General Approach to 5,6-Dihydropyridin-2-ones: Annulation Of Imines with 1,4-Ambiphilic Crotonic Acids

Herein, we describe a regio- and diastereoselective metal-free approach for the assembly of densely functionalized 3,6/5,6-dihydropyridin-2-ones from γ-EWG-substituted crotonic acids and imines under 1,1'-carbonyldiimidazole (CDI) activation. The method developed offers the advantages of a wide range of functionalities in easily accessible substrates, mild reaction conditions, and generally high yields. The synthetic utility of this method has been extended to some core and functional group transformations. Additionally, the reaction mechanism was studied by DFT calculations.