Density Functional Theory (DFT) Calculations. DFT calculations were performed using the Gaussian16 software package. The M06-2X hybrid meta-GGA functional in combination with a 6-311++G(d,p) basis set was used. A benchmark preliminary investigation is provided in the Supporting Information (Table ) to validate the choice of this level of theory. An implicit solvent polarizable continuum model (PCM) was used to model the aqueous phase. Vibrational frequencies were calculated to confirm the nature of all stationary points found and to ascertain that potential energy minima have no imaginary frequencies whilst transition states (TSs) exhibit only one imaginary frequency. Intrinsic reaction coordinate (IRC) calculations were performed on each TS to identify the minimum energy path in this kind of calculation.