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
Cu-Catalyzed switchable synthesis of functionalized pyridines and pyrroles
作者:Zheng Ling、Fang Xie、Ilya D. Gridnev、Masahiro Terada、Wanbin Zhang
DOI:10.1039/c8cc05307c
日期:——
Herein, we describe a high yielding and switchable synthesis of a range of functionalized pyridines and pyrroles via Cu-catalyzed cascadereactions with alkynes and N-sulfonyl azadienes which are readily available from saccharin. Both unsymmetrical 2,4,6-trisubstituted pyridines and multi-substituted pyrroles could be transformed into some bioactive compounds and chiral ligands.
An efficient trans-perhydroindolic acid-catalyzedasymmetricaza-Diels–Alderreaction of cyclic 1-azadienes and propanal was developed for the synthesis of chiral 3-methyl-4-aryldehydropiperidine derivatives (up to 98% yield and 99% ee). Such scaffolds are often found in bioactive compounds and medicines. A gram-scale reaction was carried out with a low catalyst loading to give the desired product
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