Experimental procedure for kinetic profiles: Stock solutions of catalyst (0.012 M), (Z)-stilbene and diphenylacetylene (0.1 M) in deuterated toluene were prepared in the glovebox. In a vial, 0.25 mL of catalyst solution and 0.3 mL of each substrate solution as needed were added (semihydrogenation and isomerization profiles volume 0.55 mL; competition catalyst 0.85 mL). With a microsyringe, 4.2 µL of mesitylene were added to the solution and mixed. The reaction mixture was transferred to a J-Young NMR tube. The tube was connected to a gas setup and degassed by two freeze-pump-thaw cycles and with the solution inside of a Dewar with liquid nitrogen, hydrogen gas was introduced. The solution was warmed up to room temperature and introduced into the NMR spectrometer at either 25 or 70 ºC.