Fig. 1. Retrosynthesis step suggestion for 13-(1,10-phenanthrolin-2-yl)-10-(9-phenyl-9H-carbazol-3-yl)-10H-phenanthro[9,10-b]carbazole using a chloro-Suzuki coupling reaction. In (a) only the reactants are predicted. In (b) all the precursors are predicted, which increases the overall difficulty of the single-step prediction task. While for (a) two molecules consisting of a total of 68 atoms are predicted, the target of (b) are six molecules consisting of 157 atoms.
