格氏试剂制备

概览

氯代烷可在无水乙醚中与镁反应，形成格氏试剂。

转化

氯代烷 → 格氏试剂

方程式

R-Cl + Mg -> R-MgCl

试剂

Mg

反应环境

无水乙醚

反应类别

有机金属化合物形成

机理

organomagnesium formation

Evidence level

教材核心内容

底物范围

适用范围

Chloroalkanes form Grignard reagents with magnesium under dry ether conditions.

来源说明

Strictly anhydrous ether is required because water destroys Grignard reagents; alkyl chlorides are less reactive than the corresponding bromo/iodoalkanes, so this is recorded as a scoped route rather than a general reactivity guarantee and is not a displayed electron-flow mechanism.

相关反应

• Chlorination: Alcohols → Chloroalkanes

  醇可转化为氯代烷，为后续取代反应引入更易离去的基团。

• Chlorination with thionyl chloride: Alcohols → Chloroalkanes

  氯化亚砜将醇转化为氯代烷，同时生成二氧化硫和氯化氢。

• Hydrochlorination: Alkenes → Chloroalkanes

  氯化氢在烯烃双键两端加成，可生成氯代烷。

• Hydrolysis: Chloroalkanes → Alcohols

  氢氧根可取代 C-Cl 中的氯，形成醇。

• Cyanation: Chloroalkanes → Nitriles

  氰根取代生成腈，使碳链增加一个碳原子。

• Amination: Chloroalkanes → Amines

  氨取代氯，形成伯胺；过量氨可限制进一步烷基化。

• Elimination: Chloroalkanes → Alkenes

  碱促进的消去反应脱去 HCl，生成烯烃。

• Free radical chlorination: Alkanes → Chloroalkanes

  光化学氯化可将烷烃转化为氯代烷。

• Grignard formation: Bromoalkanes → Grignard reagents

  溴代烷可在无水乙醚中与镁反应，形成格氏试剂。

• Grignard formation: Iodoalkanes → Grignard reagents

  碘代烷可在无水乙醚中与镁反应，形成格氏试剂。

• Carbonyl addition: Grignard reagents → Primary alcohols

  格氏试剂与甲醛加成，经后处理得到伯醇。

• Carbonyl addition: Grignard reagents → Secondary alcohols

  格氏试剂与醛加成，经后处理得到仲醇。

• Carbonyl addition: Grignard reagents → Tertiary alcohols

  格氏试剂与酮加成，经后处理得到叔醇。

• Carboxylation: Grignard reagents → Carboxylic acids

  格氏羧化经酸性后处理得到羧酸。

参考文献

1. Organic Chemistry: Reactions of Alkyl Halides: Grignard ReagentsJohn McMurry · OpenStax Organic Chemistry · 2023

   Supports alkyl chlorides, bromides, or iodides reacting with magnesium in ether or THF to form Grignard reagents; also notes chloroalkanes are less reactive than bromo/iodo analogues and that moisture destroys Grignard reagents.