Staudinger reaction

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The Staudinger reaction (also Staudinger reduction ) is a name reaction from the field of organic chemistry. It is named after its developer Hermann Staudinger .

Overview of the Staudinger reaction

The Staudinger reaction is used to synthesize primary amines from azides . The Staudinger reaction is a mild alternative to other amine syntheses, e.g. B. to the Gabriel synthesis . The azides required are usually easily accessible by substitution from the corresponding haloalkanes .

It is not to be confused with the Staudinger ketene cycloaddition (sometimes referred to as the Staudinger reaction).

Reaction mechanism

The reaction mechanism of the Staudinger reaction is not fully understood. The Staudinger reaction begins with the nucleophilic attack of triphenylphosphine on the azide 1 used . The resulting phosphazide 2 then cyclizes to form a four-ring structure 3 , which reacts to form a phosphazene 4 by splitting off molecular nitrogen . The phosphazene is converted into an amine 5 by aqueous work-up and triphenylphosphine oxide is split off.

Reaction mechanism of the Staudinger reaction

The radical R of the azide is usually an alkyl or aryl radical . Almost any other organic phosphine can be used instead of triphenylphosphine .

Staudinger Ligation

A further development for peptide or protein ligation discovered in 2000 is known as the Staudinger ligation . A special form is the so-called traceless Staudinger ligation.

criticism

The atom economy of the Staudinger reaction is poor, since stoichiometric amounts of triphenylphosphine oxide are produced in the synthesis . The reaction is therefore of interest primarily as a laboratory process and less as a technical process.

Individual evidence

  1. ↑ H. Staudinger, J. Meyer: About new organic phosphorus compounds III. Phosphinomethylene derivatives and phosphinimines. In: Helv. Chim. Acta 1919 , 2 , 635; doi : 10.1002 / hlca.19190020164 .
  2. ^ Jie Jack Li, Name reactions , 4th edition, Springer, 2009, Staudinger ketene cycloaddition , p. 521
  3. ^ For example, Thomas T. Tidwell, The first century of Ketenes (1905-2005): the birth of a family of reactive intermediates, Angewandte Chemie, Int. Edition, Volume 44, 2005, p. 5779.
  4. ↑ Fiona L. Lin, Helen M. Hoyt, Herman van Halbeek, Robert G. Bergman, and Carolyn R. Bertozzi: Mechanistic Investigation of the Staudinger Ligation In: J. Am. Chem. Soc., 2005 , 127 (8), pp. 2686-2695 doi : 10.1021 / ja044461m .
  5. ↑ a b László Kürti , Barbara Czakó: Strategic Applications of Named Reactions in Organic Synthesis . Elsevier Academic Press, Burlington / San Diego / London 2005 , pp. 428-429, ISBN 0-12-369483-3 .
  6. ^ Eliana Saxon, Carolyn R. Bertozzi: Cell Surface Engineering by a Modified Staudinger Reaction In: Science 2000 , 287 , 2007-2010; doi : 10.1126 / science.287.5460.2007 .
  7. ↑ BL Nilsson, LL Kiessling, RT Raines: Staudinger Ligation: A Peptide from a Thioester and Azide , In: Org. Lett. 2000 , 2 , 1939-1941; doi : 10.1021 / ol0060174 .