Ligand exchange between boron and silicon centers offers a convinient way for the synthesis of organoboron compounds. While such method is well-established for the preparation of arylboranes, examples of alkyl exchange between boron and silicon centers are very rare. Here, it was demonstrated that an N-heterocyclic carbene stablized hydroborenium ion readily reacts with alkylsilanes at ambient conditions to afford the corresponding alkylborenium complexes. Theoretical calculations suggest that the activation of Si—C(alkyl) bonds involves a σ-bond metathesis pathway.

Key words: boron, silicon, Si—C bond, σ-bond metathesis