Fullerotetrahydroquinolines: TfOH/TsOH ⋅ H 2 O‐Mediated One‐Pot Two‐Step Synthesis and N ‐Alkylation/Acylation/Carboamidation Reaction

A series of N ‐unsubstituted/substituted fullerotetrahydroquinolines without a directly attached nitrogen atom were synthesized in moderate to good yields via a one‐pot two‐step reaction of [60]fullerene with arylamines and paraformaldehyde in the presence of trifluoromethanesulfonic acid and p ‐toluenesulfonic acid monohydrate. Aromatic primary amines produce N ‐unsubstituted fullereotetrahydroquinolines, while aromatic secondary amines give N ‐substituted fullereotetrahydroquinoline derivatives. As precursors, N ‐unsubstituted fullerotetrahydroquinolines could be further derivatized by the N ‐alkylation/acylation/carboamidation reactions to produce a large variety of N ‐substituted fullerotetrahydroquinolines containing Cl, NO 2 , C(O), and C(O)NH functional groups, which may have applications in the field of perovskite‐based solar cells. Plausible reaction pathways for the formation of N ‐unsubstituted/substituted fullerotetrahydroquinolines were suggested to elucidate the above‐mentioned reaction process.