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Reaction of 13-Vertex Carboranes with Nucleophiles: Unprecedented Cage-Carbon Extrusion and Formation of Monocarba-closo-dodecaborate Anions


  • This work was supported by grants from the Research Grants Council of the Hong Kong Special Administration Region (Project No. 403906) and The Chinese University of Hong Kong.


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In contrast to icosahedral carboranes, instead of deboration, 13-vertex carboranes undergo cage-carbon extrusion and cluster contraction to give icosahedral monocarborane anions on reaction with nucleophiles. In the proposed mechanism, nucleophilic attack on a cage carbon atom cleaves the Ccage[BOND]Ccage bond, new Ccage[BOND]B bonds form to preserve cluster integrity, and hydrogen migration generates the final icosahedral product (see scheme).