Harnessing photocatalytic and electrochemical approaches for C–H bond trifluoromethylation and fluoroalkylation

Abstract

Owing to the importance of trifluoromethyl (CF₃) and related moieties in pharmaceuticals and agrochemicals, the photoinduced and electrochemically enabled redox functionalisation of C–H bonds has emerged as one of the most efficient, sustainable, and convenient tools to construct the C–R_f (CF₃ and fluoroalkyl) bond. Accordingly, several trifluoromethylating reagents such as CF₃I, triflyl chloride, Langlois, Umemoto, and Togni reagents serve as excellent trifluoromethyl radical sources under single-electron redox reaction conditions. The analogous fluoroalkylating reagents have also been developed to achieve C–H bond fluoroalkylation. The present article is mainly focused on recent developments in the “photocatalytic and/or electrochemical” redox approaches for direct trifluoromethylation and fluoroalkylation of diverse C–H bonds. The choice of the fluoroalkylating reagent in different photocatalytic and electrochemical systems and the mechanistic overview of such reactions are deliberated. Furthermore, the current limitations and the future prospects of such reactions are also highlighted.