The Elusive Enamine Intermediate in Proline-Catalyzed Aldol Reactions: NMR Detection, Formation Pathway, and Stabilization Trends

摘要

The detection and characterization of intermediates in organic reactions is crucial for the understanding of mechanisms and the rational optimization of reaction conditions. However, especially in the rapidly expanding field of asymmetric organocatalysis, mechanistic studies are scarce compared to new synthetic applications. Therefore, organocatalysis was characterized as still being "in its exploratory discovery phase before it can become contemplating".