Diphenylprolinol Silyl Ethercatalyzed Asymmetric Reaction Of α,β-Unsaturated Aldehyde With Aminomethyl Alkyl Ketone

Alpha amino ketones are important intermediates in organic synthesis. They can easily be converted into amino alcohols, polycycles, heterocycles and other complex molecules. They are widely used in medicine, pesticides, cosmetics, and other areas.We use Ts-aminomethyl alkyl ketones and α,β-unsaturated aldehyde to constructe three chiralcenters pyrrolidine compounds by Michael addition/hemiacetal amination cascade reaction, which is catalyzed by the diarylprolinol silyl ether. These pyrrolidine compounds are similar to some known pharmaceutical molecules, so they have potential use in the synthesis of natural medicinal products.We can get the best result by using Ts as amino protection, methylene chloride as solvent, 4-bromobenzoic acid as co-catalyst. The products have higher selectivity with the increase of alkyl steric hindrance. When 3-(9-anthracene)-acrolein is regard as the substrate, we can also get the highest activity and selectivity.At the end of this article, we also discusse the probable reaction mechanism.