Answers are grounded in this paper and cite their sources.
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. magnified image
No takes yet. Share an insight, caveat, or question.
Nandi et al. (2017) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: