Synthesis of fused tetrazole- and imidazole derivatives via iodocyclization

详细信息    查看全文

• 作者：Ek ; Fredrik ; Wistrand ; Lars-Gö ; ran ; Frejd ; Torbjö ; rn
• 关键词：tetrazoles ; nucleophilic substitution ; halocyclization
• 刊名：Tetrahedron
• 出版年：2003
• 出版时间：August 25, 2003
• 年：2003
• 卷：59
• 期：35
• 页码：6759-6769
• 全文大小：265 K

文摘

The possibility to prepare fused tetrazole- and imidazole derivatives by iodocyclization in moderate to excellent yields is demonstrated. In some examples the cyclizations were not following Baldwin's rules entirely, i.e. exo-selectivity. Nucleophilic substitution of the formed iodides gave different results depending on the hardness of the nucleophile. Thus, elimination of the iodide could be a problem but a substitution reaction with ethyl potassium xanthate and a radical reaction using acrylonitrile were tolerated. In addition, we showed that it is possible to selectively use three iodo substituents individually in one of the fused imidazole derivatives.