KOtBu-Mediated Coupling of Indoles and [60]Fullerene: Transition-Metal-Free and General Synthesis of 1,2-(3-Indole)(hydro)[60]fullerenes

Direct coupling of indoles with C-60 has been achieved for the first time. Transition-metal-free (KOBu)-Bu-t-mediated reaction of indoles to [60]fullerene has been developed as a practical and efficient method for the synthesis of various 1,2-(3-indole)(hydro)[60]fullerenes that are otherwise difficult to direct synthesize in an efficient and selective manner. This methodology tolerates sensitive functionalities such as chloro, ester, and nitro on indole and builds molecular complexity rapidly, with most reactions reaching completion in <1 h. A plausible reaction mechanism is proposed to explain the high regioselectivity at the 3-position of the indoles and the formation of 1,2-(3-indole)(hydro)[60]fullerenes.