Cu-Catalyzed Synthesis of Fluoroalkylated Isoxazoles from Commercially Available Amines and Alkynes.

A one-pot protocol for the construction of fluoroalkylated isoxazoles directly from commercially available amines and alkynes is described. The reaction is scalable, operationally simple, regioselective, mild, and tolerant of a broad range of functional groups. As such, it could be viewed as a "click synthesis" of fluoroalkylated isoxazoles. Preliminary mechanistic investigations reveal that the transformation involves an unprecedented Cu-catalyzed cascade sequence involving RfCHN2.