Borodin-Hunsdiecker reaction

Conversion of silver carboxylate to halide by treatment with halogen. 

Exanple 4, One-pot microwave-Hunsdiecker-Borodin followed by Suzuki  

Name Reactions A Collection of Detailed Mechanisms and Synthetic Applications, DOI 10.1007/978-3-319-03979-4 140, Springer International Publishing Switzerland 2014 

Hunsdiecker Reaction. In Name Reactions for Functional Group Transformations, Li, J. J., Corey, E. J., Eds., Wiley Hoboken, NJ, 2007, pp 623-629. (Review). 

Borodin, A. Justus Liebigs Ann. Chem. 1861, 119, 121. Aleksandr Porfirevic Borodin (1833-1887) was born in St Petersburg, the illegitimate son of a prince. He prepared methyl bromide from silver acetate in 1861, but another eighty years elapsed before 

Heinz and Clare Hunsdiecker converted Borodin s synthesis into a general method, the Hunsdiecker or Hunsdiecker-Borodin reaction. Borodin was also an accomplished composer and is now best known for his musical masterpiece, opera Prince Egor. He kept a piano outside his laboratory. 

Hunsdiecker, H. Hunsdiecker, C. Ber. Dtsch. Chem. Ges. 1942, 75, 291. Clare Hunsdiecker was the only woman to give a name reaction in this book. 1 hope there will be many more in future editions. Clare Hunsdiecker was born in 1903 and educated in Cologne. She developed the bromination of silver carboxylate alongside her husband, Heinz. 

Name Reactions, 4th ed., DOI 10.1007/978-3-642-01053-8 131, Springer-Verlag Berlin Heidelberg 2009 

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Naskar, D., Chowdhury, S., Roy, S. Is metal necessary in the Hunsdiecker-Borodin reaction Tetrahedron Lett. 1998, 39, 699-702. 

The Hunsdiecker reaction is the reaction of silver carboxylate 1 with bromine to give bromide 2 at elevated temperature.1The reaction also works for making chlorides and iodides. It is also known as the Hunsdiecker-Borodin reaction. 

In some cases we have combined similar reactions under one heading, for instance the Hunsdiecker-Borodin-Cristol-Firth decarboxy-iative bromination. It is not a simple task to decide whether credit is due to... 

Hunsdiecker Reaction (Borodine Reaction, Borodine-Hunsdiecker Reaction)... 

The disodium salt of l-hydroxybenzimidazole-2-carboxylic acid can be decarboxylated merely by heating in acid <88JCS(P1)681>. In a Borodin-Hunsdiecker-type reaction alkaline bromination of 4-... 

In some cases we have combined similar reactions under one heading, for instance, the Hunsdiecker-Borodin-Cristol-Firth decarboxylative bromination. It is not a simple task to decide whether credit is due to the first discoverer of a reaction or to is developer. Often an improvement on a method is more useful than the original discovery, and usually one reaction owes its inception to some previous discovery non nova sed nove. 

There are other functional group transformations that lead to alkyl halides. A classical transformation converts carboxylates to allyl bromides (C—CO2 C—Br). This transformation is called the Hunsdiecker reaction (jt jjag also been called the Borodin reaction) 3 and it is most useful for the preparation of econdary halides. The silver salt of a carboxylic acid is heated with bromine to give the bromide via decarboxylation. An example is conversion of the silver salt of cyclohexane carboxylic acid (163) to bromo-cyclohexane.1 4 Phosphorus and bromine also react with acids in the Hell-Volhard-Zelinsky reaction. 

The most useful reaction in the literature for this is the pyrolysis of a suitable per-ester in the presence of a hydrogen atom transfer reagent, but the yields are often unsatisfactory.2 8 Conversion of an acid to the corresponding aldehyde and subsequent rhodium-based decarbonylation involves two steps, but is more reliable.4 The Borodin-Hunsdiecker reaction converts the acid to a nor-halide, which can be reduced by radical methods. However, this works well only with primary acids, is incompatible with many sensitive functions,5 and is expensive since the Ag salt of the acid is usually used. 

Needless to say, this was readily proven to be the case and a variety of chlorides, bromides and iodides have been prepared from the corresponding acids in good to excellent yields, by this method.14,15,26 31 In terms of mildness of conditions, generality and yields, this method is far superior to the classical Borodin-Hunsdiecker reaction and its variants.1011,26"31 As a demonstration of the mildness of the conditions, decarboxyl-ative bromination of the heavily functionalized acid 19 was carried out by Professor Ikegami to afford 20 (75 % yield), and... 

The Borodin-Hunsdiecker reaction consists of the reaction of a silver salt of a carboxylic acid with a molecular halogen to give a chain-shortened alkyl halide. 

The phosphonate (327), a phosphorus analogue of desonoic acid, has been synthesized via application of the Borodin-Hunsdiecker reaction to 2-deoxy-o-arabino-hcxose (Scheme 75). ... 

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