Carbazole-based azahelicenes and heterohelicenes were successfully obtained via the intramolecular Scholl reaction of 3,6-bis(biphenyl-2-yl)carbazole congeners, while the reaction of 3,6-bis(naphthylphenyl)-appended carbazole gave a triple helicene via an unexpected simultaneous double aryl rearrangement. DFT calculations suggested that the rearrangement proceeded via an arenium cation intermediate. In addition, the reaction of methoxy-appended substrate gave an azaheptacirculene via the concurrent C−C bond formation. These helical dyes showed circularly polarized luminescence. The azaheptacirculene was further transformed into deeply saddle-distorted dibenzodiazacirculenes as the first example of its solution-based synthesis and unambiguous structural determination.
- circularly polarized luminescence
ASJC Scopus subject areas
- Organic Chemistry