Title:Vinyl Azides as Versatile Synthons for the Synthesis of Nitrogen-containing Heterocycles
Volume: 19
Issue: 9
Author(s): Hangcheng Ni, Guolin Zhang and Yongping Yu
Affiliation:
Keywords:
2H-azirine, nitrene, nitrogen heterocycles, synthon, vinyl azides, α-azidovinylketone.
Abstract: Vinyl azides have emerged as important synthons in recent years and a variety of
|useful synthetic methodologies have been achieved in the construction of the nitrogen heterocycles,
such as indoles, pyrroles, imidazoles, pyrazoles, pyridines and pyrimidines. The unstable
azide group and the presence of neighboring unsaturated double bond accentuate the high reactive
ity of vinyl azides with other electrophiles and nucleophiles in various manners. One of the important
features of vinyl azides is that they can decompose to vinyl nitrenes or highly strained
three-membered cyclic imines, 2H-azirines. These two three-atom intermediates can easily undergo
tandem reactions with 1,3-dipoles to generate the nitrogen-containing heterocycles. Vinyl azide can also act as a two-atom synthon
while azide group serves as a leaving group in the cycloaddition reactions. What’s more, when vinyl azide is connected with a carbonyl
group in the α-position of azide, the resulted α-azidovinylketone can react with the dinucleophiles, leading to the amino substituted ring.
The purpose of this review is to present the synthetic approaches achieved both in our group and other groups.
