Facile Synthesis of Vicinal Halohydrins Via Organocatalytic Halogen Nucleophile-Induced Regioselective Opening of Epoxides

The calix[4]pyrrole is reported as a novel organocatalyst for regioselective ringopening of epoxides under mild reaction conditions. The reaction involves elemental halogen as a nucleophile to afford vicinal halohydrins in good to excellent yield (75-95%). The reactivity of the halide ion in the reaction is governed by different factors, including solvent polarity, temperature and non-covalent interactions of the functional group present on calix[4]pyrrole moiety with halide ions. An efficient methodology has been developed for the regioselective synthesis of halohydrins in good to excellent yields.