New catalytic method promises more efficient route to amine synthesis

Researchers at the University of Wisconsin–Madison have developed a method to simplify the formation of carbon–nitrogen (C–N) bonds, a fundamental step in producing amines widely used in pharmaceuticals, agrochemicals and advanced materials.

The study, published in Science, outlines a catalytic approach that enables chemists to introduce nitrogen directly into carbon–hydrogen (C–H) bonds — a longstanding challenge in synthetic chemistry. The technique offers a more streamlined alternative to conventional processes, which often rely on pre-functionalised and comparatively costly starting materials.

Amines are a cornerstone of modern drug design, influencing both the biological activity of compounds and how they are absorbed by the body. However, selectively modifying C–H bonds to incorporate nitrogen has proved difficult, as these bonds tend to exhibit similar reactivity within a molecule, complicating efforts to target a single site.

The Wisconsin team, led by Tuan Anh Trinh, addressed this by developing a catalytic system combining a bulky ligand with three pyridyl groups and a silver triflimide salt. The system facilitates the controlled delivery of a reactive nitrene species to a specific C–H bond, enabling more precise bond formation.

The approach is compatible with readily available nitrene precursors and a broad range of chemical substrates, suggesting potential for scalability. It also allows for so-called late-stage functionalisation — the modification of complex molecules at advanced points in their synthesis — a capability that is particularly valued in medicinal chemistry, where it can accelerate the refinement of drug candidates.

In an accompanying commentary, Radim Hrdina of Charles University in Prague noted that the method appears to operate across substrates irrespective of the electronic properties of their C–H bonds. He cautioned, however, that further work would be required to improve both efficiency and selectivity.

The findings point to a potentially more direct and flexible route for producing nitrogen-containing compounds, with implications for pharmaceutical research and chemical manufacturing as companies seek to reduce costs and accelerate development timelines.