Catalytic asymmetric chemodivergent arylative dearomatization of tryptophols

The first catalytic asymmetric arylative dearomatization of tryptophols has been established. By using quinone imine ketals as aryl group surrogates and modulating the reaction conditions, the cascade reaction of tryptophols with quinone imine ketals in the presence of chiral phosphoric acid afforded two series of arylative dearomatization products with generally high yields (up to 99%), and excellent diastereo- and enantioselectivities (all > 95 : 5 dr, 90% to 99% ee) in a chemoselective manner.