A suspension of aryl boronic acid 120 (2.50 g, 8.03 mmol) in a mixture of toluene (24 mL), EtOH (8 mL), and water (8 mL) was treated with aryl iodide 108 (2.53 g, 6.7 mmol, 0.83 equiv) and solid K2CO3 (2.80 g, 20.1 mmol, 3.0 equiv) at room temperature. The resulting reaction mixture was degassed three times under a steady stream of argon before tetrakis(triphenylphosphine)palladium (0) (Pd(PPh3)4, 387 mg, 0.335 mmol, 0.05 equiv) was added. The resulting reaction mixture was degassed three times under a steady stream of argon before being warmed to reflux for 8 h. When TLC and HPLC/MS showed the reaction was complete, the reaction mixture was cooled to room temperature before being poured into water (60 mL) and EtOAc (60 mL). The two layers were separated, and the organic phase was washed with water (30 mL) and saturated aqueous NaCl (2×30 mL), dried over anhydrous Na2SO4, and concentrated in vacuo. The product was then recrystallized from EtOAc/hexanes and dried in vacuo to afford the desired (5S)-{4′-[5-(acetylamino-methyl)-2-oxo-oxazolidin-3-yl]-2′-fluoro-biphenyl-4-ylmethyl}-(3-fluoro-propyl)-carbamic acid tert-butyl ester 121 (1.3 g, 30%) as an off-white powder.
