Copper-Catalyzed Trifluoromethylation and Cyclization of Aromatic-Sulfonyl-Group-Tethered Alkenes for the Construction of 1,2-Benzothiazinane Dioxide Type Compounds

A multi‐talented system: An efficient copper‐catalyzed tandem trifluoromethylation/annulation of an electron‐deficient aromatic ring has been developed. This method provides a powerful and straightforward way to synthesize trifluoromethylated 1,2‐benzothiazinane dioxides under mild conditions (see scheme). The mechanism was investigated by a series of kinetic experiments and isotopic labeling studies.