Advances in Asymmetric Di-and Trifluoromethylthiolation, and Di- and Trifluoromethoxylation Reactions

Methods to introduce fluorine atoms or fluoroalkyl groups are highly valuable to the design and development of biologically active compounds. To date, majority of fluorinated pharmaceuticals and agrochemicals bear a fluorine atom or CF3 group at a non-stereogenic center. The development of methods for the construction of new, emerging fluorinated motifs, in particular those combining a heteroatom and a fluorocarbon moiety have witnessed tremendous advancement in recent years; however, a challenging problem is the stereocontrol of a carbon center featuring such fluorinated motifs. This review aims to summarize the advancement in the asymmetric construction of trifluorome-thylthio- and trifluoromethoxy compounds as well as their difluoromethyl analogues. Both the direct installation of the O-R-f and S-R-f groups (R-f - CF3, CF2H) and the exploitation of building blocks featuring these groups are detailed.