β,γ-Regioselective Inverse-Electron-Demand Aza-Diels–Alder Reactions with α,β-Unsaturated Aldehydes via Dienamine Catalysis

A stereoselective inverse-electron-demand aza-Diels–Alder cycloaddition process of cyclic 1-aza-1,3-butadienes and α,β-unsaturated aldehydes has been developed via dienamine catalysis. This reaction exhibits excellent β,γ-regioselectivity for enal substrates with substantial structural diversity and broad functionalities, readily producing highly enantioenriched fused piperidine derivatives and enabling efficient sequential construction of complex polycyclic frameworks.