Metal-Free Electrocyclization at Ambient Temperature: Synthesis of 1-Arylcarbazoles
摘要:
An efficient novel protocol for the construction of an hyellazole-inspired compound collection is described. Starting from 2,6-diarylacetanilides, the desired products were obtained using hypervalent iodine promoted electrocyclization. The mechanism of product formation was investigated through intramolecular competition experiments.
过渡金属催化的未活化芳基CH键与碘代芳烃的直接芳基化已成为构建联芳基的重要方法。通常,直接芳基化反应在化学计量的Ag添加剂的存在下进行;优选地,在室温下进行。此外,如果在底物中存在两个相同的芳族CH键,则通常不可避免地存在二芳基化产物。在这里,我们公开了一种有效的Pd(OAc)2 /三氟乙酸/ O 2催化体系,该体系在无银条件下促进各种芳族CH键与各种碘代芳烃的直接芳基化反应。偶联反应具有完全的单芳基化选择性。这种方法为联芳烃提供了一种简单,便捷且经济的途径。