Recyclable Trifluoromethylation Reagents from Fluoroform

We present a strategy to rationally
prepare CF3– transfer reagents at ambient
temperature from HCF3. We demonstrate that a highly reactive
CF3– adduct can be synthesized from alkali
metal hydride,
HCF3, and borazine Lewis acids in quantitative yield at
room temperature. These nucleophilic reagents transfer CF3– to substrates without additional chemical activation,
and after CF3 transfer, the free borazine is quantitatively
regenerated. These features enable syntheses of popular nucleophilic,
radical, and electrophilic trifluoromethylation reagents with complete
recycling of the borazine Lewis acid.