DBU‐Promoted [3 + 2] Cyclization/Retro‐Mannich Cascade Reaction of N‐Aminoisoquinolinium and N‐Aminoquinolinium Derivatives with para‐Quinone Methides

A DBU‐promoted [3 + 2] cyclization/retro‐Mannich cascade reaction of N‐aminoisoquinolinium and N‐aminoquinolinium derivatives with para‐quinone methides has been established employing a C=C double bond cleavage. A broad range of N‐aminoquinolinium salts, N‐aminoisoquinolinium salts, and para‐quinone methides are well tolerated, providing the corresponding rearrangement products. Moreover, scaled‐up reactions and diverse derivatizations of the products were also investigated and discussed.