硝基化合物的制备
旧文重发，温故知新
一、芳香族硝化反应
8、2,3,5,6-四溴-4-甲基-4-硝基-环己-2,5-二烯酮为硝化试剂的硝化反应
9、氧化氮类硝化反应
10、硼酸被硝基取代生成硝基化合物反应示例
芳基硼酸用 NH4NO3/(CF3CO)2O， NH4NO3/TMSCl 或 MNO3/TMSCl （M＝Ag，Na，K）处理，发生硼被硝基取代的反应，生成硝基化合物。前一个条件比较强，后两个条件相对温和，反应在室温下进行，收率高，这是最近报导的一种方法，应用面还不太广。
To the mixture of silver nitrate (374 mg, 2.2 mmol) in DCM (10 mL) was added TMSCl (238 mg, 2.2 mmol),the mixture was stirred for 15 min, followed by the addition of 3-chlorophenylboronicacid (156 mg, 1mmol). The resultingmixture was stirred at rt for 72 h, then filtered, the filtrate was washed withNaHCO3solution, extracted with DCM. The solvent was removed under reduced pressure, the residue was purifiedby column chromatography to give the desired compound (140 mg, 90%).
【Prakash, G. K. S;Panja, C; Mathew, T; Olah, G. A. Org. Lett, 2004, 2205】
11、苯胺氧化生成硝基化合物反应示例
将苯胺用如过酸、臭氧、Oxone，双氧水等氧化剂处理，则生成相应的硝基化合物，这也是合成芳香族硝基化合物的一种方法。
A 300-mL three-necked flask equipped with a Trubore stirrer, dropping funnel,and reflux condenser protected with a calcium chloride drying tube is charged with 100 mL of methylene chloride.To this solvent is added without stirring 90% hydrogen peroxide (5.4 mL, 0.20 mol)of. The hydrogen peroxide is not misciblewith the solvent and separates as the lower layer at the bottom of the flask.The flask is then cooled in an ice bath, and thestirrer is started. To this cold solution over a 20-minute period is added (34.0 mL0.24 mol) of trifluoroacetic anhydride. After addition is complete, the ice bath isremoved and the solution is stirred at room temperature for 30 minutes.
Asolution is then prepared from (8.1 g, 0.05 mole) of 2,6-dichloroanilineand 80 mL of methylenechloride. This solution is added dropwise over a 30-minute period to thepreviously prepared peroxytrifluoroacetic acidreagent. During this addition the exothermic reaction causes the mixture toreflux. After addition is complete, the mixture is heated under reflux for 1hour. It is then cooled and poured into cold water (150 mL). The organic layer is separated, washed with water(100 mL), with 10% sodiumcarbonate solution (2 x 100-mL), and finallywith water (50 mL). The organic extract is treated with activated charcoal andanhydrous magnesium sulfate. After standingovernight, the volatile solvent is removed at aspirator pressure with the aidof a warm water bath. There is obtained (8.6–8.8 g, 89–92%)of yellow 2,6-dichloronitrobenzene, mp 63–68°C.The product is recrystallized from a minimum volume (12–15mL) of ethanol and washed on the filter with10 mL of cold ethanolto give a slightly off-white product (5.7–7.0 g59–73%),mp 69–70°C
【Organic Syntheses, Coll. Vol. 5, p.367; Vol. 49, p.47.】
二、脂肪族硝化反应
硝基烷烃对α，β-不饱和羰基化合物进行Michael加成反应制备硝基化合物。
White催化剂催化烯丙位C-H活化和α硝基酯反应制备高烯丙位硝基化合物。
Tsuji-Trost反应也可以进行类似反应制备硝基化合物。
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