Hofmann Elimination

R3N(CH3)+ + OH− → alkene + R3N + H2O

概要

The Hofmann elimination converts a quaternary ammonium salt to an alkene, amine, and water upon heating with base. Unlike E2 elimination, Hofmann elimination favors the less substituted alkene (anti-Zaitsev). This reaction was historically used to determine amine structures by exhaustive methylation and elimination.

参加者

役割 物質 係数 状態
生成物 Water H₂O 1 (l)

日常の例

Hofmann elimination was crucial in determining the structures of complex alkaloids like morphine and quinine before modern spectroscopy.

産業上の重要性

ホフマン脱離は構造決定への分光学的手法の普及により大きく代替されたが、アミンと特殊アルケンの合成および有機化学の反応機構研究において依然として有用な手法である。

特性

タイプ
Organic
可逆的
いいえ
エネルギー
発熱性
ΔH
-40.0 kJ/mol
触媒
Ag₂O (for quaternary salt formation)

関連する反応

Epoxidation of Alkenes (mCPBA) Swern Oxidation Oxidation of Secondary Alcohol to Ketone E2 Elimination (Dehydrohalogenation) Claisen Condensation (Ethyl Acetate) Aldol Condensation of Acetaldehyde Kolbe Electrolysis Baeyer-Villiger Oxidation Beckmann Rearrangement (Cyclohexanone Oxime) Dehydration of Ethanol

Frequently Asked Questions

What is the equation for Hofmann Elimination?
The balanced equation is: R₃N(CH₃)⁺ + OH⁻ → alkene + R₃N + H₂O.
What type of reaction is Hofmann Elimination?
Hofmann Elimination is a organic reaction.
Is Hofmann Elimination exothermic or endothermic?
Hofmann Elimination is exothermic (releases energy). The enthalpy change (ΔH) is -40.0 kJ/mol.
What conditions are needed for Hofmann Elimination?
This reaction requires a catalyst (Ag₂O (for quaternary salt formation)).