反应 #89633

反应方程式

(3R,4S)-tert-butyl 3-acetamido-4-allyl-3-(tert-butylcarbamoyl)pyrrolidine-1-carboxylate

4,4,5,5-Tetramethyl-1,3,2-dioxaborolane

→

(3R,4S)-tert-butyl 3-acetamido-3-(tert-butylcarbamoyl)-4-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)propyl)pyrrolidine-1-carboxylate

收率 82.5%

溶剂

methylene chloride

反应条件

后处理

1. 1
   其他the solution was placed in an ice bath
2. 2
   workup.WAITto reach room temperature overnight
3. 3
   其他(18 h)
4. 4
   其他The mixture was quenched with water (75 mL)
5. 5
   workup.STIRRINGstirred 15 min
6. 6
   萃取extracted with ethyl acetate (400 mL
7. 7
   洗涤The combined organic solution was washed with saturated aqueous sodium chloride (150 mL)
8. 8
   干燥dried (MgSO4)
9. 9
   浓缩concentrated
10. 10
    其他The solid was recrystallized (2 crops) from acetonitrile

实验过程

A stirred solution of (3R,4S)-tert-butyl 3-acetamido-4-allyl-3-(tert-butylcarbamoyl)pyrrolidine-1-carboxylate (5.51 g, 15 mmol) in anhydrous methylene chloride (80 mL) under nitrogen was treated with chloro-1,5-cyclooctadiene iridium dimer (0.252 g, 0.375 mmol) and 1,2-bis(diphenylphosphino)ethane (0.299 g, 0.75 mmol), stirred for 30 min. and cooled (−20° C.). 4,4,5,5-Tetramethyl-1,3,2-dioxaborolane (3.30 mL, 22.5 mmol) was added dropwise, and the solution was placed in an ice bath and allowed to reach room temperature overnight (18 h). The mixture was quenched with water (75 mL), stirred 15 min, and extracted with ethyl acetate (400 mL, then 2×100 mL). The combined organic solution was washed with saturated aqueous sodium chloride (150 mL), dried (MgSO4), and concentrated. The solid was recrystallized (2 crops) from acetonitrile to afford (3R,4S)-tert-butyl 3-acetamido-3-(tert-butylcarbamoyl)-4-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)propyl)pyrrolidine-1-carboxylate (6.13 g, 82%) as a white solid. NMR (CDCl3) δ 6.40-6.60 (m, 1 H), 6.23 (s, 1 H), 3.95-4.05 (m, 1 H), 3.65-3.75 (m, 2 H), 2.90-3.20 (m, 2 H), 2.00 (s, 3 H), 1.45 (s, 9 H), 1.30-1.45 (m, 4 H), 1.33 (s, 9 H), 1.22 (s, 12 H), 0.70-0.80 (m, 2 H). MS (m+1): 496.4.

来源