Organocatalytic cascade 1,6-conjugate addition/annulation/tautomerization of functionalized para -quinone methides: Access to chiral 2-amino-4-aryl-4 H -chromenes

A novel organocatalytic cascade process initiated by 1,6-conjugated addition has been successfully developed. A range of pharmaceutically active 2-amino-4-aryl-4H-chromenes were readily obtained in high yields (88%-99%) and excellent enantiopurities (86%-99% ee). The functionalized para-Quinone methides (p-OMs) could be facilely obtained.