One-step exchange-labelling of piperidines, piperazines and dialkylamines with deuterium oxide: catalysis by various ruthenium complexes

A range of variously substituted piperidines, piperazines and dialkylamines can be conveniently deuterated in a single step by isotopic exchange with deuterium oxide in the presence of an appropriate ruthenium complex catalyst. The isotopic exchange can be carried out efficiently in dimethylsulfoxide, hence it is directly applicable to the deuteration of polar compounds such as pharmaceuticals. Isotopic incorporations are high, whilst recoveries are variable and generally moderate. Deuteration takes place at positions both α and β to the NH group.