Dynamic kinetic resolution of atropisomeric N-arylindoles via chiral N-triflyl phosphoramide catalyzed asymmetric reductive amination

Abstract

The first organocatalyzed asymmetric reductive amination strategy towards C–N axially chiral pentatomic heterobiaryls has been disclosed. The noncovalent n → π* interaction in the cyclic transition state plays a crucial role in ensuring that the reaction occurs through a dynamic kinetic resolution process, leading to a series of N-arylindole atropisomers in good yields and enantioselectivities (up to 96% yield and 91% ee) under the influence of a chiral N-triflyl phosphoramide catalyst.