Reaction conditions: photoredox catalyst 1 or 12 (2 mol %), triisopropylsilanethiol 13 (30 mol %), D2O (50 equivalents), Li2CO3 (1.2 equivalents, added when substrate is used as its acid salt), NMP, rt, 34-W blue LED or integrated photoreactor. The products were isolated as the appropriate acid salts shown in parentheses. Ac, acetyl group. *The two protons at the α-amino methylene position are diastereotopic and are labeled to different extents.