pg. 12 of 19 no significant differences between Ru2 and Ru3 catalysts thermodynamics (Scheme 6B). Although the energy barriers for Ru3 appear to be slightly smaller, this reduction falls beyond the precision of DFT calculations. Scheme 6. A) Subsequent cross-metathesis cycles analysed. B) Reaction pathway with the corresponding relative Gibbs energies (in kcal/mol) for Ru2 (in black) and Ru3 (in green). The transition states correspond to TS1 for the metallacycle formation and TS2 for the cycloreversion steps. In the initial cycle during precatalyst activation, the corresponding cases are labelled with an "h-" prefix, such as hTS1 and hTS2, with the chelate aperture indicated by hTS0.