反应详情

To a stirred solution of the phosphinate of Example 81 (144 mg, 0.50 mmol) in dry degassed acetonitrile (1.5 mL), was added bis-(trimethylsilyl)acetamide (73 μL, 0.30 mmol) followed immediately by the addition of a solution of H-Asp(OBn)-Trp(OBn), [Example 83 (322 mg, 0.60 mmol)] and Et3N (209 μL, 1.5 mmol) in CCl4/CH3CN (3:1, 2 mL). The reaction mixture was stirred at room temperature for 14 h and then concentrated in vacuum. Purification by flash chromatography using a gradient of EtOAc in hexane (50% to 100%) provided the title compound (0.175 g, 44%) as a white residue: Rf (100% EtOAc)=0.5; 1H NMR (CDCl3) δ 8.5 (d, 1H), 7.6 (d, 1H), 7.5–6.9 (m, 25), 5.2–4.9 (m, 6H), 4.83 (dd, 1H), 4.63 (dd, 1H), 4.22 (m, 1H), 3.91(d, 1H), 3.36 (dt, 1H), 3.28 (dt,1H), 3.01 (dd, 1H), 2.65 (dt, 1H), 2.50 (m, 2H), 1.71–1.25 (m, 6H); 31P NMR (CDCl3) δ 35.6.

1. customdegassed acetonitrile (1.5 mL)
2. concentrationconcentrated in vacuum
3. customPurification by flash chromatography