Expanding the chemistry of the 1-carba-closo-dodecaborate (1-) ion and its cyanated derivatives

Derivatives of the 1-carba-closo-dodecaborate (1-) carborane anion (CB11) have potential uses that include pharmaceuticals, catalysts for chemical industry, and optical and electronic materials. However, the adoption of these molecules in practical applications has been hindered, in part, by the limited number of efficient synthetic techniques for preparing useful derivatives of the CB11 cluster. Previous research in carborane chemistry has developed reliable methods for halogenation. Recently, a novel metal-catalyzed coupling reaction was successfully used to cyanate the 12-iodosubstituted CB11 cluster to give 12-CN-CB₁₁H₁₁⁻. In this work, reaction conditions were explored for preparing the mono-, di-, hexa-, and undecacyanated derivatives of the CB11 cluster. The effects of microwave irradiation on these reactions was also explored. Further derivatization of the cyanated compounds pursued and the synthesis of several derivatives of the mono- and dicyanated clusters are described.