反应详情

温度

-78 °C

A solution of p-bromoanisole (28.6 mL, 228 mmol, 1 equiv.) in THF (550 mL) was chilled to −78° C. (CO2(s), acetone). n-BuLi (91.2 mL, 228 mmol, 2.5M in hexanes, 1 equiv.) was added via cannula over a 5 min period. After 5 min a white precipitate begins to form. The mixture was stirred for 30 min at −78° C., after which chlorodiisopropylsilane (34.6 g, 228 mmol, 1 equiv.) was slowly added via syringe. After 1 h the ice bath was removed and the solution was allowed to come to 23° C. with stirring overnight. The reaction was quenched with NH4Cl(sat'd) (50 mL) and extracted with ether (3×500 mL). The combined organic extracts were washed with brine, dried (MgSO4), filtered and concentrated in vacuo to yield a light yellow oil. Filtration through SiO2 (gradient: 3-5% EtOAc/hexanes) yielded 47.7 g (94%) of a colorless oil. This material could also be purified by distillation bp=76-85° C. @ 275 mTorr (40 g, 63%). TLC Rf=0.61 (9:1 Hexanes/EtOAc). IR (film) 2393, 1853, 1710, 1691, 1658, 1584, 1482, 1346 cm−1. 1H NMR (500 MHz, CDCl3) δ7.48 (d, 2H, J=8.10, C3-H, C7-H), 6.95 (d, 2H, J=8.10, C4-H, C6-H), 3.97 (s, 1H, Si—H), 3.85 (s, 3H, C1-H), 1.39 (q, 2H, J=3.0, C8-H, C11-H), 1.10 (d, 6H, J=6.5, C9-H, C10-H), 1.03 (d, 6H, J=7.5, C12-H, C13-H). 13C NMR (125 MHz, CDCl3) δ137.13, 113.73, 113.62, 55.18, 18.95, 18.72, 11.08. Anal. Calcd for C13H22OSi: C, 70.21; H, 9.97; Si, 12.63. Found: C, 70.43; H, 9.83; Si, 12.39.

1. customto form
2. customAfter 1 h the ice bath was removed
3. customto come to 23° C.
4. stirringwith stirring overnight
5. customThe reaction was quenched with NH4Cl(sat'd) (50 mL)
6. extractionextracted with ether (3×500 mL)
7. washThe combined organic extracts were washed with brine
8. dry with materialdried (MgSO4)
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. customto yield a light yellow oil
12. filtrationFiltration through SiO2 (gradient: 3-5% EtOAc/hexanes)