The copper-catalyzed H-F insertion into alpha-diazocarbonyl compounds is described using potassium fluoride (KF) and hexafluoroisopropanol. Access to complex alpha-fluorocarbonyl derivatives is achieved under mild conditions, and the method is readily adapted to radiofluorination with [F-18]KF. This late-stage strategy provides an attractive route to F-18-labeled biomolecules.