Facile Two-Step Synthesis of 1,10-Phenanthroline-Derived Polyaza[7]helicenes with High Fluorescence and CPL Efficiency

Takashi Otani, Ami Tsuyuki, Taiki Iwachi, Satoshi Someya, Kotaro Tateno, Hidetoshi Kawai, Takao Saito, Stephen Kyalo Kanyiva, Takanori Shibata

Research output: Contribution to journalArticle

57 Citations (Scopus)


A facile two-step synthesis of aza[7]helicenes possessing a 6-5-6-6-6-5-6 skeleton from commercially available 2,9-dichloro-1,10-phenanthroline via double amination with aniline derivatives followed by hypervalent iodine reagent-mediated intramolecular double-NH/CH couplings was developed. Single-crystal X-ray analyses of the helicenes revealed unique structures, including both a significantly twisted center and planar terminals of the skeleton. The azahelicenes show high fluorescent quantum yields (Φs) under both neutral (Φ: 0.25–0.55) and acidic conditions (Φ: up to 0.80). An enantiomerically pure aza[7]helicene showed high circularly polarized luminescence (CPL) activity under both neutral and acidic conditions (glum: up to 0.009).

Original languageEnglish
Pages (from-to)3906-3910
Number of pages5
JournalAngewandte Chemie - International Edition
Issue number14
Publication statusPublished - 2017 Mar 27



  • azahelicene
  • circularly polarized luminescence
  • fluorescence
  • oxidative coupling
  • X-ray diffraction

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)

Cite this