Brønsted Acid-Catalyzed Reaction of <i>N</i>-arylnaphthalen-2-amines with Quinone Esters for the Construction of Carbazole and C–N Axially Chiral Carbazole Derivatives
Mingliang Zhang, Zhao Pin, Dongqing Wu, Zhichao Qiu, Chenyue Zhao, Wenyu Zhang, Feng Li, Jing Zhou, Lantao Liu
Abstract
-arylnaphthalen-2-amines and quinone esters catalyzed by Brønsted acid. With this strategy, a series of carbazole derivatives were obtained in good to excellent yields (76 to >99) under mild conditions. Large scale reaction illustrated the synthetic utility of this protocol. Meanwhile, a series of C-N axially chiral carbazole derivatives were also constructed in moderate to good yields (36-89% yield) with moderate to excellent atroposelectivities (44-94% ee) by using chiral phosphoric acid as a catalyst, which provides a novel strategy for the atroposelective construction of C-N axially chiral compounds and a new member of the C-N atropisomers.