Recent advances in enantioselective trifluoromethylation reactions

Fluorinated organic compounds have received considerable attention because they possess unique properties such as greater stability, higher lipophilicity, high electronegativity, and water and oil repellency, which are potentially beneficial in terms of development of novel pharmaceuticals and advanced materials. Such extreme and bizarre behaviors of the fluoro-organic compounds however, often make the synthesis of them all the more complicated, especially, when the synthesis of target compounds requires an enantio-controlled methodology. Many strategies can be employed for introduction of asymmetry into organic molecules, the enantio selective fluorination and fluoromethylation reactions are especially attractive because non-fluorinated prochiral substrates can be directly transformed to chiral fluoro-organic compounds with controlled absolute configuration. Significant progress has been made in the development of asymmetric fluorination reactions in recent years; however, the direct enantio selective trifluoromethylation remains a challenge. In this article, we review the recent developments in the enantioselective trifluoromethylation reactions including nucleophilic, electrophillic and radical approaches. Although the emphasis of this report will be on the enantio selective trifluoromethylation reaction, as well as the less studied enantioselective difluoromethylation and monofluoromethylation reactions will also be covered.