Carbon Dioxide → Diisopropyl(4-methoxyphenyl)silane

HRID 1008248Notes

Reaction equation

HRID 1008248 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([O:8][CH3:9])=[CH:4][CH:3]=1.C(=O)=O.[Li]CCCC.Cl[SiH:19]([CH:23]([CH3:25])[CH3:24])[CH:20]([CH3:22])[CH3:21]>C1COCC1.CC(C)=O>[CH:20]([SiH:19]([CH:23]([CH3:25])[CH3:24])[C:2]1[CH:7]=[CH:6][C:5]([O:8][CH3:9])=[CH:4][CH:3]=1)([CH3:22])[CH3:21]

Participants

7

Reactant 4

HCID 280Carbon DioxideHCID 77304-BromoanisoleHCID 2758383Chlorodi(isopropyl)silaneHCID 178418339Butyllithium

Product 1

HCID 60065702Diisopropyl(4-methoxyphenyl)silaneYield 94.1%

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

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.

Workup

  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)

Sources & evidence

ORD record
ord-910dade58f7043a089340232b5eb3353
Source dataset
uspto-grants-2004_09
Patent number
US06797819B1

Reaction notes

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