Enantioselective Trifluoromethylazidation of Styrenyl Olefins Catalyzed by an Engineered Nonheme Iron Enzyme

Abstract Organofluorines, particularly those containing trifluoromethyl (CF 3 ) groups, play a critical role in medicinal chemistry. While trifluoromethylation of alkenes provides a powerful synthetic route to construct CF 3 ‐containing compounds with broad structural and functional diversity, achieving enantioselective control in these reactions remains a formidable challenge. In this study, we engineered a nonheme iron enzyme, quercetin 2,3‐dioxygenase from Bacillus subtilis ( Bs QueD), for the enantioselective trifluoromethylazidation of alkenes. Through directed evolution, the final variant Bs QueD‐CF 3 exhibited excellent enantioselectivity, with an enantiomeric ratio (e.r.) of up to 98 : 2. Preliminary mechanistic studies suggest the involvement of radical intermediates. This work expands biocatalytic organofluorine chemistry by reprogramming metalloenzymes for innovative trifluoromethylation reactions.