One-Step Synthesis of Highly Functionalized Monofluorinated Cyclopropanes from Electron-Deficient Alkenes

The unique combination of Zn/LiCl allowed generation of reactive zinc enolate from ethyl dibromofluoroacetate. This fluorinated enolate reacts efficiently with a wide range of functionalized electron-deficient alkenes to afford the corresponding monofluorinated cyclopropylcarboxylates in good yields

Asymmetric Synthesis of Cyclopropanes with a Monofluorinated Quaternary Stereocenter

New chiral fluorinated reagents (<i>N</i>-(dibromofluoroacetyl)oxazolidinones) were easily synthesized and used in an asymmetric cyclopropanation process. The Michael initiated ring closure reaction provided chiral cyclopropanes bearing a fluorinated quaternary stereocenter. Various electron-deficient alkenes can be used to efficiently obtain chiral polysubtituted fluorinated cyclopropanes in good yields. Moderate to very good <i>cis</i>/<i>trans</i> ratios were obtained with a high level of diastereoselectivity for each isomer

Rhodium-Catalyzed Cyclopropanation of Fluorinated Olefins: A Straightforward Route to Highly Functionalized Fluorocyclopropanes

An efficient access to highly functionalized monofluorocyclopropanes is described. The developed methodology allowed straightforward access to a large panel of polysubstituted fluorinated cyclopropanes in good to excellent yields and good diastereoselectivities. The Rh-catalyzed cyclopropanation proved to be efficient on several fluorinated olefins and several diazo compounds. This method represents the first general route to complex fluorinated cyclopropanes