Cinchona Alkaloid Catalyzed Asymmetric Tandem Michael-Aza-Aldol Reaction Of Cyano-acetophenone To α,β-Unsaturated Trifluoromethyl Ketone

Fluorine-containing organic compounds has attracted more and more attentions these years.With the advantages of small dose and high efficiency, many fluorine-containing drugs have been applied in pharmaceutical more and more popular, which promotes the fluorine-containing compounds'further study and application in the field of medicine and pesticide.The strategy of catalytic asymmetric synthesis of trifluoromethyl compounds accords with "green chemistry" because of its breeding in chiralityCinchona alkaloids and their derivatives are a class of very effective small organic catalysts.Cinchona alkaloids are not expensive, convenient to get and contains more than one chiral centers.What's more,their structures are usually easy to modify. As we know,Cinchona alkaloids and their derivatives play an important role in asymmetric synthesis,and they already have been successfully used in asymmetric Michael addition, Aldol reaction,Asymmetric Aza-Henry reaction and so on.With the impacts of double bond, carbonyl and trifluoromethyl,α,β-unsaturated trifluoromethyl ketones have been successfully used in Aldol reaction and Michael addition reaction.In other words,α,β-unsaturated trifluoromethyl ketones have the potential of activation in Michael-Aza-Aldol Tandem Reaction.Quinine and its derivatives have a relatively good performance in many catalytic reactions,so we try to apply them in the reaction of cyano acetophenone andα,β-unsaturated trifluoromethyl ketones Michael-Aza-Aldol Tandem Reaction.In this paper, we achieved in the reasonable modifications of cinchona alkaloids and got a series of cinchona alkaloid catalysts.We use them to catalyze the asymmetric Michael-Aza-Aldol Tandem Reaction with satisfied results.In the end,we began with cheap raw materials.After some simple conversions, we got the multi-functional group substituted pyran derivatives containing chiral trifluoromethyl in high yield. The further research of their properties will be even more significant.