title: Remote substituent effects and regioselective enhancement of electrophilic substitutions in helical aromatic oligoamides.
abstract: The bromination of helically folded oligoamides of 8-amino-4-isobutoxy-2-quinolinecarboxylic acid by N-bromosuccinimide has been investigated. Bromination occurs preferentially if not exclusively at one position in the sequence despite the presence of multiple, up to seven, a priori comparable, reaction sites. Reactions are up to 2 orders of magnitude faster in a folded octamer than in a short nonhelical dimer, despite the steric hindrance that is expected in a compact folded conformation. The presence of substituents remote from the reaction site have considerable influence, resulting in the loss of regioselectivity, or in the slowing down of the reaction by several orders of magnitude.
authors.affiliation: Institut Européen de Chimie et Biologie, Université de Bordeaux-CNRS UMR 5248 and UMS3033, 2 rue Robert Escarpit, 33607 Pessac Cedex, France.
authors.forename: Kolupula
authors.initials: K
authors.lastname: Srinivas
authors.forename: Brice
authors.initials: B
authors.lastname: Kauffmann
authors.forename: Christel
authors.initials: C
authors.lastname: Dolain
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Léger
authors.forename: Léon
authors.initials: L
authors.lastname: Ghosez
authors.forename: Ivan
authors.initials: I
authors.lastname: Huc
mesh_terms: D000577:Amides / Q000737:chemistry*; D004583:Electrons; D008958:Models, Molecular; D008968:Molecular Conformation; D015363:Quinolones / Q000737:chemistry
chemical_list: D000577:Amides; D015363:Quinolones