Practical Synthesis of B(9)-Halogenated Carboranes with N -Haloamides in Hexafluoroisopropanol.

The B(9)-H halogenation of o -carborane and m -carborane was achieved with excellent selectivities in hexafluoroisopropanol (HFIP) under simple reaction conditions: single reagent [trichloroisocyanuric acid (TCCA), tribromoisocyanuric acid (TBCA) or N -iodosuccinimide (NIS)], catalyst-free, air-/moisture-tolerant, and convenient work-up. With this method, a variety of 9-halogenated o -carboranes and m -carboranes were obtained in good to excellent yields with broad tolerance of functional groups.