Synthesis of Perfluoroalkyl-Substituted Vinylcyclopropanes by Way of Enhanced Neighboring Group Participation

A simple, high yielding, two-step, one-pot protocol for the preparation of trifluoromethyl-substituted vinylcyclopropanes from -CF3 homoallyl alcohols is disclosed. Destabilization of the cationic intermediate by the electron-withdrawing CF3 group greatly enhances neighboring group participation of the alkene, allowing ring closure to predominate. The reaction can be extended to the difluoromethyl and pentafluoroethyl group, enabling the preparation of a diverse array of fluoroalkyl-substituted vinylcyclopropanes.