Na 2 S·9H 2 O Enabled Defluorodisulfuration and Hydrodefluorination of Perfluorobutyl Tetralones: Synthesis of Trifluoromethyl 1,2-Dithioles.

An unprecedented defluorocyclization of perfluorobutyl tetralones with Na 2 S·9H 2 O was developed for the synthesis of trifluoromethyl 1,2-dithioles, which provided chemists novel access to biologically and pharmaceutically relevant organofluorides. Successive C(sp 3 )-F bond functionalization at the perfluoroalkyl chain is vital for the formation of four C-H/C-S/S-S bonds and a five-membered S-heterocycle assembly. Cheap, weakly toxic, and odorless inorganic sulfide Na 2 S·9H 2 O acts as both a disulfurating precursor and a hydrodefluorinating reagent in this tandem multi-bond-interconverting reaction.