反应详情

A solution of iodine (2.89 g, 11.4 mmol) in anhydrous CH2Cl2 (6×10 mL, then 5mL+2 mL to rinse) was added dropwise (over 100 min) to a stirred mixture of alcohol 168 (3.28 g, 8.62 mmol), imidazole (1.50 g, 22.0 mmol) and triphenylphosphine (2.83 g, 10.8 mmol) in anhydrous CH2Cl2 (20 mL) under N2. After stirring at room temperature for 15 h, the resulting mixture was concentrated under reduced pressure, and the residue was chromatographed on silica gel. Elution with petroleum ether firstly gave foreruns, and then further elution with 5-20% CH2Cl2/petroleum ether gave tert-butyl(3-iodo-2-{[4-(trifluoromethoxy)phenoxy]methyl}propoxy)dimethylsilane (170) (3.90 g, 92%) as a pale brown oil; NMR (CDCl3) δ 7.13 (br dd, J=9.1, 0.7 Hz, 2H), 6.89 (dt, J=9.1, 3.0 Hz, 2H), 4.01 (dd, J=9.3, 5.7 Hz, 1H), 3.94 (dd, J=9.3, 6.2 Hz, 1H), 3.75 (dd, J=10.1, 5.6 Hz, 1H), 3.70 (dd, J=10.1, 5.6 Hz, 1H), 3.39 (dd, J=10.1, 5.9 Hz, 1H), 3.37 (dd, J=10.1, 6.0 Hz, 1H), 2.10 (sept, J=5.8 Hz, 1H), 0.89 (s, 9H), 0.07, 0.06 (2 s, 6H); HRCIMS calcd for C17H27F3IO3Si m/z [M+H]+ 491.0726. found 491.0721.

1. additionwas added dropwise (over 100 min)
2. concentrationthe resulting mixture was concentrated under reduced pressure
3. customthe residue was chromatographed on silica gel
4. washElution with petroleum ether firstly gave foreruns
5. washfurther elution with 5-20% CH2Cl2/petroleum ether