Prof. Simon Duttwyler, Zhejiang University, Canada

Functionalization and Applications of Icosahedral Boron Clusters

Boron cage compounds based on the monocarborane [CB₁₁H₁₂]^– and dodecaborane [B₁₂H₁₂]^2– are icosahedral cluster compounds which feature sphere-like delocalization of electron density, leading to remarkable chemical and thermal stability. The past decades have revealed their potential for applications in areas such as coordination, supramolecular and medicinal chemistry, as well as fluorescence/phosphorescence and materials science. Halogenated anionic boron cage compounds are among the most weakly coordinating anions and serve as counterions of choice for the stabilization of cationic reactive intermediates and catalysts. In order to take advantage of boron clusters as useful products or building blocks, new methodologies that allow for selective functionalization are highly desirable.

Transition metal-catalyzed functionalization of [CB₁₁H₁₂]^–- or [B₁₂H₁₂]^2–-based anions is a young field of research. Our group has demonstrated the feasibility of direct B–H activation of these clusters mediated by rhodium and iridium. The synthetic methodologies, X-ray crystal structures and applications will be discussed.