Ruthenium(II)biscarboxylate‐Catalyzed Hydrogen‐Isotope Exchange by Alkene C−H Activation

Ruthenium(II) biscarboxylate catalysis enabled efficient hydrogen isotope exchange of acrylic C−H bonds with user‐friendly D2O. The C−H labelling was characterized by excellent positional selectivity and a broad functional group tolerance. The deuteration was successfully conducted on 55 mmol scale with TONs of >1000, while mechanistic studies provided insights into ruthenium(II) oxidase catalysis. The obtained deuterated alkenes enabled the synthesis of labeled standards for mass spectrometry of irradiated foodstuffs.