Tse
mesh_terms: D018360:Crystallography, X-Ray; D007211:Indoles / Q000138:chemical synthesis / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D015394:Molecular Structure; D054852:Small Molecule Libraries; D013237:Stereoisomerism
chemical_list: D007211:Indoles; D054852:Small Molecule Libraries