关键词: 三氟甲硫基化, 不对称催化, 有机氟化合物, 立体选择性, 有机合成

Fluorine-containing groups can modulate the physicochemical and biological properties of organic molecules. Consequently, the synthesis of fluorinated organic molecules has attracted considerable attention in the field of pharmaceuticals, agrochemicals and material sciences. Among fluorine-containing groups, the trifluoromethylthio group has the highest Hansch’s hydrophobicity parameter and remarkable electron-withdrawing character. The incorporation of a trifluoromethylthio group into organic molecules can significantly enhance their membrane permeability and metabolic stability because of its high lipophilicity and strong electron-withdrawing effect. As a result, various methods have been involved to synthesize SCF₃-containing compounds using electrophilic or nucleophilic trifluoromethylthio reagents. On the other hand, the chirality of pharmaceutical molecules has an important effect on their properties, and different stereoisomers of a pharmaceutical molecules always have dramatically different pharmaceutical activities. Thus, the asymmetric trifluoromethylthiolation of organic molecules is of growing interest in recent years. Up to now, this field is still in the stage of initial development. In this perspective article, we will briefly summarize the methods of asymmetric trifluoromethylthiolation of organic molecules that have been reported so far. Two different strategies including the use of electrophilic trifluoromethylthiolating reagents and the use of trifluoromethylthio-containing building blocks will be introduced. Employing electrophilic trifluoromethylthiolating reagents, the enantioselective trifluoromethylthiolation of β-ketoesters, oxindoles as well as alkenes have been developed using Cinchona alkaloid, copper(Ⅱ) or indane-based chiral sulfide/selenide as the catalyst. Alternatively, using trifluoromethylthiolated building blocks is another approach to establish chiral centers bearing the trifluoromethylthio group. In this approach, an asymmetric trifluoromethylthiolation via enantioselective [2,3]-sigmatropic rearrangement of a sulfonium ylide generated from SCF₃-containing sulfide and metal carbene has been disclosed using chiral Rh(Ⅱ) and Cu(I) as the catalyst. Finally, we will discuss the challenges of the asymmetric trifluoromethylthiolation of organic molecules in the future.

Key words: trifluoromethylthiolation, asymmetric catalysis, organofluorine compounds, stereoselectivity, organic synthesis