We investigated the rebound mechanism starting from the [CuOH • R • ] + intermediate (7) (Fig. ). All energies can be found in Fig. and Tab. S14. In agreement with previous studies the formation of the product is significantly downhill with a reaction energy of tion). The energies are in line with the reaction energies found in previous studies ranging from -158 kJ/mol to -207 kJ/mol. to the rebound reaction. Here we note that an alternative pathway where the substrate dissociates after the HAA has been suggested recently by Brandner et al. based on enzyme essays. Thus, the cleavage of the glucosidic bonds and the saccharide oxidation would not be directly coupled. This would require the substrate dissociating from 7, i.e., it should have a lower barrier than the 66-56 kJ/mol seen for the rebound reaction. While this needs to be further verified, we speculate that such a scenario is likely.