DIFLUOROMETHYLATION REACTIONS OF ORGANIC COMPOUNDS

YERIEN, DAMIAN E.; BARATA-VALLEJO, SEBASTIAN; POSTIGO, AL

CHEMISTRY-A EUROPEAN JOURNAL

WILEY-V C H VERLAG GMBH

Año: 2017 vol. 23 p. 14676 - 14701

0947-6539

10.1002/chem.201702311The relevance of the -CF2H moiety has attracted considerable attention from organic synthetic and medicinal chemistry communities, because this group can act as a more lipophilic isostere of the carbinol, thiol, hydroxamic acid or amide groups. Being weakly acidic, the CF2H moiety can establish hydrogen bonding interactions to improve the binding selectivity of biologically active compounds. Therefore, the hydroxyl, amino, and thio substituents of lead structures are routinely replaced by a CF2H motif in drug discovery, with great benefits in the pharmacological activity of drugs and drug candidates and agrochemicals. Consequently, the late-stage introduction of CF2H is a sought-after strategy in designing bioactive compounds. Secondly, but nonetheless relevant and meaningful, is the study of synthetic pathways to introduce a CF2-Y moiety (Y  H, F) into organic substrates, since compounds that contain a CF2-Y functionality have also found vast applications in medicinal chemistry and in other areas, such as that of fungicides, insecticides, etc., which therefore deserves special attention. Although emphasis is made on difluoromethylation strategies to functionalize different families of organic compounds, three main methodological protocols will be presented in this review article for the late stage introduction of a CF2H or CF2Y moieties into organic substrates: i.-a metal-photoredox catalysis; ii.-through transition metal-catalyzed thermal protocols; and iii.-from transition metal-free strategies.