Hofmann Elimination

R3N(CH3)+ + OH− → alkene + R3N + H2O

Visão geral

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.

Participantes

Papel Substância Coeficiente Estado
Produto Water H₂O 1 (l)

Exemplo do cotidiano

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

Importância industrial

A eliminação de Hofmann é utilizada em laboratório para identificar aminas e em síntese de alcenos terminais específicos que não são acessíveis pela regra de Zaitsev.

Propriedades

Tipo
Organic
Reversível
Não
Energia
Exotérmico
ΔH
-40,0 kJ/mol
Catalisador
Ag₂O (for quaternary salt formation)

Reações relacionadas

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)).