Cesium carbonate → Biphenyl

Participants

Reaction Conditions

Reaction Steps

Isoxazolidine 56 (300 mg, 0.50 mmol, 1 eq), pinacol boronate 49 (368 mg, 1.26 mmol, 2.5 eq), Pd(dppf)Cl2 (82 mg, 0.10 mmol, 0.2 eq), potassium acetate (65 mg, 0.657 mmol, 1.3 eq), and cesium carbonate (494 mg, 1.52 mmol, 3 eq) were dissolved in anhydrous DMSO (5 mL) and the reaction vessel was flushed under positive argon pressure for 15 min. The reaction mixture was stirred at 60° C. for 2 h, then allowed to cool to rt. The reaction mixture was diluted with EtOAc (20 mL) and water (10 mL) and the aqueous phase was adjusted to pH 4 with 6 N HCl. The reaction mixture was extracted with EtOAc (3×100 mL) and the combined organics were dried over MgSO4, filtered and concentrated in vacuo to afford an oil. The crude oil was purified by gradient silica gel chromatography (10-35% acetone/hexanes) to afford 170 mg of biphenyl acid 57. Yield 53%.

Provenance & Evidence