Enamine Catalysis Birth, Rebirth, and Rapid Growth

4 ENAMINE CATALYSIS BIRTH, REBIRTH, AND RAPID GROWTH 

The Catalysis Concept of Enamine Activation Enamine catalysis is one of the most thoroughly investigated research areas within organocatalysis. The 

At present, one of the most successful catalysts for enamine activation has been proline (2). Proline is a cheap, widely and commercially available amino acid that can be found in both enantiomeric forms and, as such, represents a remarkable synthetic alternative to many established asymmetric catalysts. Given such attractive features, it has become the catalyst of choice for many enamine-catalyzed processes. However, various more recent studies have demonstrated that proline is not a universal catalyst for transformations that involve the a-functionalization of ketone or aldehyde carbonyls. Indeed, these studies have demonstrated that the iminium catalysts developed by MacMillan (imidazolidinones) and Jprgensen (pyrrolidines) are also highly effective for enamine activation with respect to 

Mannich Reactions Expanding the concept of enamine catalysis outside 

Michael Reactions The Michael and analogous conjugate addition reactions represent a cornerstone of classical and modern chemical synthesis, and not surprisingly, therefore, catalytic variants of this venerable reaction have received 

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