Activation Of An Alkyl C-h Bond Geminal To An Agostic Interaction: An Unusual Mode Of Base-induced C-h Activation

摘要

Agostic complexes are widely recognized in transition metal chemistry and are often postulated as transient intermediates on the pathway to C-H activation. C-H bond cleavage may proceed via oxidative addition, σ-bond metathesis, or electrophilic activation. In the last case, interaction with an electron-deficient metal center is thought to confer enhanced acidity on the agostic C-H bond and heterolytic cleavage can occur, often facilitated by an external base. Herein, we report the base-induced C-H activation of an agostic Ru-N-heterocyclic carbene (NHC) complex which, contrary to expectation, proceeds not at the metal-bound C-H agostic but rather at a C-H bond geminal to the agostic interaction.