Reductive Deuteration of Nitriles Using D₂O as a Deuterium Source

The first single electron transfer reductive deuteration of nitriles using D₂O as a deuterium source has been developed for the synthesis of valuable α,α-dideuterio amines. A mild reductant (SmI₂) was employed as the electron donor with Et₃N as the additive. This reaction is amenable to both aromatic and aliphatic nitriles and features high deuterium incorporation, excellent regioselectivity, and good functional group tolerance. The synthetic utility of this protocol was demonstrated by the synthesis of a series of important deuterium-labeled building blocks for medicinal chemistry and agrochemistry applications.