Divergent Synthesis of ß-Fluoroamides via Silver-Catalyzed Oxidative Deconstruction of Cyclopropanone Hemiaminals.

An expedient approach for the synthesis of challenging ß-fluoroamides from readily accessible cyclopropanone equivalents is reported. Following the addition of pyrazole used here as a transient leaving group, silver-catalyzed regiospecific ring-opening fluorination of the resulting hemiaminal leads to a ß-fluorinated N-acylpyrazole intermediate reactive to substitution with amines, ultimately affording ß-fluoroamides. The process could also be extended to the synthesis of ß-fluoroesters and γ-fluoroalcohols via the addition of alcohols or hydrides as terminal nucleophiles, respectively.