In a flow system, sulphuryl fluoride can be attached to drug precursors, peptides and proteins quickly, safely and efficiently, report researchers from Amsterdam in Nature Synthesis. They offer a convincing method for sulphur(VI) fluoride exchange click chemistry.

Click chemistry needs little introduction. The classic copper-catalysed coupling of an azide to an alkyn led to that year’s Nobel Prize. But this classic reaction was not the end of the story. Chemists have continued to develop the principle of click chemistry, and one of the successful reactions is the so-called sulphur(VI) fluoride exchange reaction (SuFEx), in which sulphuryl fluoride (SO₂F₂) is coupled to a molecule. However, sulphuryl fluoride itself is a toxic gas and is therefore avoided by many. Miguel Bernús, Daniella Mazzarella, Timothy Noël and colleagues at the University of Amsterdam have circumvented this problem and greatly increased the speed of the reaction by using flow chemistry.