Ammonium Chloride-Mediated Trifluoromethylthiolation of -Quinone Methides.

Ammonium chloride-mediated trifluoromethylthiolation of -quinone methides is reported using inexpensive and bench stable AgSCF as a nucleophilic trifluoromethylthiolating (-SCF) reagent. This method is an efficient strategy for the construction of the benzylic C(sp)-SCF bond to synthesize trifluoromethylthio-diarylmethane derivatives by 1,6-conjugate addition/aromatization under mild reaction conditions without any metal catalyst, oxidants, or additives. This is the first report of trifluoromethylthiolation of -quinone methides. In addition, di-trifluoromethylthiolation of δ-chloro--quinone methide and scalability are demonstrated.