3 - Free-radical reactions in the synthesis of organofluorine compounds

Abstract

A variety of commercially available electrophilic trifluoromethylating reagents, such as Togni’s reagent and Umemoto’s reagent, can be used in the free-radical fluoroalkylation reactions under photoredox conditions or using transition metal catalysts. Free-radical reactions, mediated by organometallic catalysts are used, for example, in the decarboxylative trifluoromethylations and difluoromethylations, and are useful for the late-stage modification of pharmaceuticals. Langlois reagent can be used as a cost-effective trifluoromethylating reagent for aromatic trifluoromethylations, oxidative- and azido-trifluoromethylation of alkenes, and dehalogenative trifluoromethylation of aryl iodides, in the presence of organometallic or photoredox catalysts. Selective trifluoromethylation of proteins can also be achieved under free-radical conditions. This chapter outlines the synthesis of organofluorine compounds, under free-radical conditions, for example, using organometallic or photoredox catalysts.