Amide-Directed Palladium-Catalyzed Direct Cage C–H Sulfenylation of o -Carboranes

Abstract Transition-metal-catalyzed direct cage C–H functionalization of o-carboranes is challenging because of the low reactivity of inert cage C–H bonds and the chemoselectivity issues between cage B–H bonds and C–H bonds. Herein, palladium-catalyzed selective C(2)-sulfenylation of a wide range of C(1)-acylamino-o-carboranes with (hetero)aryl disulfides has been developed. A series of C(2)-sulfenylated o-carboranes were synthesized in moderate to high yields. This protocol provides a powerful synthetic method for direct cage C–H functionalization of o-carboranes through transition metal catalysis, which has important reference for the chalcogenation of boron clusters.