Introducing CF3 group at alkenyl C=C bond. Recent developments

Recently, significant interest has been developed in pharmaceuticals containing fluorine The biological effects depend on the number and type of fluorine groups in the drug molecule. Much attention has been also paid to improve biological activity, in vivo stability, or bioavailability by studying the chemical modification of peptide structure. The most frequently studied fluorine-containing functional group is the trifluoromethyl group, which also occurs as a C(sp²)–CF₃ bond. The trifluoromethyl alkyl group structure helps the peptide maintain its original β-turn structure, effectively mimicking the natural peptide bond, which allows it to function as its isostere. Therefore, the development of methods for synthesizing the trifluoromethylalkene group is becoming increasingly popular due to the potential of the products as building blocks of bioactive molecules. This review describes various methods for the preparation of the compounds with a trifluoromethylalkene group using trifluorinating reagents via the transition metal-mediated and the transition metal-free trifluoromethylation reactions.