Iron-catalyzed [4 + 2] annulation of α,β-unsaturated ketoxime acetates with enaminones toward functionalized pyridines
Jindian Duan, Gaochen Xu, Binsen Rong, Huan Yan, Sai Zhang, Qinghuan Wu, Ning Zhu, Kai Guo
Abstract
The iron-catalyzed [4 + 2] annulation of α,β-unsaturated ketoxime acetates with enaminones has been developed, providing efficient access to highly substituted pyridines in moderate to good yields. Notable features of the present strategy include low-cost catalytic system, simple and mild reaction condition and wide substrate scope. Mechanistic studies reveal that FeCl2 may directly serve as a Lewis acid to activate the α,β-unsaturated ketoxime acetates for the nucleophilic addition.
Topics & Concepts
AnnulationChemistryCatalysisLewis acids and basesNucleophileSubstrate (aquarium)Organic chemistryCombinatorial chemistryMedicinal chemistryOceanographyGeologyCatalytic C–H Functionalization MethodsSynthesis and Catalytic ReactionsAsymmetric Hydrogenation and Catalysis