Triflic Acid as an Efficient Brønsted Acid Promoter for the Umpolung of N-Ac Indoles in Hydroarylation Reactions
作者:Raj Kumar Nandi、Alejandro Perez-Luna、Didier Gori、Rodolphe Beaud、Régis Guillot、Cyrille Kouklovsky、Vincent Gandon、Guillaume Vincent
DOI:10.1002/adsc.201701074
日期:2018.1.4
We report that triflic acid, a strong Brønsted acid, is a very powerful alternative to FeCl3 to mediate the hydroarylation of N−Ac indoles, which delivers regioselectively 3‐arylindolines, 3,3‐spiroindolines or 2‐arylindolines. Mechanistic explorations point towards the existence of a highly electrophilic intermediate by simultaneous activation of the acetyl and of the C2=C3 bond by protons.
我们报告说,三氟甲磺酸,一种强的布朗斯台德酸,是FeCl 3的非常强大的替代品,可介导N-Ac吲哚的氢芳基化反应,该区域可选择性地提供3-芳基二氢吲哚,3,3-螺基二氢吲哚或2-芳基二氢吲哚。机理探索指出通过质子同时激活乙酰基和C2 = C3键,存在高度亲电的中间体。