Stereospecific Synthesis of 2‐Iminothiazolidines via Domino Ring‐Opening Cyclization of Activated Aziridines with Aryl‐ and Alkyl Isothiocyanates.

Lewis acid catalyzed domino ring-opening cyclization of activated aziridines with aryl and alkyl isothiocyanates has been accomplished leading to the formation of a wide variety of highly substituted and functionalized 2-iminothiazolidines with excellent diastereo- and enantiospecificity (de, ee up to >99%). The reaction proceeds via a Lewis acid catalyzed SN2-type ring-opening of the activated aziridine followed by a concomitant 5-exo-dig cyclization in a domino fashion to furnish the 2-iminothiazolidine derivative in excellent yields (up to 99%).