We next sought to investigate iron, silane, and thiol as possible sources of the deactivation under conditions that contain a chiral thiol catalyst. We began by spiking the reaction with additional iron catalyst (Figure ) to test if the reaction would reinitiate after deactivation. We allowed the initial reaction to proceed for 7 days to ensure complete rate drop off, then added an extra 15 mol% of solid Fe(acac)3 (indicated by the light gray line on Figure ) and monitored the reaction further. The reaction rate increased after the iron spiking, giving increased overall yield. However, this rate increase is short lived and once again dwindles, further supporting iron deactivation as a main source of the decreasing rate.