S-EPMC11253176 - Chiral π–Cu(ii)-catalyzed site-, exo/endo-, and enantioselective dearomative (3 + 2) cycloadditions of isoquinolinium ylides with enamides, dienamides, and a trienamide† † Electronic supplementary information (ESI) available: For synthetic and computational methods, NMR spectra and XRD parameters. CCDC 2325969. For ESI and crystallographic data in CIF or other electronic format see DOI: https://doi.org/10.1039/d4sc02946a