Nucleophilic Ring Opening of Donor-Acceptor Cyclopropanes Catalyzed by a Bronsted Acid in Hexafluoroisopropanol

A general, Bronsted acid catalyzed method for the room temperature, nucleophilic ring opening of donor acceptor cyclopropanes in fluorinated alcohol solvent, HFIP, is described. Salient features of this method include an expanded cydopropane scope, including those bearing single keto-acceptor groups and those bearing electron-deficient aryl groups. Notably, the catalytic system proved amenable to a wide range of nucleophiles including, arenes, indoles, azides, diketones, and alcohols.