Staudinger Reaction
Staudinger Reduction

Azides may be converted to amines by hydrogenation, but another possibility is the Staudinger Reaction, which is a very mild azide reduction. As there are a variety of methods for preparing azides readily, the Staudinger Reaction makes it possible to use ^-N₃ as an ^-NH₂ synthon.

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Mechanism of the Staudinger Reaction

Triphenylphosphine reacts with the azide to generate a phosphazide, which loses N₂ to form an iminophosphorane. Aqueous work up leads to the amine and the very stable phosphine oxide.

W. Q. Tian, Y. A. Wang, J. Org. Chem. 2004, 69, 4299. DOI
F. L. Lin, H. M. Hoyt, H. v. Halbeek, R. G. Bergman, C. R. Bertozzi, J. Am. Chem. Soc, 2005, 127, 2686. DOI

Recent Literature

A One-Pot, Solid-Phase Synthesis of Secondary Amines from Reactive Alkyl Halides and an Alkyl Azide
S. Ayesa, B. Samuelsson, B. Classon, Synlett, 2008, 89-93.

ROMPgel-Supported Triphenylphosphine with Potential Application in Parallel Synthesis
E. Arstad, A. G. M. Barrett, B. T. Hopkins, J. Koebberling, Org. Lett., 2002, 1975-1977.

2,2′-Dipyridyl diselenide catalyzes a direct reaction of carboxylic acids with azides and trimethylphosphine at room temperature. The mechanism of the process, which is not an aza-Wittig reaction, has been elucidated.
J. Burés, M. Martín, F. Urpí, J. Vilarrasa, J. Org. Chem., 2009, 74, 2203-2206.

A Tandem Approach to Isoquinolines from 2-Azido-3-arylacrylates and α-Diazocarbonyl Compounds
Y.-Y. Yang, W.-G. Shou, Z.-B. Chen, D. Hong, Y.-G. Wang, J. Org. Chem., 2008, 73, 3928-3930.

Three-Component, One-Pot Sequential Synthesis of 1,3-Disubstituted 5-Arylhydantoins
F. Olimpieri, A. Volonterio, M. Zanda, Synlett, 2008, 3016-3020.