反应详情

Br2 (0.43 g, 2.68 mmol) was added to a solution of 2a (1.20 g, 2.23 mmol) in dry ether (10 mL) at 0° C. The brown reaction mixture was further stirred at room temperature for 1.5 h. After evaporation of solvent, the residue was partitioned between CH2Cl2 and FC-72. The CH2Cl2 phase was further washed with FC-72 for three times. The crude tin bromide 3a was dissolved in dry ether (10 mL) and cooled to −78° C., to which LAH (2.1 mL, 1.0 M in ether) was added. The reaction was quenched with water after stirring at −78° C. for three hours. The crude mixture was further purified by column chromatography with heptane to give 4a as a clear oil (0.72 g, 65% for two steps). 1H NMR (C6D6) δ 4.75 (s, 1H), 2.03-1.85 (m, 2H), 0.78-0.60 (m, 2H), −0.7 (s, JSn-H=17.2 Hz, 6H); 13C NMR (C6D6) δ 122.2-107.5 (m), 28.5 (t), −3.0, −13.4; 19F NMR (CDCl3) δ −81.2 (3F), −117.1 (2F), −122.4 (2F), −123.4 (2F), −123.9 (2F), −126.6 (2F); 119Sn NMR (C6D6) δ −86.8; HRMS: calcd. 496.9597, found: 496.9563. IR (thin film): 1839 cm−1.

1. customAfter evaporation of solvent
2. customthe residue was partitioned between CH2Cl2 and FC-72
3. washThe CH2Cl2 phase was further washed with FC-72 for three times
4. dissolutionThe crude tin bromide 3a was dissolved in dry ether (10 mL)
5. temperaturecooled to −78° C., to which LAH (2.1 mL, 1.0 M in ether)
6. additionwas added
7. customThe reaction was quenched with water
8. stirringafter stirring at −78° C. for three hours
9. customThe crude mixture was further purified by column chromatography with heptane