Fluoroalkyl Amino Reagents for the Introduction of the Fluoro(trifluoromethoxy)methyl Group onto Arenes and Heterocycles

Fluoroalkyl amino reagents 1a and 2a have
been developed from commercially available trifluoromethyl trifluorovinyl
ether via a hydroamination reaction with diethylamine or dimethylamine.
These reagents can be activated by treatment with a Lewis acid and
subsequently used as a mono- or dielectrophile for the introduction
of the fluoro­(trifluoromethoxy)­methyl group, either in Vilsmeier-type
acylations of aromatic substrates or in the synthesis of fluorinated
pyrazoles from CH-acidic substrates and of bis-fluorinated pyrazoles,
all being important building blocks for medicinal and agricultural
chemistry.