We have discovered that a wide range of 3-alkynyl-hydroxyalkanamine derivatives undergo 5-endo-dig cyclisations when exposed to silver nitrate supported on silica gel. Subsequent in situ dehydration of the resulting and sometimes isolable hydroxy-dihydropyrroles leads to pyrroles in essentially quantitative yields using this recoverable and reusable heterogeneous catalyst.
我们已经发现,一个宽范围的3 -炔基hydroxyalkanamine衍
生物经历5-内切-Dig环化当暴露于载于
硅胶上的
硝酸银。随后,使用这种可回收和可重复使用的非均相催化剂,所得的,有时是可分离的羟基-二氢
吡咯的原位脱
水导致
吡咯以基本上定量的产率产生。