Ruthenium(II)‐Catalyzed Hydrogen Isotope Exchange of Pharmaceutical Drugs by C−H Deuteration and C−H Tritiation

Well‐defined ruthenium(II) biscarboxylate complexes enabled selective ortho ‐deuteration with weakly‐coordinating, synthetically useful carboxylic acid with outstanding levels of isotopic labeling. The robust nature of the catalytic system was reflected by a broad functional group tolerance in an operationally‐simple manner, allowing the isotope labeling of challenging pharmaceuticals and bioactive heterocyclic motifs. The synthetic power of our method was highlighted by the selective tritium‐labeling of repaglinide, an antidiabetic drug, providing access to defined tritium labeled therapeutics.