Asymmetric tandem reactions of N-sulfonylimines and α,β-unsaturated aldehydes: an alternative reaction pathway to that of using saturated aldehydes

An organocatalyzed asymmetric tandem reaction of cyclic N-sulfonylimines and α,β-unsaturated aldehydes was developed. These substrates follow an alternative reaction pathway to that of reactions involving saturated aldehydes, affording similar piperidine derivatives.