Benzannulation of Triynes Initiated by an Alder-Ene Reaction and Subsequent Trifluoromethylthiolate Addition

A new benzannulation reaction with accompanied trifluoromethylthiolation is described. This benzannulation can generate a range of trifluoromethylthiolated benzolactams and benzolactones from 1,3,8-triynes and a stoichiometric amount of AgSCF3 at 90 °C through an initial Alder-ene reaction, 1,4-addition of AgSCF3, and a series of bond-reorganization processes that include double bond migration, 6π-electrocyclization, and a [1,3]-H shift. For certain substrates containing a triisopropylsilyl (TIPS) group, the final [1,3]-H shift-interrupted products, were obtained.