Addition of organometallic reagents to imines bearing stereogenic N-substituents. Stereochemical models explaining the 1,3-asymmetric induction [Review]

摘要

The addition of organometallic reagents to imines bearing stereogenic N-substituents was investigated by ourselves and many other groups. From the results of these studies it appears that the sense of asymmetric induction and the degree of diastereoselectivity are affected by the Structure of the imine (derived from mono or bidentate aldehyde and/or amine), the nature of the organometallic reagent RMLo (the metal and its ligands, the structure of R, the degree of association), the presence of Lewis acids, and the solvent. The reaction pathways and the stereochemical models so far proposed are critically discussed and new ones are presented. 1 Introduction 2 1-Arylethylamines as the Auxiliaries 2.1 Addition of Organolithium Reagents 2.2 Addition of Allylic Organometallic Reagents 2.3 Addition of Organometallic Reagents to the Glyoxal Diimine 2.4 Lewis Acid-Mediated Addition of Organometallic Reagents 3 alpha-Aminoacid Esters as the Auxiliaries 4 beta-Aminoalcohols and their O-Substituted Derivatives as the Auxiliaries 5 Conclusions: New Stereochemical Models for the 1,3-Asymmetric Induction. [References: 133]