Cleavage of 3-amino-o-carborane and its' N-derivatives by bases into the 3-amino-7,8-dicarbaundecaborate anion and its N-derivatives

Cleavage of 3-amino-o-carborane by alcoholic alkali results in preferential elimination of the boron atom from position six of the polyhedron with the formation of a salt of 3-amino-7,8-dicarbaundecaborate and, to a smaller degree, to elimination of the boron bonded to the NH2 group, which leads to formation of a salt of 7,8-dicarbaundecaborate. Cleavage of 3-amino-o-carborane by piperidine is even more regioselective. Cleavage of N-derivatives of 3-amino-9-carborane by alcoholic alkali or piperidine is regiospecific, leading to salts of N-substituted 7,8-dicarbaundecaborates. 3-Ammonium-7,8-dicarbaundecaborate and a number of its N-derivatives were isolated in zwitterion form for the first time.