HFIP-Promoted Aromatic Electrophilic Amidation of Indoles and Pyrroles with Isocyanates

A mild and practical method for synthesizing amidoindoles and amidopyrroles was described via the direct amidation of indoles or pyrroles with isocyanates promoted by 1,1,1,3,3,3-hexafluoroisopropanol (HFIP). In this reaction, HFIP acted as a strong hydrogen bond-donating solvent to activate isocyanates, enabling the amidation of electron-rich nitrogen-containing heterocycles.