Phosphine-catalyzed [5+1] annulation of δ-sulfonamido-substituted enones with N-sulfonylimines: a facile synthesis of tetrahydropyridines.

Phosphine-catalyzed [5+1] annulation of δ-sulfonamido-substituted enones with N-sulfonylimines: a facile synthesis of tetrahydropyridines.