A catalytic enantioselective bromocyclization of olefinic amides using amino-thiocarbamates as the catalysts has been developed. The resulting enantioenriched 2-substituted 3- bromopiperidines can readily be transformed to 3-substituted piperidines through a silver salt-mediated rearrangement. This process has been applied to the synthesis of a dopaminergic drug, Preclamol.
