腈制备胺

产物官能团类型

1. LiAlH4 2. BH3-THF 3. BH3-Me2S 4. H2-雷尼镍 5. H2-钯碳

1. LiAlH4

锂铝氢化物 (LiAlH4) 是一种强效的氢化试剂,与腈迅速反应生成胺。


案例

To a solution of the SM (0.792 g, 2.88 mmol) in dry ether under argon at 0 C was added LiAlD4 (0.225 g, 5.35 mmol). The reaction was stirred for 1 h, after which time was slowly added sat aq Na2SO4. The mixture was stirred until a precipitate formed, then anhydrous MgSO4 was added. The mixture was filtered and purified by flash chromatography (10-50% EtOAc/hexane) to provide the product as a colorless oil. [0.226 g, 28%]

UK Pat App GB2463151A, page 153

2.BH3-THF

硼烷-四氢呋喃 (BH3-THF) 对腈的还原通常在 THF 中加热进行。BH3-THF 的分解可能会生成 H2 和三丁基硼酸酯。为安全起见,建议将 BH3-THF 的保存温度控制在 35°C 以下。硼烷-二甲基硫醚 (BH3-SMe2) 是一种更稳定的替代试剂。


案例

To a stirred solution of the SM (0.660 g, 2.40 mmol) in dry THF under argon was added BH3-THF (1M in THF, 5 mL, 5 mmol). The reaction was stirred at reflux for 2.5 h, after which time it was allowed to cool to RT. To the mixture was carefully added saturated NaHCO3 followed by brine. The mixture was vigorously stirred. The org layer was separated, concentrated, and purified by flash chromatography [4% (7N NH3 in MeOH)/(DCM)] to provide the product as a colorless oil. [0.480 g, 72%]

UK Pat App GB2463151A, page 123

3.BH3-Me2S

硼烷-二甲基硫醚 (BH3-SMe2) 对腈的还原通常在 THF 中加热进行。与硼烷-四氢呋喃 (BH3-THF) 相比,BH3-SMe2 更稳定,并且可以提供更高的浓度(10 M)。BH3-SMe2 的一个缺点是其气味令人不快。


案例

To a solution of the SM (117.5 g, 519.8 mmol) in dry THF under argon was slowly added BH3-SMe2 (68 mL, 675.7 mmol) over 30 min via dropping funnel. The reaction was stirred at reflux for 2.5 h, after which time it was allowed to cool to RT. A solution of HCl (1.25 M in EtOH) was slowly added for 30 min, then the mixture was concentrated in vacuo. H2O was added and the pH of the mixture was adjusted to 12 with aq NaOH (50% wt). The product was extracted with DCM, dried (Na2SO4), and concentrated in vacuo to provide the product as a colorless oil. [104 g, 87%]

UK Pat App GB 1463151A, page 132

4. H2-雷尼镍

腈的催化加氢可以生成二级和三级胺副产物。通常添加 NH3(或 NH4OH)以帮助最小化这些副产物的生成。


案例

To a solution of the SM (6.0 g, 22.0 mmol) in MeOH (60 mL) was added Raney Ni (6.0 g). The reaction was stirred under H2 at 70 psi for 16 h, after which time the mixture was filtered through celite. The filtrate was concentrated in vacuo and the resulting material was purified by a neutral alumina column to provide the product as a thick brown liquid. [4.2 g, 69%]

Patent Reference: WO2014149164, page 214

5.H2-钯碳

腈的催化加氢可以生成二级和三级胺副产物。通常添加 NH3(或 NH4OH)以帮助最小化这些副产物的生成。


案例

A mixture of the SM (45 mg, 0.12 mmol) and Pd/C (5 mg) in 4:1 THF/NH4OH (2.5 mL) was stirred under H2 at RT for 1 h. The reaction mixture was filtered, concentrated, and purified by Prep HPLC [5-95% (MeOH)/(H2O with 0.05% NH4OH)] to provide the product as a white solid. [10 mg, 22%]

Patent Reference: WO2016011390, page 152