Isonitriles as Alkyl Radical Precursors in Visible Light Mediated Hydro‐ and Deuterodeamination Reactions**

Abstract Herein, we report the use of isonitriles as alkyl radical precursors in light‐mediated hydro‐ and deuterodeamination reactions. The reaction is scalable, shows broad functional group compatibility and potential to be used in late‐stage functionalization. Importantly, the method is general for C α ‐primary, C α ‐secondary and C α ‐tertiary alkyl isonitriles. For most examples, high yields were obtained through direct visible‐light irradiation of the isonitrile in the presence of a silyl radical precursor. Interestingly, in the presence of an organic photocatalyst (4CzIPN) a dramatic acceleration was observed. In‐depth mechanistic studies using UV/Vis absorption, steady‐state and time‐resolved photoluminescence, and transient absorption spectroscopy suggest that the excited state of 4CzIPN can engage in a single‐electron transfer with the isonitrile.