1: 4-(N,N-diphenylamino)-bromobenzene With magnesium in tetrahydrofuran 2: With boric acid trimethyl ester in tetrahydrofuran T=-78 - 20°C; 3: ethylene glycol in toluene Heating; Further stages.;

potassium phosphate; [RhCl(η2:η2-cycloocta-1,5-diene)]2; 1,1-dimethylpropan-1-ol; 1,4-di(diphenylphosphino)-butane in toluene T=100°C; 24 h; Inert atmosphere;