Hofmann elimination

What is Hofmann elimination?

Hofmann elimination, also known as exhaustive Hofmann methylation, is a chemical reaction used in organic synthesis to synthesize new organic compounds by removing a small molecule, such as water or ammonia, from a compound containing a carbon-carbon double bond (olefin). It was developed in the 19th century by German chemist August Wilhelm Hofmann and is used to synthesize a variety of olefinic compounds, including alkenes, alkyl amines, and amides..

Hofmann elimination - exhaustive methylation
Hofmann elimination

In the Hofmann elimination reaction, the starting material is typically a compound containing a quaternary carbon atom, such as a quaternary ammonium salt or a quaternary phosphonium salt. The reaction occurs through a process called “beta-elimination,” where the small molecule is removed from the compound, forming a new carbon-carbon double bond. The reaction can be catalyzed by a variety of different agents, such as acids, bases, or heat..

One of the key advantages of the Hofmann elimination is its high yield and good selectivity. It is also a relatively simple reaction that can be carried out under mild conditions. However, it is sensitive to the presence of other functional groups, which can interfere with the reaction and affect its outcome..

Hofmann elimination has a wide range of applications in the synthesis of a variety of olefinic compounds, including pharmaceuticals, fragrances, and flavorings. It has also been used in the synthesis of polymers and materials for electronic applications..


Hofmann elimination is a valuable tool for the synthesis of olefinic compounds and has had a significant impact on the field of organic synthesis. It continues to be widely used in the synthesis of a variety of organic compounds..


Hofmann, A.W. (1881), Einwirkung der Wärme auf die Ammoniumbasen. [Effect of heat on ammonium bases.] Ber. Dtsch. Chem. Ges., 14: 659-669. https://doi.org/10.1002/cber.188101401148