N-Heterocyclic Carbene-Promoted [4+2] Annulation of α-Chloro Hydrazones with α-Chloro Aliphatic Aldehydes to Access Enantioenriched Dihydropyridazinones
Yipeng Zhou, Hongwei Zhou, Jianfeng Xu
Abstract
)-ones from α-chloro hydrazones and α-chloro aliphatic aldehydes via N-heterocyclic carbene (NHC) catalysis is outlined. These in situ-generated 1,2-diaza-1,3-dienes undergo asymmetric [4+2] annulation with NHC-bound enolates to afford the desired products bearing a stereogenic center at the C4 position. The notable features of this approach include good to excellent enantioselectivities, high functional group tolerance, mild reaction conditions, simple operating procedures, and compatibility with gram-scale synthesis.
Topics & Concepts
StereocenterCarbeneAnnulationChemistryCatalysisCombinatorial chemistryCompatibility (geochemistry)Enantioselective synthesisOrganic chemistryMedicinal chemistryMaterials scienceComposite materialN-Heterocyclic Carbenes in Organic and Inorganic ChemistryCatalytic Cross-Coupling ReactionsCyclopropane Reaction Mechanisms