title: Synthesis of Indolophanes by Photochemical Macrocyclization.
abstract: Herein, we report the synthetically practical, short, and general access to novel indolophane architectures by means of a photochemical C-H activation process-the Witkop cyclization. These highly strained scaffolds were obtained by photoinduced ring closure and feature atropisomerism as well as aromatic ring current effects, which both have been investigated. The prevailing regioselectivity of theWitkop cyclization reaction was completely reversed by the presence of a quaternary carbon center, exerting a strong Thorpe-Ingold effect on the system for which experimental-evidence is provided.
authors.affiliation: Faculty of Chemistry, University of Konstanz, Universitätsstr. 10, 78457, Konstanz, Germany.
authors.forename: Magnus
authors.initials: M
authors.lastname: Pfaffenbach
authors.affiliation: Center for X-ray Analysis, Faculty of Chemistry, University of Vienna, Währingerstrasse 42, 1090, Vienna, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Roller
authors.affiliation: Faculty of Chemistry, University of Konstanz, Universitätsstr. 10, 78457, Konstanz, Germany. tanja.gaich@uni-konstanz.de.
authors.forename: Tanja
authors.initials: T
authors.lastname: Gaich
keywords: C−H activation; Thorpe-Ingold effect; Witkop photocyclization; heterophanes; indolophanes