A suspension of EtOH-H2O (3 mL, v:v = 1:1) with 1,3,5-tribromobenzene (1.0 mmol), phenylboronic acid (1.2 mmol), potassium carbonate (276 mg, 2.0 mmol), and Pd/HCCP-DABP catalyst (20 mg, 0.3 mol%) was added to the Schlenk tube. The system was evacuated and backfilled three times with nitrogen. The reaction mixture was stirred at 50 °C for 2.5 hours. After completion of the reaction, it was cooled to room temperature and extracted with dichloromethane (CH2Cl2). The organic phases were combined, dried with anhydrous sodium sulfate, concentrated under reduced pressure and purified by silica gel column chromatography to give 1-phenyl-3,5-dibromobenzene. The aqueous phase was filtered through filter paper, the solid was washed with CH2Cl2, and the recovered catalyst could be used in subsequent reactions.
