Iridium-Catalyzed Cage B(4)-Amidation Reaction of -Carboranes with Dioxazolones: Selective Synthesis of Amidated -Carboranes and Amidated and Methoxycarbonylated -Carboranes.

Described is the Ir-catalyzed cage B(4)-amidation of -carboranes with dioxazolones by carboxylic acid-assisted B(4)-H bond activation under extremely mild conditions, affording amidated -carboranes and amidated and methoxycarbonylated -carboranes through sequential B(4)-amidation, O-methylation, and B(3)-deboronation in one pot. Carboxylic acid used as a directing group after the cage B(4)-amidation is efficiently trapped by trimethylsilyldiazomethane instead of undergoing decarboxylation. Mechanism studies demonstrated that the O-methylation through trapping of acid occurred first, followed by the B(3)-deboronation.