Transition Metal Catalyzed Direct Amination of the Cage B(4)–H Bond in o‑Carboranes: Synthesis of Tertiary, Secondary, and Primary o‑Carboranyl Amines

Transition metal catalyzed regioselective amination of the cage B(4)–H bond in o-carboranes has been achieved for the first time using O-benzoyl hydroxylamines or organic azides as the amination reagents, leading to the preparation of a series of tertiary and secondary carboranyl amines. Both amination reactions proceeded under mild conditions without the addition of any external oxidants. Hydrogenolysis of the resultant product 4-N­(CH2Ph)2-o-carborane afforded the primary carboranyl amine, 4-amino-o-carborane, in quantitative yield.