A new synthetic approach to the benzazole ring system. Synthesis and electrocyclic ring closure of dialkenyl and alkenyl-aryl substituted pyrroles, imidazoles and oxazoles
✍ Scribed by Janusz Moskal; Pens van Stralen; Djurre Postma; Albert M. van Leusen
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- French
- Weight
- 241 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0040-4039
No coin nor oath required. For personal study only.
✦ Synopsis
An efficient synthesis is described of the substituted azoles referred to in the title, which are precursors of an equally successful new synthetic approach to indoles, benzimidazoles and benzoxazoles.
Benzazoles are synthesized almost exclusively by formation of the azole ring on to a benzene nucleus, either from a monosubstituted or an ortho-disubstituted benzene precursor.
For example, the well-known Fischer, Madelung, Reissert (and other) indole syntiieses are based on such principles.
2,3 The same is true for benzimidazoles and benzoxazoles.
3 Benzazole ring systems, indoles in particular, often form the core of pharmaceutically, or otherwise, important natural products. 3