Hunsdiecker reaction

[1] The reaction was first demonstrated by Alexander Borodin in 1861 in his reports of the preparation of methyl bromide (CH3Br) from silver acetate (CH3CO2Ag).

[7][8] Three decades later, Angelo Simonini, working as a student of Adolf Lieben at the University of Vienna, investigated the reactions of silver carboxylates with iodine.

Using a carboxylate-to-iodine ratio of 1:1 leads to an alkyl iodide product, in line with Borodin's findings and the modern understanding of the Hunsdiecker reaction.

However, a 2:1 ratio favours the formation of an ester product that arises from decarboxylation of one carboxylate and coupling the resulting alkyl chain with the other.

[18] For unsaturated compounds, the radical conditions associated with the Hunsdiecker reaction can also induce polymerization instead of decarboxylation.

[11] Kuang et al have found that an alternate radical halogenating agent, N-halosuccinimide, combined with a lithium acetate catalyst, gives a higher yield of β-halostyrenes.