structured aliphaticketones and electron‐deficient cyclic 1‐azadienes was developed by cascade enamine–enamine catalysis of a cinchona‐based primary amine. This sequence involved a domino Michael addition–Mannich reaction to afford spirocyclic architectures in excellent diastereo‐ and enantioselectivity. Importantly, high regioselectivity was realized for a number of unsymmetrical aliphaticketone substrates
A stereoselectiveinverse-electron-demandaza-Diels–Alder cycloaddition process of cyclic 1-aza-1,3-butadienes and α,β-unsaturatedaldehydes 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
Endo‐type cross‐conjugated trienamines between highly congested α′‐alkylidene 2‐cyclohexenones and a chiral primary amine catalyst serve as HOMO‐raised dienophiles in inverse‐electron‐demand aza‐Diels–Alder cycloadditions with a number of 1‐azadiene substrates. The reactions exhibit exclusive β,γ‐regioselectivity, and multifunctional products with high molecular complexity are efficiently constructed
modes, such as iminium ions and different dienamines, have provided versatile tools for the functionalization of cyclic enones at various sites. Described here is a previously unreported cascade dienamine/dienamine catalytic pathway for β‐substituted 2‐cyclopentenones, and even 2‐cyclohexenone. It involves domino α′‐regioselective Michael addition and a γ‐regioselective Mannich reaction with 3‐vinyl‐1
chemoselective dienophiles in normal-electron-demand Diels–Alderreactions with HOMO-raised trienamines, rather than typical 4π-participation in inverse-electron-demand versions. The enantioenriched cycloadducts could be efficiently converted to spiro or fused frameworks with high structural and stereogenic complexity by a sequential aza-benzoin reaction or other transformations.