A light approach to installing heavy hydrogens

Photoredox catalysis shines in a reaction that swaps out hydrogen for deuterium or tritium

To follow the fate of a drug or a drug metabolite as it wends its way through the body, scientists will often label the compound by switching out a hydrogen atom for one of its heavier isotopes — deuterium or tritium. This molecular switcheroo sounds simple, but it can actually be a lot of work, requiring chemists to resynthesize a molecule so it has an atom, usually a halogen, or unsaturated bond where the heavy hydrogen can be swapped in or added. The process can take months.

Chemists at Princeton University and Merck & Co. have now come up with a way to switch hydrogen out for deuterium or tritium in a matter of moments. Read more.