Parallel Minisci Reaction of -Difluorocycloalkyl Building Blocks

Parallel Minisci reactions of nonfluorinated and -difluorinated C-C cycloalkyl building blocks (trifluoroborates and carboxylic acids) with a series of electron-deficient heterocycles were studied. A comparison of the reaction's outcome revealed better product yields in the case of carboxylic acids as the radical precursors in most cases, albeit these reagents were used with three-fold excess under optimized conditions. The nature of the heterocyclic core was found to be important for successful incorporation of the cycloalkyl fragment. The impact of the CF moiety on the oxidation potential of fluorinated cycloalkyl trifluoroborates and the reaction outcome, in general, was also evaluated.