Decarboxylative bromination and chlorination of carboxylate salts: from discovery (Alexander Borodin, 1861) to development of a synthetic methodology (Cläre and Heinz Hunsdiecker, 1935–1942) and present perspectives of the reaction

The decarboxylation of carboxylic acid silver salts by bromine was discovered in 1861 by the Russian chemist and composer Alexander Porfiryevich Borodin. The discovery was neglected for nearly seventy years until Heinz and Cläre Hunsdiecker (1935–1942) reported many examples of application of the reaction, extending it to chlorine and other salts and giving a fundamental contribution to its development as a synthetic method for the preparation of alkyl bromides and chlorides. In addition to a historical introduction, in our review, we have discussed the many variations introduced over the years to the original chloro- and bromodecarboxylation procedure, with the aim to overcome the existing limitations of the method. New methodologies, developed up to the most recent years, have been reviewed; among these, a particular attention has been paid to attempts to introduce green procedures which could lead to a rebirth of this old, classical reaction.