Synthetically useful noncatalytic strategy: a stereocontrolled rapid cyclization of a three component system to afford hexahydropyrrolizines

We demonstrate a highly regio- and stereoselective annulation strategy involving unprecedented C-2-H and N-H of proline esters, alpha,beta-unsaturated aromatic aldehydes and deactivated olefins without a catalytic aid to afford medicinally important pyrrolo[3,4-a]pyrrolizines and hexahydropyrrolizines under benign reaction conditions.