title: An acid-promoted novel skeletal rearrangement initiated by intramolecular ipso-Friedel-Crafts-type addition to 3-alkylidene indolenium cations.
abstract: An acid-promoted novel skeletal rearrangement is described. Using trifluoroacetic acid as the acid promoter, an intramolecular ipso-Friedel-Crafts-type addition of phenols to 3-alkylidene indolenium cations, formation of iminium cations through rearomatization of the spirocyclohexadienone units, and intramolecular Pictet-Spengler reaction proceeded sequentially, producing tricyclic indole derivatives.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1, Inohana, Chiba 260-8675, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Yokosaka
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Nemoto
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Hamada
mesh_terms: D002384:Catalysis; D002412:Cations; D007211:Indoles / Q000138:chemical synthesis*; D015394:Molecular Structure; D010636:Phenols / Q000737:chemistry*; D013237:Stereoisomerism; D014269:Trifluoroacetic Acid / Q000737:chemistry*
chemical_list: D002412:Cations; D007211:Indoles; D010636:Phenols; D014269:Trifluoroacetic Acid