N-Phosphinoylimines: An Emerging Class of Reactive Intermediates for Stereoselective Organic Synthesis

ABSTRACT N-Phosphinoylimines have recently begun to attract significant attention from synthetic chemists for the preparation of nitrogen-containing molecules. Several methods have been developed for the synthesis, or in situ generation, of these reactive electrophilic species. N-Phosphinoylimines undergo a wide range of reactions, including nucleophilic additions and cycloadditions. These imines are also effective electrophiles in a number of diastereoselective and enantioselective reactions. An advantage of using N-phosphinoylimines is that the reaction products can be easily deprotected under mild acidic conditions, leading to amines. This review outlines the preparation and uses of N-phosphinoylimines with particular emphasis on their applications in stereoselective processes. 1 Introduction 2 Preparation of N-Phosphinoylimines 3 Addition of Nucleophiles to N-Phosphinoylimines 3.1 Heteroatom Nucleophiles 3.2 Hydride 3.3 Carbon Nucleophiles 3.3.1 Addition of Organometallics 3.3.2 Chiral Auxiliary-Controlled Addition of Organometallics 3.3.3 Enantioselective Addition Using Chiral Ligands 3.3.4 Mannich and Related Reactions 3.3.5 Addition of Nitrile Anions 3.3.6 Aza-Henry Reaction 3.3.7 Aza-Baylis-Hillman Reaction 3.3.8 Formation of Aziridines 3.3.9 Miscellaneous Addition Reactions 4 Cycloadditions and Pericyclic Reactions of N-Phosphinoylimines 5 Oxidation of N-Phosphinoylimines to Oxaziridines 6 Conclusion