Diastereoselective construction of structurally diverse polycyclic spiroindolenines via Yb(OTf)3-catalyzed cascade [1,5]-hydride transfer/cyclization

A Lewis-acid-catalyzed redox neutral cascade [1,5]-hydride transfer/cyclization between indolin-2-imines and 2-amino-substituted benzaldehydes has been disclosed. A series of novel, pharmaceutically interesting polycyclic spiroindolenines containing tetrahydroquinolines was obtained in good to excellent yields with excellent diastereoselectivity.