Stereoselective Synthesis of α‐Branched Amines by Nucleophilic Addition of Unstabilized Carbanions to Imines

Abstract

Amines bearing a stereocentera to the nitrogen atomare among themost commonly found subunits in bioactive molecules, natural products, and chiral ligands. As such, there has been much interest in developing methods for their synthesis. Of these methods, the addition of nonstabilized carbanions to activated imines constitutes one of the most reliable ways for synthesizing this important class of compounds [1, 2]. The preparation of a-branched amines from the corresponding carbonyl derivatives typically requires three steps: (1) imine formation; (2) nucleophilic addition; and (3) protecting or activating group (PG) cleavage (Scheme 1.1). Over the past 25 years, numerous variants of this process allowing the preparation of a large variety of substituted a-branched amines have been developed.