the role of Isotope labeling in organic chemistry


Dorota Jakubczyk


Karlsruhe Institute of Technology (KIT), Kaiserstraße 12,

76131 Karlsruhe


The use of isotope labels in organic chemistry has a fundamentally important role in the determination of mechanisms of reactions. There are several ways to use isotopes in mechanistic investigations, e.g. introduction of isotopes can enable control the experiment and “follow” where they go or don’t go [1].


Another important application of isotopes is the study of kinetic isotope effects (KIEs) and equilibrium isotope effect (EIEs), so the study of how much slower (or faster) a labelled molecules reacts than unlabeled material. Thus kinetic isotope effects provide unique data unavailable from other methods, since information about the transition state of a reaction is obtained.  


One of the most convenient isotope used in mechanistic as well as in KIE studies is 2H (deuterium). Deuterium labeled reagents are cheap, save and commercially available. Deuterium-labeled compounds have several important applications in many branches of science [2] e.g. in the investigation of biological activity [3] or in the analysis of drug metabolism.





[1]        Bullock R. M., Bender B. R.: Encyclopedia of Catalysis, 2000, Brookhaven National Lab., Upton, NY (US), 1-62.

[2]        Sajiki H., Esaki H., Aoki F., Maegawa T., Hirota K.: Synlett  2005, 9, 1385-1388.

[3]        Kai K., Tani A., Hayashi H.: Bioorg. Med. Chem. 2010, 18, 3776.