NHC‐Catalyzed Desymmetrization of N‐Aryl Maleimides Leading to the Atroposelective Synthesis of N‐Aryl Succinimides

Abstract

Although the construction of axially chiral C−C bonds leading to the atroposelective synthesis of biaryls and allied compounds are well-known, the related synthesis of compounds bearing axially chiral C−N bonds are relatively rare. Described herein is the N-heterocyclic carbene-catalyzed atroposelective synthesis of N-aryl succinimides having an axially chiral C−N bond via the desymmetrization of N-aryl maleimides. The NHC involved intermolecular Stetter-aldol cascade of dialdehydes with prochiral N-aryl maleimides followed by oxidation afforded N-aryl succinimides in good yields and ee values. Preliminary studies on rotation barrier for the C−N bond, the temperature dependence, and detailed DFT studies on mechanism are also provided.