Staudinger Reaction

In 1919, Hermann Staudinger and Jules Meyer published the reaction between phenyl azide and triphenylphosphine to generate phosphinimine. It was also found that benzoyl azide reacted in a similar fashion to generate the corresponding benzoyl aza-ylide. Staudinger and Meyer also reacted carbon dioxide with phenyl-aza-ylide to afford phenyl isocyanate and triphenylphosphine oxide, which was the first example of an aza-Wittig reaction. Subsequently, the reaction of organic azides with trivalent phosphorus compounds, such as triphenylphosphine, to generate the corresponding aza-ylides has become known as the Staudinger reaction.

The reaction is extremely fast and high-yielding, and does not form side products. The iminophosphorane intermediates formed when alkyl or aryl azides are reacted with trialkyl- or triarylphosphines are stable and versatile and their subsequent hydrolysis with water gives primary amines.

The reaction has been used in the synthesis of several natural products, including the marine indole alkaloid (+)-hamacanthin B and the antiviral product (–)-hennooxazole A.