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Modifying the electronic properties of olefins is the quintessential approach to tuning alkene reactivity. In this context, the exploration of trifluoromethyl groups as divergent electronic modifiers has not been considered. In this work, we describe a copper-mediated 1,2-(bis)trifluoromethylation of acetylenes to create E-hexafluorobutenes (E-HFBs) under blue light in a single step. The reaction proceeds with high yield and E/Z selectivity. Since the alkyne captures two trifluoromethyl groups from each molecule of bpyCu(CF 3 ) 3 , mechanistic studies were conducted to illuminate the role of the reactants. Interestingly, E-HFBs exhibit remarkable stability to standard olefin functionalization reactions in spite of the pendant trifluoromethyl groups. This finding has significant implications for medicine, agroscience, and materials., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Fluorinated organic compounds are becoming increasingly important in pharmaceuticals, agrochemicals and materials science. The introduction of trifluoromethoxy groups into new drugs and agrochemicals has attracted much attention due to their strongly electron-withdrawing nature and high lipophilicity. However, synthesis of trifluoromethoxylated organic molecules is difficult owing to the decomposition of trifluoromethoxide anion and β-fluoride elimination from transition-metal-trifluoromethoxide complexes, and no catalytic enantioselective trifluoromethoxylation reaction has been reported until now. Here, we present an example of an asymmetric silver-catalysed intermolecular bromotrifluoromethoxylation of alkenes with trifluoromethyl arylsulfonate (TFMS) as a new trifluoromethoxylation reagent. Compared to other trifluoromethoxylation reagents, TFMS is easily prepared and thermally stable with good reactivity. In addition, this reaction is operationally simple, scalable and proceeds under mild reaction conditions. Furthermore, broad scope and good functional group compatibility has been demonstrated by application of the method to the bromotrifluoromethoxylation of double bonds in natural products and natural product derivatives.

Herein, we report a practical and mild synthetic protocol for a three-component reaction among alkenes, trifluoromethyl aromatics, and arylthiols. In this reaction, the selective C–F activation of trifluoromethyl aromatics occurs. The arenethiolate in the system plays dual roles: an electron donor and a radical trapping reagent. This process only releases a fluoride anion as a by-product within 2 hours. Moreover, the obtained difluoromethyl thioether could be further oxidized with meta-chloroperoxybenzoic acid (m-CPBA) to obtain unique yet challenging and almost unprecedented sulfonyl-based gem-difluoromethyl products with more than 36 substrates and up to 95% yield. Our protocol could easily scale up to yield 3.4 grams of product, which is the core structure required for further functionalization. These transformations can be applied to late-stage molecular development, which could be of great interest and potential in bio-relevant and pharmaceutical fields. Essentially, both experimental studies and DFT calculations were conducted and the results suggested a pathway of photo-induced EDA (electron donor–acceptor) complex, followed by a radical–radical cross-coupling process. [ABSTRACT FROM AUTHOR]

Modifying the electronic properties of olefins is the quintessential approach to tuning alkene reactivity. In this context, the exploration of trifluoromethyl groups as divergent electronic modifiers has not been considered. In this work, we describe a copper‐mediated 1,2‐(bis)trifluoromethylation of acetylenes to create E‐hexafluorobutenes (E‐HFBs) under blue light in a single step. The reaction proceeds with high yield and E/Z selectivity. Since the alkyne captures two trifluoromethyl groups from each molecule of bpyCu(CF3)3, mechanistic studies were conducted to illuminate the role of the reactants. Interestingly, E‐HFBs exhibit remarkable stability to standard olefin functionalization reactions in spite of the pendant trifluoromethyl groups. This finding has significant implications for medicine, agroscience, and materials. [ABSTRACT FROM AUTHOR]