Direct and Regioselective Palladium(II)-Catalyzed B(4)–H Monoacyloxylation and B(4,5)–H Diacetoxylation of o-Carborane Acids with Phenyliodonium Dicarboxylates

A direct B(4)–H monoacyloxylation via a Pd-catalyzed regioselective B(4)–H activation of o-carborane acids with phenyliodonium dicarboxylates was developed, and a series of B(4)–H monoacyloxylated o-carboranes decorated with active groups were synthesized with moderate to good yields as well as excellent selectivity. In addition, a direct B(4,5)–H diacetoxylation from o-carborane acids with phenyliodonium diacetate was demonstrated.