Ionic Liquid Media Resulted in the First Asymmetric Aminohalogenation Reaction of Alkenes

The first asymmetric aminohalogenation of functionalized alkenes has been established. The ionic liquid [bmim][BF4] was found to be the only
effective media for success as normal organic solvents failed to give any product for this reaction. The reaction is also very convenient to
perform by simply mixing the three reactants, cinnamates, N,N-dichloro-p-toluenesulfonamide, and catalyst, together with 4 Å molecular sieves
at room temperature in [bmim][BF4] in any convenient vial of appropriate size without special protection from inert gases. Good chemical
yields (60−72%) and diastereoselectivities (up to 75% de) have been obtained with a good scope of substrates. The resulting individual
diastereomers have been cleanly separated via column chromatography. The absolute stereochemistry of the reaction was unambiguously
determined by X-ray structural analysis.