Organophotocatalytic\nSelective Deuteration of Metabolically\nLabile Heteroatom Adjacent C–H Bonds via H/D Exchange with\nD<sub>2</sub>O

We report a general approach for efficient deuteration\nof the\nmetabolically labile α-C–H bonds of widespread amides\nand amines. Temporarily masking the secondary amine group as a carbamate\nallows an unprecedented photoredox hydrogen atom transfer-promoted\nα-carbamyl radical formation for efficient H/D exchange with\nD<sub>2</sub>O. The mild protocol delivers structurally diverse α-deuterated\nsecondary amines including “privileged” piperidine and\npiperazine structures highly regioselectively with excellent levels\nof deuterium incorporation (≤100%). Furthermore, we successfully\nimplemented the strategy for α-deuteration of amides, lactams,\nand ureas with high regioselectivity and high levels of D incorporation.\nFinally, the observed efficient deuteration of secondary alcohol moieties\nin late-stage modification of complex amine-containing pharmaceuticals\nallows for the development of a viable method for efficient α-deuteration\nof the important functionality.