Reaction type Substitution reaction | Organic Chemistry Portal hunsdiecker-reaction | |
Named after Heinz Hunsdiecker
Cläre Hunsdiecker | ||
The Hunsdiecker reaction (also called the Borodin reaction after Alexander Borodin) is the organic reaction of silver salts of carboxylic acids with halogens to give organic halides. It is an example of a halogenation reaction. The reaction is named after Heinz Hunsdiecker and Cläre Hunsdiecker, but was first noted by Borodin in 1861 when he prepared methyl bromide from silver acetate.
Contents
Several reviews have been published.
Mercuric oxide will also effect this transformation.
Reaction mechanism
The reaction mechanism of the Hunsdiecker reaction is believed to involve organic radical intermediates. The silver salt of the carboxylic acid 1 will quickly react with bromine to form the acyl hypohalite intermediate 2. Formation of the diradical pair 3 allows for radical decarboxylation to form the diradical pair 4, which will quickly recombine to form the desired organic halide 5. The yield of halide is primary>secondary>tertiary.
Simonini reaction
The reaction of silver salts of carboxylic acids with iodine is called the Simonini reaction, named after Angelo Simonini, a student of Adolf Lieben at the University of Vienna. The ratio of the reagents play an important role in the determination of products, namely, if 1:1 ratio of salt and iodine is used alkyl iodide is formed. On the other hand, a 2:1 ratio gives RCOOR. and 3:2 ratio gives both the products.