Isothiourea and Brønsted Acid Cooperative Catalysis: Enantioselective Construction of Dihydropyridinones.

Asymmetric annulation of bench-stable α,β-unsaturated aryl esters with enamines was realized via cooperative catalysis of chiral isothiourea and Brønsted acid. This reaction proceeds via a chiral α,β-unsaturated acyl ammonium intermediate and offers a rapid access to functionalized 3,4-dihydropyridin-2-ones in high yields and excellent enantioselectivities.