Synthesis of o -Carborane Amides from o -Carborane Carboxylic Acids via Acyloxyphosphonium Ion

Herein, we have achieved the one-step synthesis of a series of o-carborane amide derivatives directly from o-carborane carboxylic acids using commercially available triphenylphosphine dibromide as the activating reagent. Mechanistic studies demonstrate that the strong bond-forming tendency and excellent leaving ability of the P-O bond effectively inhibit both the decarboxylation and the leaving tendency of the o-carborane unit.