A chiral monophosphoric acid-catalyzed tandem aza-ene type reaction/cyclization cascade enabled the rapid construction of enantioenriched piperidine derivatives as key structural elements of numerous natural products. The potential of such cascade transformations is highlighted through their ability to achieve a rapid increase in molecular complexity from simple enecarbamates and a broad range of aldimines while also controlling three stereogenic centers in a highly diastereo- and enantioselective manner.