Intramolecular Heterocyclization/Fluoromethylthiolation of Alkynes Enabled by a Multicomponent Reagent System.

The BnSR f (R f = CF 2 H or CF 3 )/ m CPBA/Tf 2 O system was found to be an effective multicomponent reagent system for the one-pot synthesis of di/trifluoromethylthiolated heterocycles from alkynes. The reaction was postulated to proceed via a cascade sequence involving the oxidation of BnSR f by m CPBA, activation of the in situ-generated sulfoxide by Tf 2 O, and intramolecular cyclization/fluoromethylthiolation of the alkyne substrates enabled by the formed electrophilic sulfonium salt to give di/trifluoromethylthiolated heterocycles.