All QM/MM calculations were performed using the Amsterdam Modeling Suite (AMS Version 2020.203). The Amsterdam Density Functional (ADF) engine was used for the QM part applying density functional theory (DFT) with the PBE exchange-correlation functional employing a DZ and a TZP Slater-type orbital basis set 49 for all geometry optimizations and single point calculations, respectively. For the MM region the ForceField engine of AMS was used with the AMBER95 force field, which was extended by parameters for SAM and catecholate using Antechamber 51,52 and acpype. Electrostatic embedding as implemented in AMS was applied for the interaction be- All QM/MM geometry optimizations were performed using the FIRE minimization algorithm with all solvent molecules fixed to their initial coordinates. All charges evaluated for charge convergence tests are calculated from the Voronoi deformation density (VDD) of the reactant structure only.