The importance of fluorine in the life science industry

Fluorine-containing compounds are at the leading edge of many new developments in the life science industry. In recent years a steady increase in the number of fluorinated organic molecules reaching commercial status as crop protection products and pharmaceutical drugs has been observed: in 1978, ca. 600 pesticides were known, but only approximately 25 (4%) contained fluorine. Today, fluorine-containing compounds account for more than 17% of all commercially available crop protection agents and many others are currently under development. The structures of the fluorine-containing development compounds proposed for ISO common names between 1997 and 2002 are highlighted in this paper. In the pharmaceutical area around 220 fluorinated drugs were on the market in 1990, representing ca. 8% of all synthetic drugs. Six years later already more than 1500 fluorine-containing drugs were under development. Fluorine-containing compounds have also been successful in the marketplace, such as the insecticides fipronil and lambda-cyhalothrin, the fungicides epoxiconazole and trifloxystrobin, the herbicides trifluralin and clodinafop, and the pharmaceutical blockbusters Fluoxetine (Prozac(R)), Paroxetine (Paxil(R)), Ciprofloxacin (Cipro(R)) and Cisaprid (Propulsid(R)). This success is mainly due to the fact that selectively fluorinated compounds can exhibit dramatically improved potency when compared to the non-fluorinated analogues. The incorporation of fluorine into a biologically active compound alters the electronic, lipophilic and steric parameters and can critically increase the intrinsic activity, the chemical and metabolic stability, and the bioavailability. The positive effects of fluorine on the biological efficiency is outlined by three examples: in the chemical class of herbicidal thiatriazines, the presence or the absence of fluorine leads to dramatic effects on the biological activity; the metabolic stability and the pharmacokinetics of aminopyrazinone acetamide thrombin inhibitors were improved by the introduction of fluorine, and in a novel class of insecticides/acaricides any modification of the gem-difluorovinyl group results in a strong decrease of biological activity.