Access to Fluoroalkylated Azoles and 2-Acylaminoketones via Anhydride-Mediated Cleavage of NH-1,2,3-Triazoles

NH-1,2,3-Triazoles undergo a ring cleavage in reactions with fluorinated acid anhydrides (trifluoroacetic, difluoroacetic chlorodifluoroacetic and pentafluoropropionic anhydrides) by nitrogen acylation and acid-mediated triazole ring opening. Structurally diverse fluoroalkylated oxazoles were prepared from 4,5-disubstituted-1,2,3-triazoles. Efficient synthesis of 2-acylaminoketones was achieved from 4-substituted-1,2,3-triazoles. Finally, easy access to fluoroalkylated imidazoles and 1,2,4-tetrazines was developed by one-pot two step routes from fluorinated anhydrides and NH-triazoles.