Design And Synthesis Of A New Class Of Chiral Amine Organocatalysts And Their Application In Catalyzing The Synthesis Of Flavanones

Organocatalysis is keep pace with the enzyme catalysis, metal catalysis in the synthesis of optical active compounds. Compared with the enzyme catalysis and organic metal catalysis, Organocatalysis is characterized by operational simplicity, ready availability and low toxicity. These advantages make organocatalysis particularly useful in pharmaceutical synthesis. As one of key part among organocatalysts, L-proline and its derivatives have experienced rapid growth recently. Because of their simple structure, abundant, cheap and good asymmetric catalytic effect, L-prolin and its derivatives have appealed researchers’attention and extensive research. We have reviewed the development of catalytic asymmetric reactions catalyzed by L-proline and its derivatives in this paper. On the basis of research progress, we have developed a new type of organocatalysts, and applied them to catalyze asymmetric synthesis of optical active compounds.Flavanone widely exists in nature and has a broad range of biological activities, such as anti-tumor, antioxidant, antiviral, sterilization, anti-inflammatory, and many other pharmacological activities. At the same time, the structural variability makes the flavanone compounds has great potential to realize structure modification. Because of these remarkable bioactivities, numerous chemists committed to the synthesis of the flavanones and the study of its structure-activity relationship. Based on the existing research on the study of the asymmetric catalytic synthesis, we have developed a class of new type of organocatalysts based on aminoquinoline and pyrrolidine, and used them to catalyze the direct and highly enantioselective cyclization of2’-hydroxychalcones in imitation of the natural process of chalcone oxa-Michael addition. The approach realized high selective synthesis of a series of flavanone compounds and ee value was up to99%.The new organocatalysts can catalytic synthesis of chiral flavanone under mild reaction conditions. This approach is high atom economy and has wide range of substrates, and it provides a facile and efficient access to chiral flavanones.