反应 #89628

反应方程式

(2R,3S)-3-acetamido-2-allyl-N-tert-butyltetrahydrofuran-3-carboxamide

4,4,5,5-tetramethyl-[1,3,2]dioxaborolane

water

→

(2R,3S)-3-acetamido-N-tert-butyl-2-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)propyl)tetrahydrofuran-3-carboxamide

收率 63.0%

溶剂

dichloromethane

反应条件

后处理

1. 1
   workup.STIRRINGthe reaction was stirred overnight at room temperature
2. 2
   萃取the aqueous solution was extracted
3. 3
   洗涤The combined organic layers were washed with saturated aqueous sodium chloride
4. 4
   干燥dried over anhydrous magnesium sulfate
5. 5
   过滤filtered
6. 6
   浓缩concentrated
7. 7
   其他Purification by flash column chromatography (silica gel, 50-80% ethyl acetate in dichloromethane)

实验过程

A solution of (2R,3S)-3-acetamido-2-allyl-N-tert-butyltetrahydrofuran-3-carboxamide (930 mg, 3.47 mmol) in dichloromethane (20 mL), was treated with chloro-1,5-cyclooctadiene iridium(I) dimer (70 mg, 3 mol %) and 1,2-bis(diphenylphosphino)-ethane (83 mg, 6 mol %). The solution was stirred at room temperature for 30 minutes and then 4,4,5,5-tetramethyl-[1,3,2]dioxaborolane (1.01 mL, 6.94 mmol) was added dropwise, and the reaction was stirred overnight at room temperature. The next day, the reaction mixture was poured into water and the aqueous solution was extracted using ethyl acetate (3×). The combined organic layers were washed with saturated aqueous sodium chloride, dried over anhydrous magnesium sulfate, filtered and concentrated. Purification by flash column chromatography (silica gel, 50-80% ethyl acetate in dichloromethane) gave (2R,3S)-3-acetamido-N-tert-butyl-2-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)propyl)tetrahydrofuran-3-carboxamide as a colorless oil (864 mg, 63%). 1H NMR (CDCl3, 300 MHz) δ 7.01 (s, NH, 1 H), 6.10 (s, NH, 1 H), 4.38 (m, 1 H), 4.12 (m, 1 H), 4.00 (m, 1 H), 2.96 (m, 1 H), 2.02-2.18 (m, 2 H), 1.99 (s, 3 H), 1.42-1.62 (m, 3 H), 1.36 (s, 9 H), 1.22 (s, 12 H), 0.76 (m, 2 H); MS (+CI): m/z for C20H37BN2O5: expected 396.3; found 397.4 (M+H)+.

来源