Kinetic Resolution of α-Tertiary Propargylic Amines through Asymmetric Remote Aminations of Anilines

Abstract

A practical method for kinetic resolution of α-tertiary propargylic amines has been achieved via asymmetric remote aminations of anilines with azodicarboxylates enabled by chiral phosphoric acid catalysis. A broad range of aryl and alkyl groups at the α-position, as well as the substituted alkynyl and N-aryl groups were well tolerated in these reactions, providing high kinetic resolution performances (with an s-factor up to 111). In addition, the α-tertiary amines bearing an α-CN group (the Strecker reaction product) could be kinetically resolved with excellent stereoselectivity as well under the same reaction conditions. Fruitful transformations of the chiral amination products and the recovered propargylic amines demonstrated the power of this method in asymmetric synthesis of α-tertiary amines and their derivatives.