As described for the first time in 1974 by Olah, diazo function can be directly converted to a combination of a fluorine atom with other substituents (such as hydrogen atom, another fluorine atom, other halogens, oxy or amino substituents or an aromatic ring). These reactions offer a direct entry into novel fluorinated scaffolds via metal-catalyzed or metal-free reactions. Some of these methods can be adopted to the stringent requirements of producing short-lived ¹⁸F tracers for positron emission tomography. The full range of literature (1974–2020) on the topic is reviewed in this digest.