Enantioselective Organocatalysis from Concepts to Applications in the Synthesis of Natural Products and Pharmaceuticals

Abstract

The synthesis of natural products and pharmaceuticals has been of the driving forces to develop new methodologies in organic chemistry. Organocatalysis presents several advantages, in front of its organometallic chemistry couterpartners, like the benign reaction conditions, the high functional group tolerance, and the easy stereoprediction. One of the most elegant examples of the application of enamine chemistry for the synthesis of natural products was reported by List in 2008. In nature, enzymes are the most efficient catalysts and almost half of them are metal free. However, in organic chemistry, only very few examples of enantioselective metal-free catalysis can be found in the last century. The basis of the mechanisms of enamine and iminium chemistry illustrates some remarkable applications in the synthesis of natural products and pharmaceuticals. Enamine and iminium chemistry coupled with organocascade reactions was exploited in the synthesis of hirsutene, paroxetine, and strychnine.