title: Acid-promoted cascade cyclization to produce fused-polycyclic indole derivatives.
abstract: An acid-promoted novel cascade cyclization is described. Using 8 equiv of trifluoroacetic acid or a catalytic amount of Lewis acid as the promoter, structurally diverse polycyclic cyclopenta[b]indoles were obtained in moderate to excellent yield. This cascade process was extremely effective for the synthesis of 8-membered ring-fused cyclopenta[b]indole derivatives.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University , 1-8-1, Inohana, Chuo-ku, Chiba, 260-8675, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Yokosaka
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nakayama
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Nemoto
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Hamada
mesh_terms: D002384:Catalysis; D003500:Cyclization; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry*; D058116:Lewis Acids / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism; D014269:Trifluoroacetic Acid / Q000737:chemistry
chemical_list: D007211:Indoles; D058116:Lewis Acids; C030374:indole; D014269:Trifluoroacetic Acid