Impact of the Carbene Derivative Charge on the Decomposition Rates of Hoveyda-Grubbs-like Metathesis Catalysts.

Hoveyda-Grubbs metathesis catalysts undergo a relatively fast decomposition in the presence of olefins. Using a computational density functional theory approach, we show that positively charged derivatives of N-heterocyclic carbenes have little impact on the degradation/deactivation rates of such catalysts with respect to neutral carbenes. On the other hand, the hypothetical anionic Hoveyda-Grubbs-like catalysts are predicted to less likely undergo degradation in the presence of the olefin, while being as active as standard, neutral Hoveyda-Grubbs catalysts.