Synthesis of functionalized thiazoles via attack of heterocyclic nucleophiles on allenyl isothiocyanates |
| |
Authors: | Baker Jawabrah Al-Hourani Klaus Banert Nermeen Gomaa Kai Vrobel |
| |
Affiliation: | aInstitute of Chemistry, Chemnitz University of Technology, Strasse der Nationen 62, 09111 Chemnitz, Germany |
| |
Abstract: | New examples of substituted thiazole derivatives carrying different heterocyclic ring systems at C-2 position were prepared via the reaction of several allenyl isothiocyanates with nucleophiles such as imidazoles, pyrazoles, benzimidazoles, indazole, 1,2,3-triazole, 1,2,4-triazole, and 1H-benzotriazole. Although these allenyl isothiocyanates are very reactive electrophiles and tend to polymerize, the yield of the thiazole products ranked between modest and very good. The regiochemistry of the reactions was proved by NMR and X-ray studies indicating that the attack of ambident nucleophiles proceeded very selectively. In some cases, however, the products were formed as mixtures of aromatic heterocycles and non-aromatic isomers. The latter could be rearranged to yield the uniform aromatic thiazoles. |
| |
Keywords: | Allenes Isothiocyanates Addition reactions Ring closure Thiazoles Heterocycles |
本文献已被 ScienceDirect 等数据库收录! |
|