Recent Advances in Transition Metal-Catalyzed Selective C-H Difluoromethylation Reactions

Fluorine is well-known as a very special element. Approximately 30% of agrochemicals and 20% of all drugs contain fluorine; most of those compounds have unique functions in biochemistry, pharmacy, and bioscience and those containing difluoromethyl functional groups often have irreplaceable roles. Therefore, the selective introduction of difluoromethylated functional groups into various aromatic substrates has significant practical application. This review describes recent advances in selective difluoroalkylation of aromatic substrates by using different catalytic strategies (cyclometalated ruthenium complex, transient regulating and visible-light-induced strategies).