Aza-Wittig Reaction

• General Characteristics

Nucleophilic phosphorus reagents such as triphenylphosphine react with azides to generate, via the Staudinger reaction, N-P ylide (iminophosphorane) intermediates, which react with carbonyl compounds to produce imines. Therefore, this reaction is considered the nitrogen version of the Wittig reaction.

• General References

Shah, S.;Protasiewicz，J. D. Coord. Chem. Rev. 2000, 210, 181. doi:10.1016/S0010-8545(00)00311-8

• History

In 1919, Staudinger and Myers reported that azides and phosphines reacted to form N-P ylides, which could be converted to amines after hydrolysis (the Staudinger reaction). About 30 years later, it was demonstrated that the N-P ylides could react with carbonyl compounds to give imines. This and related reactions are called the aza-Wittig reaction.

• Reaction Mechanism

• Examples

Iminophosphoranes can react with a variety of electrophiles to give the corresponding products, as summarized below.

An application to the synthesis of a secondary amine.

• Experimental Procedure

• Experimental Tips

• References

• Related Reactions

Bode Peptide Synthesis

Staudinger Reaction

Horner-Wadsworth-Emmons (HWE) Reaction

Wittig Reaction

• Related Books

[amazonjs asin=”0470519983″ locale=”US” title=”Organic Azides: Syntheses and Applications”]

• External Links

Bertozzi ResearchGroup (UC Berkeley)

A New way to Engineer Cells: The Staudinger Ligation: Chemoselective, mild, and high-yielding chemical ligation based on the Staudinger reaction.

iminophosphorane, reduction of azides, synthesis of amines, synthesis of imines