Access to Fluorazones by Intramolecular Dehydrative Cyclization of Aromatic Tertiary Amides: A Synthetic and Mechanistic Study
作者:Béla Mátravölgyi、Tamás Hergert、Erika Bálint、Péter Bagi、Ferenc Faigl
DOI:10.1021/acs.joc.7b03176
日期:2018.2.16
the high functional group tolerance of this transformation. In addition, study of the reaction mechanism is also presented to unfold the exact role of the applied base additive. Herein, as a first example, we report our findings that Tf2O-mediated amide activation is obstructed by the easy protonation of amides by the formed triflic acid during the activation step. Additionally, it has been also proven
已开发出一种有效的合成方法,可通过一锅酰胺和吡咯形成步骤,从容易获得的邻氨基苯甲酸衍生物制备9 H-吡咯并[1,2 - a ]吲哚-9-酮(氟唑酮)分子内环脱水 环脱水过程是由三氟甲磺酸酐(Tf 2 O)活化芳族叔酰胺介导的。各种苯并取代基的比较显示出证明了这种转化的高官能团耐受性。此外,还对反应机理进行了研究,以揭示所用基础添加剂的确切作用。在此,作为第一个示例,我们报告我们的发现,即Tf 2在活化步骤中,形成的三氟甲磺酸使酰胺易于质子化,从而阻碍了O介导的酰胺活化。另外,还已经证明,该碱添加剂不参与将O-三氟甲磺酸三氟甲磺酸盐转化成反应性物种(例如,三氟甲磺酸腈),并且仅负责中和超酸以避免仲酰胺或叔酰胺的质子化。 。