Synthetic Access to Fluorocyclopropylidenes

Herein we report an approach for the straightforward preparation of fluorocyclopropylidene group from aldehydes and ketones via Julia–Kocienski olefination using the newly developed reagent 5-((2-fluorocyclopropyl)sulfonyl)-1-phenyl-1H-tetrazole. Derivatization of monofluorocyclopropylidene compounds includes hydrogenation to deliver fluorocyclopropylmethyl compounds and fluorinated cyclobutanones. The utility of the described method is demonstrated by the synthesis of a fluorocyclopropyl-containing analogue of ibuprofen. Bioisosteric replacement of isobutyl with the fluorocyclopropyl group may be used for tuning biological properties of drug molecules.