Palladium-Catalyzed Cross-Coupling Reaction

An oven-dried sealed tube containing a stirring bar was charged with Pd(OAc)₂ (5.6 mg, 0.025 mmol, 5 mol%) and XantPhos (14.5 mg, 0.025 mmol, 5 mol%). The sealed tube was then evacuated and backfilled with nitrogen gas three times. The anhydrous DMF (2 mL), aryl fluorosulfate 1 (0.5 mmol, 1 equiv.), aryl formate 2 (1.0 mmol, 2 equiv.), and Et₃N (101.2 mg, 1.0 mmol, 2 equiv.) were then added under nitrogen atmosphere. The reaction mixture was stirred at 80 °C (oil bath) for 12 h before quenching with saturated NH₄Cl solution (10 mL) and extracting with EtOAc (20 mL × 3). The organic layers were combined, washed with saturated brine, and dried over Na₂SO₄. The extracts were concentrated under reduced pressure to obtain the crude product, which was further purified through silica gel column chromatography (using EtOAc/petroleum ether as eluents) to yield the products 3-4.