Fig. 4. Computed free energies (kcal mol–1) for C1-catalysed hydrogenation. The redox mechanism is shown for substrates terpinen-4-ol (R = OH, blue line) and its methoxy derivative (R = OMe, orange line). The metallacycle mechanism is shown for terpinen-4-ol (black line). All energies are referenced to the 1R state of each substrate.
