9H-carbazole (10 g, 59.8 mmol) and 3,3′-dibromo-1,1′-biphenyl (41.1 g, 132 mmol) were dissolved in xylene (100 ml). Sodium 2-methylpropan-2-olate (8.62 g, 90 mmol), Tris(dibenzylideneacetone)dipalladium(0) (Pd2dba3) (0.548 g, 0.598 mmol) and 1,1′-bis(diphenylphosphanyl) ferrocene (dppf) (0.663 g, 1.196 mmol) were then added into the mixture. The reaction mixture was degassed with nitrogen for 30 minutes, and heated to reflux for 48 h. The crude mixture was filtered through a pad of Celite® and washed with DCM. The solvents were evaporated under vacuum and the material was purified via column chromatography using hexane and DCM (95/5). After the excess of dibromobiphenyl came out, the polarity was increased gradually to 30% DCM in hexane. The compound 9-(3′-bromo-[1,1′-biphenyl]-3-yl)-9H-carbazole (13.02 g, 32.7 mmol, 54.7% yield) was afforded as white solids.
