Applied Dienamine Catalysis

Significance

Cyclization of unsaturated dialdehydes 1 in the presence of a catalytic amount of chiral diphenylprolinol silyl ether 2 and benzoic acid led to the formation of highly enantioenriched bicyclic frameworks 3 (after reduction to the corresponding alcohols). Moreover, dienals 4 could be efficiently converted into monocyclic products 5. Both transformations rely on vinylogous en­amine activation of an enal as electron-rich dien­amine prone to undergo a rapid intramolecular Diels-Alder (IMDA) reaction or a vinylogous aldol condensation in the case of α-methylene aldehydes 4.