Pyramidal Stereogenic Nitrogen Centers (SNCs)

Abstract The configuration at a stereogenic nitrogen center (SNC) determines the spatial organization of a molecule as do stereogenic carbon centers or other stereochemical moieties. The contributions of SNCs to molecular function and their consideration in molecular design are rarely prominently presented. Underlying is the configurational lability of SNCs with a free electron pair and the scarcity of methods for the stereoselective synthesis of compounds with SNCs in general. In this review, we discuss methods to access compounds with configurationally stable SNCs and highlight some of the synthetically most relevant applications. We hope to draw attention to the potential of this stereochemical feature that can be present in diverse compounds such as N-oxides, oxaziridines, haloamines, ammonium ions, metal-bound amines, and constrained amines and amides. 1 Introduction 2 Some Historical Notes 3 Factors That Influence The Nitrogen Inversion Barrier 4 Preparation and Isolation of Compounds with Configurationally Stable Stereogenic Nitrogen Centers 5 Selected Applications of Compounds with Stereogenic Nitrogen Centers 6 Final Remarks