Fig. 2: Synthesis of π-extended helicenes.
a π-extended [7]helicene 233. b [9]helicene 1. c [5]helicene 3. The ORTEP drawings of 1 and 3 recorded at 143 and 100 K, respectively, showing 50% probability thermal ellipsoids. Hydrogen atoms are omitted for clarity in the ORTEP drawings.
