Synthesis and Use of Trifluoromethylthiolated Ketenimines

The synthesis of trifluoromethylthiolated ketenimines is herein described. They are easily synthesized from the corresponding α-trifluoromethylthiolated oximes upon activation with triflic anhydride and a base. The presumed nitrilium ion resulting from the Beckmann rearrangement is deprotonated to lead to the key intermediate, whose stability brought by the fluorinated substituent was unforeseeable. The reaction of these new building blocks with a variety of nucleophiles affords a vast array of cyclic and acyclic products bearing the valuable SCF₃ moiety.