Researchers at the University of Gothenburg have developed a new class of boron–fluorine compounds that could make late‑stage optimisation of drugs and imaging agents both simpler and more sustainable. The work, published in Angewandte Chemie, introduces stable “BF₂‑boracycles” that can be made metal‑free, at scale, and without time‑consuming purification – yet remain highly reactive in subsequent transformations.

The Gothenburg team shows that BF₂‑boracycles can be used to replace a single hydrogen atom in a finished drug or bioactive molecule, creating a handle that is later swapped for different functional groups. This enables medicinal chemists to attach scores of alternative substituents at a late stage to fine‑tune efficacy, pharmacokinetics or side‑effect profiles – without having to rebuild the molecule from scratch.

According to project lead Henrik Sundén, the new reagents cut process steps, reduce waste and improve resource efficiency compared with many existing routes, supporting greener process development. The study demonstrates that BF₂‑boracycles can stand in for a wide range of functional groups, including halogens, alcohols and azides, and participate in key coupling reactions used across drug discovery.

One particularly attractive application is radiolabelling. The method works for introducing radioactive iodine, a critical component in cancer diagnostics and therapy, including scintigraphy‑based imaging of metastases and organ function.

The research was carried out with partners at the Universities of Caen and Ljubljana and in collaboration with AstraZeneca, which sees potential to use the approach for late‑stage tuning of candidate drugs without restarting lengthy synthesis campaigns.