Recent Progress in Metal-Mediated Trifluoroethylation

Because of the lack of naturally occurring pathways to form C-F bonds, and the high toxicity and/or explosive nature of the fluorination reagents (HF and F2), chemists have to seek alternative reagents and relevant fluorination and fluoroalkylation methods to construct oragnofluorides that we widely use today. The direct transition-metal mediated/catalyzed trifluoroethylation of organic scaffolds, such as arylboronic acids or esters, aryl iodides, arene, alkynes, and alkenes, has been encouragingly established. This review narrates the recent progress of the reactions with using CF3CH2X (X = I, OTs, NH2) as the trifluoroethyl reagents in the past few years. Given the high potential of trifluoroethyl-containing compounds as bioactive agents, these synthetic methodologies will find wide applications in the life-science-related fields. To overcome the negative intrinsic factors of the current trifluoroethylation reagents in these reactions, future research work will doubtlessly focus on the development of effective catalytic systems, the design of new reagents, and the investigation of the possible CF3CH2-metal intermediates.