The highly efficient synthesis of the enantioenriched spiroindolines by iridium-catalyzed asymmetric allylic dearomatization and reduction is presented. Spiroindolines containing three contiguous stereogenic centers were obtained with excellent diastereo- and enantioselectivity. In addition, a chiral tryptamine derivative could be easily accessed in good yield with excellent ee value through an unprecedented dearomatization/retro-Mannich/hydrolysis cascade reaction of an indole derivative.
Zhuo CX,Zhou Y,Cheng Q,et al. Enantioselective Construction of Spiroindolines with Three Contiguous Stereogenic Centers and Chiral Tryptamine Derivatives via Reactive Spiroindolenine Intermediates[J]. Angew. Chem.-Int. Edit.,2015,54(47):14146-14149.