反应详情

To a solution of 3.2 g (8.2 mmol) of 4-(t-butyldiphenylsilyoxymethyl)phenylboronic acid (Step C) in 64 mL of benzene was added 2.2 mL of water, 6.4 mL of 5N aqueous sodium hydroxide, and 8.3 mL of isopropanol. To this mixture was added 180 mg (0.16 mmol) of tetrakis(triphenylphosphine) palladium and 2.20 g (7.81 mmol) of N-(t-butoxycarbonyl)-2-bromobenzylamine (Step D). The resulting mixture was heated under nitrogen at reflux for 2 hours then cooled to room temperature. The reaction mixture was diluted with 100 mL of water, transferred to a separators funnel and extracted with ether (3×150 mL). The combined ether extracts were washed with saturated aqueous sodium bicarbonate (100 mL) and saturated aqueous sodium chloride (100 mL), dried over magnesium sulfate and filtered. The solvent was removed under vacuum to give a crude product which was purified by column chromatography on silica gel eluting with hexaneslethyl acetate (9:1) to afford 4.31 g (100%) of the product as a clear oil. 1H NMR (200 MHz, CDCl3): d 1.11 (s, 9 H), 1.41 (s, 9 H), 4.27 (d, 6 Hz, 2 H), 4.45 (m, 1 H), 4.81 (s, 2 H), 7.20-7.49 (m, 14 H), 8.72 (m, 4 H). FAB-MS: calculated for C35H41NO3Si 551; found 552 (M+H).

1. temperatureThe resulting mixture was heated under nitrogen
2. temperatureat reflux for 2 hours
3. customtransferred to a separators funnel
4. extractionextracted with ether (3×150 mL)
5. washThe combined ether extracts were washed with saturated aqueous sodium bicarbonate (100 mL) and saturated aqueous sodium chloride (100 mL)
6. dry with materialdried over magnesium sulfate
7. filtrationfiltered
8. customThe solvent was removed under vacuum
9. customto give a crude product which
10. customwas purified by column chromatography on silica gel eluting with hexaneslethyl acetate (9:1)