For all hydrogenation experiments, a 2 mL aliquot of precursor sample was loaded into the reactor via syringe injection, and given ~10 s to reach 85°C. The reactor was sealed, and parahydrogen was bubbled into the reaction solution at approximately 6 L/min for a time (60 s unless otherwise specified) at a pressure of 8.5 bar. The flow rate was set by a needle valve at the outlet of the gas manifold. After bubbling, the sample was pneumatically ejected through a PTFE capillary into a 10 mm NMR tube in the magnetic shield underneath by manually opening a twoway microfluidic valve. In order to prevent the sample from passing through any fields that could lead to undesired state-mixing during sample transport in/out of the shield, a penetrating solenoid was used to provide a 10 µT guiding field. Upon landing in the 10 mm NMR tube, a 2 s magnetic field cycle from 50 nT to 1 µT was applied. 0.6 mL of the solution was extracted through a 1/16 inch PTFE capillary into a syringe, and this was the 'control' sample.