A solution of 3-triisopropylsilyoxy-1-bromonaphthalene (3.17 g, 8.4 mmol), 4-ethynyl-N,N-dibutylaniline (2.87 g, 12.5 mmol), Pd(PPh3)2Cl2 (176 mg, 3 mol %), PPh3 (329 mg, 15 mol %) and CuI (120 mg, 7.5 mol %) in Et3N (20 mL) under N2 was heated at reflux for 3 h. The resulting mixture was cooled, poured into water (200 mL), extracted with DCM (3×50 mL), dried (MgSO4) and the solvent removed under reduced pressure. The residue was chromatographed on silica using DCM (20% in hexanes) as eluent. The solvent was removed under reduced pressure and the residue dissolved in Et2O (30 mL). Tetrabutylammonium fluoride (3.8 mL, 1 M, 3.8 mmol) was added and stirring continued for 10 min. The solution was poured into water (100 mL), extracted with Et2O (3×40 mL), dried (MgSO4) and the solvent removed under reduced pressure. The residue was filtered through a short plug of silica using DCM (15% in hexanes to 0% in EtOAc gradient) as eluent. The solvent was removed under reduced pressure to give the title compound (1.40 g, 21%) as a brown oil.
