The electrochemical synthesis of hetero [7]helicenes including pyrrole and furan rings has been established. A single electrochemical operation led to an oxidative heterocoupling and dehydrative cyclization sequence to afford oxaza [7]helicenes in 50-86% yields with 45-77% Faradic efficiencies. Their derivatization and chiroptical properties were also investigated.

Pure organic materials with the circularly polarized luminescence (CPL) property have attracted significant research interest over the past few decades. In this study, a series of axially chiral bibenzo­[b]­carbazole derivatives were synthesized by adopting palladium- and iridium-catalyzed direct C–H functionalization reactions as the key steps. These compounds exhibited CPL characteristics with considerably large dissymmetry factors up to 2.81 × 10–2 in the solid state, indicating the formation of well-ordered aggregates.

A series of optically active bisbenzofuro[2,3-b:3’,2’-e]pyridine (BBZFPy) derivatives was synthesized starting with the readily available (S)- and (R)-1,1’-bi-2-naphthols through a palladium-catalyzed multiple intramolecular C–H/C–H coupling as the key ring-closure step. The effect of terminal tert-butyl substituents on the BBZFPy skeleton was systematically investigated to uncover a unique aggregation-induced enhancement of CPL characteristics in the solid state. The crystal structures of the coupling products were also evaluated by single crystal X-ray analysis and the well-ordered intermolecular stacking arrangements appeared to be responsible for the enhanced CPL.