Abstract
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 language | English |
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Pages (from-to) | 3906-3910 |
Number of pages | 5 |
Journal | Angewandte Chemie - International Edition |
Volume | 56 |
Issue number | 14 |
DOIs | |
Publication status | Published - 2017 Mar 27 |
Keywords
- X-ray diffraction
- azahelicene
- circularly polarized luminescence
- fluorescence
- oxidative coupling
ASJC Scopus subject areas
- Catalysis
- Chemistry(all)