Diverse products accessible via [2 + 2] photocycloadditions of 3-aminocyclopentenones

Abstract

Intra- and intermolecular [2 + 2] photocycloadditions on 3-aminocyclopentenones are described. Fragmentation of the resultant aminocyclobutanes by retro-Mannich reactions leads to the formation of diketones, ketoimines or conjugated enaminones, the latter of which can undergo further reactions to afford γ-aminotropones and Diels–Alder adducts.