Facile access to benzofuran-fused tetrahydropyridines via catalytic asymmetric [4 + 2] cycloaddition of aurone-derived 1-azadienes with 3-vinylindoles

Abstract

A highly enantioselective [4 + 2] cycloaddition reaction of aurone-derived 1-azadienes with 3-vinylindoles has been developed. In the presence of chiral phosphoric acids, a wide range of benzofuran-fused tetrahydropyridines with three contiguous stereogenic centers were obtained in good yields, and with excellent diastereo- and enantio-selectivities.