Regiocontrollable\nB(2/3)–H Alkenylation of <i>nido</i>-Carboranes

Anionic <i>nido</i>-carboranes, as open-cage\nanalogues\nof <i>closo</i>-carboranes with strong hydrophilicity and\nhigher potential in the development of biomedicines, have been notably\nmore challenging because of their strong interaction with transition\nmetals. While the <i>exo</i>-cage B–H activation\nreactions of <i>nido</i>-carboranes have been widely studied,\nthere are few reports on the direct functionalization of B–H\nbonds located on a closed polyhedral sphere. Here, we report an efficient\npalladium-catalyzed regioselective B(2/3)–H alkenylation of <i>nido</i>-carboranes with various alkenes and alkyne coupling\npartners, enabled by 3-methylpyridine directing groups, to achieve\na regiocontrollable functionalization of B(2/3)–H vertices\nover highly reactive <i>exo</i>-cage B11–H vertex\nin <i>nido</i>-carboranes.