Recyclable Trifluoromethylation Reagents from Fluoroform.

We present a strategy to rationally prepare CF transfer reagents at ambient temperature from HCF We demonstrate that a highly reactive CF adduct can be synthesized from alkali metal hydride, HCF, and borazine Lewis acids in quantitative yield at room temperature. These nucleophilic reagents transfer CF to substrates without additional chemical activation, and after CF 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.