Lewis acid-catalyzed intramolecular cyclization of 7-alkynylcycloheptatrienes with carbonyls: access to 3,4-disubstituted 2,5-dihydropyrroles

We herein report a Lewis acid-catalyzed intramolecular cyclization of 7-alkynylcycloheptatrienes with carbonyls. A variety of highly functionalized 2,5-dihydropyrroles were obtained in moderate yields. This protocol straightforwardly led to a solvent-controlled divergent synthesis of 2,5-dihydropyrroles, which may serve as privileged skeletons in drug discovery. Additionally, scale-up reactions and late-stage derivatizations highlight the potential synthetic utility of this methodology.