Reaction of 4‐Bpin‐o‐Carborane with Ketones: Sequential Carbon Vertex Alkylation and B−B Bond Activation.

Diboron compounds are important reagents in a series of transition metal catalyzed or metal‐free borylation reactions. We describe herein a unique reactivity of 4‐Bpin‐o‐carborane with ketones under basic conditions, leading to sequential cage carbon alkylation, B−B bond activation and unexpected O‐migration. The reaction was compatible with a good substrate scope including dialkyl or alkyl aryl ketones. The reaction mechanism is also proposed, involving cage CH deprotonation, nucleophilic attack of ketone, and O‐migration along with B−B bond cleavage. [ABSTRACT FROM AUTHOR]